Low Levels Of Genetic Diversity Research Articles

Range wide genetic differentiation in the bull kelp Nereocystis luetkeana with a seascape genetic focus on the Salish Sea

IntroductionIn temperate regions, one of the most critical determinants of present range-wide genetic diversity was the Pleistocene climate oscillations, the most recent one created by the last glacial maximum (LGM). This study aimed to describe N. luetkeana genetic structure across its entire range (Alaska to California) and test different models of population connectivity within the Salish Sea. This region was colonized after the LGM and has been under increased disturbance in recent decades.MethodsWe utilized microsatellite markers to study N. luetkeana genetic diversity at 53 sites across its range. Using higher sampling density in the Salish Sea, we employed a seascape genetics approach and tested isolation by hydrodynamic transport and environment models.ResultsAt the species distribution scale, we found four main groups of genetic co-ancestry, Alaska; Washington with Vancouver Island’s outer coast and Juan de Fuca Strait; Washington’s inner Salish Sea; and Oregon with California. The highest allelic richness (AR) levels were found in California, near the trailing range edge, although AR was also high in Alaska. The inner Salish Sea region had the poorest diversity across the species distribution. Nevertheless, a pattern of isolation by hydrodynamic transport and environment was supported in this region.DiscussionThe levels of allelic, private allele richness and genetic differentiation suggest that during the LGM, bull kelp had both northern and southern glacial refugia in the Prince of Wales Island-Haida Gwaii region and Central California, respectively. Genetic diversity in Northern California sites seems resilient to recent disturbances, whereas the low levels of genetic diversity in the inner Salish Sea are concerning.

Phylogeographic analysis reveals early Pleistocene divergence and strong genetic structure in Euphorbia phosphorea (Euphorbiaceae), an endemic species to the semi-arid Caatinga Biome

Abstract The largest continuous patch of Seasonally Dry Tropical Forests (SDTF) is the Caatinga Biome in north-eastern Brazil, which has the greatest biodiversity and highest degree of endemism compared to any other SDTF patch of South America. Our aim was to conduct a phylogeographic study with Euphorbia phosphorea to understand the evolutionary history of this species endemic to the Caatinga Biome. We studied genetic diversity and structure, demographic dynamics, as well as intraspecific phylogenetic relationships, based on plastidial and nuclear DNA. In addition, we conducted species distribution modelling (SDM) to infer connectivity since the Last Interglacial. Our results recovered a stronger genetic structure for plastidial than for nuclear genome, which probably result from distinct species capability to seed and pollen dispersal, and low levels of genetic diversity within populations. Although SDM results suggest higher connectivity during Last Maximum Glacial, demographic analyses detected no signs of demographic expansion in this period. In agreement with previous studies with rock specialists, our data reveal remarkable among-population differentiation and low within-population genetic diversity, which make populations more prone to drift effects. Furthermore, our results shed light on the importance of early Pleistocene events in the diversification of lineages within the Caatinga Biome, although further comparative work is required.

Genetic diversity and population structure of Mastacembelus armatus in the river systems of southern China revealed by microsatellites

The Zig-zag eel (Mastacembelus armatus) is an economically important species in southern China. Its natural resources have declined year by year due to overfishing. Understanding its genetic diversity and population structure is very important for resource conservations. Here, we first successfully developed 28 polymorphic microsatellite markers for zig-zag eels and ten of them were used to examine the genetic diversity and differentiation of 7 populations collected from the major river systems of south China. In total, 224 alleles were found with the 10 microsatellite loci in 7 populations, ranging from 4.6 (Nandujiang: NDJ) to 11.1 (Xijiang, XJ), with an average of 8.871 alleles. The average observed and expected heterozygosity ranged from 0.550 (NDJ) to 0.964 (Yuangjiang, YJ) and from 0.537 (NDJ) to 0.775 (Tanjiang, TJ), respectively. The average polymorphism-information content ranged from 0.472 (NDJ) to 0.757 (TJ). Hardy–Weinberg equilibrium test results revealed the loci showed differing deviation in different populations. In total, low level of genetic diversity was only found in HJ (Hanjiang) and NDJ populations. Besides, evidence of recent bottleneck was found in the HJ populations. Analysis of molecular variation showed that the percent variation within individuals (75.00%) was higher than that among populations (25%). In addition, population structure and the pairwise FST revealed that there was low differentiation among XJ, TJ and YJ populations. These data provide important genetic resources for understanding the population differentiation and facilitating genetic conservation and utilization of this species.

Morphological Traits and Nuclear Genetic Diversity of Coptis sp. in Hoang Lien National Park, Lao Cai Province, Vietnam

Coptis is a medicinal plant genus in the Ranunculaceae family, and is also known as “Hoang Lien” in Vietnamese. It is a perennial herb that grows in some regions of the world. However, Coptis is endangered and faces global threats. This study aimed to characterize some main morphological characteristics and performed a phylogenetic analysis of 11 samples of Coptis sp. collected from Hoang Lien National Park using nuclear DNA sequence analyses. All sample species have unique morphological traits with distinct yellow rhizomes and basal leaves with five segments. The petiole measures 13-25 cm and is smooth, while the leaf blade is ovate, ranging from 7 to 15.5 cm in length and 5.5 to 14 cm in width. The leaves are subleathery, glabrous on the underside, and sparsely puberulous on the veins on the upper side. The molecular characterization of Coptis sp. genotypes was determined by ITS markers. The length of the ITS1-ITS2 sequences varied from 363 to 371 nucleotides. The average nucleotide composition was 17.11% A, 31.25% C, 32.247% G and 19.41% T, respectively. The comparison with the GenBank database showed that the samples had 95.71- 96.37% similarity with the species Coptis quinquesecta. The genetic distance among the 11 Coptis samples fluctuated from 0.00 to 0.017. A neighbor-joining tree was constructed to show the genetic relationships among Coptis samples. The results indicated that this endangered species had low levels of genetic diversity. The study has provided valuable information for genetic-based conservation of this rare endemic species and suggested some conservation strategies.

High connectivity among Vesicomyid bivalves from cold seeps and deep-sea fans of Congo

Chemosynthetic ecosystems are scattered in the deep ocean, harbouring highly specialized communities, among which the degree of connectivity and dispersal is scarcely studied. This gap is largely due to limited range distribution, either real or due to highly partial exploration, preventing the availability of a sufficient number of samples for population genetic analysis. For the few species that escaped this gap, large-scale panmixia was often reported, raising wonders as to the evolutionary mechanisms involved in the first steps of speciation. Vesicomyid bivalves are one of the most abundant groups of chemosynthetic fauna, for which depth was proposed as an essential driver of differentiation. Early stages of speciation are thus expected to involve genetic differentiation along depth gradients. The vesicomyid bivalve Christineconcha regab was studied across widely separated localities along the Western African margin, from the cold-seeps of Regab pockmarks located at 3150 m depth on the Congo margin to the turbiditic lobes of the Congo deep-sea fan located at 5000 m depth, using mitochondrial (COI) sequences and eight microsatellite loci. Despite rather high density in relation to high organic matter availability, results obtained showed rather low levels of genetic diversity at both mtDNA and microsatellites. The main consistent pattern of differentiation was observed across depths from Regab pockmark (South-Western part) and lobe areas (Lobe B and C). This is likely due to the largest sample sizes characterizing Regab_SW and Lobe C allowing the detection of faint genetic differentiation, and possibly to a stronger signature in the demographically declining (thus acknowledgedly under sampled) Lobe B. Other significant results were not congruent among markers, suggesting low statistical power due to limited sample size or the occurrence of chaotic genetic patchiness. Altogether, the results suggest the occurrence of effective gene flow at regional scale, and departure from equilibrium in the recently discovered lobes of the Congo River, possibly resulting from unstable environmental conditions and recurrent events of extinction recolonization.

Genetic Diversity and Population Structure in Captive Populations of Formosan Sambar Deer (Rusa unicolor swinhoei).

Formosan sambar deer (Rusa unicolor swinhoei) are of great economic significance in Taiwan, resulting in a substantial increase in deer farming to meet the high demand for velvet antlers. Inbreeding depression and reduced genetic variability can lead to the deterioration of captive populations. In this study, 239 Formosan sambar deer were genotyped using 13 microsatellites to analyze their genetic diversity and population genetic structure. Our results indicate a high-resolution power of these microsatellites in individual discrimination and parentage analysis. However, captive populations exhibit a low level of genetic diversity, likely because of inbreeding and bottleneck effects. Both principal coordinate analysis (PCoA) and STRUCTURE analyses revealed two distinct and segregated genetic groups within the captive populations and indicated no clear population genetic structure among the captive populations. Introducing new genetic material from the wild through translocation offers a potential solution for mitigating the impact of inbreeding and enhancing genetic diversity. The comprehensive information obtained from these genetic analyses is crucial for the development of effective breeding strategies aimed at preserving and enhancing Formosan sambar deer populations.

Genetic and Ecological Approaches to Introduced Populations of Pumpkinseed Sunfish (Lepomis gibbosus) in Southwestern Europe

Freshwater systems are among the most affected by the introduction of exotic species. The pumpkinseed sunfish Lepomis gibbosus, a centrarchid native to eastern North America, is listed among the top ten introduced freshwater fishes with the greatest ecological impact globally. Despite this, genetic and evolutionary studies of the species are still scarce. Here, we analyzed the genetic variability of introduced populations of L. gibbosus using three mitochondrial genes (COI, d-loop, and ND1). In addition, we used species distribution modeling to compare the niche of introduced versus native populations to assess the present and potential future distribution of the species under different climate change scenarios. Compared with the native populations, introduced ones present a lower level of genetic variability, indicating these populations originated from a small number of individuals from the native (Atlantic) population in the USA and Canada. The low variability was likely driven by a founder effect and subsequent bottleneck, as often occurs in invasive species. Our modeling results suggest not only that L. gibbosus modified its niche during the invasion process in Europe but also the possible global expansion of the species under future climatic conditions, which could facilitate its establishment in almost all continents.

Are rare plant species less resistant than common ones to herbivores? A multi-plant species study using above- and below-ground generalist herbivores.

Rare plant species are suggested to be less resistant to herbivores than common species. Their lower apparency and the fact that they often live in isolated populations, resulting in fewer herbivore encounters, might have led to the evolution of reduced defences. Moreover, their frequent lower levels of genetic diversity compared with common species could negatively affect their resistance against enemies. However, the hypothesis that plant resistance depends on plant regional and local rarity, independently of habitat and competitive and growth strategy, lacks evidence. To test this hypothesis, we assessed the performance and preference of one belowground and three aboveground generalist invertebrate herbivores from different taxonomic groups as indicators of plant resistance. Herbivores were fed a total of 62 regionally and locally rare and common plant species from Switzerland. We accounted for differences in a plant's growth and competitive strategy and habitat resource availability. We found that regionally and locally rare and common plant species did not generally differ in their resistance to most generalist herbivores. However, one herbivore species even performed better and preferred locally and regionally common plant species over rarer ones, indicating that common species are not more resistant, but tend to be less resistant. We also found that all herbivore species consistently performed better on competitive and large plant species, although different herbivore species generally preferred and performed better on different plant species. The latter indicates that the use of generalist herbivores as indicators of plant-resistance levels can be misleading. Synthesis: Our results show that rare plant species are not inherently less resistant than common ones to herbivores. Instead, our results suggest that the ability of plants to allocate resources away from defence towards enhancing their competitive ability might have allowed plants to tolerate herbivory, and to become locally and regionally common.

Guidelines and quantitative standards for improved cetacean taxonomy using full mitochondrial genomes.

In many organisms, especially those of conservation concern, traditional lines of evidence for taxonomic delineation, such as morphological data, are often difficult to obtain. In these cases, genetic data are often the only source of information available for taxonomic studies. In particular, population surveys of mitochondrial genomes offer increased resolution and precision in support of taxonomic decisions relative to conventional use of the control region or other gene fragments of the mitochondrial genome. To improve quantitative guidelines for taxonomic decisions in cetaceans, we build on a previous effort targeting the control region and evaluate, for whole mitogenome sequences, a suite of divergence and diagnosability estimates for pairs of recognized cetacean populations, subspecies, and species. From this overview, we recommend new guidelines based on complete mitogenomes, combined with other types of evidence for isolation and divergence, which will improve resolution for taxonomic decisions, especially in the face of small sample sizes or low levels of genetic diversity. We further use simulated data to assist interpretations of divergence in the context of varying forms of historical demography, culture, and ecology.

Genomic analyses indicate the North American Ap-ha variant of the tick-vectored bacterium Anaplasma phagocytophilum was introduced from Europe

BackgroundAnaplasma phagocytophilum is a tick-vectored, obligately intracellular bacterium that infects a diversity of vertebrate hosts. In North America, the Ap-ha variant of A. phagocytophilum can cause dangerous infections in humans, whereas symptomatic human infections in Europe are rare. Conversely, the European host-generalist ecotype of A. phagocytophilum frequently causes illness in domestic ruminants while no comparable infections have been recorded from North America. Despite these differences in pathogenicity, the Ap-ha variant is closely aligned phylogenetically with the European host-generalist ecotype. Furthermore, North American populations of A. phagocytophilum are less genetically diverse than those in Europe. Taken together, these observations suggest that the North American Ap-ha variant may represent an introduced population of this bacterium.Methods Data from publicly available whole genomes of A. phagocytophilum were used to compare phylogeographic patterns and the extent of genetic divergence between the North American Ap-ha variant and the European host-generalist ecotype.ResultsThe results confirm that North American Ap-ha samples are phylogenetically nested within the diversity of the European host-generalist ecotype, and that Ap-ha likely radiated within the last 100 years. As expected, the Ap-ha variant also exhibited relatively low genetic diversity levels compared to the European host-generalist ecotype. Finally, North American Ap-ha harbored significantly more derived alleles than the European host-generalist A. phagocytophilum population.ConclusionsCollectively, these results support the hypothesis that the Ap-ha variant was recently introduced to North America from Europe and underwent a strong genetic bottleneck during this process (i.e. a ‘founder event’). Adaptation to novel vectors may have also played a role in shaping genetic diversity and divergence patterns in these pathogenic bacteria. These findings have implications for future studies aimed at understanding evolutionary patterns and pathogenicity variation within A. phagocytophilum.Graphical

Open areas associated with traditional agriculture promote functional connectivity among amphibian demes in Mediterranean agrosystems

ContextFunctional connectivity across fragmented habitat patches is essential for the conservation of animal populations in humanized landscapes. Given their low dispersal capacity, amphibians in the Mediterranean region are threatened by habitat fragmentation and loss due to changes in land use, including agricultural intensification.ObjectivesWe assessed patterns of functional connectivity of a Near Threatened Mediterranean amphibian, the sharp ribbed newt (Pleurodeles waltl), in an agricultural landscape matrix in NW Spain subject to different intensification regimes.MethodsWe sampled newts in 17 ponds embedded in a terrestrial habitat matrix dominated by agricultural land uses. Genome-wide molecular markers (1390 SNPs) were used to assess patterns of genetic diversity and gene flow among ponds. We tested the role of landscape features on functional connectivity using isolation by resistance models incorporating information on Normalized Difference Vegetation Index (NDVI) data.ResultsWe found low levels of genetic diversity in all sampled populations. Global FST estimates and cluster analyses revealed shallow but significant genetic structure in the study area, with NDVI-based resistance models showing that open areas (rainfed crops and grasslands) offer lower resistance to gene flow and thus promote functional connectivity among demes.ConclusionsOur study highlights the important role of landscape features, such as open areas resulting from traditional rainfed agriculture, in promoting functional connectivity between amphibian populations in Mediterranean agrosystems. Conservation policies must adopt a functional network strategy and protect groups of inter-connected temporary ponds across the traditional agricultural matrix to efficiently preserve their associated biotic communities.

Genetic analysis of emerging fungal pathogens: Trichosporon asahii

Trichosporon asahii is an emerging opportunistic fungus that mainly causes fatal disseminated trichosporonosis, especially in immunocompromised patients. T. asahii infection has been reported in Thailand, but few studies of this fungus have been published. Therefore, this study investigated the genetic diversity of 51 clinical strains of T. asahii from urine samples in Thailand. We sequenced and characterized the beta-1-tubulin (TUB1), copper-exporting ATPase (ATP), phosphate carrier protein (PHCP), and topoisomerase-1 (TOP1) genes. In addition, intergenic spacer 1 (IGS1) sequences from our previous studies were investigated. The numbers of haplotypes were 3, 3, 2, 2, and 2 for IGS1, TUB1, ATP, PHCP, and TOP1, respectively. The results suggested a relatively low level of genetic diversity among the strains. The findings illustrated that IGS1, TUB1, ATP, PHCP, and TOP1 can be collectively used as an alternative molecular typing tool for investigating the population diversity and structure of T. asahii.

Deep spatial profiling of Venezuelan equine encephalitis virus reveals increased genetic diversity amidst neuroinflammation and cell death during brain infection.

Venezuelan equine encephalitis virus (VEEV) causes a febrile illness that can progress to neurological disease with the possibility of death in human cases. The evaluation and optimization of therapeutics that target brain infections demands knowledge of the host's response to VEEV, the dynamics of infection, and the potential for within-host evolution of the virus. We hypothesized that selective pressures during infection of the brain may differ temporally and spatially and so we investigated the dynamics of the host response, viral transcript levels, and genetic variation of VEEV TC-83 in eight areas of the brain in mice over 7 days post-infection (dpi). Viral replication increased throughout the brain until 5-6 dpi and decreased thereafter with neurons as the main site of viral replication. Low levels of genetic diversity were noted on 1 dpi and were followed by an expansion in the genetic diversity of VEEV and nonsynonymous (Ns) mutations that peaked by 5 dpi. The pro-inflammatory response and the influx of immune cells mirrored the levels of virus and correlated with substantial damage to neurons by 5 dpi and increased activation of microglial cells and astrocytes. The prevalence and dynamics of Ns mutations suggest that the VEEV is under selection within the brain and that progressive neuroinflammation may play a role in acting as a selective pressure. IMPORTANCE Treatment of encephalitis in humans caused by Venezuelan equine encephalitis virus (VEEV) from natural or aerosol exposure is not available, and hence, there is a great interest to address this gap. In contrast to natural infections, therapeutic treatment of infections from aerosol exposure will require fast-acting drugs that rapidly penetrate the blood-brain barrier, engage sites of infection in the brain and mitigate the emergence of drug resistance. Therefore, it is important to understand not only VEEV pathogenesis, but the trafficking of the viral population within the brain, the potential for within-host evolution of the virus, and how VEEV might evolve resistance.

Range-wide evolutionary relationships and historical demography of brown bears (Ursus arctos) revealed by whole-genome sequencing of isolated central Asian populations.

Phylogeographic studies uncover hidden pathways of divergence and inform conservation. Brown bears (Ursus arctos) have one of the broadest distributions of all land mammals, ranging from Eurasia to North America, and are an important model for evolutionary studies. Although several whole genomes were available for individuals from North America, Europe and Asia, limited whole-genome data were available from Central Asia, including the highly imperilled brown bears in the Gobi Desert. To fill this knowledge gap, we sequenced whole genomes from nine Asian brown bears from the Gobi Desert of Mongolia, Northern Mongolia and the Himalayas of Pakistan. We combined these data with published brown bear sequences from Europe, Asia and North America, as well as other bear species. Our goals were to determine the evolutionary relationships among brown bear populations worldwide, their genetic diversity and their historical demography. Our analyses revealed five major lineages of brown bears based on a filtered set of 684,081 single nucleotide polymorphisms. We found distinct evolutionary lineages of brown bears in the Gobi, Himalayas, northern Mongolia, Europe and North America. The lowest level of genetic diversity and the highest level of inbreeding were found in Pakistan, the Gobi Desert and Central Italy. Furthermore, the effective population size (Ne ) for all brown bears decreased over the last 70,000 years. Our results confirm the genetic distinctiveness and ancient lineage of brown bear subspecies in the Gobi Desert of Mongolia and the Himalayas of Pakistan and highlight their importance for conservation.

Effects of Forest Fragmentation on Connectivity and Genetic Diversity in an Endemic and an Invasive Rodent in Northwestern Madagascar.

Habitat loss and fragmentation are of concern to conservation biologists worldwide. However, not all organisms are affected equally by these processes; thus, it is important to study the effects of living in fragmented habitats on species that differ in lifestyle and habitat requirements. In this study, we examined the dispersal and connectivity patterns of rodents, one endemic (Eliurus myoxinus) and one invasive (Rattus rattus), in two landscapes containing forest fragments and adjacent continuous forest patches in northwestern Madagascar. We generated genetic (RADseq) data for 66 E. myoxinus and 81 R. rattus individuals to evaluate differences in genetic diversity as well as inbreeding and connectivity in two landscapes. We found higher levels of inbreeding and lower levels of genetic diversity in E. myoxinus compared with R. rattus. We observed related dyads both within and between habitat patches and positive spatial autocorrelation at lower distance classes for both species, with a stronger pattern of spatial autocorrelation in R. rattus. Across each site, we identified contrasting migration rates for each species, but these did not correspond to habitat-matrix dichotomies. The relatively low genetic diversity in the endemic E. myoxinus suggests ecological constraints that require further investigation.

Extremely Low Levels of Genetic Variation and Predicted Shifts in Suitable Niche Space for a Geographically Disjunct, Federally Endangered Legume, Leafy Prairie-Clover (Dalea foliosa)

Extremely Low Levels of Genetic Variation and Predicted Shifts in Suitable Niche Space for a Geographically Disjunct, Federally Endangered Legume, Leafy Prairie-Clover (Dalea foliosa)

Lack of genetic differentiation between two sympatric lacustrine morpho-species within the Astyanax (Characidae: Teleostei) genus, Mexico

We analyzed two morpho-species, Astyanax aeneus and Astyanax caballeroi, coexisting in Lake Catemaco, with ecological differences previously associated with different trophic niches. While A. aeneus is a widely distributed species, A. caballeroi is endemic to Lake Catemaco. Due to the contrasting morphology between these two sympatric species, they were originally assigned to different genera, but little is known about their genetic differentiation. We hypothesized that these two species, which present differentiation in morphology and in trophic niches, co-occur in concomitance with assortative mating and form distinct genetic clusters. We tested this prediction by typing a set of 12 microsatellites in 348 individuals of the two morpho-species, comparing their genetic structure patterns with that of an allopatric population of A. aeneus (i.e., the Maquinas population). Genetic structure analysis, assignment analyses, and estimation of gene flow between the sympatric morpho-species were carried out. Contrary to expectations, there is a lack of genetic differentiation between the A. aeneus and A. caballeroi morpho-species. However, there was a genetic differentiation between Lake Catemaco and Río Maquinas populations of A. aeneus. In addition, we found an asymmetric gene flow pattern, with a larger migration rate from A. aeneus to A. caballeroi than in the other direction. Finally, the allopatric population of A. aeneus showed lower levels of genetic diversity than those reported for both morpho-species in the lacustrine system. Consequently, our results support the notion that these morpho-species are either in an early phase of speciation or represent a single polymorphic species. This model provides relevant information to understanding the presence of polymorphisms under gene flow and their potential impact on the speciation process.

Nuclear genetic structure of the white shark (Carcharodon carcharias) from the Northeastern Pacific

The Northeastern Pacific (NEP) population of white sharks (Carcharodon carcharias) is genetically distinct from the rest of the world. This uniqueness results from adult fidelity to central California and Guadalupe Island aggregations sites. The strong mitochondrial genetic structure between the white sharks of central California and Guadalupe Island is also present, which indicates female philopatry. To date, few studies using nuclear DNA have found evidence of genetic patterns in the NEP white shark population, which could indicate that these sharks exhibit sex-biased dispersal. In this study, we evaluated the genetic structure, connectivity, and genetic diversity of NEP white sharks using samples from the southern California Bight (SCB), Baja California (including Sebastian Vizcaino Bay), the Gulf of California, and Guadalupe Island (GI) using nDNA (i.e. microsatellite loci). A total of five loci were successfully genotyped in 54 individuals. The patterns found in this study indicated low levels of genetic diversity among all localities (observed heterozygosity: Ho = 0.47), likely due to a founder effect. A slight genetic structure was present for NEP localities in this study (FST = 0.045, P = 0.0001), mainly identified between the SCB and GI locations. A sibship assignment analysis indicated low and moderate probabilities of full- and half-siblings between white shark juveniles from coastal areas, suggesting a high degree of connectivity between nursery areas in the NEP. Our results suggest that juveniles can mask the genetic structure in coastal zones.

Genetic diversity and population structure of Coryphantha durangensis, a narrow endemic in the chihuahuan desert

The Chihuahuan Desert is the largest arid zone in North America and is recognized as the most important center of diversity for cacti. Coryphantha durangensis is an endemic species of the Chihuahuan Desert that is currently listed in both the IUCN and NOM-059-SEMARNAT-2010. We used microsatellite markers to analyze the diversity and genetic structure of populations of this species. Low levels of genetic diversity were found among populations, but there was genetic differentiation within individuals. The isolation analyses suggest that the population genetic structure can be explained by isolation-by-resistance in climate and isolation-by-resistance in altitude. Poor gene flow was observed between populations, which may be due to several factors, such as climatic fluctuations that have occurred in its distribution area since the Pleistocene, the lack of known pollinators for the species, and the distribution area of this species in small discontinuous mountains that have allowed the isolation of populations, coupled with slow growth and the long time lapse between germination and the first flowering that this species presents. This is the first report on the genetic diversity and population structure of C. durangensis, and the results of the study can be used to develop and promote management and conservation strategies.

New Insights into the Taxonomy of Myotis Bats in China Based on Morphology and Multilocus Phylogeny

The genus Myotis is one of the most diverse and widely distributed mammals, providing a good model for studies of speciation and diversification across large geographic scales. However, the classification within this genus has long been chaotic. Taxonomic revisions based on multiple data sources are essential and urgent. In this study, morphometrics and genetic markers with different modes of inheritance were used to clarify the taxonomy of Myotis distributed in China. Based on 173 mitochondrial Cytb sequences and five morphological characteristics, 114 specimens collected nationwide over the past 20 years were assigned to 11 Myotis species. All Chinese samples classified into M. davidii and M. longipes were revised to M. alticraniatus and M. laniger. Then, two nuclear fragments (Rag2 and Chd1) and Cytb sequences from representative individuals of Chinese Myotis were used for multilocus phylogeny reconstruction and genetic divergence evaluation. The phylogenetic relationships were clearly demonstrated in the species tree: M. alticraniatus and M. laniger; M. fimbriatus, M. pilosus, M. macrodactylus, and M. petax; and M. pequinius, M. chinensis, and M. blythii formed three strongly supported monophyletic clades. Mitochondrial divergence was almost 10 times that of nuclear divergence, with interspecific K2P distances ranging from 8% to 20% for Cytb and 0.3% to 2.3% for concatenated nuclear genes. Low levels of genetic divergence were observed between M. alticraniatus and M. laniger, as well as M. fimbriatus and M. pilosus. These results provide new insights into the taxonomy and phylogeny of Myotis bats in China and are important for the future research and conservation of Chinese Myotis.