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Journal articles on the topic 'Spatial genetic structures'

Author: Grafiati

Published: 4 June 2021

Last updated: 3 February 2022

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Dupuis, Julian R., Forest T. Bremer, Thibaut Jombart, Sheina B. Sim, and Scott M. Geib. "mvmapper: Interactive spatial mapping of genetic structures." Molecular Ecology Resources 18, no. 2 (2017): 362–67. http://dx.doi.org/10.1111/1755-0998.12724.

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Grzywiński, Maksym, and Jacek Selejdak. "Weight Minimization of Spatial Trusses with Genetic Algorithm." Quality Production Improvement - QPI 1, no. 1 (2019): 238–43. http://dx.doi.org/10.2478/cqpi-2019-0032.

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Abstract A genetic algorithm is proposed to solve the weight minimization problem of spatial truss structures considering size and shape design variables. A very recently developed metaheuristic method called JAYA algorithm (JA) is implemented in this study for optimization of truss structures. The main feature of JA is that it does not require setting algorithm specific parameters. The algorithm has a very simple formulation where the basic idea is to approach the best solution and escape from the worst solution. Analyses of structures are performed by a finite element code in MATLAB. The effectiveness of JA algorithm is demonstrated through benchmark spatial truss 39-bar, and compare with results in references.

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NAMROUD, MARIE-CLAIRE, ANDREW PARK, FRANCINE TREMBLAY, and YVES BERGERON. "Clonal and spatial genetic structures of aspen (Populus tremuloides Michx.)." Molecular Ecology 14, no. 10 (2005): 2969–80. http://dx.doi.org/10.1111/j.1365-294x.2005.02653.x.

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Degen, B. "SGS--Spatial Genetic Software: A Computer Program for Analysis of Spatial Genetic and Phenotypic Structures of Individuals and Populations." Journal of Heredity 92, no. 5 (2001): 447–48. http://dx.doi.org/10.1093/jhered/92.5.447.

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Xiao, Jian Chun, Jing Chen, Qi Li, and Shao Quan Xia. "Shape and Cross-Section Optimization of Spatial Grid Structures Using Genetic Algorithm." Advanced Materials Research 479-481 (February 2012): 1463–67. http://dx.doi.org/10.4028/www.scientific.net/amr.479-481.1463.

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The optimization of the structures is difficult because the variables have different physical property or different quantitative attribute. The shape and cross-section optimization of spatial grid structures is performed by an improved genetic algorithm. The constraint conditions are composed of the structural deformation, the stability of the compressive members, the slender ratios, and etc. The treatment of the constraint conditions and the optimization function gives an unconstrained analytic function by adopting Lagrange multipliers. The method enhances the running efficiency of the genetic algorithm. The programme for structural optimization containing the mixed codes of continuous real variables, discontinuous real variables, and integer variables is coded by using MATLAB Toolbox functions for genetic algorithm. The analysis of examples shows that the programme is reliable, and the convergence of the algorithm is fast as well.

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Brickner, Jason. "Genetic and epigenetic control of the spatial organization of the genome." Molecular Biology of the Cell 28, no. 3 (2017): 364–69. http://dx.doi.org/10.1091/mbc.e16-03-0149.

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Eukaryotic genomes are spatially organized within the nucleus by chromosome folding, interchromosomal contacts, and interaction with nuclear structures. This spatial organization is observed in diverse organisms and both reflects and contributes to gene expression and differentiation. This leads to the notion that the arrangement of the genome within the nucleus has been shaped and conserved through evolutionary processes and likely plays an adaptive function. Both DNA-binding proteins and changes in chromatin structure influence the positioning of genes and larger domains within the nucleus. This suggests that the spatial organization of the genome can be genetically encoded by binding sites for DNA-binding proteins and can also involve changes in chromatin structure, potentially through nongenetic mechanisms. Here I briefly discuss the results that support these ideas and their implications for how genomes encode spatial organization.

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MITSUI, Kazuo, and Nobuyoshi TOSAKA. "AN APPLICATION OF GENETIC ALGORITHMS TO FORM FINDING ANALYSIS OF SPATIAL STRUCTURES." Journal of Structural and Construction Engineering (Transactions of AIJ) 61, no. 484 (1996): 75–83. http://dx.doi.org/10.3130/aijs.61.75_1.

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Monestiez, P., M. Goulard, and G. Charmet. "Geostatistics for spatial genetic structures: study of wild populations of perennial ryegrass." Theoretical and Applied Genetics 88, no. 1 (1994): 33–41. http://dx.doi.org/10.1007/bf00222391.

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Padrón, Mariana, and Katell Guizien. "Modelling the effect of demographic traits and connectivity on the genetic structuration of marine metapopulations of sedentary benthic invertebrates." ICES Journal of Marine Science 73, no. 7 (2015): 1935–45. http://dx.doi.org/10.1093/icesjms/fsv158.

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Abstract Accounting for connectivity is essential in marine spatial planning and the proper design and management of marine protected areas, given that their effectiveness depends on the patterns of dispersal and colonization between protected and non-protected areas. The genetic structure of populations is commonly used to infer connectivity among distant populations. Here, we explore how population genetic structure is affected by pre- and settlement limitations with a spatially explicit coupled metapopulation-gene flow model that simulates the effect of demographic fluctuations on the allele frequencies of a set of populations. We show that in closed populations, regardless of population growth rate, the maintenance of genetic diversity at saturating initial population density increases with species life expectancy as a result of density-dependent recruitment control. Correlatively, at low initial population density, the time at which a population begins to lose its genetic diversity is driven larval and post-settlement mortality (comprised in the recruitment success parameter)—the larger the recruitment success, the stronger the genetic drift. Different spatial structures of connectivity established for soft bottom benthic invertebrates in the Gulf of Lions (NW Mediterranean, France) lead to very different results in the spatial patterns of genetic structuration of the metapopulation, with high genetic drift in sites where the local retention rate was larger than 2%. The effect of recruitment failure and the loss of key source populations on heterozygosity confirm that transient demographic fluctuations help maintain genetic diversity in a metapopulation. This study highlights the role of intraspecific settlement limitations due to lack of space when the effective number of breeders approaches saturating capacity, causing a strong reduction in effective reproduction. The present model allows to: (i) disentangle the relative contribution of local demography and environmental connectivity in shaping seascape genetics, and (ii) perform in silico evaluations of different scenarios for marine spatial planning.

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Epperson, B. K. "Spatial distributions of genotypes under isolation by distance." Genetics 140, no. 4 (1995): 1431–40. http://dx.doi.org/10.1093/genetics/140.4.1431.

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Abstract The spatial distributions of single-locus diploid genotypes, produced within populations of sexually reproducing individuals under isolation by distance, are measured and characterized in detail by quantifying the join-counts for simulated model populations. The models more realistically reflect spatially explicit distributions of genotypes in populations, because unlike the classical theory, they include the stochasticity inherent in the process of matings between genotypes. This stochasticity causes the formation of large areas or patches containing mostly one homozygous genotype, which is not predicted by the classical theory. A number of previously uncharacterized features of the spatial structures produced under isolation by distance are revealed. Spatial autocorrelation measures based on counts of pairs of homozygotes are highly consistent quantifications of the concentrations of homozygotes in patchy genotypic distributions for a given level of dispersal. Most strikingly, the degree of intermixing of homozygotes with heterozygotes over small spatial scales is much higher than previously thought, unless dispersal is extremely limited (e.g., Wright's neighborhood size less than approximately 5.0). Among implications for studies of spatial structure of real populations, one is that the results provide a basis for using join-counts as estimators of gene dispersal based solely on genetic data.

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Messier, Gabrielle Dubuc, Dany Garant, Patrick Bergeron, and Denis Réale. "Environmental conditions affect spatial genetic structures and dispersal patterns in a solitary rodent." Molecular Ecology 21, no. 21 (2012): 5363–73. http://dx.doi.org/10.1111/mec.12022.

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Kahilainen, Aapo, Inka Keränen, Katja Kuitunen, Janne S. Kotiaho, and K. Emily Knott. "Interspecific interactions influence contrasting spatial genetic structures in two closely related damselfly species." Molecular Ecology 23, no. 20 (2014): 4976–88. http://dx.doi.org/10.1111/mec.12916.

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Jacquier, Mickaël, Jean-Michel Vandel, François Léger, et al. "Population genetic structures at multiple spatial scales: importance of social groups in European badgers." Journal of Mammalogy 101, no. 5 (2020): 1380–91. http://dx.doi.org/10.1093/jmammal/gyaa090.

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Abstract Population viability and metapopulation dynamics are strongly affected by gene flow. Identifying ecological correlates of genetic structure and gene flow in wild populations is therefore a major issue both in evolutionary ecology and species management. Studying the genetic structure of populations also enables identification of the spatial scale at which most gene flow occurs, hence the scale of the functional connectivity, which is of paramount importance for species ecology. In this study, we examined the genetic structure of a social, continuously distributed mammal, the European badger (Meles meles), both at large spatial scales (among populations) and fine (within populations) spatial scales. The study was carried out in 11 sites across France utilizing a noninvasive hair trapping protocol at 206 monitored setts. We identified 264 badgers genotyped at 24 microsatellite DNA loci. At the large scale, we observed high and significant genetic differentiation among populations (global Fst = 0.139; range of pairwise Fst [0.046–0.231]) that was not related to the geographic distance among sites, suggesting few large-scale dispersal events. Within populations, we detected a threshold value below which badgers were genetically close (&lt; 400 m), highlighting that sociality is the major structuring process within badger populations at the fine scale.

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Nair, Abhilash, Toby Fountain, Suvi Ikonen, Sami P. Ojanen, and Saskya van Nouhuys. "Spatial and temporal genetic structure at the fourth trophic level in a fragmented landscape." Proceedings of the Royal Society B: Biological Sciences 283, no. 1831 (2016): 20160668. http://dx.doi.org/10.1098/rspb.2016.0668.

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A fragmented habitat becomes increasingly fragmented for species at higher trophic levels, such as parasitoids. To persist, these species are expected to possess life-history traits, such as high dispersal, that facilitate their ability to use resources that become scarce in fragmented landscapes. If a specialized parasitoid disperses widely to take advantage of a sparse host, then the parasitoid population should have lower genetic structure than the host. We investigated the temporal and spatial genetic structure of a hyperparasitoid (fourth trophic level) in a fragmented landscape over 50 × 70 km, using microsatellite markers, and compared it with the known structures of its host parasitoid, and the butterfly host which lives as a classic metapopulation. We found that population genetic structure decreases with increasing trophic level. The hyperparasitoid has fewer genetic clusters ( K = 4), than its host parasitoid ( K = 15), which in turn is less structured than the host butterfly ( K = 27). The genetic structure of the hyperparasitoid also shows temporal variation, with genetic differentiation increasing due to reduction of the population size, which reduces the effective population size. Overall, our study confirms the idea that specialized species must be dispersive to use a fragmented host resource, but that this adaptation has limits.

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MAZZITELLO, KARINA I., CONSTANCIO M. ARIZMENDI, ALVARO L. SALAS BRITO, and HILARY G. E. HENTSCHEL. "EMBRYONIC SOMITE FORMATION GENERATED BY GENETIC NETWORK OSCILLATIONS WITH NOISE." International Journal of Bifurcation and Chaos 20, no. 02 (2010): 341–47. http://dx.doi.org/10.1142/s021812741002579x.

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In most vertebrate species, the body axis is generated by the formation of repeated transient structures called somites. This spatial periodicity in somitogenesis has been related to the genetic network oscillations in certain mRNAs and their associated gene products in the cells forming the presomitic mesoderm. The current molecular view of the mechanism underlying these oscillations involves negative-feedback regulation at transcriptional and translational levels. The spatially periodic nature of somite formation suggests that the genetic network involved must display intracellular oscillations that interact with a longitudinal positional information gradient, called determination front, down the axis of vertebrate embryos to create this spatial patterning. Here, we consider a simple model for diploid cells based on this current biological picture considering gene regulation as a noisy process relevant in a real developmental situation and study its consequences for somitogenesis. Comparison is made with the known properties of somite formation in the zebrafish embryo.

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Lee, Soo-Rang, Bo-Yun Kim, and Young-Dong Kim. "Genetic diagnosis of a rare myrmecochorous species, Plagiorhegma dubium (Berberidaceae): Historical genetic bottlenecks and strong spatial structures among populations." Ecology and Evolution 8, no. 17 (2018): 8791–802. http://dx.doi.org/10.1002/ece3.4362.

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Visser, J. H., T. J. Robinson, and B. Jansen van Vuuren. "Spatial genetic structure in the rock hyrax (Procavia capensis) across the Namaqualand and western Fynbos areas of South Africa — a mitochondrial and microsatellite perspective." Canadian Journal of Zoology 98, no. 8 (2020): 557–71. http://dx.doi.org/10.1139/cjz-2019-0154.

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The interplay between biotic and abiotic environments is increasingly recognized as a major determinant of spatial genetic patterns. Among spatial genetic studies, saxicolous or rock-dwelling species remain underrepresented in spite of their strict dependence on landscape structure. Here we investigated patterns and processes operating at different spatial (fine and regional scales) and time scales (using mitochondrial and microsatellite markers) in the rock hyrax (Procavia capensis (Pallas, 1766)). Our focus was on the western seaboard of South Africa and included two recognized biodiversity hotspots (Cape Floristic Region and Succulent Karoo). At fine spatial scale, significant genetic structure was present between four rocky outcrops in an isolated population, likely driven by the social system of this species. At a broader spatial scale, ecological dependence on rocky habitat and population-level processes, in conjunction with landscape structure, appeared to be the main drivers of genetic diversity and structure. Large areas devoid of suitable rocky habitat (e.g., the Knersvlakte, Sandveld, and Cape Flats, South Africa) represent barriers to gene flow in the species, although genetic clusters closely follow climatic, geological, and phytogeographic regions, possibly indicating ecological specialization or adaptation as contributing factors enforcing isolation. Taken together, our study highlights the need to consider both intrinsic and extrinsic factors when investigating spatial genetic structures within species.

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Dostálek, Jiří, Tomáš Frantík, and Miroslava Lukášová. "Genetic differences within natural and planted stands of Quercus petraea." Open Life Sciences 6, no. 4 (2011): 597–605. http://dx.doi.org/10.2478/s11535-011-0034-8.

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AbstractFive sessile oak [Quercus petraea (Matt.) Liebl.] stands from the Czech Republic were studied to learn about the impact of different types of forest management regimes on the genetic differences among tree populations and on population structures. One population had not been markedly affected by human activity, two populations represented unplanted stands that were extensively managed for a long period of time using the coppice system, and two populations were planted stands. Approximately 100 trees from each stand were mapped and subsequently genotyped using 10 nuclear microsatellite loci. We determined the spatial genetic structure of each population and the genetic differentiation among the populations. We found that: (i) the populations were genetically differentiated, but the differences between the unplanted and planted stands were not markedly significant; (ii) the genetic differentiation among the populations depended on the geographical distribution of the populations; (iii) within unplanted stands, a strong spatial genetic structure was seen; and (iv) within planted stands, no spatial genetic structure was observed. Our findings implies that the analysis of spatial genetic structure of the sessile oak forest stand can help reveal and determine its origin.

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Finkeldey, Reiner. "Forschung zur Vielfalt, vielfältige Forschung: Ziele und Wege der Forstgenetik | Research on diversity, diverse research: objectives and approaches in forest genetics." Schweizerische Zeitschrift fur Forstwesen 152, no. 5 (2001): 162–68. http://dx.doi.org/10.3188/szf.2001.0162.

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The genetic information about forest trees is not only of crucial importance for the yield of forestry production systems,but also for determining the evolutionary adaptive potential of tree populations. Thus, the stability of forest ecosystems depends on the sustainable management of forest genetic resources. In this context, tree breeding and conservation of forest genetic resources are mentioned as main applications of research in forest genetics. Genetic inventories are conducted in order to observe the spatial distribution of genetic information at gene marker loci. Such studies allow us to elucidate the evolutionary history of populations and, thus, to draw conclusions about their evolutionary adaptability. Results of a genetic inventory of oak (Quercus spp.) populations native to Switzerland are presented, and their significance for the characterization of genetic systems and adaptive potential is discussed. Future research into forest genetics should aim at improving our understanding of the relationship between variation at biochemical and molecular marker loci and adaptive processes in forest tree populations. The temporal dynamics of genetic structures of forest tree populations as a consequence of anthropogenic environmental change is another important topic of forest genetics in particular for the conservation of rare species.

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Kingsford, Michael J., Jodie A. Schlaefer, and Scott J. Morrissey. "Population Structures and Levels of Connectivity for Scyphozoan and Cubozoan Jellyfish." Diversity 13, no. 4 (2021): 174. http://dx.doi.org/10.3390/d13040174.

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Understanding the hierarchy of populations from the scale of metapopulations to mesopopulations and member local populations is fundamental to understanding the population dynamics of any species. Jellyfish by definition are planktonic and it would be assumed that connectivity would be high among local populations, and that populations would minimally vary in both ecological and genetic clade-level differences over broad spatial scales (i.e., hundreds to thousands of km). Although data exists on the connectivity of scyphozoan jellyfish, there are few data on cubozoans. Cubozoans are capable swimmers and have more complex and sophisticated visual abilities than scyphozoans. We predict, therefore, that cubozoans have the potential to have finer spatial scale differences in population structure than their relatives, the scyphozoans. Here we review the data available on the population structures of scyphozoans and what is known about cubozoans. The evidence from realized connectivity and estimates of potential connectivity for scyphozoans indicates the following. Some jellyfish taxa have a large metapopulation and very large stocks (>1000 s of km), while others have clade-level differences on the scale of tens of km. Data on distributions, genetics of medusa and polyps, statolith shape, elemental chemistry of statoliths and biophysical modelling of connectivity suggest that some of the ~50 species of cubozoans have populations of surprisingly small spatial scales and low levels of connectivity. Despite their classification as plankton, therefore, some scyphozoans and cubozoans have stocks of small spatial scales. Causal factors that influence the population structure in many taxa include the distribution of polyps, behavior of medusa, local geomorphology and hydrodynamics. Finally, the resolution of patterns of connectivity and population structures will be greatest when multiple methods are used.

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Kunin, William E., Philippine Vergeer, Tanaka Kenta, et al. "Variation at range margins across multiple spatial scales: environmental temperature, population genetics and metabolomic phenotype." Proceedings of the Royal Society B: Biological Sciences 276, no. 1661 (2009): 1495–506. http://dx.doi.org/10.1098/rspb.2008.1767.

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Range margins are spatially complex, with environmental, genetic and phenotypic variations occurring across a range of spatial scales. We examine variation in temperature, genes and metabolomic profiles within and between populations of the subalpine perennial plant Arabidopsis lyrata ssp. petraea from across its northwest European range. Our surveys cover a gradient of fragmentation from largely continuous populations in Iceland, through more fragmented Scandinavian populations, to increasingly widely scattered populations at the range margin in Scotland, Wales and Ireland. Temperature regimes vary substantially within some populations, but within-population variation represents a larger fraction of genetic and especially metabolomic variances. Both physical distance and temperature differences between sites are found to be associated with genetic profiles, but not metabolomic profiles, and no relationship was found between genetic and metabolomic population structures in any region. Genetic similarity between plants within populations is the highest in the fragmented populations at the range margin, but differentiation across space is the highest there as well, suggesting that regional patterns of genetic diversity may be scale dependent.

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Mitteroecker, Philipp, Silvester Bartsch, Corinna Erkinger, Nicole D. S. Grunstra, Anne Le Maître, and Fred L. Bookstein. "Morphometric Variation at Different Spatial Scales: Coordination and Compensation in the Emergence of Organismal Form." Systematic Biology 69, no. 5 (2020): 913–26. http://dx.doi.org/10.1093/sysbio/syaa007.

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Abstract It is a classic aim of quantitative and evolutionary biology to infer genetic architecture and potential evolutionary responses to selection from the variance–covariance structure of measured traits. But a meaningful genetic or developmental interpretation of raw covariances is difficult, and classic concepts of morphological integration do not directly apply to modern morphometric data. Here, we present a new morphometric strategy based on the comparison of morphological variation across different spatial scales. If anatomical elements vary completely independently, then their variance accumulates at larger scales or for structures composed of multiple elements: morphological variance would be a power function of spatial scale. Deviations from this pattern of “variational self-similarity” (serving as a null model of completely uncoordinated growth) indicate genetic or developmental coregulation of anatomical components. We present biometric strategies and R scripts for identifying patterns of coordination and compensation in the size and shape of composite anatomical structures. In an application to human cranial variation, we found that coordinated variation and positive correlations are prevalent for the size of cranial components, whereas their shape was dominated by compensatory variation, leading to strong canalization of cranial shape at larger scales. We propose that mechanically induced bone formation and remodeling are key mechanisms underlying compensatory variation in cranial shape. Such epigenetic coordination and compensation of growth are indispensable for stable, canalized development and may also foster the evolvability of complex anatomical structures by preserving spatial and functional integrity during genetic responses to selection.[Cranial shape; developmental canalization; evolvability; morphological integration; morphometrics; phenotypic variation; self-similarity.]

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Hämmerli, A., and T. B. H. Reusch. "Genetic neighbourhood of clone structures in eelgrass meadows quantified by spatial autocorrelation of microsatellite markers." Heredity 91, no. 5 (2003): 448–55. http://dx.doi.org/10.1038/sj.hdy.6800310.

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Strugnell, Jan M., A. Louise Allcock, and Phillip C. Watts. "Closely related octopus species show different spatial genetic structures in response to the Antarctic seascape." Ecology and Evolution 7, no. 19 (2017): 8087–99. http://dx.doi.org/10.1002/ece3.3327.

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Zhao, Xiang, She Liang Wang, Xi Cheng Zhao, and Jian Bo Dai. "Fuzzy Control on Large-Span Spatial Structure Dynamical Response." Advanced Materials Research 368-373 (October 2011): 1023–29. http://dx.doi.org/10.4028/www.scientific.net/amr.368-373.1023.

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Focused on the dynamical collapse of large-span spatial structure, this paper uses giant magnetostrictive material to design a kind of new GMM actuator, which could be used in active vibration control of large-span spatial structure. The genetic algorithm has been used to optimize the position of actuators in large-span spatial structure and the structure of fuzzy control system is introduced. A standard fuzzy logic controller is designed. Fuzzy control routine established by the matlab software is used to carry on the active control simulation analysis on the long-span spatial structures. The research shows that the GMM actuator has fine actuating effectiveness, and can improve the computational efficiency of optimization design at the same time. The genetic algorithm also achieves the overall optimization of the structure and the effect to the fuzzy control is obvious.

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Poznyak, Stepan, Ihor Papish, Halyna Ivaniuk, and Taras Yamelynets. "Soil-geographical zonation of Lviv oblast: structure and principles." Visnyk of the Lviv University. Series Geography, no. 52 (June 27, 2018): 251–65. http://dx.doi.org/10.30970/vgg.2018.52.10191.

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The scheme of soil-geographical zonation of Lviv oblast is developed on the principles of structural approach to the spatial organization of soil cover. Criteria for allocation of the ranked taxonomic units, their spatial and genetic properties are qualitative and genetic indicators of soil cover with the analysis of the spatial arrangement of soil combinations and structures. The following taxonomic units are identified in the proposed scheme of soil-geographical zonation: soil-geographic kraina (soil-geographic country), soil-bioclimatic zona/poias (soil-geographic zone/mountain belt), krai (region), okrug (county or mountainous soil region), rayon (district), masyv (massif). A mandatory criterion for all taxonomic units of soil-geographical zonation is the type of soil cover mesostructures (spatial-geometric characteristics of elemental soil areals and their spatial structures, as well as the dominated class of soil combinations). Two soil-geographic kraina (countries) are identified within Lviv oblast: the East European Plain and the Carpathians; three soil-bioclimatic zones: moraine-sander (popilnyakova) zone of mixed forests, broadleaf forest, forest-steppe (loess) and mountain-brownsoil zone; six soil krai: Malopoliskyi, Volynskyi, Roztots’ko-Opilskyi, Zahidnopodilskyi, Peredkarpatskyi highland, the Carpathian mountain; 13 soil counties and 4 regions. Key words: zonation, soil cover structure, zone, krai, okrug, Lviv oblast.

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Gerttula, S., Y. S. Jin, and K. V. Anderson. "Zygotic expression and activity of the Drosophila Toll gene, a gene required maternally for embryonic dorsal-ventral pattern formation." Genetics 119, no. 1 (1988): 123–33. http://dx.doi.org/10.1093/genetics/119.1.123.

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Abstract Maternal expression of the Toll gene is required for the production and the correct spatial organization of all lateral and ventral structures of the Drosophila embryo. We show here that the Toll gene is transcribed zygotically in the embryo and that zygotic expression is important for the viability of the larva. Both genetic and molecular data indicate that the zygotic Toll product has the same biochemical activity as the maternal product. The spatial distribution of the Toll transcript in the embryo was analyzed. In contrast to the uniform distribution of the maternal RNA, the zygotic Toll RNA is present in a complex spatial and temporal pattern in the embryo. A striking feature of this pattern is the correlation of the regions of invaginating cells with sites of accumulation of zygotic Toll RNA.

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Papura, D., F. Delmotte, X. Giresse, et al. "Comparing the spatial genetic structures of the Flavescence dorée phytoplasma and its leafhopper vector Scaphoideus titanus." Infection, Genetics and Evolution 9, no. 5 (2009): 867–76. http://dx.doi.org/10.1016/j.meegid.2009.05.009.

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CHOO, J., T. E. JUENGER, and B. B. SIMPSON. "Consequences of frugivore-mediated seed dispersal for the spatial and genetic structures of a neotropical palm." Molecular Ecology 21, no. 4 (2012): 1019–31. http://dx.doi.org/10.1111/j.1365-294x.2011.05425.x.

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Harter, David E. V., Mike Thiv, Alfons Weig, Anke Jentsch, and Carl Beierkuhnlein. "Spatial and ecological population genetic structures within two island‐endemic Aeonium species of different niche width." Ecology and Evolution 5, no. 19 (2015): 4327–44. http://dx.doi.org/10.1002/ece3.1682.

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Hu, Li-Jiang, Kentaro Uchiyama, Hai-Long Shen, and Yuji Ide. "Multiple-scaled spatial genetic structures of Fraxinus mandshurica over a riparian–mountain landscape in Northeast China." Conservation Genetics 11, no. 1 (2009): 77–87. http://dx.doi.org/10.1007/s10592-009-0004-0.

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Magota, Kana, Shota Sakaguchi, Shun K. Hirota, et al. "Comparative analysis of spatial genetic structures in sympatric populations of two riparian plants,Saxifraga acerifoliaandSaxifraga fortunei." American Journal of Botany 108, no. 4 (2021): 680–93. http://dx.doi.org/10.1002/ajb2.1644.

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Epperson, B. K. "Spatial structure of two-locus genotypes under isolation by distance." Genetics 140, no. 1 (1995): 365–75. http://dx.doi.org/10.1093/genetics/140.1.365.

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Abstract Extensive Monte Carlo simulations are conducted of spatial distributions of two-locus genotypes in large, continuous populations under isolation by distance models. The results show that substantial patches of double homozygotes are present in the spatial structures, even when loci are unlinked. The stochastic spread of identical two-locus genotypes largely outpowers the tendency for recombination to decouple patterns for separate loci. A spatial patch is a large area containing mostly one double homozygous genotype in a highly contiguous constellation. This patch structure is reflected in high positive spatial autocorrelations and large excesses of pairs, or joins, of identical double homozygotes at short-to-intermediate distances of spatial separation. Although spatial patches of double homozygotes are the dominant spatial feature, and the major contributors to overall high levels of autocorrelations among two-locus genotypes, other substantial features include areas of concentrations of identical genotypes heterozygous at only one locus. One implication of the patch structure is the presence of high levels of linkage disequilibrium, caused by isolation by distance even for unlinked loci, at some spatial scales; yet the disequilibrium in the large total populations is near 0. Thus linkage disequilibrium produced by isolation by distance is highly dependent on spatial scale. Another implication is that high degrees of spatial structuring and autocorrelations are produced for genetic variation controlling quantitative traits, at least when the number of loci is relatively small, under a wide range of situations, even if the trait is selectively neutral. The significance of the results to field studies is also examined.

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Goldbeter, Albert. "Dissipative structures in biological systems: bistability, oscillations, spatial patterns and waves." Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences 376, no. 2124 (2018): 20170376. http://dx.doi.org/10.1098/rsta.2017.0376.

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The goal of this review article is to assess how relevant is the concept of dissipative structure for understanding the dynamical bases of non-equilibrium self-organization in biological systems, and to see where it has been applied in the five decades since it was initially proposed by Ilya Prigogine. Dissipative structures can be classified into four types, which will be considered, in turn, and illustrated by biological examples: (i) multistability, in the form of bistability and tristability, which involve the coexistence of two or three stable steady states, or in the form of birhythmicity, which involves the coexistence between two stable rhythms; (ii) temporal dissipative structures in the form of sustained oscillations, illustrated by biological rhythms; (iii) spatial dissipative structures, known as Turing patterns; and (iv) spatio-temporal structures in the form of propagating waves. Rhythms occur with widely different periods at all levels of biological organization, from neural, cardiac and metabolic oscillations to circadian clocks and the cell cycle; they play key roles in physiology and in many disorders. New rhythms are being uncovered while artificial ones are produced by synthetic biology. Rhythms provide the richest source of examples of dissipative structures in biological systems. Bistability has been observed experimentally, but has primarily been investigated in theoretical models in an increasingly wide range of biological contexts, from the genetic to the cell and animal population levels, both in physiological conditions and in disease. Bistable transitions have been implicated in the progression between the different phases of the cell cycle and, more generally, in the process of cell fate specification in the developing embryo. Turing patterns are exemplified by the formation of some periodic structures in the course of development and by skin stripe patterns in animals. Spatio-temporal patterns in the form of propagating waves are observed within cells as well as in intercellular communication. This review illustrates how dissipative structures of all sorts abound in biological systems. This article is part of the theme issue ‘Dissipative structures in matter out of equilibrium: from chemistry, photonics and biology (part 1)’.

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Mroginski, Javier Luis, Pablo Alejandro Beneyto, Guillermo J. Gutierrez, and Ariel Di Rado. "A selective genetic algorithm for multiobjective optimization of cross sections in 3D trussed structures based on a spatial sensitivity analysis." Multidiscipline Modeling in Materials and Structures 12, no. 2 (2016): 423–35. http://dx.doi.org/10.1108/mmms-08-2015-0048.

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Purpose – There are many problems in civil or mechanical engineering related to structural design. In such a case, the solution techniques which lead to deterministic results are no longer valid due to the heuristic nature of design problems. The purpose of this paper is to propose a computational tool based on genetic algorithms, applied to the optimal design of cross-sections (solid tubes) of 3D truss structures. Design/methodology/approach – The main feature of this genetic algorithm approach is the introduction of a selective-smart method developed in order to improve the convergence rate of large optimization problems. This selective genetic algorithm is based on a preliminary sensitivity analysis performed over each variable, in order to reduce the search space of the evolutionary process. In order to account for the optimization of the total weight, the displacement (of a specific section) and the internal stresses distribution of the structure a multiobjective optimization function was proposed. Findings – The numerical results presented in this paper show a significant improvement in the convergence rate as well as an important reduction in the relative error, compared to the exact solution. Originality/value – The variables sensitivity analysis put forward in this approach introduces a significant improvement in the convergence rate of the genetic algorithm proposed in this paper.

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Lin, Yuting, Achyut Kumar Banerjee, Haidan Wu, et al. "Prominent genetic structure across native and introduced ranges of Pluchea indica, a mangrove associate, as revealed by microsatellite markers." Journal of Plant Ecology 13, no. 3 (2020): 341–53. http://dx.doi.org/10.1093/jpe/rtaa022.

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Abstract Aims Pluchea indica is a mangrove-associate species, known for its medicinal properties in its native range and being invasive in part of its introduced range. This study aimed to assess geographic distribution of genetic variation of this species across its distribution range, identify the factors influencing its genetic structure and use this information to suggest conservation and management strategies in its native and introduced ranges, respectively. Methods We assessed the genetic diversity and population structure of 348 individuals from 31 populations across its native (Asia) and introduced (USA) ranges for 15 nuclear microsatellite loci. The spatial pattern of genetic variation was investigated at both large and regional spatial scales with the hypothesis that geographic distance and natural geographic barriers would influence the population structure with varying levels of differentiation across spatial scales. Important Findings We found relatively high genetic diversity at the population level and pronounced genetic differentiation in P. indica, as compared with the genetic diversity parameters of mangroves and mangrove associates in this region. Most of the populations showed heterozygote deficiency, primarily due to inbreeding and impediment of gene flow. Analysis of population structures at large spatial scale revealed the presence of two major clusters across the species’ natural range separating populations in China from those in Indonesia, Malaysia, Singapore, Thailand, Cambodia and Philippines, and that the USA population might have been introduced from the population cluster in China. Genetic differentiation between populations was also observed at the regional scale. A large number of populations showed evidence of genetic bottleneck, thereby emphasizing the risk of local extinction. Based on these findings, our study recommends in situ conservation strategies, such as to prioritize populations for conservation actions and to maintain genetic diversity.

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Dounavi, A., N. Koutsias, M. Ziehe, and H. H. Hattemer. "Spatial patterns and genetic structures within beech populations (Fagus sylvatica L.) of forked and non-forked individuals." European Journal of Forest Research 129, no. 6 (2010): 1191–202. http://dx.doi.org/10.1007/s10342-010-0409-9.

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Tian, Lei, Lixia Ku, Zan Yuan, et al. "Large-scale reconstruction of chromatin structures of maize temperate and tropical inbred lines." Journal of Experimental Botany 72, no. 10 (2021): 3582–96. http://dx.doi.org/10.1093/jxb/erab087.

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Abstract Maize is a model plant species often used for genetics and genomics research because of its genetic diversity. There are prominent morphological, genetic, and epigenetic variations between tropical and temperate maize lines. However, the genome-wide chromatin conformations of these two maize types remain unexplored. We applied a Hi-C approach to compare the genome-wide chromatin interactions between temperate inbred line D132 and tropical line CML288. A reconstructed maize three-dimensional genome model revealed the spatial segregation of the global A and B compartments. The A compartments contain enriched genes and active epigenome marks, whereas the B compartments are gene-poor, transcriptionally silent chromatin regions. Whole-genome analyses indicated that the global A compartment content of CML288 was 3.12% lower than that of D132. Additionally, global and A/B sub-compartments were associated with differential gene expression and epigenetic changes between two inbred lines. About 25.3% of topologically associating domains (TADs) were determined to be associated with complex domain-level modifications that induced transcriptional changes, indicative of a large-scale reorganization of chromatin structures between the inbred maize lines. Furthermore, differences in chromatin interactions between the two lines correlated with epigenetic changes. These findings provide a solid foundation for the wider plant community to further investigate the genome-wide chromatin structures in other plant species.

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Neophytou, Charalambos, Elisabeth Pötzelsberger, Manuel Curto, Harald Meimberg, and Hubert Hasenauer. "Population bottlenecks have shaped the genetic variation of Ailanthus altissima (Mill.) Swingle in an area of early introduction." Forestry: An International Journal of Forest Research 93, no. 4 (2019): 495–504. http://dx.doi.org/10.1093/forestry/cpz019.

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Abstract Ailanthus altissima is a common tree species of the European non-native flora. In Eastern Austria, Ailanthus has both a long tradition, dating back to the late 18th century, and a high frequency of occurrence. Here, we apply molecular markers from the nuclear and chloroplast DNA in order to study the origin, as well as the clonal and genetic structure of the species in forest stands of this region. Our results indicate a single area of origin for all our study populations from the north-eastern part of the native range, in agreement with historical reports. Within populations, vegetative reproduction has resulted in extensive clonal structures at some sites. Long presence and repeated vegetative recruitment might have led to expansion of clones in areas of early introduction. In addition, limited mate availability may also have promoted vegetative reproduction. Tests for recent bottlenecks were significant in almost all stands, possibly reflecting founder effects since the introduction of Ailanthus in our study area. Among populations, we found a very pronounced and significant genetic structure, which did not follow a spatial pattern. We argue that founder effects due to population establishment with a low number of propagules – whether naturally or artificially – have caused genetic drift and a structured gene pool. The lack of spatial pattern or isolation-by-distance suggests that seed transfer by humans might have been a major factor shaping the genetic variation of Ailanthus in Eastern Austria.

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Zhang, Hong-Xiang, Qian Wang, and Su-Wen Jia. "Genomic Phylogeography of Gymnocarpos przewalskii (Caryophyllaceae): Insights into Habitat Fragmentation in Arid Northwestern China." Diversity 12, no. 9 (2020): 335. http://dx.doi.org/10.3390/d12090335.

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Extensive range of deserts and gobis (rocks) had promoted habitat fragmentation of species in arid northwestern China. Distribution of endangered Gymnocarpos przewalskii Maxim. covers most of gobis (rocks) and desert terrain across arid regions of northwestern China. In the present study, we had employed genomic phylogeographical analysis to investigate population structure of G. przewalskii and test the effect of environmental conditions on spatial pattern of genetic diversity. Results showed four groups were identified from east to west: Edge of the Alxa Desert, Hexi Corridor, Hami Basin, and North edge of the Tarim Basin. Genetic diversity was at an equal level among four groups. General linear model (GLM) analysis showed spatial pattern of genetic diversity was significant correlated with three habitat variables including habitat suitability at present (Npre) and last glacial maximum (LGM) (NLGM) periods, and locality habitat stability (NStab). It concluded that habitat fragmentation had triggered lineage divergences of G. przewalskii in response to long-term aridification. Genome-wide single nucleotide polymorphisms (SNPs) could increase the ability of clarifying population structures in comparison with traditional molecular markers. Spatial pattern of genetic diversity was determined by fragmented habitats with high habitat suitability (Npre and NLGM) and stability (NStab). At last, we propose to establish four conservation units which are in consistent with the population grouping to maintain the genetic integrity of this endangered species.

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Hulianytskyi, Leonid, and Sergii Chornozhuk. "Genetic Algorithm with New Stochastic Greedy Crossover Operator for Protein Structure Folding Problem." Cybernetics and Computer Technologies, no. 2 (July 24, 2020): 19–29. http://dx.doi.org/10.34229/2707-451x.20.2.3.

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Introduction. The spatial protein structure folding is an important and actual problem in biology. Considering the mathematical model of the task, we can conclude that it comes down to the combinatorial optimization problem. Therefore, genetic and mimetic algorithms can be used to find a solution. The article proposes a genetic algorithm with a new greedy stochastic crossover operator, which differs from classical approaches with paying attention to qualities of possible ancestors. The purpose of the article is to describe a genetic algorithm with a new greedy stochastic crossover operator, reveal its advantages and disadvantages, compare the proposed algorithm with the best-known implementations of genetic and memetic algorithms for the spatial protein structure prediction, and make conclusions with future steps suggestion afterward. Result. The work of the proposed algorithm is compared with others on the basis of 10 known chains with a length of 48 first proposed in [13]. For each of the chain, a global minimum of free energy was already precalculated. The algorithm found 9 out of 10 spatial structures on which a global minimum of free energy is achieved and also demonstrated a better average value of solutions than the comparing algorithms. Conclusion. The quality of the genetic algorithm with the greedy stochastic crossover operator has been experimentally confirmed. Consequently, its further research is promising. For example, research on the selection of optimal algorithm parameters, improving the speed and quality of solutions found through alternative coding or parallelization. Also, it is worth testing the proposed algorithm on datasets with proteins of other lengths for further checks of the algorithm’s validity. Keywords: spatial protein structure, combinatorial optimization, genetic algorithms, crossover operator, stochasticity.

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ALPER, KUTAY O., and CAREY K. BAGDASSARIAN. "COUPLED GENETIC ALGORITHM/KOHONEN NEURAL NETWORK (GANN) FOR PROJECTION OF THREE-DIMENSIONAL PROTEIN STRUCTURES ONTO THE PLANE." Journal of Theoretical and Computational Chemistry 01, no. 01 (2002): 45–52. http://dx.doi.org/10.1142/s0219633602000051.

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An algorithm is presented for projecting — at the amino acid level — the three-dimensional crystal structure of a protein molecule onto a planar surface. The scheme is topologically consistent: if two amino acid residues are closely juxtaposed in three-dimensional space, they remain so upon projection. Through such projections, a single resulting picture captures the spatial relations amongst a protein molecule's amino acids. Operationally, a genetic algorithm is used to "evolve" a parameter set which serves as input for a self-organizing Kohonen neural network responsible for the projection itself. A fitness function characterizing the quality of the projections is defined and maximized via the genetic algorithm. The workings of both the genetic algorithm and neural network are discussed in detail. In this work, we seek to optimize projections resulting from the inherently "frustrated" task of collapsing a space-filling collection of amino acid residues onto a simpler surface. Ultimately, the chosen application is a testing ground for establishing the success of our coupled genetic algorithm/Kohonen neural network scheme which can easily be adapted for other uses.

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Zhou, Huiyu, Shingo Mabu, Wei Wei, Kaoru Shimada, and Kotaro Hirasawa. "Traffic Flow Prediction with Genetic Network Programming (GNP)." Journal of Advanced Computational Intelligence and Intelligent Informatics 13, no. 6 (2009): 713–25. http://dx.doi.org/10.20965/jaciii.2009.p0713.

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In this paper, a method for traffic flow prediction has been proposed to obtain prediction rules from the past traffic data using Genetic Network Programming (GNP). GNP is an evolutionary approach which can evolve itself and find the optimal solutions. It has been clarified that GNP works well especially in dynamic environments since GNP is consisted of directed graph structures, creates quite compact programs and has an implicit memory function. In this paper, GNP is applied to create a traffic flow prediction model. And we proposed the spatial adjacency model for the prediction and two kinds of models forN-step prediction. Additionally, the adaptive penalty functions are adopted for the fitness function in order to alleviate the infeasible solutions containing loops in the training process. Furthermore, the sharing function is also used to avoid the premature convergence.

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Hernández-Velasco, Javier, José Ciro Hernández-Díaz, Matthias Fladung, Álvaro Cañadas-López, José Ángel Prieto-Ruíz, and Christian Wehenkel. "Spatial genetic structure in four Pinus species in the Sierra Madre Occidental, Durango, Mexico." Canadian Journal of Forest Research 47, no. 1 (2017): 73–80. http://dx.doi.org/10.1139/cjfr-2016-0154.

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In this study, we examined the spatial genetic structure (SGS) in extensively managed, but naturally regenerated forest stands of Pinus cembroides Zucc., Pinus discolor Bailey et Hawksworth, Pinus durangensis Martínez, and Pinus teocote Schiede ex Schltdl. & Cham. at local (within the stands) and large (among the stands) scales using amplified fragment length polymorphisms (AFLP), with respect to conservation and sustainable management of genetic resources of these species. Because these four pine species grow in different landscape structures, we expected to find differences in their SGS, although all of them are widely spread, wind pollinated, and often occur at high population densities. At the local scale, there was no evidence of significant SGS in the four species under study (except in 1 out of 18 seed stands), suggesting that the genetic variants of these species are almost always randomly distributed in space, probably due to high wind pollination and seed dispersal. At a larger scale, the significant SGS found may be the result of isolation by distance among populations. We recommend (i) establishing a tight network of seed stands, with a maximum distance of 3–11 km between seed stands, to prevent greater loss of local genetic structure, and (ii) using these seeds to establish reforestations within a maximal radius of 3–5 km from seed provenances.

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Loison, A., G. Darmon, S. Cassar, J. M. Jullien, and D. Maillard. "Age- and sex-specific settlement patterns of chamois (Rupicapra rupicapra) offspring." Canadian Journal of Zoology 86, no. 6 (2008): 588–93. http://dx.doi.org/10.1139/z08-031.

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The social, spatial, and genetic structures of populations depend on where offspring settle and reproduce in relation to their parent’s home range. However, the patterns of settlement in wild populations of large mammals are often poorly described owing to the difficulty of monitoring mother–offspring pairs over a long period. Here, we investigated sex-specific settlement patterns in chamois ( Rupicapra rupicapra (L., 1758)) based on the study of 31 mother–offspring pairs. We calculated the distance between the center of the mother’s range and the center of her offspring’s range, and tested whether this distance differed when the offspring was immature (i.e., a yearling) and after offspring sexual maturity (>2 years of age). We found no sex effect on the distance between centers of mother and offspring ranges for yearling offsprings. However, mature sons ranged farther away from their mother than mature daughters. Daughters appear to settle close to their mother’s home range. The distance at which a daughter settles compared with her mother’s range seems to be determined before 2 years of age. On the contrary, the distance between the center of the locations of yearling males and the center of locations of their mother does not predict how far away males will eventually settle when mature. We discuss the implications of these patterns for generating female social structures, as well as population spatial and genetic structures.

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Alle, Benn R., Lupe Furtado-Alle, Cedric Gondro, and João Carlos M. Magalhães. "Kuri: A Simulator of Ecological Genetics for Tree Populations." Journal of Artificial Evolution and Applications 2009 (July 26, 2009): 1–5. http://dx.doi.org/10.1155/2009/783647.

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This paper presents Kuri, a software package developed to simulate the temporal and spatial dynamics of genetic variability in populations and multispecies communities of trees, as well as their interactions with environmental factors. A conceptual model using agents inspired on Echo models is used to define the environment, the hierarchical structures, and the low-level rules of the system. At the individual agent (tree) level a genetic algorithm is used to model the genotypic structure and the genetic processes, from a small set of simple rules, complex higher-order population, and environmental interactions emerge. The program was written in Delphi for the Windows environment, and was designed to be used for educational and research purposes.

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Štefánik, Martin, Jan Christian Habel, Thomas Schmitt, and Jonas Eberle. "Geographical disjunction and environmental conditions drive intraspecific differentiation in the chalk-hill blue butterfly." Biological Journal of the Linnean Society 133, no. 1 (2021): 202–15. http://dx.doi.org/10.1093/biolinnean/blab022.

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Abstract Drivers of evolution are often related to geographical isolation and/or diverging environmental conditions. Spatial variation in neutral genetic markers mostly reflects past geographical isolation, i.e. long-lasting allopatry, whereas morphology is often driven by local environmental conditions, resulting in more rapid evolution. In Europe, most thermophilic species persisted during the past glacial periods in geographically disjunct refugia, representing long-lasting isolates, frequently with diverging environmental conditions. This situation has driven the evolution of intraspecific signatures in species. Here, we analysed wing shape and wing pigmentation of the chalk-hill blue butterfly, Polyommatus coridon, across its entire distribution range restricted to the western Palaearctic. In addition, we compiled abiotic environmental parameters for each sampling site. Wing colour patterns differentiated a western and an eastern lineage. These lineages might represent two main Pleistocene refugia and differentiation centres, one located on the Italian Peninsula and the other in the Balkan region. The two lineages showed evidence of hybridization across Central Europe, from the Alps and across Germany. The intraspecific differentiation was strongest in the width of the brown band on the outer margin of the wings. The morphological structures obtained are in line with genetic signatures found in previous studies, but the latter are more fine-grained. Current environmental conditions, such as mean temperatures, were only marginally correlated with colour patterns. Our study underlines that Pleistocene range shifts, often resulting in allopatric isolation, shape intraspecific phenotypic structures within species; that pigmentation responds in a more sensitive manner to spatial disjunction than wing shape; and that morphometric and genetic structures in P. coridon provide concordant patterns and thus support identical biogeographical conclusions.

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Japaridze, Aleksandre, Sylvain Renevey, Patrick Sobetzko, et al. "Spatial organization of DNA sequences directs the assembly of bacterial chromatin by a nucleoid-associated protein." Journal of Biological Chemistry 292, no. 18 (2017): 7607–18. http://dx.doi.org/10.1074/jbc.m117.780239.

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Structural differentiation of bacterial chromatin depends on cooperative binding of abundant nucleoid-associated proteins at numerous genomic DNA sites and stabilization of distinct long-range nucleoprotein structures. Histone-like nucleoid-structuring protein (H-NS) is an abundant DNA-bridging, nucleoid-associated protein that binds to an AT-rich conserved DNA sequence motif and regulates both the shape and the genetic expression of the bacterial chromosome. Although there is ample evidence that the mode of H-NS binding depends on environmental conditions, the role of the spatial organization of H-NS-binding sequences in the assembly of long-range nucleoprotein structures remains unknown. In this study, by using high-resolution atomic force microscopy combined with biochemical assays, we explored the formation of H-NS nucleoprotein complexes on circular DNA molecules having different arrangements of identical sequences containing high-affinity H-NS-binding sites. We provide the first experimental evidence that variable sequence arrangements result in various three-dimensional nucleoprotein structures that differ in their shape and the capacity to constrain supercoils and compact the DNA. We believe that the DNA sequence-directed versatile assembly of periodic higher-order structures reveals a general organizational principle that can be exploited for knowledge-based design of long-range nucleoprotein complexes and purposeful manipulation of the bacterial chromatin architecture.

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Al-Qthanin, Rahmah N., and Samah A. Alharbi. "Spatial Structure and Genetic Variation of a Mangrove Species (Avicennia marina (Forssk.) Vierh) in the Farasan Archipelago." Forests 11, no. 12 (2020): 1287. http://dx.doi.org/10.3390/f11121287.

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Avicennia marina (Forssk.) Vierh is distributed in patches along the Farasan archipelago coast and is the most common mangrove species in the Red Sea. However, to date, no studies have been directed towards understanding its genetic variation in the Farasan archipelago. In this investigation, genetic variations within and among natural populations of Avicennia marina in the Farasan archipelago were studied using 15 microsatellite markers. The study found 142 alleles on 15 loci in nine populations. The observed (Ho) and expected (He) heterozygosity values were 0.351 and 0.391, respectively, which are much lower than those of earlier studies on A. marina in the Arabian Gulf. An inbreeding effect from self-pollination might explain its heterozygote deficiency. Population genetic differentiation (FST = 0.301) was similar to other mangrove species. Our findings suggest that the sea current direction and coastal geomorphology might affect genetic dispersal of A. marina. The more isolated populations with fewer connections by sea currents exhibited lower genetic variation and differentiation between populations. The genetic clustering of populations fell into three main groups—Group 1 (populations of Farasan Alkabir Island), Group 2 (populations of Sajid Island), and Group 3 (mix of one population of Farasan Alkabir Island and a population of Zifaf Island). More genetic variation and less genetic differentiation occurred when the population was not isolated and had a direct connection with sea currents. Both of these factors contributed to limited propagule dispersal and produced significant structures among the population. It is expected that the results of this research will be useful in determining policy and species-conservation strategies and in the rehabilitation of A. marina mangrove stands on the Farasan islands in an effort to save this significant natural resource.

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Regilme, Maria Angenica F., Thaddeus M. Carvajal, Ann–Christin Honnen, Divina M. Amalin, and Kozo Watanabe. "The influence of roads on the fine-scale population genetic structure of the dengue vector Aedes aegypti (Linnaeus)." PLOS Neglected Tropical Diseases 15, no. 2 (2021): e0009139. http://dx.doi.org/10.1371/journal.pntd.0009139.

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Dengue is endemic in tropical and subtropical countries and is transmitted mainly by Aedes aegypti. Mosquito movement can be affected by human-made structures such as roads that can act as a barrier. Roads can influence the population genetic structure of Ae. aegypti. We investigated the genetic structure and gene flow of Ae. aegypti as influenced by a primary road, España Boulevard (EB) with 2000-meter-long stretch and 24-meters-wide in a very fine spatial scale. We hypothesized that Ae. aegypti populations separated by EB will be different due to the limited gene flow as caused by the barrier effect of the road. A total of 359 adults and 17 larvae Ae. aegypti were collected from June to September 2017 in 13 sites across EB. North (N1-N8) and South (S1-S5) comprised of 211 and 165 individuals, respectively. All mosquitoes were genotyped at 11 microsatellite loci. AMOVA FST indicated significant genetic differentiation across the road. The constructed UPGMA dendrogram found 3 genetic groups revealing the clear separation between North and South sites across the road. On the other hand, Bayesian cluster analysis showed four genetic clusters (K = 4) wherein each individual samples have no distinct genetic cluster thus genetic admixture. Our results suggest that human-made landscape features such as primary roads are potential barriers to mosquito movement thereby limiting its gene flow across the road. This information is valuable in designing an effective mosquito control program in a very fine spatial scale.

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