Croatian genetic landscape - Y chromosomal perspective

Sixteen biallelic and eight microsatellite markers were typed in the sample of 457 Croatian men from the mainland and four Eastern Adriatic islands (Krk, Brac, Hvar, Korcula). Based on the analysis of biallelic markers nine different haplogroups were characterized. The most frequent was haplogroup I followed by R1a and R1b haplogroups. High frequency of haplogroup I in Croatian populations and the pattern of its microsatellite diversity make Adriatic coast a likely source of the recolonization of Europe following the Last Glacial Maximum. A higher frequency of haplogroup I in the southern island populations is contrasted with higher frequency of haplogroup R1a chromosomes in the northern island of Krk and in the mainland confirming different routes of settlement. R1a frequency could be a sign of the Slavic impact in the Balkan region. Haplogroups J, G, and E that are related to the spread of farming characterize the minor part (12.5%) of the Croatian Y chromosomal lineages. A relatively high frequency (14%) of lineages belonging to P*(xM173) cluster, unusual for European populations, was found in the southern island of Hvar indicating a connection with Central Asian populations, possibly the Avars. In sum, clear and meaningful in terms of ethnogenesis, gradients and diversity of Croatian paternal lineages testify to their largely Paleolithic European ancestry, a minor Neolithic influx from the Near East, as well as Slavic and Avar expansions.