Single-Locus and Multilocus Analysis of Genetic Differentiation of the Races of Man: A Critique

AbstractThe delineation of conservation units (CUs) is a challenging issue that has profound implications for minimizing the loss of biodiversity and ecosystem services. CU delineation typically seeks to prioritize evolutionary significance and genetic methods play a pivotal role in the delineation process by quantifying overall differentiation between populations. While CUs that primarily reflect overall genetic differentiation do protect adaptive differences between distant populations, they do not necessarily protect adaptive variation within highly connected populations. Advances in genomic methodology facilitate the characterization of adaptive genetic variation, but the potential utility of this information for CU delineation is unclear. Here we use genomic methods to investigate the evolutionary basis of premature migration in Pacific salmon, a complex behavioral and physiological adaptation that exists within highly-connected populations and has experienced severe declines. Strikingly, we find that premature migration is associated with the same single locus across multiple populations in each of two different species. Patterns of variation at this locus suggest that the premature migration alleles arose from a single evolutionary event within each species and were subsequently spread to distant populations through straying and positive selection. Our results reveal that complex adaptive variation can depend on rare mutational events at a single locus, demonstrate that CUs reflecting overall genetic differentiation can fail to protect evolutionarily significant variation that has substantial ecological and societal benefits, and suggest that a supplemental framework for protecting specific adaptive variation will sometimes be necessary to prevent the loss of significant biodiversity and ecosystem services.

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Genetic differentiation in populations of lane snapper (Lutjanus synagris – Lutjanidae) from Western Atlantic as revealed by multilocus analysis

Fisheries Research ◽

10.1016/j.fishres.2017.10.005 ◽

2018 ◽

Vol 198 ◽

pp. 138-149 ◽

Cited By ~ 3

Author(s):

Danillo Silva ◽

Kely Martins ◽

Joiciane Oliveira ◽

Raimundo da Silva ◽

Iracilda Sampaio ◽

...

Keyword(s):

Genetic Differentiation ◽

Western Atlantic ◽

Multilocus Analysis

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Multilocus Analysis of Genetic Susceptibility to Myocardial Infarction in Russians: Replication Study

Acta Naturae ◽

10.32607/20758251-2017-9-4-74-83 ◽

2017 ◽

Vol 9 (4) ◽

pp. 74-83

Author(s):

N. G. Kukava ◽

B. V. Titov ◽

G. J. Osmak ◽

N. A. Matveeva ◽

O. G. Kulakova ◽

...

Keyword(s):

Myocardial Infarction ◽

Genetic Markers ◽

Prognostic Significance ◽

Cumulative Effect ◽

Mthfr Gene ◽

Composite Model ◽

Replication Study ◽

Epistatic Interactions ◽

Multilocus Analysis ◽

Lipid Metabolism Genes

In search of genetic markers of myocardial infarction (MI) risk, which have prognostic significance for Russians, we performed a replication study of MI association with genetic variants of PCSK9 (rs562556), APOE (epsilon polymorphism, rs7412 and rs429358), LPL (rs320), MTHFR (rs1801133), eNOS (rs2070744), and the 9p21 region (rs1333049) in 405 patients with MI and 198 controls. Significant MI association was observed with variants of the lipid metabolism genes (PCSK9, APOE and LPL), and of eNOS. The SNPs in the MTHFR gene and the 9p21 region were not significantly associated with MI one by one but were included in several different MI-associated allelic combinations identified by multilocus analysis. Since we have not revealed nonlinear epistatic interactions between the components of the identified combinations, we postulate that the cumulative effect of genes that form a combination arises from the summation of their small independent contributions. The prognostic significance of the additive composite model built from the PCSK9, APOE, LPL, and eNOS genes as genetic markers was assessed using ROC analysis. After we included these markers in the previously published composite model of individual genetic risk of MI, the prognostic efficacy in our sample reached AUC = 0.676. However, the results obtained in this study certainly need to be replicated in an independent sample of Russians.

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