Low Genetic Diversity in a Potential (Glacial) Relict: The Rocky Mountain Capshell, Acroloxus coloradensis (Henderson, 1930) (Gastropoda: Acroloxidae)

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.

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Low genetic diversity in an isolated red fox (Vulpes vulpes) population on Mt. Hakodate, Japan, revealed by microsatellite analyses of fecal samples

Mammal Study ◽

10.3106/ms2017-0055 ◽

2018 ◽

Vol 43 (3) ◽

pp. 141-152

Author(s):

Yosuke Amaike ◽

Takahiro Murakami ◽

Ryuichi Masuda

Keyword(s):

Genetic Diversity ◽

Vulpes Vulpes ◽

Red Fox ◽

Fecal Samples ◽

Low Genetic Diversity ◽

Microsatellite Analyses

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Geographic patterns of genetic variation and population structure in Pinus aristata, Rocky Mountain bristlecone pine

Canadian Journal of Forest Research ◽

10.1139/x11-152 ◽

2012 ◽

Vol 42 (1) ◽

pp. 23-37 ◽

Cited By ~ 16

Author(s):

Anna W. Schoettle ◽

Betsy A. Goodrich ◽

Valerie Hipkins ◽

Christopher Richards ◽

Julie Kray

Keyword(s):

Genetic Diversity ◽

Population Structure ◽

Bark Beetles ◽

Climatic Factors ◽

Rocky Mountain ◽

Conservation Strategies ◽

Restricted Gene Flow ◽

Populations At Risk ◽

Bristlecone Pine ◽

Pinus Aristata

Pinus aristata Engelm., Rocky Mountain bristlecone pine, has a narrow core geographic and elevational distribution, occurs in disjunct populations, and is threatened by rapid climate change, white pine blister rust, and bark beetles. Knowledge of genetic diversity and population structure will help guide gene conservation strategies for this species. Sixteen sites across four mountain ranges in the core distribution of P. aristata were sampled and genetic diversity was assessed with 21 isozyme loci. Low species and population level genetic diversity (He = 0.070 and 0.062, respectively) occurred with moderate among-population differentiation (FST = 0.131). Genetic diversity correlated with longitude, latitude, and elevation and a strong mountain island effect may contribute to substructuring and isolation. Using multiple complementary analyses, sampled trees were assigned to three genetic lineages that varied in diversity and admixture and were associated with different climatic factors. The distribution of genetic diversity and substructuring of P. aristata may be an outcome of a combination of restricted gene flow due to geographic and phenological isolation, random processes of genetic drift, life history traits, natural selection, and postglacial migrations. The combination of low genetic diversity, moderate population isolation, and a protracted regeneration dynamic puts populations at risk for extirpation by novel stresses.

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

Silvae Genetica ◽

10.1515/sg-2016-0008 ◽

2016 ◽

Vol 65 (1) ◽

pp. 59-66 ◽

Cited By ~ 3

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.

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

Folia Geobotanica ◽

10.1007/s12224-009-9030-4 ◽

2009 ◽

Vol 44 (1) ◽

pp. 65-81 ◽

Cited By ~ 6

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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Marked differences in genetic diversity and differentiation between the centre and edge of the geographical range of Megaleranthis saniculifolia (Ranunculaceae), a Korean endemic species

Australian Journal of Botany ◽

10.1071/bt12033 ◽

2012 ◽

Vol 60 (7) ◽

pp. 582

Author(s):

Ji Hee Jeong ◽

Zin-Suh Kim

Keyword(s):

Genetic Diversity ◽

Peripheral Region ◽

Issr Markers ◽

Ex Situ ◽

Allele Frequency Distribution ◽

Low Genetic Diversity ◽

Long Time ◽

Megaleranthis Saniculifolia ◽

Degree Of Differentiation ◽

Substantial Degree

The amount and distribution of genetic diversity within and between Megaleranthis saniculifolia Ohwi populations were compared between the central and peripheral regions of the species distribution. Allozyme and ISSR markers were used for genetic analysis of six populations from the central region (DY) and five populations from the peripheral region (MJ). Genetic diversity was substantially higher in the DY region than in the MJ region. Relatively uniform homozygote excess at many loci in most populations indicated that M. saniculifolia was influenced by a substantial degree of inbreeding in both regions. The degree of differentiation between populations was remarkably higher in the MJ region than in the DY region. Cluster analysis showed a trend towards separation between regions, although populations in the MJ region exhibited a slightly different trend according to the markers. We conclude that genetic drift has been affecting the populations in the MJ region for a long time, on the basis of their low genetic diversity, high differentiation, U-shaped allele-frequency distribution, and fixation of alleles towards opposing frequencies (1 or 0) among populations. In contrast, the DY region maintained relatively stable populations, although evidence of a recent bottleneck was found in one population. Along with some practical measures for genetic conservation, we present an optimal sample size for ex situ conservation to secure as many common alleles as possible.

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