Homologous chromosomal locations of the four genes for inter-alpha-inhibitor and pre-alpha-inhibitor family in human and mouse: assignment of the ancestral gene for the lipocalin superfamily.
The inter-alpha-inhibitor (I alpha I) and pre-alpha-inhibitor (P alpha I) family is composed of three plasma protease inhibitors, I alpha I, P alpha I, and bikunin, whose chains are encoded by a set of three evolutionarily related heavy (H) chain genes designated H1, H2, and H3 and a fourth gene, the so-called alpha 1-microglobulin/bikunin precursor (AMBP) gene. The latter codes for a precursor that splits into: (i) alpha 1-microglobulin, which belongs to the lipocalin superfamily; and (ii) bikunin, which is made up of two tandemly arranged protease inhibitor domains and belongs to the superfamily of Kunitz-type protease inhibitors. The bikunin chain is found in I alpha I and P alpha I molecules and it is also present as a free molecule in plasma. In human, the AMBP and H2 genes have been mapped to 9q32-q34 and 10p14-p15, respectively, while the H1 and H3 genes are tandemly located at 3p21.1-p21.2. In situ hybridization mappings indicate that the mouse AMBP gene (Intin-4) is located at 4C1----C4, and the H1 (Intin-1) and H3 (Intin-3) genes are colocated at 14A2----C1. In interspecific backcrosses (C57BL/6Pas x Mus spretus) a TaqI restriction variant in (and/or near) the H2 (Intin-2) gene identified a linkage of this gene with other polymorphic loci, which assigns Intin-2 to the centromeric area of chromosome 2. All such assignments are in conserved chromosomal regions between human and mouse. Therefore the genetic events that gave rise to the four I alpha I family genes took place prior to the divergence between human and mouse.(ABSTRACT TRUNCATED AT 250 WORDS)
Salier
J P
JP
Institut National de la Santé et de la Recherche Médicale Unit-78, Boisguillaume, France.
Simon
D
D
Rouet
P
P
Raguenez
G
G
Muscatelli
F
F
Gebhard
W
W
Guenet
J L
JL
Mattei
M G
MG
D000510:Alpha-Globulins / Q000235:genetics*; D000818:Animals; D015139:Blotting, Southern; D002879:Chromosomes, Human, Pair 10; D002899:Chromosomes, Human, Pair 9; D015342:DNA Probes; D004587:Electrophoresis, Agar Gel; D006239:Haplotypes; D006801:Humans; D051379:Mice / Q000235:genetics*; D008810:Mice, Inbred C57BL; D009115:Muridae; D009693:Nucleic Acid Hybridization; D011498:Protein Precursors / Q000235:genetics*; D014361:Trypsin Inhibitors / Q000235:genetics*
D000510:Alpha-Globulins; D015342:DNA Probes; D011498:Protein Precursors; D014361:Trypsin Inhibitors; C016001:alpha-1-microglobulin; C061151:pre-alpha-trypsin inhibitor; C011877:inter-alpha-inhibitor