Phylogeny of Y-chromosome haplogroup C3b-F1756, an important paternal lineage in Altaic-speaking populations

In previous studies, a specific paternal lineage with a null value for the y-chromosome short tandem repeat (y-str) marker dys448 was identified as common among mongolic- and turkic-speaking populations. this paternal lineage (temporarily named c3*-dys448del) was determined to be m217+, m93–, p39–, m48–, m407–, and p53.1–, and its origin and phylogeny remain ambiguous. here, we analyzed y-chromosome sequences of 10 male that are related this paternal lineage and redefined it as c3b1a1a1a-f1756 (c3b-f1756). we generated a highly revised phylogenetic tree of haplogroup c3b-f1756, including 21 sub-clades and 360 non-private y-chromosome polymorphisms. additionally, we performed a comprehensive analysis of the c3*-dys448del lineage in eastern eurasia, including 18 270 samples from 297 populations. whole y-chromosome sequences, y-str haplotypes, and frequency data were used to generate a distribution map, a network, and age estimations for lineage c3*-dys448del and its sub-lineages. considering the historical records of the studied populations, we propose that two major sub-branches of c3b-f1756 may correspond to early expansions of ancestors of modern mongolic- and turkic-speaking populations. the large number of newly defined y-chromosome polymorphisms and the revised phylogenetic tree for c3b-f1756 will assist in investigation of the early history of altaic-speaking populations in the future.