Microsatellite Loci Research Articles

Genetic analysis of harvest samples reveals population structure in a highly mobile generalist carnivore.

Delineating wildlife population boundaries is important for effective population monitoring and management. The bobcat (Lynx rufus) is a highly mobile generalist carnivore that is ecologically and economically important. We sampled 1225 bobcats harvested in South Dakota, USA (2014-2019), of which 878 were retained to assess genetic diversity and infer population genetic structure using 17 microsatellite loci. We assigned individuals to genetic clusters (K) using spatial and nonspatial Bayesian clustering algorithms and quantified differentiation (F ST and ) among clusters. We found support for population genetic structure at K = 2 and K = 4, with pairwise F ST and values indicating weak to moderate differentiation, respectively, among clusters. For K = 2, eastern and western clusters aligned closely with historical bobcat management units and were consistent with a longitudinal suture zone for bobcats previously identified in the Great Plains. We did not observe patterns of population genetic structure aligning with major rivers or highways. Genetic divergence observed at K = 4 aligned roughly with ecoregion breaks and may be associated with environmental gradients, but additional sampling with more precise locational data may be necessary to validate these patterns. Our findings reveal that cryptic population structure may occur in highly mobile and broadly distributed generalist carnivores, highlighting the importance of considering population structure when establishing population monitoring programs or harvest regulations. Our study further demonstrates that for elusive furbearers, harvest can provide an efficient, broad-scale sampling approach for genetic population assessments.

Taxonomy of Naumann’s and dusky, red-throated and black-throated thrush complexes (Aves: Turdidae) using morphological and molecular characteristics

Abstract Species are the basic units in evolution and biodiversity and thus a reasonable species classification is essential to assess and protect biodiversity. The classifications of the Naumann’s and dusky thrush complexes and the red-throated and black-throated thrush complexes are not well defined in Turdidae (Aves, Passeriformes). Herein, we use qualitative and quantitative morphological characters and molecular data to review the taxonomy of these thrush complexes. These four thrushes can be distinguished with qualitative features of feather color and striping. These birds cannot be divided by quantitative features, which only work on two groups of thrush complexes. Phylogenetic analysis based on mitochondrial genes indicate that all haplotypes might be divided into two monophyletic clades corresponding to two groups of thrush complexes. According to coalescence-based species delimitation and the gen-morph species concept, these two groups of thrush complexes should be separated as two distinctive species (T. naumanni and T. ruficollis) and including two subspecies per species. This species classification is also supported by gene flow analysis. There is a significant mixing between these two thrush species in the neighbor-joining (NJ) tree and the cluster analysis using a few microsatellite loci. This leads to a pattern of nuclear-mitochondrial discordance between the two birds that can be explained by several potential mechanisms. This study provides the first comprehensive classification of the two thrush complexes on a population level using morphological and molecular characteristics, which will be useful in expanding our understanding of species division among thrush complexes.

Optimizing Bangkaew dog breed identification using DNA technology.

The Bangkaew dog is an indigenous dog breed in the Phitsanulok province of Thailand. This breed is recognized by the Fédération Cynologique Internationale (FCI), a global canine organization. The unique traits of the Bangkaew breed lead to purebred selection for breeding, while only their traits and pedigree from parental history are recorded. Determination of the risk of inbreeding depression and the origin of unknown DNA profiles is essential due to the challenges in predicting puppy characteristics, which are crucial for breed management and conservation. This study aimed to emphasize that current allelic frequency data for the Bangkaew dog breed must be considered for precise individual identification. Approximately 82 Bangkaew dogs from various Thai localities were studied using 15 microsatellite markers for genotypic monitoring and individual identification. Maternal genetic inheritance was assessed via mtDNA D-loop analysis. The results revealed high genetic diversity in the Bangkaew breed, indicating low potential for inbreeding. We also found that using a 15 loci microsatellite panel was effective for the identification of Bangkaew dogs. The optimized 10 loci microsatellite genotyping panel developed in this study presents improved identification testing efficiency, promoting both time- and cost-effectiveness. Analysis of microsatellite DNA markers in Bangkaew dogs using an optimized panel of 10 loci selected from 15 loci effectively facilitated individual identification. This approach not only enhances time and cost efficiency, but also provides accurate allelic frequency estimates, which are crucial for the realistic evaluation of DNA evidence.

Identification and characterization of 29 microsatellite loci for Tripneustes gratilla based on high-throughput sequencing

Identification and characterization of 29 microsatellite loci for Tripneustes gratilla based on high-throughput sequencing

Variations in Genetic Diversity of Invasive Species Lithobates catesbeianus in China.

The introduction and subsequent range expansion of the American bullfrog (Lithobates catesbeianus) is part of a rising trend of troublesome biological invasions happening in China. This detrimental amphibious invasive species has strong adaptability. After its introduction and spread, it established its own ecological niche in many provinces of China, and its range has continued to expand to more areas. Previous studies recorded the introduction time of bullfrogs and calculated the changes in their genetic diversity in China using mitochondria, but the specific introduction route in China is still unknown. Expanding upon previous research, we employed whole-genome scans (utilizing 2b-RAD genomic sequencing) to examine single nucleotide polymorphisms (SNPs) and microsatellites within Lithobates catesbeianus to screen the genomes of these invasive amphibian species from eight Chinese provinces and two U.S. states, including Kansas, where bullfrogs originate. A total of 1,336,475 single nucleotide polymorphic loci and 17 microsatellite loci were used to calculate the genetic diversity of bullfrogs and their migration pathways. Our results suggest that the population in Hunan was the first to be introduced and to spread, and there may have been multiple introductions of subpopulations. Additionally, the genetic diversity of both the SNP and microsatellite loci in the Chinese bullfrog population was lower than that of the US population due to bottleneck effects, but the bullfrogs can adapt and spread rapidly. This study will offer crucial insights for preventing and controlling future introductions into the natural habitats in China. Additionally, it will assist in devising more precise strategies to manage the existing populations and curtail their continued expansion, as well as aim to improve clarity and originality while mitigating plagiarism risk.

Detection of novel Plasmodium falciparum coronin gene mutations in a recrudescent ACT-treated patient in South-Western Nigeria.

Routine surveillance for antimalarial drug resistance is critical to sustaining the efficacy of artemisinin-based Combination Therapies (ACTs). Plasmodium falciparum kelch-13 (Pfkelch-13) and non-Pfkelch-13 artemisinin (ART) resistance-associated mutations are uncommon in Africa. We investigated polymorphisms in Plasmodium falciparum actin-binding protein (Pfcoronin) associated with in vivo reduced sensitivity to ART in Nigeria. Fifty-two P. falciparum malaria subjects who met the inclusion criteria were followed up in a 28-day therapeutic efficacy study of artemether-lumefantrine in Lagos, Nigeria. Parasite detection was done by microscopy and molecular diagnostic approaches involving PCR amplification of genes for Pf18S rRNA, varATS, telomere-associated repetitive elements-2 (TARE-2). Pfcoronin and Pfkelch-13 genes were sequenced bi-directionally while clonality of infections was determined using 12 neutral P. falciparum microsatellite loci and msp2 analyses. Antimalarial drugs (sulfadoxine-pyrimethamine, amodiaquine, chloroquine and some quinolones) resistance variants (DHFR_51, DHFR_59, DHFR_108, DHFR_164, MDR1_86, MDR1_184, DHPS_581 and DHPS_613) were genotyped by high-resolution melting (HRM) analysis. A total of 7 (26.92%) cases were identified either as early treatment failure, late parasitological failure or late clinical failure. Of the four post-treatment infections identified as recrudescence by msp2 genotypes, only one was classified as recrudescence by multilocus microsatellites genotyping. Microsatellite analysis revealed no significant difference in the mean allelic diversity, He, (P = 0.19, Mann-Whitney test). Allele sizes and frequency per locus implicated one isolate. Genetic analysis of this isolate identified two new Pfcoronin SNVs (I68G and L173F) in addition to the P76S earlier reported. Linkage-Disequilibrium as a standardized association index, IAS, between multiple P. falciparum loci revealed significant LD (IAS = 0.2865, P=0.02, Monte-Carlo simulation) around the neutral microsatellite loci. The pfdhfr/pfdhps/pfmdr1 drug resistance-associated haplotypes combinations, (108T/N/51I/164L/59R/581G/86Y/184F), were observed in two samples. Pfcoronin mutations identified in this study, with potential to impact parasite clearance, may guide investigations on emerging ART tolerance in Nigeria, and West African endemic countries.

Broad-scale genetic assessment of Southern Ground-Hornbills (Bucorvus leadbeateri) to inform population management

The Southern Ground-hornbill (SGH) (Bucorvus leadbeateri) is considered an umbrella species for biodiversity conservation in savannah biomes since they require large territories and significant protection measures that help to conserve a wide range of biodiversity with similar savanna and grassland requirements. Declines of the species are attributed to low reproductive rates coupled with multiple anthropogenic threats, including secondary poisoning, and persecution. Little is known about connectivity and population structure of SGH populations in Africa, south of the equator. Knowledge of population differentiation is needed to ensure that targeted conservation management plans can be implemented to slow population declines and ensure survival of the species. To inform a long-term conservation strategy, we investigated the broad-scale population structure of Southern Ground-hornbill across their sub-equatorial range. Our study based on 16 microsatellite loci identified moderate variation (average of 5.889 alleles per locus and a mean observed heterozygosity of 0.546) similar to other long-lived avian species. In contrast, mitochondrial DNA sequences analysis identified low diversity (Hd = 0.3313, π = 0.0015). A Bayesian assignment approach, principal component analysis, analysis of molecular variance and phylogenetic analysis identified weak to moderate population structuring across long distances and mitochondrial data showed a shallow phylogeny. Restriction to long-distance dispersal was detected that could not be attributed to isolation by distance, suggesting that other factors, such as their dispersal biology, are shaping the observed genetic differentiation. Although our study does not support the designation of populations as independent conservation units, we advocate that population management should continue to follow the Precautionary Principle (mixing founders from the same range state, rather than allowing mixing of founders from the extremes of the range) until there is scientific certainty. Following further research, if no independent conservation units are detected, then the global captive population can contribute to reintroductions across the range. In the wild, populations at the edge of the species range may need additional management strategies and gene flow should be promoted between neighbouring populations.

A panel of tetranucleotide STR markers as an alternative approach to forensic DNA identification of wolf and dog.

Commercial panels of microsatellite (STR) loci are focused on the use of DNA of the domestic dog (Canis lupus familiaris) and are often inapplicable for genotyping the DNA of the gray wolf (Canis lupus lupus). We propose a CPlex test system, including one hexa- and 12 tetranucleotide autosomal STR loci, as well as two sex loci, that is equally efficient in DNA identification of biological samples of the wolf and the dog. Analysis of molecular variance between samples revealed significant differentiation values (FST = 0.0784, p < 0.001), which allows to use the panel to differentiate wolf and dog samples. Population subdivision coefficients (θ-values) were calculated for each of the 13 STR loci of the developed test system. It was shown that the values of the genotype frequency for dogs and wolves, without and with considering the θ-value, differ by three orders of magnitude (for dogs 8.9 × 10-16 and 2.1 × 10-14 and for wolves 1.9 × 10-15 and 4.5 × 10-14, respectively). The use of population subdivision coefficients will allow to identify the most reliable results of an expert identification study and the power of exclusion provided by the STR loci of the CPlex test system makes it possible to achieve a reliable level of evidence in forensic DNA analysis of both wolves and dogs. The test system has been validated for use in forensic identification of the dog and wolf based on biological traces found at crime scenes, as well as for individual identification and establishing biological relationship of animals of these species.

Development of microsatellite markers for the endangered butterfly Luehdorfia japonica Leech, 1889 (Lepidoptera: Papilionidae)

ABSTRACTThe endangered butterfly species Luehdorfia japonica Leech, 1889 (Lepidoptera, Papilionidae) is endemic to the central and western parts of Honshu, Japan. This species inhabits deciduous forests and coppices, but areas of optimal habitats are decreasing due to the development of land and the abandonment of regular coppice management. We developed 17 microsatellite loci for L. japonica based on de novo genome sequence data and found that 16 of these loci exhibited polymorphisms in 34 individuals of L. japonica. In addition, polymorphisms of 15 of these microsatellite loci were observed in two individuals of L. puziloi. The number of alleles and the expected heterozygosity per locus in L. japonica were 2–11 and 0.11–0.83, respectively. A principal coordinate analysis based on this genetic information revealed genetic differentiation both within and among geographic populations of L. japonica. Thus, these microsatellite loci could potentially be useful for future conservation genetic studies, including monitoring the genetic diversity and population structure of this endangered butterfly species.

Genetic insights into Cyphocharax magdalenae (Characiformes: Curimatidae): Microsatellite loci development and population analysis in the Cauca River, Colombia.

Cyphocharax magdalenae, a Colombian freshwater fish species, plays a vital role in nutrients distribution and serves as a significant food source for other fish species and local fishing communities. Considered a short-distance migratory species, C. magdalenae populations face substantial extinction risk due to human activities impacting their habitats. To address the lack of knowledge on genetic diversity and population structure, this study used next-generation sequencing technology to develop species-specific microsatellite loci and conducted a population genetics analysis of C. magdalenae in the middle and lower sections of the Cauca River, Colombia. Out of 30 pairs of microsatellite primers evaluated in 324 individuals, 14 loci were found to be polymorphic, at linkage equilibrium and, in at least one population, their genotypic frequencies were in Hardy-Weinberg equilibrium. Results showed high genetic diversity levels compared to other neotropical Characiformes, with inbreeding coefficients similar to those reported for phylogenetically related species. Moreover, C. magdalenae exhibits seasonal population structure (rainy-dry) consisting of two genetic stocks showing bottleneck signals and high effective population sizes. This information is essential for understanding the current species genetics and developing future management programs for this fishery resource.

STUDY OF GENETIC DIVERSITY OF APPLE TREE IN THE GUBIN REGION OF AZERBAIJAN

The work is devoted to the study of the genetic diversity of local apple varieties common in the Guba region of Azerbaijan. The purpose of this work was to study biomorphological characteristics, identify them based on molecular markers and determine the degree of genetic relationship between species and forms of apple varieties. Based on DNA analysis of apple tree varieties from the collection, patterns of distribution of genes that control the long-term preservation of fruits in apple tree varieties and forms were identified. Unique genotypes carrying rare alleles at microsatellite loci were identified.

Plant invasion alters movement behaviour in endangered butterflies but not their morphology or genetic variability

Invasions of alien plants often result in biodiversity loss and may impact the biology of native species. However, the effects of biological invasions on the behavioural responses of native species have rarely been investigated. We studied how the alteration of habitat due to the invasion of alien goldenrod (Solidago spp) affects a native butterfly, the scarce large blue Phengaris teleius, which is a flagship species for grassland biodiversity conservation. To better understand immediate responses in flight behaviour (daily movements, resting, and dispersal) to a new habitat, we performed observations of experimentally translocated butterflies of two origins (invaded vs. non-invaded habitats) to four different environments: invaded habitat, non-invaded habitat, invaded matrix, non-invaded matrix. Moreover, we tested whether the level of invasion may be related to the variation in morphological traits associated with flight (wing size, body mass) and genetic variability. Flight behaviour was affected by the high goldenrod cover and the sex of the butterflies, regardless of the butterflies’ origin. In the habitat and matrix invaded by goldenrod, the butterflies tended to display dispersal behaviour more often compared to the non-invaded ones. Flight distances were longest in the matrix with goldenrod and resting time was longest in habitats invaded by goldenrod. Analysis of morphological traits as well as eight microsatellite loci did not reveal significant differences in morphology or genetic variation among the populations studied.

Same landscape, different connectivity: contrasting patterns of gene flow in two sympatric ungulates in a mountain area

Comparative landscape genetics studies provide insights on the impact of landscape elements on gene flow patterns of different species inhabiting the same geographic area. We investigated the population genetic structure of two sympatric ungulates, roe deer Capreolus capreolus and Northern chamois Rupicapra rupicapra, in a mountain area of the central Italian Alps (Trentino, northern Italy). A total of 122 chamois and 72 roe deer samples were genotyped by two species-specific panels of 11 polymorphic microsatellite loci and analyzed by aspatial and spatially explicit analyses. While the roe deer population resulted unstructured, a clear population structure was detected in chamois, with two main groups, one inhabiting the eastern and the other spread in the western part of the study area. Landscape genetics analysis confirmed these scenarios and revealed a different effect of landscape on gene flow. An IBD (Isolation-By-Distance) model best explained genetic variation in roe deer, while IBR (Isolation-By-Resistance) was found as the process underlying genetic variation patterns in chamois, suggesting arable lands, coniferous forests, watercourses, and main roads as potential barriers. Species distribution and landscape use might explain these results: roe deer mostly occupy valley floors relatively connected to each other, and their spatial behavior may promote gene flow across areas. On the other hand, chamois prefer higher elevations and their movements may be hindered by valleys, rivers, and road networks. This study highlights the different impacts of natural and anthropic landscape elements on gene flow in two sympatric species, resulting from their different ecological requirements.

Development and characterization of microsatellite markers for population genetics of the cocoa pod borer Conopomorpha cramerella (Snellen) (Lepidoptera: Gracillaridae).

The cocoa pod borer (CPB) Conopomorpha cramerella (Snellen) (Lepidoptera: Gracillaridae) is one of the major constraints for cocoa production in South East Asia. In addition to cultural and chemical control methods, autocidal control tactics such as the Sterile Insect Technique (SIT) could be an efficient addition to the currently control strategy, however SIT implementation will depend on the population genetics of the targeted pest. The aim of the present work was to search for suitable microsatellite loci in the genome of CPB that is partially sequenced. Twelve microsatellites were initially selected and used to analyze moths collected from Indonesia, Malaysia, and the Philippines. A quality control verification process was carried out and seven microsatellites found to be suitable and efficient to distinguish differences between CPB populations from different locations. The selected microsatellites were also tested against a closely related species, i.e. the lychee fruit borer Conopomorpha sinensis (LFB) from Vietnam and eight loci were found to be suitable. The availability of these novel microsatellite loci will provide useful tools for the analysis of the population genetics and gene flow of these pests, to select suitable CPB strains to implement the SIT.

Genetic Variation in the Pallas’s Cat (Otocolobus manul) in Zoo-Managed and Wild Populations

The Pallas’s cat (Otocolobus manul) is one of the most understudied taxa in the Felidae family. The species is currently assessed as being of “Least Concern” in the IUCN Red List, but this assessment is based on incomplete data. Additional ecological and genetic information is necessary for the long-term in situ and ex situ conservation of this species. We identified 29 microsatellite loci with sufficient diversity to enable studies into the individual identification, population structure, and phylogeography of Pallas’s cats. These microsatellites were genotyped on six wild Pallas’s cats from the Tibet Autonomous Region and Mongolia and ten cats from a United States zoo-managed population that originated in Russia and Mongolia. Additionally, we examined diversity in a 91 bp segment of the mitochondrial 12S ribosomal RNA (MT-RNR1) locus and a hypoxia-related gene, endothelial PAS domain protein 1 (EPAS1). Based on the microsatellite and MT-RNR1 loci, we established that the Pallas’s cat displays moderate genetic diversity. Intriguingly, we found that the Pallas’s cats had one unique nonsynonymous substitution in EPAS1 not present in snow leopards (Panthera uncia) or domestic cats (Felis catus). The analysis of the zoo-managed population indicated reduced genetic diversity compared to wild individuals. The genetic information from this study is a valuable resource for future research into and the conservation of the Pallas’s cat.

A taxonomic revision of the Palaearctic species of the ant genus Tapinoma Mayr 1861 (Hymenoptera: Formicidae)

A taxonomic revision of the Palaearctic species of the ant genus Tapinoma Emery 1861 is provided. Due to the extreme rarity of discernable characters, the female castes of 64% of the species are not separable by primary visual perception of an expert and are thus truly cryptic. The main working rationale of the revision is Numeric Morphology-Based Alpha-Taxonomy (NUMOBAT) with formation of species hypotheses largely based on exploratory data analyses and checking these hypotheses by discriminant analysis. NUMOBAT data of all considered species comprise 648 worker samples with 2014 individuals and 30,000 primary data. Species are depicted by z-stack imaging in three standard visual positions. Numeric data on 15 phenotypical characters are presented in comparative tables and supplementary verbal descriptions are given. Analysis of nuclear DNA was based on evaluation of 15 microsatellite loci in 274 nest samples. The NUMOBAT-based classification of eight species of the Tapinoma nigerrimum and T. simrothi group which are inseparable by subjective visual inspection was confirmed by nuclear DNA data in 98.3% of 169 samples where both morphological and nuDNA data were available. The three cases of disagreement between NUMOBAT and nuDNA classification were discussed. Excluding Nomina Nuda and unavailable names, the revision recognized 34 available names which divide into 21 valid species, 11 junior synonyms and two names placed under Incertae Sedis. Four species are described as new: Tapinoma hispanicum n. sp., T. insularis n. sp., T. dabashanica n. sp. and T. sichuense n. sp. The following synonymies were stated: T. collina Foerster 1850, T. erraticum platyops Emery 1925 and T. erraticum bononiensis Emery 1925 as synonyms of T. erraticum (Latreille 1798); T. tauridis Emery 1925 and T. breve Emery 1925 as synonyms of T. glabrella (Nylander 1849) that is erected to species level; T. minor Bernard 1945 as synonym of T. simrothi Krausse-Heldrungen 1911; T. simrothi azerbaidzhanica Karavajev 1932 as synonym of Tapinoma karavaievi Emery 1925 that is erected here to species level; T. erraticum ambiguum Emery 1925 as synonym of T. madeirense Forel 1895 and T. emeryanum Kuznetzov-Ugamsky 1927 as synonym of T. sinense Emery 1925. Despite an insufficient separation of the female castes of Tapinoma madeirense and T. subboreale Seifert 2011 by NUMOBAT characters and detection of a hybrid zone in southern France, the heterospecific status of the two taxa was maintained based on sufficient differences in male genitalia and of nuclear DNA over a larger geographic scale. Formica caerulescens Losana 1834 is removed from genus Tapinoma and recognized as member of the subfamily Formicinae.

Baleen whale microsatellite panel for individual identification and parentage assignment in Mysticeti

Highly polymorphic single tandem repeat loci (STR, also known as microsatellite loci) remain a familiar, cost efficient class of genetic markers in genetic studies in ecology, behavior and conservation. Here we characterize a new, universal set of ten STR loci in seven species of baleen whales, optimized for PCR amplification in two multiplex reactions along with a Y chromosome marker for sex determination. The optimized, universal set of STR loci provides a convenient starting point for new genetic studies in baleen whales aimed at identifying individuals and populations. Data from the new STR loci were combined with genotypes from previously published STR loci to assess the power to assign parentage using paternity exclusion in four species: fin whale (Balaenoptera physalus), humpback whale (Megaptera novaeangliae), blue whale (B. musculus) and bowhead whale (Balaena mysticetus). Our results suggest that parentage studies should always be accompanied by a power analysis in order to ascertain that each individual specific study is based upon data with sufficient power to assign parentage with statistical rigor.

The genetic status and rescue measure for a geographically isolated population of Amur tigers

The Amur tiger is currently confronted with challenges of anthropogenic development, leading to its population becoming fragmented into two geographically isolated groups: smaller and larger ones. Small and isolated populations frequently face a greater extinction risk, yet the small tiger population’s genetic status and survival potential have not been assessed. Here, a total of 210 samples of suspected Amur tiger feces were collected from this small population, and the genetic background and population survival potentials were assessed by using 14 microsatellite loci. Our results demonstrated that the mean number of alleles in all loci was 3.7 and expected heterozygosity was 0.6, indicating a comparatively lower level of population genetic diversity compared to previously reported studies on other subspecies. The genetic estimates of effective population size (Ne) and the Ne/N ratio were merely 7.6 and 0.152, respectively, representing lower values in comparison to the Amur tiger population in Sikhote-Alin (the larger group). However, multiple methods have indicated the possibility of genetic divergence within our isolated population under study. Meanwhile, the maximum kinship recorded was 0.441, and the mean inbreeding coefficient stood at 0.0868, both of which are higher than those observed in other endangered species, such as the African lion and the grey wolf. Additionally, we have identified a significant risk of future extinction if the lethal equivalents were to reach 6.26, which is higher than that of other large carnivores. Further, our simulation results indicated that an increase in the number of breeding females would enhance the prospects of this population. In summary, our findings provide a critical theoretical basis for further bailout strategies concerning Amur tigers.

Conservation genetics of Roosevelt elk: population isolation and reduced diversity

Species reintroductions have the potential to cause genetic bottleneck events resulting in increased genetic drift, increased inbreeding, and reduced genetic diversity creating negative fitness consequences for populations. Roosevelt elk ( Cervus canadensis roosevelti Erxleben, 1777) are “at risk” in British Columbia (BC), Canada. Once widespread along the west coast, Roosevelt elk were likely extirpated from the mainland by 1900 and experienced a substantial population bottleneck on Vancouver Island at that time, and again in the 1950s. Reintroduced to the mainland from Vancouver Island in the 1980s, this re-established population became the source for subsequent mainland translocations. To understand the effects of reintroduction strategy on genetic diversity, we analyzed genetic variation in 355 Roosevelt elk from Vancouver Island and mainland BC. Using mitochondrial DNA and 10 microsatellite loci, molecular analyses showed overall reduced genetic diversity relative to other extant elk populations, genetic isolation of the southern Vancouver Island population, and increased genetic drift among reintroduced herds. Four reintroduced populations were found to have increased levels of inbreeding. Results of this study contribute to our knowledge of reintroduction biology and can be used to guide continued conservation and management of at-risk species.

Across two phylogeographic breaks: Quaternary evolutionary history of a mountain aspen (Populus rotundifolia) in the Hengduan Mountains

Biogeographical barriers to gene flow are central to plant phylogeography. In East Asia, plant distribution is greatly influenced by two phylogeographic breaks, the Mekong-Salween Divide and Tanaka-Kaiyong Line, however, few studies have investigated how these barriers affect the genetic diversity of species that are distributed across both. Here we used 14 microsatellite loci and four chloroplast DNA fragments to examine genetic diversity and distribution patterns of 49 populations of Populus rotundifolia, a species that spans both the Mekong-Salween Divide and the Tanaka-Kaiyong Line in southwestern China. Demographic and migration hypotheses were tested using coalescent-based approaches. Limited historical gene flow was observed between the western and eastern groups of P. rotundifolia, but substantial flow occurred across both the Mekong-Salween Divide and Tanaka-Kaiyong Line, manifesting in clear admixture and high genetic diversity in the central group. Wind-borne pollen and seeds may have facilitated the dispersal of P. rotundifolia following prevalent northwest winds in the spring. We also found that the Hengduan Mountains, where multiple genetic barriers were detected, acted on the whole as a barrier between the western and eastern groups of P. rotundifolia. Ecological niche modeling suggested that P. rotundifolia has undergone range expansion since the last glacial maximum, and demographic reconstruction indicated an earlier population expansion around 600 Ka. The phylogeographic pattern of P. rotundifolia reflects the interplay of biological traits, wind patterns, barriers, niche differentiation, and Quaternary climate history. This study emphasizes the need for multiple lines of evidence in understanding the Quaternary evolution of plants in topographically complex areas.