Y chromosome STR haplotypes in four populations from northwest Africa

The eight short tandem repeat (STR) polymorphic systems mapping on the male -specific region of the human Y chromosome, DYS19, DYS388, DYS389I, DYS389I I, DYS390, DYS391, DYS392 and DYS393, were typed in four populations from n orthwest (NW) Africa (Moroccan Arabs, southern Moroccan Berbers, Saharawis and Mozabites). Allele frequency distributions showed statistically signifi cant differences for ail loci among all the populations except for DYS19. C omplete typing was obtained for 185 chromosomes, which showed 74 different haplotypes. The two most frequent haplotypes were found in 16.2% and 15.1% of the individuals, although the latter was almost exclusively found in the Mozabites. Locus and haplotype informativeness were measured by means of t he gene diversity (D). The haplotype diversity ranged from 0.856 (Mozabites ) to 0.967 (southern Moroccan Berbers). For some loci, allele frequencies i n NW Africans were clearly different from those in Europeans. The most comm on NW African haplotype was found only in one individual out of a total of 494 Europeans typed for the whole STR set. Thus, NW African and European Y chromosomes are clearly differentiated.