Weak Population Genetic Structure of the Eurasian Crane <i>Grus grus</i> L.

Abstract

The article presents an extended (as compared with our previous studies) analysis of the population genetic structure of a migratory wide-range bird species with a high abundance, the Eurasian Crane Grus grus L. Using seven highly polymorphic microsatellite loci, high and very similar values of genetic diversity parameters were obtained in the samples of both the western (G. g. grus) and eastern (G. g. lilfordi) subspecies. Coefficients of genetic differentiation between these subspecies (FST = 0.008, GST = 0.002) were also found to be low. According to AMOVA, 99% of genetic variation of G. grus is attributed to individual levels. Using the Bayesian clustering algorithm implemented in STRUCTURE software, no clear population-genetic structuring of the species was revealed. However, visualization of spatial patterns of genetic variability in Geneland showed the presence of a cluster of “pure” subspecies G. g. grus and G. g. lilfordi surrounding a cluster of individuals from the zone of intergradation of these subspecies. This result, along with the observed very low FST values, may indicate subtle genetic differences between cranes from the studied area, possibly having a mutational nature. The lower allelic richness and lack of private alleles in the eastern subspecies suggest that G. g. lilfordi is relatively evolutionary young and suggest its recent origin from some eastern marginal populations of the nominative western subspecies.