STUDY OF GENETIC DIVERSITY OF THE CAPTIVE GYPS VULTURE POPULATIONS AT VULTURE CONSERVATION BREEDING CENTRE VCBC PINJORE HARYANA

Abstract

Deoxyribonucleic acid (DNA) is the hereditary material present in all living forms and some viruses; DNA also carries information necessary for development, functioning and reproduction of cells and thereby organisms. Mostly, the DNA molecule is composed of two biopolymer chains/strands coiled around each other to form a double helix. The two DNA strands are complimentary and run anti-parallel to each other. The two strands are held together by hydrogen bonds formed between the monomers of the two DNA strands, the monomers are termed as nucleotides or deoxynucleotides or deoxyribose nucleoside triphosphates (dNTPs) (Hartl 1999). The nucleotides are composed of three molecules, a nitrogen base, a pentose sugar (deoxyribose) and a phosphate group. The phosphate group and the pentose sugar forms the backbone of the DNA strand wherein the phosphate group binds to the 3 and 5 OH groups of the pentose sugar by a phosphodiester bond to form a chain like structure and the nitrogen base binds to the 1 OH group of the pentose sugar by a glycosidic bond. Four different nitrogen bases are present in DNA this includes two pyrimidine bases, adenine (A) and guanine (G) and two purine bases cytosine (C) and thymine (T). Thus, there are four dNTPs depending on which nitrogen base binds to the pentose sugar. The dNTPs, deoxyadenine triphosphate (dATP) is complimentary to deoxythymine triphosphate (dTTP) and deoxyguanine triphosphate (dGTP) is complimentary to deoxycytosine triphosphate (dCTP) (Hartl 1999). The complimentary nucleotides form hydrogen bonds in a double helix structure of DNA when the two strands are coiled around each other and run anti-parallel; this provides a cohesive force to hold two strands of DNA together. A new phosphate group or a nucleotide can be added at the 3 end of the pentose sugar and thus DNA replication or DNA duplication always occurs in 5 to 3 direction (Alba 2001).