Haplogroup frequencies of Y chromosomes with the 92R7T allele in Puerto Rico.

摘要

For over two decades, Y chromosome polymorphisms have successfully been used as lineage markers in evolutionary studies to determine human origins, migrations waves, and admixture. Determining the frequency and geographic distribution of the Y chromosome haplogroups is essential in order to determine paternal ancestry in Puerto Rico. Preliminary studies undertaken in 2002 suggested that most Puerto Rican men had the derived state of the 92R7 allele; 92R7T. This allele defines the P clade which includes European and Native American haplogroups. A substantial number of 92R7T Y chromosomes could not be classified into any specific haplogroup, thus remaining classified simply as 92R7T Y chromosomes. In this study, 99 individuals were sampled to test Puerto Rican Y chromosomes for the 92R7T allele and classified into well-defined haplogroups by identifying five polymorphisms. By using molecular techniques such as polymerase chain reaction (PCR), restriction fragment length polymorphism (RFLP) and DNA sequencing, samples with the 92R7T allele were identified and then classified into haplogroups by the analysis of the following single nucleotide polymorphisms (SNPs): P25, M242, M3, SRY10831, and M207. The results showed the presence of the 92R7T allele in 57 of the samples of which 54 are of European origin, belonging to haplogroups R1a, R1b1, and R(xR1a, R1b1), one to Native American haplogroup Q3, and the other two could not be classified into well defined haplogroups. Thus this study revealed a strong patrilineal contribution of European population to modern Puerto Rican and a very poor Native American contribution.