DNA in relation to the major histocompatibility complex

Abstract

The histocompatibility antigens or HLA system, are proteic molecular which are localized on the nucleated cell membranes. The system is located on the short arm or chromosome 6 where types of molecular called class I, II and III molecules are coded. Class I genes code for antigens HLA-A-B-C-E-F and G. These genes are made up of one polymorphic glycoprotein heavy chain and one light beta 2 macroglobulin chain. Class II genes are heterodimers composed of a common alpha chain and a polymorphic beta chain. Five well defined subregions have been described: HLA-DR, DQ, DP, DO and DN. The class III or "non-HLA" products Include complement components C2, Bf, C4A and C4B, 21 hydroxylase A and B, the dipeptide repeat RD gene, the major heat shock protein HSP70, the B-associated transcripts BAT and the alpha and beta TNF (Tumor Necrosis Factor).
Because of the system Importance, the laboratory techniques and the molecular biology methods used its study are described: Polymerase Chain Reaction (PCR) and restriction fragment length polymorphism (RFLP).