The Journal of Heredity 1985:76(5):315-320
© 1985 The American Genetic Association 76:315-320
research-article |
Frequency of polymorphisms for alleles encoding for liver proteins of domesticated mice
Drs. Neel and Erickson are affiliated with the Department of Human Genetics, and Drs. Baier and Hanash with the Department of Pediatrics, University of Michigan Medical School, Ann Arbor, MI 48109. Research supported by National Cancer Institute program project 5-PO1-CA-26803.
Abstract
Three different inbred strains of mice have been crossed with a lethal albino line (cch/c3H) and the liver polypeptides of the parents and offspring examined by two-dimensional polyacrylamide gel electrophoresis for evidences of protein polymorphisms, different alleles of which have gone to fixation in different strains. In the battery of polypeptides considered most favorable for scoring, 3.3 ± 1.6 percent of the battery exhibited paired variants and 1.6 ± 1.2 percent, unpaired. An adjustment for the fact the same allele of a biallelic polymorphism may go to fixation in two inbred lines of common ancestry leads to the suggestion that in the stock from which these inbred lines were ultimately derived, there were some 11.0 percent paired and 5.3 percent unpaired polymorphisms in the average mouse. This is about half the frequency of polymorphisms observed in wild European Musmusculus musculus and Mus musculus domesticus with one-dimensional electrophoresis of blood plasma and erythrocyte proteins. Three explanations were considered for the lower estimated frequency for liver protein polymorphisms: 1) the difference is real, 2) the apparent difference is due to the lower resolving power of two-dimensional gels, or 3) the mouse strains from which the present inbred lines were drawn had already, lost through inbreeding, a considerable amount of their genetic varlation before the inbreeding leading to the present strains commenced.