Introduction

The Alu insertions are short interspersed nuclear elements (SINEs) present in the human genome. The insertion of an Alu-element at a particular locus can be regarded as a unique event as once inserted, most Alu elements, being stable genetic markers. Alu deletions are rare and even then the deletion leaves behind a foot print. Alu insertion/deletion polymorphisms have gained importance in the study of genetic structure of human populations as they lack selection pressure. A number of populations in India and other parts of the world are found to be highly polymorphic for these markers. They have been used extensively in recent years to trace human history (Batzer et al. 1996; Stoneking et al. 1997; Majumder et al. 1999; Watkins et al. 2001). In the present investigation, we present the allele frequencies of four Alu markers in jatt sikh population from Jammu, J&K.

 Materials and Methods

Jatt Sikh (also Jat Sikh) refers to a sub group of the Sikh ethnoreligious group from the Indian subcontinent. They form the majority of the Sikh community. About 5 ml of intravenous blood samples were collected in vials containing EDTA. DNA was extracted by using inorganic (salting out) method (Miller et al. 1988). PCR reactions were carried out in a 25μl volume containing 100 ng DNA, 200 µM dNTPs, 1.5 mMMgCl₂, 25 ng each primer, 1.25 U Taq polymerase,50 mM KCl 10 mm tris – HCl (pH 8.4). 30 cycles of    94º C for 4 min, 58º C for 1 min, 72º C for 1 min were used for ACE in a thermocycler, 30 cycles of    94º C for 4 min, 54º C for 1 min, 72º C for 1 min were used for pv92, 30 cycles of    94º C for 4 min, 50º C for 1 min, 72º C for 1 min were used for apo and 30 cycles of    94º C for 4 min, 60º C for 1 min, 72º C for 1 min were used for plat. pcr products of each marker was visualized in UV– light after separation in a 2% Agarose gel (1.5% for Alu ACE) and ethidium bromide staining.

Results and Discussion

All the four loci are found to be polymorphic in nature and showed high levels of heterozygosity. The allele frequencies and heterozygosities for the insertion/deletion alleles for the four loci studied in the jatt sikh population are given in table 1. The heterozygosity is recorded as 0.4608 to 0.4928 which is close to the values that of study conducted by Kaur et al. (2002) on jatt Sikhs of Punjab.It may be pertinent to point out here that Majumder et al (1999) reported consistently high levels of average heterozygosity in 14 populations from India ranging from 0.351 to 0.449. The present study population also exhibits high levels of heterozygosity. The Alu APO was found to be most heterozygous in the study conducted.

Table 1: Showing heterozygosity and average heterozygosity of four Alu (Alu ACE, Alu APO, Alu PV92 and Alu PLAT) polymorphic loci in 50 individuals of Gujjar population of Jammu region of J&K.

Finally it may be concluded here with the observation made by Majumder et al. (1999) that consistent with the findings of classical markers, the Alu insertion/deletion markers show high levels of genomic diversity in Indian populations. Therefore, further studies are to be taken up on Alu markers in more Indian populations in near future.

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