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opennotspecifiedFeb 2014View details →

Figure 1 in Complete mitogenome of Chinese shrew mole Uropsilus soricipes (Milne- Edwards, 1871) (Mammalia: Talpidae) and genetic structure of the species in the Jiajin Mountains (China)

Figure 1. Study area and sampling sites for Chinese shrew mole (Uropsilus soricipes) in this study. Sample sizes can be found in Table 1.

opennotspecifiedFeb 2014View details →

Figure 5. Bayesian inference tree using the TIM2 in Complete mitogenome of Chinese shrew mole Uropsilus soricipes (Milne- Edwards, 1871) (Mammalia: Talpidae) and genetic structure of the species in the Jiajin Mountains (China)

Figure 5. Bayesian inference tree using the TIM2 + I + G model depicting the relationship of Uropsilus soricipes. The phylogenetic tree was rooted using Rattus rattus and Neotetracus sinensis. Numbers represent node supports inferred from Bayesian posterior probabilities. Clade A. Jiajin Mountains (JM); Dujiangyan (DJY); Tianquan (TQ); Maoxian (MX); Lixian (LX); Jiuzhaigou (JZG); Clade B. Yuexi (YX).

Agriculture creates subtle genetic structure among migratory and non-migratory populations of burrowing owls throughout North America

Population structure across a species distribution primarily reflects historical, ecological and evolutionary processes. However, large-scale contemporaneous changes in land use have the potential to create changes in habitat quality and thereby cause changes in gene flow, population structure, and distributions. As such, land-use changes in one portion of a species range may explain declines in other portions of their range. For example, many burrowing owl populations have declined or become extirpated near the northern edge of the species' breeding distribution during the second half of the 20th century. In the same period, large extensions of thornscrub were converted to irrigated agriculture in northwestern Mexico. These irrigated areas may now support the highest densities of burrowing owls in North America. We tested the hypothesis that burrowing owls that colonized this recently created owl habitat in northwestern Mexico originated from declining migratory populations from the northern portion of the species' range (migration-driven breeding dispersal whereby long-distance migrants from Canada and the U.S. became year-round residents in the newly created irrigated agriculture areas in Mexico). We used 10 novel microsatellite markers to genotype 1,560 owls from 36 study locations in Canada, Mexico, and the United States. We found that burrowing owl populations are practically panmictic throughout the entire North American breeding range. However, an analysis of molecular variance provided some evidence that burrowing owl populations in northwestern Mexico and Canada together are more genetically differentiated from the rest of the populations in the breeding range, lending some support to our migration-driven breeding dispersal hypothesis. We found evidence of subtle genetic differentiation associated with irrigated agricultural areas in southern Sonora and Sinaloa in northwestern Mexico. Our results suggest that land-use can produce location-specific population dynamics leading to subtle genetic structure even in the absence of dispersal barriers.

Figure 5 in Geographical variations in waving display and barricade-building behaviour, and genetic population structure in the intertidal brachyuran crab Ilyoplax pusilla (de Haan, 1835)

Figure 5. Mean number of barricades per burrow in Ilyoplax pusilla at six localities (bar indicates SD). Localities arranged according to latitude. Shared alphabetical letters indicate no significant difference (p.0.05) by Tukey's honestly significant difference test.

Figure 2 in Geographical variations in waving display and barricade-building behaviour, and genetic population structure in the intertidal brachyuran crab Ilyoplax pusilla (de Haan, 1835)

Figure 2. Cheliped path movement in Ilyoplax pusilla: circular type and vertical type. Arrows indicate wave path.

Figure 6 in Geographical variations in waving display and barricade-building behaviour, and genetic population structure in the intertidal brachyuran crab Ilyoplax pusilla (de Haan, 1835)

Figure 6. Parsimony network of mitochondrial DNA cytochrome oxidase subunit I (COI) haplotypes of Ilyoplax pusilla. Haplotypes correspond to Table 5. Single solid line indicates one base. Circle size indicates number of each haplotype. Largest circle, n542; second largest, n514 or 15; third, n58; fourth, n54 or n55; fifth, n52; smallest circle, n51.

Figure 1 in Geographical variations in waving display and barricade-building behaviour, and genetic population structure in the intertidal brachyuran crab Ilyoplax pusilla (de Haan, 1835)

Figure 1. Geographic distribution of Ilyoplax pusilla in Japan (broken line) from Wada et al. (1992), and six localities studied.

Figure 4 in Geographical variations in waving display and barricade-building behaviour, and genetic population structure in the intertidal brachyuran crab Ilyoplax pusilla (de Haan, 1835)

Figure 4. Proportion of extended waves in 30 waving motions of Ilyoplax pusilla at six localities (bar indicates SD). Localities arranged according to latitude. Shared alphabetical letters indicate no significant difference (p.0.05) by Tukey's honestly significant difference test.

Figure 3 in Geographical variations in waving display and barricade-building behaviour, and genetic population structure in the intertidal brachyuran crab Ilyoplax pusilla (de Haan, 1835)

Figure 3. Maximum cheliped extension during waving movements in Ilyoplax pusilla: extended type and non-extended type.

Rooting out genetic structure of invasive wild pigs in Texas

Invasive wild pigs (Sus scrofa), also called feral swine or wild hogs, are recognized as among the most destructive invasive species in the world. Throughout the United States, invasive wild pigs have expanded rapidly over the past 30 years with populations now established in 38 states. Of the estimated 6.9 million wild pigs distributed throughout the United States, Texas supports approximately 40% of the population and similarly bears disproportionate ecological and economic costs. Genetic analyses are an effective tool for understanding invasion pathways and tracking dispersal of invasive species such as wild pigs and have been used recently in California and Florida, USA, which have similarly long-established populations and high densities of wild pigs. Our goals were to use molecular approaches to elucidate invasion and migration processes shaping wild pig populations throughout Texas, compare our results with patterns of genetic structure observed in California and Florida, and provide insights for effective management of this invasive species. We used a high-density single nucleotide polymorphism (SNP) array to evaluate population genetic structure. Genetic clusters of wild pigs throughout Texas demonstrate 2 distinct patterns: weakly resolved, spatially dispersed clusters and well-resolved, spatially localized clusters. The disparity in patterns of genetic structure suggests disparate processes are differentially shaping wild pig populations in various localities throughout the state. Our results differed from the patterns of genetic structure observed in California and Florida, which were characterized by localized genetic clusters. These differences suggest distinct biological and perhaps anthropogenic processes are shaping genetic structure in Texas. Further, these disparities demonstrate the need for location-specific management strategies for controlling wild pig populations and mitigating associated ecological and economic costs.

Oxytenanthera abyssinica (A. Rich.) Munro; lowland bamboo (Poaceae, Bambusinea) in Ethiopia: Genetic diversity, population structure and gene flow analysis

As one of the most important non-timber forest resources, a potential alternative to wood and wood product and fastest-growing plant in the world (91 cm (35 in) per day), bamboo is a member of the grass family (Poaceae) and constitutes a single subfamily Bambusoideae. 67% of total area of bamboo in Africa and 7% of world total is contributed by Ethiopia giving more than 1.44 million hectares. Silica gel dried young fresh leaves from 130 individuals of O. abyssinica were collected for DNA extraction and PCR amplification. Each of the PCR amplified ISSR fragments using 19 ISSR primers were used to study band pattern and heterozigosity, level of polymorphism, calculating marker efficiency, Nei`s (H) and Shannon (I) genetic diversity, analysis of molecular variance (AMOVA), analysis for cluster, principal coordinates (PCoA) and admixture results. High genetic variation at species level was observed with the percentage of the polymorphic loci (PPL) = 84.48%. The H, I, observed number of alleles (Na) and effective number of alleles (Ne) at species level was 0.2702, 0.4061, 1.8448, and 1.4744, respectively, showing a relatively high level of genetic diversity. However, the genetic differentiation at the population level was relatively low. AMOVA using grouped populations revealed that, most of the diversity was distributed within the populations (61.05%) with FST = 0.38949, FSC = 0.10486 and FCT = 0.31797. Cluster analysis grouped the populations into sharply distinct clusters, which could be attributed to cross pollination nature of the plant and long lived to the area. STRUCTURE analyses for all population and excluding Gambella population gives different result K = 2 and K = 11. Using these markers, we find strong evidence linking geographic origin of diversity and samples from Gambella Region found different from others and might tell the availability of additional bamboo species in the country.

Contemporary genetic structure affects genetic stock identification of steelhead trout in the Snake River basin

Genetic stock identification is a widely applied tool for the mixed-stock management of salmonid species throughout the North Pacific Rim. The effectiveness of genetic stock identification is dependent on the level of differentiation among stocks which is often high due to the life history of these species that involves high homing fidelity to their natal streams. However, the utility of this tool can be reduced when natural genetic structuring has been altered by hatchery translocation and/or supplementation. We examined the genetic population structure of ESA-listed steelhead in the Snake River basin of the United States. We analyzed 9,613 natural-origin adult steelhead returning to Passive Integrated Transponder detection sites throughout the basin from 2010 through 2017. Individuals were genotyped at 180 single nucleotide polymorphic genetic markers and grouped into 20 populations based on their return location. While we expected to observe a common pattern of hierarchical genetic structuring due to isolation by distance, we observed low genetic differentiation between populations in the upper Salmon River basin compared to geographically distant populations in the lower Snake River basin. These results were consistent with lower genetic stock assignment probabilities observed for populations in this upper basin. We attribute these patterns of reduced genetic structure to the translocation of lower basin steelhead stocks and ongoing hatchery programs in the upper Salmon River basin. We discuss the implications of these findings on the utility of genetic stock identification in the basin and discuss opportunities for increasing assignment probabilities in the face of low genetic structure.

opennotspecifiedAug 2013View details →

Figure 3 in Contemporary genetic structure reflects historical drainage isolation in an Australian snapping turtle, Elseya albagula

Figure 3. Bayesian population assignments for Elseya albagula individuals based on 12 microsatellite loci analysed in STRUCTURE, indicating structure by region and catchment. Individuals are represented by coloured vertical bars, which represent per cent genetic membership (y axis) within genetic units as indicated above each diagram. A, individual differentiation between two regional units (K = 2), and B, further substructuring amongst catchments within the southern region (K = 3). Black lines separate sampling locations, identified below (x axis). B, Burnett, F, Fitzroy; M, Mary.

opencc-zeroDec 2020View details →

Genetic diversity and population structure of two endangered neotropical parrots inform In Situ and Ex Situ conservation strategies

A key aspect in the conservation of endangered populations is understanding patterns of genetic variation and structure, which can provide managers with critical information to support evidence-based status assessments and management strategies. This is especially important for species with small wild and larger captive populations, as found in many endangered parrots. We used genotypic data to assess genetic variation and structure in wild and captive populations of two endangered parrots, the blue-throated macaw, Ara glaucogularis, of Bolivia, and the thick-billed parrot, Rhynchopsitta pachyrhyncha, of Mexico. In the blue-throated macaw, we found evidence of weak genetic differentiation between wild northern and southern subpopulations, and between wild and captive populations. In the thick-billed parrot we found no signal of differentiation between the Madera and Tutuaca breeding colonies or between wild and captive populations. Similar levels of genetic diversity were detected in the wild and captive populations of both species, with private alleles detected in captivity in both, and in the wild in the thick-billed parrot. We found genetic signatures of a bottleneck in the northern blue-throated macaw subpopulation, but no such signal was identified in any other subpopulation of either species. Our results suggest both species could potentially benefit from reintroduction of genetic variation found in captivity, and emphasize the need for genetic management of captive populations.

Nonrandom missing data can bias PCA inference of population genetic structure

Population genetic studies in non-model systems increasingly use next-generation sequencing to obtain more loci, but such methods also generate more missing data that may affect downstream analyses. Here we focus on the Principal Component Analysis (PCA) which has been widely used to explore and visualize population structure with mean-imputed missing data. We simulated data of different population models with various total missingness (1%, 10%, 20%) introduced either randomly or biased among individuals or populations. We found that individuals biased with missing data would be dragged away from their real population clusters to the origin of PCA plots, making them indistinguishable from true admixed individuals and potentially leading to misinterpreted population structure. We also generated empirical data of the big brown bat (Eptesicus fuscus) using restriction site-associated DNA sequencing (RADseq). We filtered three data sets with 19.12%, 9.87%, and 1.35% total missingness, all showing nonrandom missing data with biased individuals dragged towards the PCA origin, consistent with results from simulations. We highlight the importance of considering missing data effects on PCA in non-model systems where nonrandom missing data are common due to varying sample quality. To help detect missing data effects, we suggest to 1) plot PCA with a color gradient showing per sample missingness, 2) interpret samples close to the PCA origin with extra caution, 3) explore filtering parameters with and without the missingness-biased samples, and 4) use complementary analyses (e.g., model-based methods) to cross-validate PCA results and help interpret population structure.

opennotspecifiedOct 2013View details →

Figure 2 in Historical demography and spatial genetic structure of the subterranean rodent Ctenomys magellanicus in Tierra del Fuego (Argentina)

Figure 2. Bayesian inference trees of Ctenomys genus. A, tree derived from the D-loop marker. B, tree derived from Cyt b. Numbers next to branches are bootstrap support values and Bayesian posterior probabilities, respectively.

opennotspecifiedOct 2013View details →

Figure 1 in Historical demography and spatial genetic structure of the subterranean rodent Ctenomys magellanicus in Tierra del Fuego (Argentina)

Figure 1. Geographical distribution of Ctenomys magellanicus sampling sites along the study area. Squares show the two regions: north (steppe, chromosome form 2n = 34) and south (ecotone, chromosome form 2n = 36). Each region was subdivided into subpopulations: two for the north (subpopulations A and B) and four for the south (subpopulations C–F).

opencc-zeroOct 2021View details →

Microsatellites data set: Correlated population genetic structure in a three-tiered host-parasite system: the potential for coevolution and adaptive divergence

Three subspecies of Northern Bahamian Rock Iguanas, Cyclura cychlura, are currently recognized: C. c. cychlura,restricted to Andros Island, and C. c. figginsi and C. c. inornata, native to the Exuma Island chain. Populations on Andros are genetically distinct from Exuma Island populations, yet genetic divergence among populations in the Exumas is inconsistent with the two currently recognized subspecies from those islands. The potential consequences of this discrepancy might include the recognition of a single subspecies throughout the Exumas rather than two. That inference also ignores evidence that populations of C. cychlura are potentially adaptively divergent. We compared patterns of population relatedness in a three-tiered host-parasite system: C. cychlura iguanas, their ticks (genus Amblyomma, preferentially parasitizing these reptiles), and Rickettsia spp. endosymbionts (within tick ectoparasites). Our results indicate that while C. c. cychlura on Andros is consistently supported as a separate clade, patterns of relatedness among populations of C. c. figginsi and C. c. inornata within the Exuma Island chain are more complex. The distribution of the hosts, different tick species, and Rickettsia spp., supports the evolutionary independence of C. c. inornata. Further, these patterns are also consistent with two independent evolutionarily significant units within C. c. figginsi. Our findings suggest coevolutionary relationships between the reptile hosts, their ectoparasites, and rickettsial organisms, suggesting local adaptation. This work also speaks to the limitations of using neutral molecular markers from a single focal taxon as the sole currency for recognizing evolutionary novelty in populations of endangered species.

opencc-by-4.0Oct 2022View details →

Population structure and genetic variation of fragmented mountain birch forests in Iceland

Data avilability for the manuscript JOH-2022-096.R2 accepted for application