Fish Immunology (1+1)

Unit 2 - Evolution of immune system

2.4. Immunoglobulins
The development of adaptive immune system lead to the production of immunoglobulins where, among living animals immunoglobulins are first found in cartilaginous fish like sharks, skates and rays. These are generated by a somatic recombination mechanism. Among immunoglobulins, IgM is the most ancient antibody class and conserved the same function in all gnathostomes. In cartilaginous fish, IgM is abundantly secreted as monomer, but in bony fish it is secreted as tetramer. In addition to IgM and IgD other immunoglobulins are also found in higher vertebrates. IgG, which is involved in memory responses, Ig E, involved in inflammatory (and allergic) responses at epithelial surfaces. IgA involved in mucosal antibody. IgG and IgE are evolved from IgY, this IgY was found in amphibians and perform the function similar to IgG.