טכניון מכון טכנולוגי לישראל
הטכניון מכון טכנולוגי לישראל - בית הספר ללימודי מוסמכים  
Ph.D Thesis
Ph.D StudentBehar Doron
SubjectGenomic Diversity among Near Eastern Populations
DepartmentDepartment of Medicine
Supervisor Professor Karl Skorecki


Abstract

Phylogeography makes use of sequence variation in mitochondrial DNA (mtDNA) and in the non-recombining region of the Y-chromosome (NRY) to address questions related respectively to maternal and paternal origins and demographic patterns in various human populations. The Near East presents a mosaic of diverse populations residing contemporaneously in geographic proximity that are thought to have originated from different continents and to have been founded by different mechanisms. One of the most intensively studied of the populations in this mosaic is that of Ashkenazi Jews known to have undergone several founding events and repeated bottlenecks followed by a dramatic expansion in size. This unique demography has fueled a lively debate regarding the reasons for the accumulation of over 20 rare Mendelian disorders in Ashkenazi populations, namely, heterozygote advantage versus simple genetic drift. In the current study, we have studied in depth the NRY and mtDNA variation among Ashkenazi Jews and contrasted it against the background of overall diversity found in the Near East. This enabled us to unravel the major haplogroups, haplotypes and lineages comprising the entire uniparental genetic compositions of this population. The combined mtDNA and NRY data demonstrated that the Ashkenazi population experienced a long period of accentuated genetic drift, a reduced level of overall genetic variation, a paucity of founding ancestors most probably originating in the Near East, and low introgression from surrounding host populations.