scholarly journals Narwhal Genome Reveals Long-Term Low Genetic Diversity despite Current Large Abundance Size

iScience ◽  
2019 ◽  
Vol 15 ◽  
pp. 592-599 ◽  
Author(s):  
Michael V. Westbury ◽  
Bent Petersen ◽  
Eva Garde ◽  
Mads Peter Heide-Jørgensen ◽  
Eline D. Lorenzen
Keyword(s):  
Genetic Diversity ◽  
Low Genetic Diversity

Weak genetic structuring suggests historically high genetic connectivity among recently fragmented urban populations of the scincid lizard, Ctenotus fallens

2015 ◽  
Vol 63 (4) ◽  
pp. 279 ◽  
Author(s):  
Josef Krawiec ◽  
Siegfried L. Krauss ◽  
Robert A. Davis ◽  
Peter B. S. Spencer
Keyword(s):  
Genetic Diversity ◽  
Gene Flow ◽  
Large Population ◽  
Geographic Distance ◽  
Genetic Erosion ◽  
Genetic Connectivity ◽  
Genetic Structuring ◽  
Low Genetic Diversity ◽  
Population Sizes

Populations in fragmented urban remnants may be at risk of genetic erosion as a result of reduced gene flow and elevated levels of inbreeding. This may have serious genetic implications for the long-term viability of remnant populations, in addition to the more immediate pressures caused by urbanisation. The population genetic structure of the generalist skink Ctenotus fallens was examined using nine microsatellite markers within and among natural vegetation remnants within a highly fragmented urban matrix in the Perth metropolitan area in Western Australia. These data were compared with samples from a large unfragmented site on the edge of the urban area. Overall, estimates of genetic diversity and inbreeding within all populations were similar and low. Weak genetic differentiation, and a significant association between geographic and genetic distance, suggests historically strong genetic connectivity that decreases with geographic distance. Due to recent fragmentation, and genetic inertia associated with low genetic diversity and large population sizes, it is not possible from these data to infer current genetic connectivity levels. However, the historically high levels of gene flow that our data suggest indicate that a reduction in contemporary connectivity due to fragmentation in C. fallens is likely to result in negative genetic consequences in the longer term.

Nuclear and cytoplasmic genetic diversity reveals long-term population decline in Abies semenovii, an endemic fir of central Asia

2012 ◽  
Vol 42 (12) ◽  
pp. 2142-2152 ◽  
Author(s):  
Svetlana A. Semerikova ◽  
Martin Lascoux ◽  
Vladimir L. Semerikov
Keyword(s):  
Genetic Diversity ◽  
Central Asia ◽  
Population Decline ◽  
Population Expansion ◽  
Nuclear Marker ◽  
Effective Population ◽  
Species Status ◽  
Siberian Fir ◽  
Low Genetic Diversity

The genus Abies is one of the largest conifer genera and many of the marginal species remain poorly characterized. Abies semenovii B. Fedtsch. is a rare mountain fir species from central Asia, and its species status is still disputed. We used both nuclear (allozymes and AFLP) and chloroplastic (cpSSR) markers to show that A. semenovii deserves to be considered as a species and that its low genetic diversity justifies more a proactive conservation policy. First, A. semenovii was significantly differentiated from the Siberian fir Abies sibirica Ledeb. and we did not detect gene flow between the two species. Second, A. semenovii has a very low nuclear genetic diversity, suggesting a prolonged restricted effective population size. Abies semenovii had low cpSSR diversity too but the identification of seven closely related haplotypes suggests that these mutations accumulated recently during a phase of population expansion. This agrees well with the palynological record and is in contrast with the situation observed in another rare Eurasian fir endemic to Kamchatka, Abies gracilis Kom., which was devoid of variation in cpSSRs but that also had a more substantial nuclear marker diversity than A. semenovii, thereby suggesting a more recent but less severe population bottleneck.

Long-term survival despite low genetic diversity in the critically endangered Madagascar fish-eagle

2008 ◽  
Author(s):  
JEFF A. JOHNSON ◽  
RUTH E. TINGAY ◽  
MELANIE CULVER ◽  
FRANK HAILER ◽  
MICHÈLE L. CLARKE ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Critically Endangered ◽  
Term Survival ◽  
Long Term Survival ◽  
Low Genetic Diversity

Low genetic diversity and small long-term population sizes in the spring endemic watercress darter, Etheostoma nuchale

2010 ◽  
Vol 11 (6) ◽  
pp. 2267-2279 ◽  
Author(s):  
Brook L. Fluker ◽  
Bernard R. Kuhajda ◽  
Nicholas J. Lang ◽  
Phillip M. Harris
Keyword(s):  
Genetic Diversity ◽  
Low Genetic Diversity ◽  
Population Sizes

scholarly journals Diversitas Genetika dan Identifikasi Jenis Kelamin Burung Pelikan (Pelecanus conspicillatus Temminck, 1824) di Penangkaran Taman Margasatwa Ragunan Jakarta

2021 ◽  
Vol 17 (2) ◽  
pp. 105-114
Author(s):  
Anik Budhi Dharmayanthi ◽  
Achmad Muchsinin ◽  
Afriana Pulungan ◽  
Moch Syamsul Arifin Zein
Keyword(s):  
Genetic Diversity ◽  
Nucleotide Diversity ◽  
Haplotype Diversity ◽  
Population Expansion ◽  
Bird Populations ◽  
Low Genetic Diversity ◽  
In Captivity ◽  
D Loop ◽  
Haplotype 1

Pelicans (Pelecanus conspicillatus) is one of the wild species that have a widely distribution. This bird has been successfully bred in Ragunan Zoo, Jakarta. The indicator of inbreeding in the captive population is shown by the decrease of nucleotide diversity and number of haplotypes. The result of genetic diversity analysis using D-loop fragment sequences showed low genetic diversity with nucleotide diversity (p) = 0.00064 ± 0.00010 and haplotype diversity (Hd) = 0.532 ± 0.061 in Pelecanus conspicillatus populations in the Ragunan Zoo. However, negative Fu's Fs value (-3,246) indicates population expansion. We found that there were seven haplotypes in bird populations in the captivity: haplotype 1, 2 and 3 consist of 43 individuals (65.15%), five individuals (7.57%), and 14 individuals (21.21%), respectively. For each haplotype 4, 5, 6 and 7 is only represented by one individual of Pelecanus conspicillatus (1.51%). The sex ratio of males to females is 1: 8.86 with four males identified as haplotype 1, and one male on haplotypes 3, 5 and 7, respectively. Genetic diversity data of the population is an important way for designing long-term plans and goals in efforts to maintain genetic diversity of the Pelecanus conspicillatus population in captivity.

scholarly journals Conservation concerns associated with low genetic diversity for K’gari–Fraser Island dingoes

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
G. C. Conroy ◽  
R. W. Lamont ◽  
L. Bridges ◽  
D. Stephens ◽  
A. Wardell-Johnson ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Genetic Factors ◽  
Conservation Management ◽  
Future Research ◽  
Effective Population ◽  
Tissue Samples ◽  
Island Populations ◽  
Low Genetic Diversity ◽  
Sample Set

AbstractThe dingo population on world heritage-listed K’gari-Fraser Island (K’gari) is amongst the most well-known in Australia. However, an absence of population genetic data limits capacity for informed conservation management. We used 9 microsatellite loci to compare the levels of genetic diversity and genetic structure of 175 K’gari dingo tissue samples with 264 samples from adjacent mainland regions. Our results demonstrated that the K'gari population has significantly lower genetic diversity than mainland dingoes (AR, HE, PAR; p < 0.05) with a fourfold reduction in effective population size (Ne = 25.7 vs 103.8). There is also strong evidence of genetic differentiation between the island and mainland populations. These results are in accordance with genetic theory for small, isolated, island populations, and most likely the result of low initial diversity and founder effects such as bottlenecks leading to decreased diversity and drift. As the first study to incorporate a large sample set of K’gari dingoes, this provides invaluable baseline data for future research, which should incorporate genetic and demographic monitoring to ensure long-term persistence. Given that human-associated activities will continue to result in dingo mortality, it is critical that genetic factors are considered in conservation management decisions to avoid deleterious consequences for this iconic dingo population.

scholarly journals Genetic variability and conservation of the endangered Pannonian root vole in fragmented habitats of an agricultural landscape

2021 ◽  
Vol 43 ◽  
pp. 167-191
Author(s):  
Krisztina A. Kelemen ◽  
Felicita Urzi ◽  
Elena Buzan ◽  
Győző F. Horváth ◽  
Filip Tulis ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Gene Flow ◽  
Genetic Variability ◽  
Agricultural Landscape ◽  
Isolation By Distance ◽  
Term Survival ◽  
Long Term Survival ◽  
Root Vole ◽  
Low Genetic Diversity

The distribution of the endangered glacial relict subspecies, the Pannonian root vole Alexandromys oeconomus mehelyi Éhik, 1928, is restricted to scattered localities in south-western Slovakia, which belong to the north-eastern zone of its range. Human-induced changes and fragmentation of the landscape have led to the gradual loss of suitable habitats and threaten its long-term survival. The study area in the Danubian Lowland is characterised by small habitat fragments and temporal fluctuations of the habitat area. Root voles were sampled at nine sites to study the level of genetic variability and structure of local subpopulations by scoring 13 microsatellite loci in 69 individuals. Genetic differentiation varied amongst local populations and we did not find a significant isolation-by-distance pattern. Bayesian clustering analysis suggested that dispersal effectively prevents marked genetic subdivision between studied habitat fragments. Significant pairwise differentiation between some subpopulations, however, may be the result of putatively suppressed gene flow. Low genetic diversity in the recent populations probably reflects the isolated location of the study area in the agricultural landscape, suggesting that long-term survival may not be assured. In order to maintain genetic diversity, it is essential to preserve (or even restore) habitats and ensure the possibility of gene flow; habitat protection is, therefore, recommended. Continuous assessment is necessary for effective conservation management and to predict the long-term survival chances of the Pannonian root vole in the study area.

scholarly journals Genetic diversity, inbreeding and cancer

2018 ◽  
Vol 285 (1875) ◽  
pp. 20172589 ◽  
Author(s):  
Beata Ujvari ◽  
Marcel Klaassen ◽  
Nynke Raven ◽  
Tracey Russell ◽  
Marion Vittecoq ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Immune Surveillance ◽  
Term Survival ◽  
Low Genetic Diversity ◽  
Increased Risk ◽  
Loss Of Genetic Diversity ◽  
Risk Of Cancer ◽  
The Impact ◽  
Increased Susceptibility

Genetic diversity is essential for adaptive capacities, providing organisms with the potential of successfully responding to intrinsic and extrinsic challenges. Although a clear reciprocal link between genetic diversity and resistance to parasites and pathogens has been established across taxa, the impact of loss of genetic diversity by inbreeding on the emergence and progression of non-communicable diseases, such as cancer, has been overlooked. Here we provide an overview of such associations and show that low genetic diversity and inbreeding associate with an increased risk of cancer in both humans and animals. Cancer being a multifaceted disease, loss of genetic diversity can directly (via accumulation of oncogenic homozygous mutations) and indirectly (via increased susceptibility to oncogenic pathogens) impact abnormal cell emergence and escape of immune surveillance. The observed link between reduced genetic diversity and cancer in wildlife may further imperil the long-term survival of numerous endangered species, highlighting the need to consider the impact of cancer in conservation biology. Finally, the somewhat incongruent data originating from human studies suggest that the association between genetic diversity and cancer development is multifactorial and may be tumour specific. Further studies are therefore crucial in order to elucidate the underpinnings of the interactions between genetic diversity, inbreeding and cancer.

scholarly journals The importance of long-term genetic monitoring of reintroduced populations: inbreeding in the natterjack toad (Epidalea calamita)

2020 ◽  
pp. 159-167
Author(s):  
Susanna Phillips
Keyword(s):  
Genetic Diversity ◽  
Conservation Management ◽  
Genetic Monitoring ◽  
Source Population ◽  
Genetic Rescue ◽  
Management Actions ◽  
Low Genetic Diversity ◽  
Population Structuring ◽  
Epidalea Calamita

Genetic monitoring is an important, but frequently lacking, component of management actions to support long-term persistence in reintroduced populations. Populations that remain small, due to demographic processes and genetic diversity, are more likely to experience a second extinction event. The natterjack toad (Epidelea calamita) is legally protected in Britain and was the subject of a reintroduction programme in the 1990s. However, subsequent genetic assessment has been mostly lacking. The aim of this study was to assess the genetic diversity of two reintroduced populations of natterjack toads in order to inform conservation management. Adults were sampled and nine microsatellites amplified to assess neutral genetic variation within each site and for comparison with the source population. Inbreeding was observed at the reintroduction sites, as evidenced by high FIS values (0.43 and 0.72), low observed compared to expected heterozygosities, and significant deviation from Hardy-Weinberg equilibrium. Observed heterozygosity is currently lower in the reintroduction sites than it was in the source population at the time of the reintroductions (Red Rocks: 0.15±0.20; Talacre: 0.12±0.20; Ainsdale (source): 0.29). Evidence for a bottleneck was not found, although this is likely a result of sampling overlapping generations. No withinsite population structuring was observed. Such low genetic diversity has not previously been recorded in any natterjack population. Genetic rescue, combined with pool creation, is the most viable option for safeguarding the species at these sites into the future. Our work highlights the importance of ongoing genetic monitoring, in collaboration with conservation organisations, to support conservation management.

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