1	One Step Further Genetic Basis for Immunoglobulin Diversity OSF - 7 Pages 100 - 102
2	Immunoglobulin Diversity - 2 Immunoglobulin genes: eChromosomes do not contain genes for immunoglobulin synthesis eChromosomes contain multiple coding segments (building blocks) from which developing B lymphocytes assemble the immunoglobulin genes eThese multiple coding segments are called exons when incoporated into the B lymphocyte=s DNA molecule eThese exons are seperated by non-coding DNA segments called introns eThe recombination of immunoglobulin exons to form functional genes takes place whenever the B lymphocyte (plasma cell) needs to produce more immunoglobulins.
3	Immunoglobulin Diversity - 3 Functional Ig Genes: eGenes that code for the Ig molecule: ŽH gene ŽL gene contains code for heavy chains heavy chain contains code for light chains light chain
4	Immunoglobulin Diversity - 4 Heavy Chain genes (H): eHeavy chains consist of two regions : variable region constant region exons coding for this: V D J exons coding for this: C( if IgG class C: if IgM class C* if IgD class C, if IgE class
5	Immunoglobulin Diversity - 5 Light Chain genes (L): eLight chains consist of two regions: variable region constant region exons coding for this: V J exons coding for this: C₆ if kappa type C₈ if lambda type
6	Immunoglobulin Diversity - 6 Some Nice-to-Know Information: eOnce a L or H chain gene is assembled and becomes functional further gene arrangements are prevented within the same B cell Žthus antigen specificity is maintained Žthis antigen specificity is passed on to progeny Žthe progeny will also have the same light chain types (6 or 8) eHeavy chains may undergo rearrangement during clonal development resulting in progeny with different classes of immunoglobulins (class switching) eSlight changes in the tail end of constant region of heavy chains also determines whether the Ig is attached to the surface or released into circulation.
7	Immunoglobulin Diversity - 6