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15,277 results for “GENETICS”
Data from: Influence of ethnolinguistic diversity on the sorghum genetic patterns in subsistence farming systems in eastern Kenya
Understanding the effects of actions undertaken by human societies on crop evolution processes is a major challenge for the conservation of genetic resources. This study investigated the mechanisms whereby social boundaries associated with patterns of ethnolinguistic diversity have influenced the on-farm distribution of sorghum diversity. Social boundaries limit the diffusion of planting material, practices and knowledge, thus shaping crop diversity in situ. To assess the effect of social boundaries, this study was conducted in the contact zone between the Chuka, Mbeere and Tharaka ethnolinguistic groups in eastern Kenya. Sorghum varieties were inventoried and samples collected in 130 households. In all, 297 individual plants derived from seeds collected under sixteen variety names were characterized using a set of 18 SSR molecular markers and 15 morphological descriptors. The genetic structure was investigated using both a Bayesian assignment method and distance-based clustering. Principal Coordinates Analysis was used to describe the structure of the morphological diversity of the panicles. The distribution of the varieties and the main genetic clusters across ethnolinguistic groups was described using a non-parametric MANOVA and pairwise Fisher tests. The spatial distribution of landrace names and the overall genetic spatial patterns were significantly correlated with ethnolinguistic partition. However, the genetic structure inferred from molecular makers did not discriminate the short-cycle landraces despite their morphological distinctness. The cases of two improved varieties highlighted possible fates of improved materials. The most recent one was often given the name of local landraces. The second one, that was introduced a dozen years ago, displays traces of admixture with local landraces with differential intensity among ethnic groups. The patterns of congruence or discordance between the nomenclature of farmers' varieties and the structure of both genetic and morphological diversity highlight the effects of the social organization of communities on the diffusion of seed, practices, and variety nomenclature.
Data from: Morphological and genetic evidence for a new karst specialist lizard from New Guinea (Cyrtodactylus: Gekkonidae).
Exposed limestone karst landscapes, especially in the tropics, are often home to distinctive and specialised biotas. Amongst vertebrates, a particularly large number of karst-associated lizard taxa have been described, but for the vast majority, evidence of specific adaptions to karst is lacking. A number of studies, however, have provided evidence of consistent morphological trends in lizards that utilise complex, three-dimensional, saxicoline habitats such as those that typify karst areas. Here we combine morphological and genetic data to test whether a newly discovered gecko from an extremely rugged karst area in New Guinea shows morphological trends matching these observed in other lizards associated with complex rock habitats such as karst and caves. Consistent with predictions, the new species' head is flatter and narrower than similar-sized relatives, and it has proportionally larger eyes and longer limbs. These trends indicate this taxon represents the second documented instance of karst specialisation in a New Guinean vertebrate, and suggest morphological traits to test for evidence of specialised ecological associations in the many karst-associated Cyrtodactylus taxa from Southeast Asia.
Data from: Challenges of NGS in conservation management: insights from long-term monitoring of corridor effects on the genetic diversity of mouse lemurs in a fragmented landscape
Long-term genetic monitoring of populations is essential for efforts aimed at preserving genetic diversity of endangered species. Here, we employ a framework of long-term genetic monitoring to evaluate the effects of fragmentation and the effectiveness of the establishment of corridors in restoring population connectivity and genetic diversity of mouse lemurs Micocebus ganzhorni. To this end, we supplement estimates of neutral genetic diversity with the assessment of adaptive genetic variability of the MHC. In addition, we address the challenges of long-term genetic monitoring of functional diversity by comparing the genotyping performance and estimates of MHC variability generated by SSCP/Sanger-sequencing with those obtained by high throughput sequencing (NGS, Illumina), an issue that is particularly relevant when previous work serves as a baseline for planning management strategies that aim to ensure the viability of a population. We report that SSCP greatly underestimates individual diversity and that discrepancies in estimates of MHC diversity attributable to the comparisons of traditional and NGS genotyping techniques can influence the conclusions drawn from conservation management scenarios. Evidence of migration among fragments in Mandena suggests that mouse lemurs are robust to the process of fragmentation and that the effect of corridors is masked by ongoing gene flow. Nonetheless, results based on a larger number of shared private alleles at neutral loci between fragment pairs found after the establishment of corridors in Mandena suggest that gene flow is augmented as a result of enhanced connectivity. Our data points out that despite low effective population size, M. ganzhorni maintains high individual heterozygosity at neutral loci and at MHC II DRB gene and that selection plays a predominant role in maintaining MHC diversity. These findings highlight the importance of long-term genetic monitoring in order to disentangle between the processes of drift and selection maintaining adaptive genetic diversity in small populations.
Data from: Genetic evidence for multiple events of hybridization between wolves and domestic dogs in the Iberian Peninsula
Hybridization between wild species and their domestic counterparts may represent a major threat to natural populations. However, high genetic similarity between the hybridizing taxa makes the detection of hybrids a difficult task and may hinder attempts to assess the impact of hybridization in conservation biology. In this work, we used a combination of 42 autosomal microsatellites together with Y-chromosome microsatellite-defined haplotypes and mtDNA sequences to investigate the occurrence and dynamics of wolf–dog hybridization in the Iberian Peninsula. To do this, we applied a variety of Bayesian analyses and a parallel set of simulation studies to evaluate (i) the differences between Iberian wolves and dogs, (ii) the frequency and geographical distribution of hybridization and (iii) the directionality of hybridization. First, we show that Iberian wolves and dogs form two well-differentiated genetic entities, suggesting that introgressive hybridization is not a widespread phenomenon shaping both gene pools. Second, we found evidence for the existence of hybridization that is apparently restricted to more peripheral and recently expanded wolf populations. Third, we describe compelling evidence suggesting that the dynamics of hybridization in wolf populations is mediated by crosses between male dogs and female wolves. More importantly, the observation of a population showing the occurrence of a continuum of hybrid classes forming mixed packs may indicate that we have underestimated hybridization. If future studies confirm this pattern, then an intriguing avenue of research is to investigate how introgression from free-ranging domestic dogs is enabling wolf populations to adapt to the highly humanized habitats of southern Europe while still maintaining their genetic differentiation.
Data from: Evidence of genetic erosion in a peripheral population of a North American game bird: the Montezuma quail (Cyrtonyx montezumae)
Population extirpations are often precursors to species extinctions. Anthropogenic activities often lead to smaller populations that are more prone to extirpations and advocates for active conservation management have recently called for the preservation and monitoring of genetic diversity, particularly with regard to the adaptive potential of vulnerable populations. We used genomics and curated arrays of molecular markers, including those expected to impact key fitness traits, to quantify evidence of genomic erosion in core and peripheral populations of a gallinaceous bird. The Montezuma quail (Cyrtonyx montezumae) is a game species considered vulnerable to extirpation in Texas, but core populations in Arizona and New Mexico are robust and have the potential to serve as genetic reservoirs. We sequenced the Montezuma quail genome then developed a single nucleotide polymorphism (SNP) assay to quantify genetic variation, effective population sizes, signatures of natural selection, and population structure. We genotyped SNPs from gene deserts and from genes associated with fitness traits and found the isolated Texas population exhibits an extremely small effective population size, is genetically distinct from our Arizona and New Mexico samples, and has reduced heterozygosity at the fitness-related markers. Thus, our samples from Texas exhibit symptoms of genetic erosion that could exacerbate future risk of local extirpation. Management agencies must decide if active conservation efforts such as assisted gene flow or genetic rescue are now warranted. This decision may not be straightforward because the current conservation status of the Texas population reflects its isolated geographic locale on the periphery of the species' range.
Data from: Genetic surfing, not allopatric divergence, explains spatial sorting of mitochondrial haplotypes in venomous coralsnakes
Strong spatial sorting of genetic variation in contiguous populations is often explained by local adaptation or secondary contact following allopatric divergence. A third explanation, spatial sorting by stochastic effects of range expansion, has been considered less often though theoretical models suggest it should be widespread, if ephemeral. In a study designed to delimit species within a clade of venomous coralsnakes, we identified an unusual pattern within the Texas coral snake (Micrurus tener): strong spatial sorting of divergent mitochondrial (mtDNA) lineages over a portion of its range, but weak sorting of these lineages elsewhere. We tested three alternative hypotheses to explain this pattern—local adaptation, secondary contact following allopatric divergence, and range expansion. Collectively, near panmixia of nuclear DNA, the signal of range expansion associated sampling drift, expansion origins in the Gulf Coast of Mexico, and species distribution modeling suggest that the spatial sorting of divergent mtDNA lineages within M. tener has resulted from genetic surfing of standing mtDNA variation—not local adaptation or allopatric divergence. Our findings highlight the potential for the stochastic effects of recent range expansion to mislead estimations of population divergence made from mtDNA, which may be exacerbated in systems with low vagility, ancestral mtDNA polymorphism, and male-biased dispersal.
Data from: Population genetics of the American eel (Anguilla rostrata): FST = 0 and NAO effects on demographic fluctuations of a panmictic species
We performed population genetic analyses on the American eel (Anguilla rostrata) with three main objectives. First, we conducted the most comprehensive analysis of neutral genetic population structure to date in order to revisit the null hypothesis of panmixia in this species. Second, we used this data to provide the first estimates of contemporary effective population size (Ne) and to document temporal variation in effective number of breeders (Nb) in American eel. Third, we tested for statistical associations between temporal variation in the North Atlantic Oscillation (NAO) index, the effective number of breeders and two indices of recruit abundance. A total of 2142 eels from 32 sampling locations were genotyped with 18 microsatellite loci. All measures of differentiation were essentially zero, and no evidence for significant spatial or temporal genetic differentiation was found. The panmixia hypothesis should thus be accepted for this species. Nb estimates varied by a factor of 23 among 12 cohorts, from 473 to 10 999. The effective population size Ne was estimated to be around 22 382. This study also showed that genetically based demographic indices, namely Nb and allelic richness (Ar), can be used as surrogates for the abundance of breeders and recruits, which were both shown to be positively influenced by variation during high (positive) NAO phases. Thus, long-term genetic monitoring of American glass eels at several sites along the North American Atlantic coast would represent a powerful and efficient complement to census monitoring to track demographic fluctuations and better understand their causes.
Data from: A molecular genetic time scale demonstrates Cretaceous origins and multiple diversification rate shifts within the order Galliformes (Aves)
The phylogeny of Galliformes (landfowl) has been studied extensively; however, the associated chronologies have been criticized recently due to misplaced or misidentified fossil calibrations. As a consequence, it is unclear whether any crown-group lineages arose in the Cretaceous and survived the Cretaceous–Paleogene (K–Pg; 65.5 Ma) mass extinction. Using Bayesian phylogenetic inference on an alignment spanning 14,539 bp of mitochondrial and nuclear DNA sequence data, four fossil calibrations, and a combination of uncorrelated lognormally distributed relaxed-clock and strict-clock models, we inferred a time-calibrated molecular phylogeny for 225 of the 291 extant Galliform taxa. These analyses suggest that crown Galliformes diversified in the Cretaceous and that three-stem lineages survived the K–Pg mass extinction. Ideally, characterizing the tempo and mode of diversification involves a taxonomically complete phylogenetic hypothesis. We used simple constraint structures to incorporate 66 data-deficient taxa and inferred the first taxon-complete phylogenetic hypothesis for the Galliformes. Diversification analyses conducted on 10,000 timetrees sampled from the posterior distribution of candidate trees show that the evolutionary history of the Galliformes is best explained by a rate-shift model including 1–3 clade-specific increases in diversification rate. We further show that the tempo and mode of diversification in the Galliformes conforms to a three-pulse model, with three-stem lineages arising in the Cretaceous and inter and intrafamilial diversification occurring after the K–Pg mass extinction, in the Paleocene–Eocene (65.5–33.9 Ma) or in association with the Eocene–Oligocene transition (33.9 Ma).
Data from: Genetic signs of multiple colonization events in Baltic ciscoes with radiation into sympatric spring and autumn-spawners confined to early post-glacial arrival
Presence of sympatric populations may reflect local diversification or secondary contact of already distinct forms. The Baltic cisco (Coregonus albula) normally spawns in late autumn, but in a few lakes in Northern Europe sympatric autumn and spring- or winter-spawners have been described. So far, the evolutionary relationships and taxonomic status of these main life history forms have remained largely unclear. With microsatellites and mtDNA sequences, we analyzed extant and extinct spring- and autumn-spawners from a total of 23 Swedish localities, including sympatric populations. Published sequences from Baltic ciscoes in Germany and Finland, and Coregonus sardinella from North America were also included together with novel mtDNA sequences from Siberian C. sardinella. A clear genetic structure within Sweden was found that included two population assemblages markedly differentiated at microsatellites and apparently fixed for mtDNA haplotypes from two distinct clades. All sympatric Swedish populations belonged to the same assemblage, suggesting parallel evolution of spring-spawning rather than secondary contact. The pattern observed further suggests that postglacial immigration to Northern Europe occurred from at least two different refugia. Previous results showing that mtDNA in Baltic cisco is paraphyletic with respect to North American C. sardinella were confirmed. However, the inclusion of Siberian C. sardinella revealed a more complicated pattern, as these novel haplotypes were found within one of the two main C. albula clades and were clearly distinct from those in North American C. sardinella. The evolutionary history of Northern Hemisphere ciscoes thus seems to be more complex than previously recognized.
Data from: Comprehensive evaluation of genetic population structure for anadromous river herring with single nucleotide polymorphism data
Anthropogenic activities are placing increasing pressure on many species, particularly those that rely on more than one ecosystem. River herring (alewife, Alosa pseudoharengus and blueback herring, A. aestivalis collectively) are anadromous fishes that reproduce in rivers and streams of eastern North America and migrate to the western Atlantic Ocean. Here, we use data from single nucleotide polymorphisms (SNPs) to provide a comprehensive analysis of population structure for both species of river herring throughout their native ranges. We sampled river herring spawning runs in rivers from Newfoundland to Florida, examining a total of 108 locations, and genotyping over 8000 fish. We identified geographic population groupings (regional genetic groups) in each species, as well as significant genetic differentiation between most populations and rivers. Strong correlations between geographic and genetic distances (i.e., isolation by distance) were found range-wide for both species, although the patterns were less consistent at smaller spatial scales. River herring are caught as bycatch in fisheries and estimating stock proportions in mixed fishery samples is important for management. We assessed the utility of the SNP datasets as reference baselines for genetic stock identification. Results indicated high accuracy of individual assignment (76–95%) to designated regional genetic groups, and some individual populations, as well as highly accurate estimates of mixing proportions for both species. This study is the first to evaluate genetic structure across the entire geographic range of these species and provides an important foundation for conservation and management planning. The SNP reference datasets will facilitate continued multi-lateral monitoring of bycatch, as well as ecological investigation to provide information about ocean dispersal patterns of these species.
Data from: Survival relative to new and ancestral host plants, phytoplasma infection and genetic constitution in host races of a polyphagous insect disease vector
Dissemination of vectorborne diseases depends strongly on the vector's host range and the pathogen's reservoir range. Because vectors interact with pathogens, the direction and strength of a vector's host shift is vital for understanding epidemiology and is embedded in the framework of ecological specialization. This study investigates survival in host-race evolution of a polyphagous insect disease vector, Hyalesthes obsoletus, whether survival is related to the direction of the host shift (from field bindweed to stinging nettle), the interaction with plant-specific strains of obligate vectored pathogens/symbionts (stolbur phytoplasma), and whether survival is related to genetic differentiation between the host races. We used a twice repeated, identical nested experimental design to study survival of the vector on alternative hosts and relative to infection status. Survival was tested with Kaplan–Meier analyses, while genetic differentiation between vector populations was quantified with microsatellite allele frequencies. We found significant direct effects of host plant (reduced survival on wrong hosts) and sex (males survive longer than females) in both host races and relative effects of host (nettle animals more affected than bindweed animals) and sex (males more affected than females). Survival of bindweed animals was significantly higher on symptomatic than nonsymptomatic field bindweed, but in the second experiment only. Infection potentially had a positive effect on survival in nettle animals but due to low infection rates the results remain suggestive. Genetic differentiation was not related to survival. Greater negative plant-transfer effect but no negative effect of stolbur in the derived host race suggests preadaptation to the new pathogen/symbiont strain before strong diversifying selection during the specialization process. Physiological maladaptation or failure to accept the ancestral plant will have similar consequences, namely positive assortative mating within host races and a reduction in the likelihood of oviposition on the alternative plant and thus the acquisition of alternative stolbur strains.
Data from: Physiological conditions and genetic controls of phaeomelanin pigmentation in nestling barn swallows
Phaeomelanin is a common pigment that confers a reddish color to animals. Since phaeomelanogenesis requires the sulfhydryl group from cysteine or glutathione (GSH), which is an important antioxidant, this pigmentation and the associated coloration may be an honest signal, whereby only high-quality individuals (e.g., with lower oxidative stress) are able to develop showy plumage. The present study tested the mechanisms underlying the honest signal hypothesis using nestling barn swallows, Hirundo rustica gutturalis, which exhibit phaeomelanic throat plumage patches. We examined the relationship between phaeomelanin pigmentation levels and physiological condition during trait development, and the expression of the phaeomelanin-related gene agouti-signaling protein (ASIP) and the GSH-related gene glutathione S-transferase (GST) in throat feather follicles. We found that during phaeomelanogenesis, heavier nestlings produced more pigmented feathers, indicating that nestlings with high phaeomelanin concentrations are in better condition. We also found that phaeomelanin concentration was negatively correlated with total GSH level, but not significantly related with measures of oxidative stress. Among the GST genes, GSTM3 exhibited the highest expression in the developing feathers during phaeomelanogenesis. The expression levels of ASIP were positively associated with the amount of phaeomelanin deposition and negatively associated with the expression of GSTM3, reducing the amount of GSH that was available as an antioxidant. These findings suggest that high-quality individuals produce high concentrations of phaeomelanin in their plumage without experiencing increased oxidative stress, despite phaeomelanin production, which is triggered by ASIP, potentially actively consuming the sulfhydryl group from GSH.
Data from: Accounting for kin sampling reveals genetic connectivity in Tasmanian and New Zealand school sharks, Galeorhinus galeus
Fishing represents a major problem for conservation of chondrichthyans, with a quarter of all species being overexploited. School sharks, Galeorhinus galeus, are targeted by commercial fisheries in Australia and New Zealand. The Australian stock has been depleted to below 20% of its virgin biomass, and the species is recorded as Conservation Dependent within Australia. Individuals are known to move between both countries, but it is disputed whether the stocks are reproductively linked. Accurate and unbiased determination of stock and population connectivity is crucial to inform effective management. In this study, we assess the genetic composition and population connectivity between Australian and New Zealand school sharks using genome‐wide SNPs, while accounting for non‐random kin sampling. Between 2009 and 2013, 88 neonate and juvenile individuals from Tasmanian and New Zealand nurseries were collected and genotyped. Neutral loci were analyzed to detect fine‐scale signals of reproductive connectivity. Seven full‐sibling groups were identified and removed for unbiased analysis. Based on 6,587 neutral SNPs, pairwise genetic differentiation from Tasmanian and New Zealand neonates was non‐significant (FST = 0.0003, CI95 = [−0.0002, 0.0009], p = 0.1163; Dest = 0.0006 ± 0.0002). This pattern was supported by clustering results. In conclusion, we show a significant effect of non‐random sampling of kin and identify fine‐scale reproductive connectivity between Australian and New Zealand school sharks.
Data from: Heterogeneity in genetic diversity among non-coding loci fails to fit neutral coalescent models of population history
Inferring aspects of the population histories of species using coalescent analyses of non-coding nuclear DNA has grown in popularity. These inferences, such as divergence, gene flow, and changes in population size, assume that genetic data reflect simple population histories and neutral evolutionary processes. However, violating model assumptions can result in a poor fit between empirical data and the models. We sampled 22 nuclear intron sequences from at least 19 different chromosomes (a genomic transect) to test for deviations from selective neutrality in the gadwall (Anas strepera), a Holarctic duck. Nucleotide diversity among these loci varied by nearly two orders of magnitude (from 0.0004 to 0.029), and this heterogeneity could not be explained by differences in substitution rates. Using two different coalescent methods to infer models of population history and then simulating neutral genetic diversity under these models, we found that the among-locus heterogeneity in nucleotide diversity was significantly higher than expected for these simple models. Defining more complex models of population history demonstrated that a pre-divergence bottleneck was also unlikely to explain this heterogeneity. However, both selection and interspecific hybridization could account for the heterogeneity observed among loci. Regardless of the cause of the deviation, our results illustrate that violating key assumptions of coalescent models can mislead inferences of population history.
Data from: Genetic diversity and population structure of Varronia curassavica: a medicinal polyploid species in a threatened ecosystem
Varronia curassavica is an important medicinal species associated with the restinga, one of the most threatened coastal ecosystems of the Atlantic Forest. These circumstances call for studies aimed at estimating effective population size and gene flow to improve conservation efforts. Hence, the present study aimed to characterize the genetic diversity, ploidy level and population structure of this species in different areas of restinga using microsatellites. Varronia curassavica was characterized as an autotetraploid, with high genetic variability, low divergence, and no significant fixation indices, indicating the absence of, or reduced, inbreeding and genetic drift in the study area. About 44 % of the alleles occurred at low frequency in adults of all populations and 41 % in the progenies evaluated. Gene flow was high, consistent with outcrossing species with high dispersal capacity (Nm = 4.87). The results showed no tendency toward isolation by distance. The estimated effective size indicates that the populations studied have the potential to ensure conservation of the species in the long term. The genetic variability and population structure of V. curassavica, as determined in this study, could form the foundation for activities directed toward the sustainable use of this resource and its conservation. Even though the restinga ecosystem has suffered dramatic reductions in area, this study provides evidence that this species is resilient to anthropogenic threats to its genetic integrity, since it is a polyploid with self-incompatibility mechanisms that contribute to maintaining high genetic diversity in an panmictic meta-population along the coast of Santa Catarina.
Data from: The genetic architecture of reproductive isolation during speciation-with-gene-flow in lake whitefish species pairs assessed by RAD sequencing
During speciation-with-gene-flow, effective migration varies across the genome as a function of several factors, including proximity of selected loci, recombination rate, strength of selection, and number of selected loci. Genome scans may provide better empirical understanding of the genome-wide patterns of genetic differentiation, especially if the variance due to the previously mentioned factors is partitioned. In North American lake whitefish (Coregonus clupeaformis), glacial lineages that diverged in allopatry about 60,000 years ago and came into contact 12,000 years ago have independently evolved in several lakes into two sympatric species pairs (a normal benthic and a dwarf limnetic). Variable degrees of reproductive isolation between species pairs across lakes offer a continuum of genetic and phenotypic divergence associated with adaptation to distinct ecological niches. To disentangle the complex array of genetically based barriers that locally reduce the effective migration rate between whitefish species pairs, we compared genome-wide patterns of divergence across five lakes distributed along this divergence continuum. Using restriction site associated DNA (RAD) sequencing, we combined genetic mapping and population genetics approaches to identify genomic regions resistant to introgression and derive empirical measures of the barrier strength as a function of recombination distance. We found that the size of the genomic islands of differentiation was influenced by the joint effects of linkage disequilibrium maintained by selection on many loci, the strength of ecological niche divergence, as well as demographic characteristics unique to each lake. Partial parallelism in divergent genomic regions likely reflected the combined effects of polygenic adaptation from standing variation and independent changes in the genetic architecture of postzygotic isolation. This study illustrates how integrating genetic mapping and population genomics of multiple sympatric species pairs provide a window on the speciation-with-gene-flow mechanism.
Data from: Evolution of resistance to a multiple-herbavore community: genetic correlations, diffuse coevolution, and constraints on the plant's response to selection
Although plants are generally attacked by a community of several species of herbivores, relatively little is known about the strength of natural selection for resistance in multiple-herbivore communities—particularly how the strength of selection differs among herbivores that feed on different plant organs or how strongly genetic correlations in resistance affect the evolutionary responses of the plant. Here, we report on a field study measuring natural selection for resistance in a diverse community of herbivores of Solanum carolinense. Using linear phenotypic-selection analyses, we found that directional selection acted to increase resistance to seven species. Selection was strongest to increase resistance to fruit feeders, followed by flower feeders, then leaf feeders. Selection favored a decrease in resistance to a stem borer. Bootstrapping analyses showed that the plant population contained significant genetic variation for each of 14 measured resistance traits and significant covariances in one-third of the pairwise combinations of resistance traits. These genetic covariances reduced the plant's overall predicted evolutionary response for resistance against the herbivore community by about 60%. Diffuse (co)evolution was widespread in this community, and the diffuse interactions had an overwhelmingly constraining (rather than facilitative) effect on the plant's evolution of resistance.
Data from: Genetic and morphological variation in sexual and asexual parasitoids of the genus Lysiphlebus: an apparent link between wing shape and reproductive mode
Background Endoparasitoids of aphids belonging to the genus Lysiphlebus Foerster (Hymenoptera: Braconidae: Aphidiinae) comprise over 20 species that exploit over a hundred species of aphid hosts including many important pest aphid species. Within the genus Lysiphlebus two genetically and morphologically well defined species groups are recognized: the "fabarum" and the "testaceipes" group both including taxa with sexual (arrhenotoky) and asexual (thelytoky) reproduction modes. However the diverse patterns of morphological variation which include clearly distinguishable morphotypes and genetic variation within species groups are not yet resolved. To address the relationship between morphological evolution and genetic divergence in Lysiphlebus wasps we explored both genetic differentiation (mitochondrial and nuclear gene sequences) and morphological variation (wing size and shape) and the changes in wing size and shape in the phylogenetic context. Results and Discussion Analyses of mitochondrial and nuclear gene sequences determine the separation of the genus into two species groups ("testaceipes" and "fabarum" groups) revealed three well defined phylogenetic lineages within "fabarum" species group including yet undefined species. Mapping wing shape data onto molecular phylogenetic indicated that the concordance between genetic diversification and divergence in the wing shape results from the deep split between two main species group. No association between pattern of genetic diversification morphotypes and wing shape variation within species groups was observed. The clear association between wing shape and reproductive mode was the most surprising result of our study. We propose two possible mutually non-exclusive mechanisms which may explain the link between reproductive mode and the shape of the wing Conclusions Combining molecular analysis with analysis of wing shape allows us determining existence of one cryptic yet undescribed species. At the same time we determine that Lysiphlebus fabarum group need detailed taxonomic revision because species boundaries as defined cannot be upheld. Mapping wing shape onto independently derived molecular phylogeny revealed that deep genetic divergence is associated with evolutionary changes in wing shape of Lysiphlebus wasps. Among most recently diverged taxa the morphological variation in the wing shape can be explained by the reproduction mode.
Data from: Fine-scale population genetic structure of the Bengal tiger (Panthera tigris tigris) in a human-dominated western Terai Arc Landscape, India
Despite massive global conservation strategies, tiger populations continued to decline until recently, mainly due to habitat loss, human-animal conflicts, and poaching. These factors are known to affect the genetic characteristics of tiger populations and decrease local effective population sizes. The Terai Arc Landscape (TAL) at the foothills of the Himalaya is one of the 42 source sites of tigers around the globe. Therefore, information on how landscape features and anthropogenic factors affect the fine-scale spatial genetic structure and variation of tigers in TAL is needed to develop proper management strategies for achieving long-term conservation goals. We document, for the first time, the genetic characteristics of this tiger population by genotyping 71 tiger samples using 13 microsatellite markers from the western region of TAL (WTAL) (1800 km2). Specifically, we aimed to estimate the genetic variability, population structure, and gene flow. The microsatellite markers indicated that the levels of allelic diversity (MNA = 6.6) and genetic variation (Ho =0.50, HE = 0.64) were slightly lower than those reported previously in other Bengal tiger populations. We observed moderate gene flow and significant genetic differentiation (FST= 0.060), and identified the presence of cryptic genetic structure using Bayesian and non-Bayesian approaches. There was low and significantly asymmetric migration between the two main subpopulations of the Rajaji Tiger Reserve and the Corbett Tiger Reserve in WTAL. Sibship relationships indicated that the functionality of the corridor between these subpopulations may be retained if the quality of the habitat does not deteriorate. However, we found that gene flow is not adequate in view of changing land use matrices. We discuss the need to maintain connectivity by implementing the measures that have been suggested previously to minimize the level of human disturbance, including relocation of villages and industries, prevention of encroachment, and banning sand and boulder mining in the corridors.
Data from: Past climate change drives current genetic structure of an endangered freshwater mussel species
Historical-to-recent climate change and anthropogenic disturbance affect species distributions and genetic structure. The Rio Grande watershed of the United States and Mexico encompasses ecosystems that are intensively exploited, resulting in substantial degradation of aquatic habitats. While significant anthropogenic disturbances in the Rio Grande are recent, inhospitable conditions for freshwater organisms likely existed prior to such disturbances. A combination of anthropogenic and past climate factors may contribute to current distributions of aquatic fauna in the Rio Grande basin. We used mitochondrial DNA and 18 microsatellite loci to infer evolutionary history and genetic structure of an endangered freshwater mussel, Popenaias popeii, throughout the Rio Grande drainage. We estimated spatial connectivity and gene flow across extant populations of P. popeii and used ecological niche models (ENMs) and approximate Bayesian computation (ABC) to infer its evolutionary history during the Pleistocene. structure results recovered regional and local population clusters in the Rio Grande. ENMs predicted drastic reductions in suitable habitat during the last glacial maximum. ABC analyses suggested that regional population structure likely arose in this species during the mid-to-late Pleistocene and was followed by a late Pleistocene population bottleneck in New Mexico populations. The local population structure arose relatively recently, perhaps due to anthropogenic factors. Popenaias popeii, one of the few freshwater mussel species native to the Rio Grande basin, is a case study for understanding how both geological and anthropogenic factors shape current population genetic structure. Conservation strategies for this species should account for the fragmented nature of contemporary populations.
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Allen Brain Atlas
Allen Brain Atlas is an Allen Institute collection of brain map atlases, datasets, APIs, and analysis tools covering mouse, human, and non-human primate brain resources.
Annotated Behaviour and Observability Dataset (ABODe)
ABODe is a University of Edinburgh DataShare dataset for behavior classification in group-housed mice using home-cage video, identities, bounding boxes, ground-plate positions, and annotator labels.
DANDI Archive for NWB datasets
DANDI is a BRAIN Initiative archive for publishing and sharing neurophysiology data, including electrophysiology, optophysiology, and behavioral data packaged as NWB and related standards.
International Brain Laboratory public data
The International Brain Laboratory public data releases expose standardized mouse decision-making experiments, including Neuropixels recordings, widefield calcium imaging, behavior, and session metadata accessed through the ONE API.
OpenNeuro
OpenNeuro is a free, open platform for sharing neuroimaging datasets, with public search, dataset pages, and download paths for web, S3, DataLad, and the OpenNeuro CLI.