Analele Ştiinţifice ale Universităţii Alexandru Ioan Cuza, Secţiunea Genetică şi Biologie Moleculară, TOM XIV, 2013 DISTRIBUTION OF CCR2-64I GENE AMONG THE TRIBES AND CASTE POPULATION OF VIDARBHA, INDIA CHAVHAN ARVIND 1,2 , PATIL KISHOR 2 , JADHAO RAJUSING 1 , ZADE SURESH 3 , PAWAR SANTOSH 4* Keywords: CCR2 gene, Polymorphism, Tribes, Vidarbha, India. Abstract: Aim: This study was aimed to evaluate the distribution of CCR2-64I gene among the tribal and caste population of Vidarbha region. Materials and Methods: Polymerase chain reaction (PCR-RFLP) using specific primers followed by amplicon digestion by Bse BI restriction enzyme was used for CCR2-64I gene polymorphism analysis. Total of 108 samples from 6 tribes and a caste were analysed. Results: The genotyping for the CCR2-64I mutation among the selected tribe and a caste reveal that all of the tribes and a caste was found to be heterozygous for the CCR2-64I mutation. Among the tribes Gonds showed highest genotype frequency (29.28%) and (11.76%) for heterozygous (CCR2/64I) and Homozygous (64I/64I) respectively, having an allelic frequency (0.233). A pooled allelic frequencies of the wild-type allele CCR2 and CCR2 64I the variant were found to be 0.854 and 0.146, respectively. No significant deviations from the HWE were observed for tribes and a caste population for the CCR2- 64I mutant χ 2 =2.76. The study reports the presence of mutant CCR2- 64I gene in tribes and caste population from Vidarbha region. INTRODUCTION HIV-1 infection has spread to all population groups in India and has reached epidemic proportions (Misra et al., 1998). The rate of progression of HIV-1 disease exhibits a remarkable variation among different individuals. Many host genetic factors are now known to affect disease progression rates, especially polymorphisms in genes encoding chemokine receptors (Berger, 1999; O'Brien and Goedert, 1998; Moore, 1997; Fuici, 1996). The chemokine receptor CCR-2 is identified as a minor HIV1 co-receptor, (Carrington et al., 1997; de Roda et al., 1997). The mutation within the CCR-2 gene is a replacement of valine to isoleucine at position 64 in the first transmembrane domain of the CCR-2 receptor (Smith et al., 1997), which is present at an allelic frequency of 10-25% in different populations (de Roda et al., 1997). The presence of this mutation in either heterozygote or homozygote has no effect on HIV-1 transmission but is associated with delayed progression to AIDS and death (Kostrikis et al., 1998; Smith et al., 1997). In contrast with CCR5-Δ-32 mutation, it provides protection against HIV disease progression in races other than the whites. (Smith et al., 1997; Kostrikis et al., 1998; Mazzucchelli et al., 2001). The distribution of CCR2-64I varies among different ethnic groups. The frequency of the CCR2-64I allele varies from 10.0% to 25.0% in both African-Americans and Caucasians, and in all other ethnic groups studied. The protective allele A occurs at a population frequency of 15.0%-17.0% in Chinese, ~12.0% in the North Indians (Kaur et al., 2007), and 3.0%-15.0% in the South Indian populations (Ramana et al., 2001). India is known for the enormous cultural and genetic diversity of its people (Majumder, 1998). Considering genetic relationships among casts groups are varying across the geographical region of India (Majumder, 1998; Baig et al., 2004), we put forth this study among the tribal group of Vidarbha region. MATERIALS AND METHODS Population: The Kolam (Tribes): Besides inhabiting the adjoining state, a substantial number of these people inhabit in few district of Vidarbha. They speak the Gondi dialect which belongs to the Dravidian linguistic group (Haimendorf, 1982). We sampled 15 samples from this group Village of Yavatmal district. The Bhil (Tribes): Bhils are listed as Adivasi residents of the states of Gujarat, Madhya Pradesh, Chhattisgarh, Maharashtra and Rajasthan in western and central India as well as in Tripura in far-eastern India on the border with Bangladesh. Bhils are divided into a number of endogamous territorial divisions, which in turn have a number of clans and lineages. Most Bhils now speak the language of the region they reside in, such as Marathi and Gujarati. We sampled 15 samples from this group Village of Yavatmal district. 1