The Chukchi of Kamchatka: A genetic portrait based on the wide array of Y-chromosome markers

Results and discussion. Y-chromosomes of the Kamchatkan Chukchi show a low diversity, being dominated by two variants N3a5b-B202 (57%) and N3*-M178* (19%), both virtually absent in the neighboring groups of Kamchatka. Phylogenetic analysis of the major lineages reveals some similarity with the populations of Chukotka (including Yupik Eskimo) at the level of clusters and closely matching haplotypes. More likely, this similarity can be explained by the gene flow from the Chukchi homeland to the south (i.e. to the northern regions of Kamchatka) over the past two centuries. The phylogenetic analysis of the N3a5b-B202 haplogroup revealed a correspondence between its two NGS-identified sub-branches (N3a5b1-B203, N3a5b2-B204) and two clusters found using STR markers. This concordance made it possible to compare the age estimates of these haplogroups obtained by different methods; the ages fell within the interval of 0.5-1.5 thousand years ago. N3*-M178* lineage is represented by a single STR-cluster (~800 years old) for which no “full-genome” analogue has yet been identified. The rest of the Chukchi paternal gene pool includes haplogroups C2-M48x (SK1066) (7%) and Q-M242 (7%), which are also present in the neighboring populations, primarily Koryaks, as well as Evens and Evenks. Conclusions. As expected, due to historical considerations, Chukchi of Kamchatka are most similar in Y-chromosome to the Chukotkan populations. The dating of the major branches of haplogroup N3 found in the Chukchi indicates a likely population growth within the past 0.5-1.5 thousand years. There is also a minor component in Chukchi, shared with the populations of Kamchatka, but its strict dating and origin is still unclear: it can be attributed both to the shared ancient NE Asian ancestry and to a recent admixture with local Kamchatkan groups.