Germ Line Theories

《英文msh詞典》Germ Line Theories
[入口詞] Germ Line Theories
[主題詞] Antibody Diversity
[英文釋義] The phenomenon of immense variability characteristic of ANTIBODIES,which enables the IMMUNE SYSTEM to react specifically against the essentially unlimited kinds of ANTIGENS it encounters. Antibody diversity is accounted for by three main theories: (1) the Germ Line Theory,which holds that each antibody-producing cell has genes coding for all possible antibody specificities,but expresses only the one stimulated by antigen; (2) the Somatic Mutation Theory,which holds that antibody-producing cells contain only a few genes,which produce antibody diversity by mutation; and (3) the Gene Rearrangement Theory,which holds that antibody diversity is generated by the rearrangement of VARIABLE REGION gene segments during the differentiation of the ANTIBODY-PRODUCING CELLS.