ISSN:
1432-1777
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
,
Medicine
Notes:
Abstract Inter-α-inhibitor (IαI) and related molecules in human are comprised of three evolutionarily related, heavy (H) chains and one light (L) chain, also termed bikunin. The latter originates from a precursor molecule that is cleaved to yield the bikunin and another protein designated α-1-microglobulin (A1m). The four H and L chains are encoded by four distinct genes designated H1, H2, H3, and L. The L and H2 genes are localized onto human chromosomes (chr) 9 and 10, respectively, whereas the H1 and H3 genes are tandemly arranged on chr 3. Mouse poly(A)+ RNAs or endonuclease-restricted mouse DNA were analyzed by standard and pulsedfield gel electrophoresis (PFGE) techniques in agarose gels and blot-hybridized with human H1, H2, H3 or L cDNA probes. The variable sized transcripts and unique restriction fragment patterns detected with each probe indicate that four genes, including one common L gene for Alm and bikunin also exist in mouse. The co-migration of H1- and H3-hybridizing fragments on PFGE suggest that the mouse H1 and H3 genes are also tandemly arranged. An Msp I restriction fragment length polymorphism (RFLP) in the mouse L gene (proposed symbol, Intin-4) links this gene to other genes already mapped at mouse Chr 4 near the brown (b) locus, a homologous region to the human chr 9q32-34 band where the human IαI L gene is located. Therefore, a similar number and arrangement of IαI genes is found in mouse and human, including the triplication of an H gene ancestor. These results point to an ancient origin of this complex set of genes.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00355432
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