The Y chromosome specific biallelic marker DYS271 defines the
most common haplogroup (E3a) currently found in sub-Saharan
Africa. A sister clade, E3b (E-M215), is rare in sub-Saharan
Africa , but very common in northern and eastern Africa . On the
whole, these two clades represent more than 70% of the Y
chromosomes of the African continent. A third clade belonging to
E3 (E3c or E-M329) has been recently reported to be present only
in eastern Africa, at low frequencies. In this study we analyzed
more than 1,600 Y chromosomes from 55 African populations, using
both new and previously described biallelic markers, in order to
refine the phylogeny and the geographic distribution of the E3a
haplogroup. The most common E-DYS271 sub-clades (E-DYS271*,
E-M191, E-U209) showed a non uniform distribution across sub-
Saharan Africa. Most of the E-DYS271 chromosomes found in
northern and western Africa belong to the paragroup E-DYS271*,
which is rare in central and southern Africa. In these latter
regions, haplogroups E-M19