A unifying hypothesis for the molecular mechanism of somatic mutation and gene conversion in rearranged immunoglobulin variable genes.

We have reviewed available data concerning the mechanism of somatic hypermutation in rearranged variable genes of Ig in B lymphocytes of mice and the gene conversion process which generates diversity in these genes in the B lymphocytes of chickens. In our view, these data are consistent with a unifying hypothesis of diversity generating mechanisms involving reverse transcription to produce cDNA from RNA transcripts followed by homologous recombination into chromosomal DNA. Thus, seemingly different processes in the mouse and chicken may have a common molecular basis.