Low genetic diversity and high inbreeding of the endangered yews in Central Himalaya: implications for conservation of their highly fragmented populations

2014 ◽  
Vol 20 (11) ◽  
pp. 1270-1284 ◽  
Author(s):  
Ram C. Poudel ◽  
Michael Möller ◽  
Jie Liu ◽  
Lian-Ming Gao ◽  
Sushim R. Baral ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Central Himalaya ◽  
Fragmented Populations ◽  
Low Genetic Diversity

scholarly journals Demographic decline and lineage-specific adaptations characterize New Zealand kiwi

2021 ◽  
Vol 288 (1965) ◽  
Author(s):  
Jordan B. Bemmels ◽  
Else K. Mikkelsen ◽  
Oliver Haddrath ◽  
Rogan M. Colbourne ◽  
Hugh A. Robertson ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Genetic Structure ◽  
Population Size ◽  
Genetic Drift ◽  
Demographic History ◽  
Small Population ◽  
Population Declines ◽  
Demographic Stochasticity ◽  
Fragmented Populations ◽  
Low Genetic Diversity

Small and fragmented populations may become rapidly differentiated due to genetic drift, making it difficult to distinguish whether neutral genetic structure is a signature of recent demographic events, or of long-term evolutionary processes that could have allowed populations to adaptively diverge. We sequenced 52 whole genomes to examine Holocene demographic history and patterns of adaptation in kiwi ( Apteryx ), and recovered 11 strongly differentiated genetic clusters corresponding to previously recognized lineages. Demographic models suggest that all 11 lineages experienced dramatic population crashes relative to early- or mid-Holocene levels. Small population size is associated with low genetic diversity and elevated genetic differentiation ( F ST ), suggesting that population declines have strengthened genetic structure and led to the loss of genetic diversity. However, population size is not correlated with inbreeding rates. Eight lineages show signatures of lineage-specific selective sweeps (284 sweeps total) that are unlikely to have been caused by demographic stochasticity. Overall, these results suggest that despite strong genetic drift associated with recent bottlenecks, most kiwi lineages possess unique adaptations and should be recognized as separate adaptive units in conservation contexts. Our work highlights how whole-genome datasets can address longstanding uncertainty about the evolutionary and conservation significance of small and fragmented populations of threatened species.

The Response to Past Climate Perturbations Explains Extremely Low Genetic Diversity in the Genome of an Abundant Ice-Age Remnant, the Alpine Marmot

2018 ◽  
Author(s):  
Toni I. Gossmann​ ◽  
Achchuthan Shanmugasundram​ ◽  
Stefan Börno ◽  
Ludovic Duvaux ◽  
Christophe Lemaire​ ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Ice Age ◽  
Past Climate ◽  
Low Genetic Diversity ◽  
Alpine Marmot

Season of birth interacts with measures of inbreeding in multiplex schizophrenia pedigrees: evidence from genetic isolates in Daghestan

Open Medicine ◽  
2006 ◽  
Vol 1 (4) ◽  
pp. 392-398
Author(s):  
Kazima Bulayeva ◽  
John McGrath
Keyword(s):  
Genetic Diversity ◽  
Family History ◽  
Age Of Onset ◽  
Population Genetic Study ◽  
Season Of Birth ◽  
High Genetic Diversity ◽  
Low Genetic Diversity ◽  
High Prevalence ◽  
History Of ◽  
Genetic Isolates

AbstractWhile the season-of-birth effect is one of the most consistent epidemiological features of schizophrenia, there is a lack of consistency with respect to the interaction between season of birth and family history of schizophrenia. Apart from family history, measures related to consanguinity can be used as proxy markers of genomic heterogeneity. Thus, these measures may provide an alternate, indirect index of genetic susceptibility. We had the opportunity to explore the interaction between season of birth and measure of consanguinity in well-described genetic isolates in Daghestan, some of which are known for their relatively high prevalence of schizophrenia. Our previous population-genetic study showed Daghestan has an extremely high genetic diversity between the ethnic populations and a low genetic diversity within them. The isolates selected for this study include some with more than 200 and some with less than 100 generations of demographical history since their founding. Based on pedigrees of multiply-affected families, we found that among individuals with schizophrenia, the measure of consanguinity was significantly higher in the parents of those born in winter/spring compared to those born in summer/autumn. Furthermore, compared to summer/autumn born, winter/spring born individuals with schizophrenia had an earlier age-of-onset, and more prominent auditory hallucinations. Our results suggest that the offspring of consanguineous marriages, and thus those with reduced allelic heterogeneity, may be more susceptible to the environmental factor(s) underpinning the season-of-the effect in schizophrenia.

scholarly journals Low genetic diversity in the endangered Taxus yunnanensis following a population bottleneck, a low effective population size and increased inbreeding

2016 ◽  
Vol 65 (1) ◽  
pp. 59-66 ◽  
Author(s):  
Y. C. Miao ◽  
Z. J. Zhang ◽  
J. R. Su
Keyword(s):  
Genetic Diversity ◽  
Habitat Fragmentation ◽  
Population Size ◽  
Effective Population Size ◽  
Spatial Genetic Structure ◽  
Population Bottleneck ◽  
Effective Population ◽  
Taxus Yunnanensis ◽  
Low Genetic Diversity ◽  
Two Populations

Abstract Taxus yunnanensis, which is an endangered tree that is considered valuable because it contains the effective natural anticancer metabolite taxol and heteropolysaccharides, has long suffered from severe habitat fragmentation. In this study, the levels of genetic diversity in two populations of 136 individuals were analyzed based on eleven polymorphic microsatellite loci. Our results suggested that these two populations were characterized by low genetic diversity (NE = 2.303/2.557; HO = 0.168/0.142; HE = 0.453/0.517), a population bottleneck, a low effective population size (Ne = 7/9), a high level of inbreeding (FIS = 0.596/0.702), and a weak, but significant spatial genetic structure (Sp = 0.001, b = −0.001*). Habitat fragmentation, seed shadow overlap and limited seed and pollen dispersal and potential selfing may have contributed to the observed gene tic structure. The results of the present study will enable development of practical conservation measures to effectively conserve the valuable genetic resources of this endangered plant.

scholarly journals Low Genetic Diversity in the Rare Madeiran Endemic Armeria maderensis (Plumbaginaceae)

2009 ◽  
Vol 44 (1) ◽  
pp. 65-81 ◽  
Author(s):  
Rosalía Piñeiro ◽  
Javier Fuertes Aguilar ◽  
Miguel Menezes de Sequeira ◽  
Gonzalo Nieto Feliner
Keyword(s):  
Genetic Diversity ◽  
Low Genetic Diversity
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