scholarly journals Is there low maternal genetic variation in West Asian populations of leopard?

2020 ◽  
Vol 65 (4) ◽  
pp. 701-708
Author(s):  
Mohammad S. Farhadinia ◽  
Mohammad Reza Ashrafzadeh ◽  
Helen Senn ◽  
Sohrab Ashrafi ◽  
Hamid Farahmand ◽  
...  

Abstract Persian leopards Panthera pardus saxicolor have been extirpated from over 84% of their historic range and are now limited to rugged landscapes of West Asia and the Caucasus. Understanding and maintaining genetic diversity and population connectivity is important for preventing inbreeding and genetic drift, both of which can threaten population viability. All previous analyses of intraspecific genetic variation of West Asian leopards based on the NADH dehydrogenase subunit 5 gene have reported low mitogenomic diversity. In the current study, we sequenced 959 bp of the mtDNA cytochrome b gene to describe the spatial genetic structure of 22 wild Persian leopards across Iran, which hosts most of the subspecies extant range. The findings based on phylogenetic trees and median-joining network indicated that leopards from Iran formed a distinct subclade, i.e., P. p. saxicolor. The AMOVA analysis showed significant differentiation (88.55%) between the subclades of Persian leopards and other Asian leopards. The lowest levels of haplotype (0.247) and nucleotide (0.00078) diversity were estimated in Persian leopards from Iran. Mitochondrial genome sequencing revealed only two closely related haplotypes. There was no evidence for recent sudden demographic expansion scenario in Persian leopards. The low diversity in cytochrome b gene could potentially be brought about by selective pressure on mitochondria to adapt to oxidative stress and higher metabolic rates in cold environments.

2020 ◽  
Vol 58 (1) ◽  
pp. 93-97 ◽  
Author(s):  
Rosline James Muku ◽  
Hong-Bin Yan ◽  
John Asekhaen Ohiolei ◽  
Abubakar Ahmed Saaid ◽  
Sara Ahmed ◽  
...  

The cestode <i>Taenia hydatigena</i> uses canids, primarily dogs, as definitive hosts, while the metacestode larval stage cysticercus infects a range of intermediate hosts, including domestic animals such as goats, sheep, and pigs. Cysticercosis due to <i>T. hydatigena</i> has large veterinary and economic drawbacks. Like other taeniids, e.g., <i>Echinococcus</i>, intraspecific variation is found among the members of the genus Taenia. In Africa, few studies are available on the epidemiology and distribution of <i>T. hydatigena</i>, and even fewer studies are available on its genetic variation. In this study, we molecularly identified 11 cysticerci from sheep in Sudan and demonstrated the genetic variation based on the NADH dehydrogenase subunit 1 (<i>nad</i>1) and cytochrome c oxidase subunit 1 (<i>cox</i>1) mitochondrial genes. The isolates were correctly identified as <i>T. hydatigena</i> with more than 99% similarity to those in the GenBank database. Low diversity indices and insignificant neutrality indices were observed, with 3 and 2 haplotypes for the <i>nad</i>1 and <i>cox</i>1 genes, respectively. The results suggest the presence of unique <i>T. hydatigena</i> haplotypes in Sudan, as haplotypes with 100% similarity were not found in the GenBank database. With few available studies on the genetic variation of <i>T. hydatigena</i> in Africa, this report represents the first insights into the genetic variation of <i>T. hydatigena</i> in Sudan and constitutes useful data.


2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Kelly B. Klingler ◽  
Joshua P. Jahner ◽  
Thomas L. Parchman ◽  
Chris Ray ◽  
Mary M. Peacock

Abstract Background Distributional responses by alpine taxa to repeated, glacial-interglacial cycles throughout the last two million years have significantly influenced the spatial genetic structure of populations. These effects have been exacerbated for the American pika (Ochotona princeps), a small alpine lagomorph constrained by thermal sensitivity and a limited dispersal capacity. As a species of conservation concern, long-term lack of gene flow has important consequences for landscape genetic structure and levels of diversity within populations. Here, we use reduced representation sequencing (ddRADseq) to provide a genome-wide perspective on patterns of genetic variation across pika populations representing distinct subspecies. To investigate how landscape and environmental features shape genetic variation, we collected genetic samples from distinct geographic regions as well as across finer spatial scales in two geographically proximate mountain ranges of eastern Nevada. Results Our genome-wide analyses corroborate range-wide, mitochondrial subspecific designations and reveal pronounced fine-scale population structure between the Ruby Mountains and East Humboldt Range of eastern Nevada. Populations in Nevada were characterized by low genetic diversity (π = 0.0006–0.0009; θW = 0.0005–0.0007) relative to populations in California (π = 0.0014–0.0019; θW = 0.0011–0.0017) and the Rocky Mountains (π = 0.0025–0.0027; θW = 0.0021–0.0024), indicating substantial genetic drift in these isolated populations. Tajima’s D was positive for all sites (D = 0.240–0.811), consistent with recent contraction in population sizes range-wide. Conclusions Substantial influences of geography, elevation and climate variables on genetic differentiation were also detected and may interact with the regional effects of anthropogenic climate change to force the loss of unique genetic lineages through continued population extirpations in the Great Basin and Sierra Nevada.


Pathogens ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 41
Author(s):  
Marcos Godoy ◽  
Daniel A. Medina ◽  
Rudy Suarez ◽  
Sandro Valenzuela ◽  
Jaime Romero ◽  
...  

Piscine orthoreovirus (PRV) belongs to the family Reoviridae and has been described mainly in association with salmonid infections. The genome of PRV consists of about 23,600 bp, with 10 segments of double-stranded RNA, classified as small (S1 to S4), medium (M1, M2 and M3) and large (L1, L2 and L3); these range approximately from 1000 bp (segment S4) to 4000 bp (segment L1). How the genetic variation among PRV strains affects the virulence for salmonids is still poorly understood. The aim of this study was to describe the molecular phylogeny of PRV based on an extensive sequence analysis of the S1 and M2 segments of PRV available in the GenBank database to date (May 2020). The analysis was extended to include new PRV sequences for S1 and M2 segments. In addition, subgenotype classifications were assigned to previously published unclassified sequences. It was concluded that the phylogenetic trees are consistent with the original classification using the PRV genomic segment S1, which differentiates PRV into two major genotypes, I and II, and each of these into two subgenotypes, designated as Ia and Ib, and IIa and IIb, respectively. Moreover, some clusters of country- and host-specific PRV subgenotypes were observed in the subset of sequences used. This work strengthens the subgenotype classification of PRV based on the S1 segment and can be used to enhance research on the virulence of PRV.


2014 ◽  
Vol 11 (22) ◽  
pp. 6495-6507 ◽  
Author(s):  
S. H. Árnason ◽  
Ǽ. Th. Thórsson ◽  
B. Magnússon ◽  
M. Philipp ◽  
H. Adsersen ◽  
...  

Abstract. Sea sandwort (Honckenya peploides) was one of the first plants to successfully colonize and reproduce on the volcanic island Surtsey, formed in 1963 off the southern coast of Iceland. Using amplified fragment length polymorphic (AFLP) markers, we examined levels of genetic variation and differentiation among populations of H. peploides on Surtsey in relation to populations on the nearby island Heimaey and from the southern coast of Iceland. Selected populations from Denmark and Greenland were used for comparison. In addition, we tested whether the effects of isolation by distance could be seen in the Surtsey populations. Using two primer combinations, we obtained 173 AFLP markers from a total of 347 plant samples. The resulting binary matrix was then analysed statistically. The main results include the following: (i) Surtsey had the highest proportion of polymorphic markers as well as a comparatively high genetic diversity (55.5% proportion of polymorphic loci, PLP; 0.1974 HE) and Denmark the lowest (31.8% PLP; 0.132 HE), indicating rapid expansion during an early stage of population establishment on Surtsey and/or multiple origins of immigrants; (ii) the total genetic differentiation (FST) among Surtsey (0.0714) and Heimaey (0.055) populations was less than half of that found among the mainland populations in Iceland (0.1747), indicating substantial gene flow on the islands; (iii) most of the genetic variation (79%, p < 0.001) was found within localities, possibly due to the outcrossing and subdioecious nature of the species; (iv) a significant genetic distance was found within Surtsey, among sites, and this appeared to correlate with the age of plant colonization; and (v) the genetic structure analysis indicated multiple colonization episodes on Surtsey, whereby H. peploides most likely immigrated from the nearby island of Heimaey and directly from the southern coast of Iceland.


2006 ◽  
Vol 43 (4) ◽  
pp. 701-706 ◽  
Author(s):  
Mario A. Rodríguez-pérez ◽  
Claudia A. Núñez-gonzález ◽  
Cristian Lizarazo-ortega ◽  
Alejandro Sánchez-varela ◽  
Michael C. Wooten ◽  
...  

1996 ◽  
Vol 26 (8) ◽  
pp. 1454-1462 ◽  
Author(s):  
Naoki Tani ◽  
Nobuhiro Tomaru ◽  
Masayuki Araki ◽  
Kihachiro Ohba

Japanese stone pine (Pinuspumila Regel) is a dominant species characteristic of alpine zones of high mountains. Eighteen natural populations of P. pumila were studied in an effort to determine the extent and distribution of genetic diversity. The extent of genetic diversity within this species was high (HT = 0.271), and the genetic differentiation among populations was also high (GST = 0.170) compared with those of other conifers. In previous studies of P. pumila in Russia, the genetic variation within the species was also high, but the genetic differentiation among populations was low. We infer that this difference originates from differences in geographic distribution and ecological differences between the two countries. The genetic variation within each population tended, as a whole, to be smaller within marginal southern populations than within northern populations. Genetic relationships among populations reflect the geographic locations, as shown by unweighted pair-group method with arithmetic means and neighbor-joining phylogenetic trees.


2005 ◽  
Vol 86 (1) ◽  
pp. 1-11 ◽  
Author(s):  
LAURENCE MOUSSON ◽  
CATHERINE DAUGA ◽  
THOMAS GARRIGUES ◽  
FRANCIS SCHAFFNER ◽  
MARIE VAZEILLE ◽  
...  

Aedes (Stegomyia) aegypti (L.) and Aedes (Stegomyia) albopictus (Skuse) are the most important vectors of the dengue and yellow-fever viruses. Both took advantage of trade developments to spread throughout the tropics from their native area: A. aegypti originated from Africa and A. albopictus from South-East Asia. We investigated the relationships between A. aegypti and A. albopictus mosquitoes based on three mitochondrial-DNA genes (cytochrome b, cytochrome oxidase I and NADH dehydrogenase subunit 5). Little genetic variation was observed for A. albopictus, probably owing to the recent spreading of the species via human activities. For A. aegypti, most populations from South America were found to be genetically similar to populations from South-East Asia (Thailand and Vietnam), except for one sample from Boa Vista (northern Amazonia), which was more closely related to samples from Africa (Guinea and Ivory Coast). This suggests that African populations of A. aegypti introduced during the slave trade have persisted in Boa Vista, resisting eradication campaigns.


Botany ◽  
2009 ◽  
Vol 87 (11) ◽  
pp. 1089-1095 ◽  
Author(s):  
Stephen B. Heard ◽  
Linley K. Jesson ◽  
Kirby Tulk

The Gulf of St. Lawrence aster ( Symphyotrichum laurentianum (Fernald) G.L. Nesom) is an endemic annual of saline habitats in the southern Gulf of St. Lawrence. It is listed as a threatened species, and has recently experienced population declines in much of its range. We used 11 allozyme markers to assay population genetic variation in six wild populations of S. laurentianum from the Magdalen Islands, Quebec (QC), the only remaining wild population from Prince Edward Island National Park (PEI), and a greenhouse population founded in 1999 with seed collected from PEI. Symphyotrichum laurentianum harbours moderate genetic diversity (Ps = 0.36, As = 1.54), with only modest spatial genetic structure (pairwise FST < 0.15) and no significant isolation by distance. The PEI population had greatly reduced allelic diversity compared with the populations from the Magdalen Islands, which likely act as a reservoir of genetic variation in S. laurentianum. Recent loss of alleles during population decline in PEI is suggested by the retention of greater allelic diversity in the greenhouse population. Estimates of breeding structure suggest small but nonzero rates of outcross pollination (FIS = 0.73, 95% CI = 0.48–0.97; outcrossing rate ∼16%). Population genetic structure in S. laurentianum can inform those forming and carrying out conservation and recovery plans for this threatened species.


2017 ◽  
Vol 95 (12) ◽  
pp. 901-907 ◽  
Author(s):  
Benoit Talbot ◽  
Maarten J. Vonhof ◽  
Hugh G. Broders ◽  
M. Brock Fenton ◽  
Nusha Keyghobadi

Subdivided populations can be described by different models of population structure that reflect population organization, dynamics, and connectivity. We used genetic data to investigate population structure in two geographically sympatric, congeneric species of generalist ectoparasites of warm-blooded animals. We characterized the spatial genetic structure of the eastern bat bug (Cimex adjunctus Barber, 1939), an understudied and fairly abundant species, using microsatellite markers at a spatial scale representing contemporary dispersal of the species. We found seven genetic clusters, global [Formula: see text] of 0.2, 33% of genetic variation among sites, and nonsignificant isolation-by-distance. We compared these results with the common bed bug (Cimex lectularius L., 1758), a closely related but conversely well-known species, in the same geographic area. We found stronger genetic structuring in C. lectularius than in C. adjunctus, with 11 genetic clusters, [Formula: see text] of 0.7, 57% of genetic variation among sites, and significant but weak isolation-by-distance (R2 = 0.09). These results suggest that while both species can be described as having classic metapopulation structure, C. adjunctus leans more towards a patchy population and C. lectularius leans more towards a nonequilibrium metapopulation. The difference in population structure between these species may be attributable to differences in movement potential and extinction–colonization dynamics.


2020 ◽  
Author(s):  
Kelly Brie Klingler ◽  
Joshua P Jahner ◽  
Thomas L Parchman ◽  
Chris Ray ◽  
Mary Peacock

Abstract Background: Distributional responses by alpine taxa to repeated, glacial-interglacial cycles throughout the last two million years have significantly influenced the spatial genetic structure of populations. These effects have been exacerbated for the American pika (Ochotona princeps), a small alpine lagomorph constrained by thermal sensitivity and a limited dispersal capacity. As a species of conservation concern, long-term lack of gene flow has important consequences for landscape genetic structure and levels of diversity within populations. Here, we use reduced representation sequencing (ddRADseq) to provide a genome-wide perspective on patterns of genetic variation across pika populations representing distinct subspecies. To investigate how landscape and environmental features shape genetic variation, we collected genetic samples from distinct geographic regions as well as across finer spatial scales in two geographically proximate mountain ranges of eastern Nevada. Results: Our genome-wide analyses corroborate range-wide, mitochondrial subspecific designations and reveal pronounced fine-scale population structure between the Ruby Mountains and East Humboldt Range of eastern Nevada. Populations in Nevada were characterized by low genetic diversity (𝜋=0.0006–0.0009; 𝜃W=0.0005–0.0007) relative to populations in California (𝜋=0.0014–0.0019; 𝜃W=0.0011–0.0017) and the Rocky Mountains (𝜋=0.0025–0.0027; 𝜃W=0.0021–0.0024), indicating substantial genetic drift in these isolated populations. Tajima’s D was positive for all sites (D=0.240-0.811), consistent with recent contraction in population sizes range-wide. Conclusions: Substantial influences of geography, elevation and climate variables on genetic differentiation were also detected and may interact with the regional effects of anthropogenic climate change to force the loss of unique genetic lineages through continued population extirpations in the Great Basin and Sierra Nevada.


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