Date of Award:


Document Type:


Degree Name:

Doctor of Philosophy (PhD)


Wildland Resources

Department name when degree awarded


Committee Chair(s)

John R. Simmons


John R. Simmons


Eldon Gardner


Hugh P. Stanley


Paul B. Carter


James T. Bowman


The ry+ gene of Drosophila melanogaster and its associated enzyme, xanthine dehydrogenase, were employed in an analysis of the relationship between regulation and the location of a gene in the genome. Enzyme assays as an indication of gene activity were performed on genotypes containing zero, one and two doses of ry+ genes. Xanthine dehydrogenase activity of rosy genes in normal and relocated positions was determined during development.

The results indicate: 1) the gene ry+ is differentially active during ontogeny; 2) the activity during ontogeny is proportional to the number of ry+ genes present in the genome; and 3) a unique level of xanthine dehydrogenase activity is associated with relocated ry+ genes in the absence of a structurally normal third chromosome.

Genotypes containing relocated ry+ genes have a similar developmental curve of enzyme activity as that of the control. The genotypes with a relocated ry+ gene and lacking a structurally normal third chromosome consistently have a higher level of enzyme activity than the control, except in the late pupal stage. This increased level of activity is not the result of a general physiological effect since the ontogenic profile of glucose-6-phosphate dehydrogenase activity is the same in wild type and relocated ry+ genotypes. The relevance of the data to models for gene regulation is discussed.