2 Y-CHROMOSOME-SPECIFIC RESTRICTION-FRAGMENT-LENGTH-POLYMORPHISMS (DYS11 AND DYZ8) IN ITALIAN AND GREEK MIGRANTS TO AUSTRALIA

The part of the Y chromosome not involved in recombination has been fo und to exhibit an extremely low frequency of DNA restriction fragment length polymorphisms (RFLPs) compared with either the X chromosome or autosomes. Also, the few Y-chromosome-specific RFLPs that have been id entified have rarely been examined in more than one population. In thi s study two Y-chromosome-specific RFLPs at loci DYS11 and DYZ8 are exa mined in Italian and Greek migrants to Australia. The frequency of the rarer (8.5-kb) TaqI allele at DYS11 was 21% in Italians and even grea ter (34%) in Greeks. There is an inverse relationship between the freq uency of the 8.5-kb allele and latitude on the Italian mainland; the r egional variation (based on subject's birthplace in Italy) was signifi cant (p < 0.01). The incidence of the 8.5-kb allele in southern Italy may reflect Greek colonization during pre-Roman times when this region was part of Magna Graecia. The frequency of the variant TaqI allele ( 7, 4 kb) at the DYZ8 locus is much higher in both Greeks and Italians (31% in each) than in Germans (5%), the only previously examined popul ation. DYZ8 shows considerably less variation than DYS11 cross the reg ional divisions of both Greece and Italy. The present findings, when a dded to the few other data available, indicate that these two Y-chromo some-specific loci are useful markers for investigating population aff inities through the paternal line. Also, heterogeneity at these two lo ci (and added to that at the DYS1 locus) suggests that Mediterranean p opulations, compared with other groups, exhibit a high level of divers ity of Y-chromosome-specific RFLPs.