11 - The molecular diversity of the Niokholo Mandenkalu from Eastern Senegal: an insight into West Africa genetic history

Summary

Introduction

The Senegalese Niokholo Mandenka population is located in the Niokholo Hills, 30 km North-West of Kedougou (Fig. 11.1). This population includes some 3000 individuals distributed in a dozen villages constituting an endogamous group with rare exchanges with two surrounding ethnic groups (Fulani and Bedik), and more commonly with other Mandenka populations living along the Gambia river and in the Saraya region (de Montal, 1985). The Niokholo Mandenkalu (Mandenkalu is the plural form of Mandenka) belong to the large Mande linguistic group, including several millions of speakers distributed between Mali and the Atlantic Ocean. The Mande is a subfamily of the large Niger–Congo family spreading from West Africa to Southern Africa. The Mandenkalu are thought to have settled in Eastern Senegal between the fourteenth and sixteenth century during the decline of the Mali Empire, coming from the East. A field trip in January and February 1990 allowed us to collect 203 blood samples in six villages a few kilometres distant from each other. Two hundred lymphoblastoid cell lines were successfully established, providing a continuous source of nuclear and mitochondrial DNA. The DNA polymorphism of several loci, such as α- and β-globin, HLA class I and class II, Y chromosome, mitochondrial DNA (mtDNA), and 80 random nuclear loci was then assessed in collaboration with several Swiss and international laboratories.