Y chromosomes traveling south: the cohen modal haplotype and the origins of the Lemba--the "Black Jews of Southern Africa"

Abstract

The Lemba are a traditionally endogamous group speaking a variety of Bantu languages who live in a number of locations in southern Africa. They claim descent from Jews who came to Africa from "Sena." "Sena" is variously identified by them as Sanaa in Yemen, Judea, Egypt, or Ethiopia. A previous study using Y-chromosome markers suggested both a Bantu and a Semitic contribution to the Lemba gene pool, a suggestion that is not inconsistent with Lemba oral tradition. To provide a more detailed picture of the Lemba paternal genetic heritage, we analyzed 399 Y chromosomes for six microsatellites and six biallelic markers in six populations (Lemba, Bantu, Yemeni-Hadramaut, Yemeni-Sena, Sephardic Jews, and Ashkenazic Jews). The high resolution afforded by the markers shows that Lemba Y chromosomes are clearly divided into Semitic and Bantu clades. Interestingly, one of the Lemba clans carries, at a very high frequency, a particular Y-chromosome type termed the "Cohen modal haplotype," which is known to be characteristic of the paternally inherited Jewish priesthood and is thought, more generally, to be a potential signature haplotype of Judaic origin. The Bantu Y-chromosome samples are predominantly (>80%) YAP+ and include a modal haplotype at high frequency. Assuming a rapid expansion of the eastern Bantu, we used variation in microsatellite alleles in YAP+ sY81-G Bantu Y chromosomes to calculate a rough date, 3,000-5,000 years before the present, for the start of their expansion.

Figure 1

Cladogram of UEP, distinguishing UEP groups. Explanations of abbreviations are as in table 1.

Figure 2

Frequently encountered haplotypes (frequency >10% in any population), in AI (red), SI (blue), Y (green), S (pink), L (yellow), and B (black); the colors indicate the population with the most chromosomes of the given haplotype. Numbers within the boxes are number of Y chromosomes in the population; numbers below the boxes are the frequency within the population (i.e., frequency within a UEP group). Explanations of abbreviations are as in table 1.

Figure 3

UEP group 1 genealogical tree of Y-chromosome haplotypes. The neighbor-joining tree was drawn by use of NEIGHBOR (part of the PHYLIP package), with the distance measure ASD calculated by use of the program MICROSAT. Colors next to the haplotype index numbers indicate the presence of Y chromosomes in the relevant population. H.I. = haplotype index number, H/L = high (⩾15 [brown]), low (⩽12 [white]), or intermediate (13 or 14 [gray]) number of repeats for microsatellite DYS388. Results are for AI (red), SI (blue), Y (green), S (pink), L (yellow), and B (black). Explanations of abbreviations are as in table 1.