Mice homozygous for chromosomal deletions at the albino locus region lack specific polypeptides in two-dimensional gels

Abstract

Radiation-induced chromosomal deletions involving the albino locus region of the mouse result, when homozygous, in abnormalities ranging from sterility to lethality at various stages of development. We have utilized two-dimensional electrophoresis to search for polypeptide alterations in livers from newborn mice homozygous for the c14CoS and c3H deletions and also from c3H/c6H compound heterozygote mice. Five-hundred polypeptide spots detectable in normal mouse liver gels were scored. Alterations involving five polypeptides were observed in the various overlapping deletions. A spot corresponding to a polypeptide with a 38,000 Mr was missing from mice homozygous for the short c14CoS and the longer overlapping c3H deletions. Another polypeptide with a 29,000 Mr was missing from c3H homozygotes and c3H/c6H heterozygotes. A third polypeptide with a 62,000 Mr was missing only from c3H homozygotes. Two additional polypeptides were markedly increased in amount in c14CoS and c3H homozygotes. The partial overlap between the three deletions analyzed allows provisional genetic mapping of previously unknown loci for three of the five electrophoretically identifiable polypeptides expressed in newborn mouse livers. The results obtained provide a basis for studying radiation-induced deletions with two-dimensional electrophoresis gels.