Document Type

Thesis - Open Access

Award Date


Degree Name

Master of Science (MS)


Animal Science

First Advisor

Nels H. Granholm


The lethal yellow gene, (Ay) is a genetic mutation in mice which causes a number of defects. First described in 1905 by Cuenot, the Ay/- mouse has been the subject of one hundred or more studies. Yet, primary genetic and molecular lesions caused by Ay remain unknown. Cuenot reported that Ay caused three aberrant phenotypic alterations; these included yellow coat color, obesity, and embryonic lethality in Ay homozygous embryos (Ay/Ay). Since 1905, a number of other Ay-induced abnormalities have been reported. Among these aberrations is Ay-induced reproductive senescence. It is this particular Ay character (i.e. reproductive failure of Ay/- mice) upon which this thesis is focused. In addition to Ay- induced reproductive failures, the lethal yellow gene also promotes a number of other abnormalities of interest to animal science and production agriculture. Some of these abnormalities include: 1. Reciprocal embryo-uterine relationships during implantation, i. e., experimental utilization of the Ay/Ay embryos and uteri from yellow (Ay/a) and nonyellow (a/a) dams as components of a model system to investigate mammalian implantation. Increased carcass size. Carpenter and Mayer Heston and Vlahakis, and others have shown that Ay causes a significantly increased skeletal size over that of non-mutant controls. 3. Defects in the regulation of body heat. 4. Unique nutritional pathways that channel food into fat rather than protein. The most comprehensive study on the relationship of Ay to energy flow and other components of feed efficiency was conducted by Dickerson and Gowen; they concluded that Ay lowers feed requirements and increases energy storage per g of weight gain. Also, Hollifield and Parson concluded that the yellow gene (Ay) alters cellular metabolism" ... in particular with regard to handling fat". From an animal science perspective, it would be worthwhile to determine precisely how Ay changes cellular metabolism, because once understood, we could then develop treatments to channel incoming dietary energy to protein rather than fat, thus increasing feed efficiency, and 5. Abnormal biochemistry leading to a diabetic-like condition and obesity. The concepts briefly outlined in items 1-5 immediately above are all of interest (in varying degrees) to the general discipline of animal science. They are all induced by a known "treatment", gene. i.e. the lethal yellow gene.

Library of Congress Subject Headings

Mice -- Diseases
Mice -- Reproduction
Mice -- Weight
Lethal mutation



Number of Pages



South Dakota State University


No Copyright - United State