A processed J chain pseudogene on human chromosome 8 that is shared by several primate species

Human DNA contains two sequences that hybridize to a human J chain gene probe: the J chain gene itself and a second previously uncharacterized sequence. By cloning and sequence analysis we now show this related sequence to be a processed pseudogene, which we have localized using somatic hybrids to chromosome 8 (distinct from the functional gene on chromosome 4) and mapped by linkage analysis to 8q13-q21. The pseudogene provides evidence of an additional DNA insertion event as it contains an AluI element embedded in sequence corresponding to the 3' untranslated region of the gene. The extent of sequence divergence between the pseudogene and the functional J chain gene suggests that the pseudogene was created roughly 40-50 million years ago; consistent with this estimate, Southern blots suggest that the pseudogene is shared by great apes as well as Old World monkeys.