Human-specific insertion/deletion polymorphisms in Indian populations and their possible evolutionary implications

Abstract

DNA samples from 396 unrelated individuals belonging to 14 ethnic populations of India, inhabiting various geographical locations and occupying various positions in the socio-cultural hierarchy, were analysed in respect of 8 human-specific polymorphic insertion/deletion loci. All loci, except Alu CD4, were found to be highly polymorphic in all populations. The levels of average heterozygosities were found to be very high in all populations and, in most populations, also higher than those predicted by the island model of population structure. The coefficient of gene differentiation among Indian populations was found to be higher than populations in most other global regions, except Africa. These results are discussed in the light of two possible scenarios of evolution of Indian populations in the broader context of human evolution.

Analysis of CAG and CCG repeats in Huntingtin gene among HD patients and normal populations of India

“…It has recently been proposed that these Austro-Asiatic speaking groups moved to India from Africa and settled 60 000 years ago. 23 Our studies on CTG repeat variation in these populations in the DM-PK gene (Basu et al) (submitted) and CAG repeat variation in the huntingtin gene (present manuscript) support this notion.…”

“…The remaining are IndoEuropean speaking caste populations at different levels of social hierarchy. Further details about the populations studied have been described by Majumder et al 23 …”

A Tale of Aborigines, Conquerors and Slaves: Alu Insertion Polymorphisms and the Peopling of Canary Islands

“…Polymorphic Alu insertions (PAI), scattered throughout the human genome, occur as unique events in our evolution and are apparently selectively neutral (Batzer & Deininger, 2002). These markers have been used extensively for population structure and evolution, both at global (Bazter et al 1996;Antúnez-de-Mayolo et al 2002;Romualdi et al 2002;Bamshad et al 2003) and regional levels (Majumder et al 1999;Comas et al 2000Comas et al , 2004Martínez de Pancorbo et al 2001;Nasidze et al 2001). In this study, we genotyped 10 PAI in samples from the seven main islands of the Canarian archipelago, in order to fill in the gaps in autosomal studies.…”

Human Alu Insertion Polymorphisms in North African Populations

“…Among these young Alu elements, approximately 25% have inserted so recently that they are polymorphic among different human population groups, families, or even individuals with respect to their presence or absence in the genome (Batzer and Deininger, 2002). Because Alu insertions are unique events that are identical bydescent, they have been useful in genetic mapping and population genetics studies (Batzer et al, 1994;Batzer and Deininger, 1991;Perna et al, 1992;Roy-Engel et al, 2001;Salem et al, 2003;Stoneking et al, 1997;Tishkoff et al, 2000) Alu markers have been used extensively for population structure and evolution, both at global (Bazter et al 1996;Romualdi et al 2002;Bamshad et al 2003) and regional levels (Majumder et al 1999;Comas et al 2000Comas et al , 2004de Pancorbo et al 2001;Nasidze et al 2001;Ennafaa et al 2006;Bahri et al 2008;Frigi et al 2010a). The objective of this study is to compare the genetic structure of some North African populations with respect to the other populations of North Africa, Western, Eastern and Central Europe, by using MDS and AMOVA methods.…”