Genetics, Vol 121, 811-818, Copyright © 1989

INVESTIGATIONS

Physical and Genetic Characterization of a 75-Kilobase Deletion Associated with a(l), a Recessive Lethal Allele at the Mouse agouti Locus

G. S. Barsh and C. J. Epstein
Department of Pediatrics and Department of Biochemistry and Biophysics, University of California, San Francisco, California 94143

The agouti locus (A) of the mouse determines the timing and type of pigment deposition in the growing hair bulb, and several alleles at this locus are lethal when homozygous. Apparent instances of intragenic recombination and complementation between different recessive lethal alleles have suggested that the locus has a complex structure. We have begun to investigate the molecular basis of agouti gene action and recessive lethality by using a series of genetically linked DNA probes and pulsed field gel electrophoresis to detect structural alterations in radiation-induced agouti mutations. Hybridization probes from the Src and Emv-15 loci do not reveal molecular alterations in DNA corresponding to the a(e), a(x), and a(l) alleles, but a probe from the parotid secretory protein gene (Psp) detects a 75-kilobase (kb) deletion in DNA containing the non-agouti lethal allele (a(l)). The deletion is defined by a 75-kb reduction in the size of BssHII, NotI, NruI and SacII high molecular weight restriction fragments detected with the Psp probe and is located between 25 kb and 575 kb from Psp coding sequences. Because the genetic distance between A and Emv-15 is much less than A and Psp, there may be a preferred site of recombination close to Psp, or suppression of recombination between A and Emv-15. The a(l) deletion has allowed us to determine the genotype of mice heterozygous for different recessive lethal alleles. We find that three different recessive lethal complementation groups are present at the agouti locus, two of which are contained within the a(l) deletion.

This article has been cited by other articles:

				R. J. Miltenberger, R. L. Mynatt, J. E. Wilkinson, and R. P. Woychik The Role of the agouti Gene in the Yellow Obese Syndrome J. Nutr., September 1, 1997; 127(9): 1902 - 1902. [Abstract] [Full Text]

				D. Duhl, M. Stevens, H Vrieling, P. Saxon, M. Miller, C. Epstein, and G. Barsh Pleiotropic effects of the mouse lethal yellow (Ay) mutation explained by deletion of a maternally expressed gene and the simultaneous production of agouti fusion RNAs Development, January 6, 1994; 120(6): 1695 - 1708. [Abstract] [PDF]

				M W Miller, D M Duhl, H Vrieling, S P Cordes, M M Ollmann, B M Winkes, and G S Barsh Cloning of the mouse agouti gene predicts a secreted protein ubiquitously expressed in mice carrying the lethal yellow mutation. Genes & Dev., March 1, 1993; 7(3): 454 - 467. [Abstract] [PDF]