IMM250H1 Study Guide - Rag1, Immunoglobulin M, Antigen
Document Summary
Mhc diversity is in the population lots in pop"l, individual only expresses 6. Tcr / ig diversity is in each individual somatic recombination. Produced by recombination in each t or b cell: each t cell leaving thymus has a different binding capability, recombination is not in germline cells. Produces a repertoire of 1013 antibody specificities. Gene segments encoding variable and constant regions are separate. C codes for constant domain of heavy chain. Variable (v) segments are upstream each ig domain is 100 aas given by seq"s 300 bp long: human 40 diff domains for ig 30 for ig 40 for igh. Each v domain is preceded by a leader sequence. Codes short hydrophobic segment if it is to be presented on cell surface. Not transcribed if ig is to be secreted. Separated by introns (:) of up to 2000 bps. V domains differ in sequence, but this doesn"t really have to do w/ fxn (evolutionary origin)
