Date of Award:

5-1973

Document Type:

Dissertation

Degree Name:

Doctor of Philosophy (PhD)

Department:

Biology

Committee Chair(s)

John R. Simmons

Committee

John R. Simmons

Committee

Eldon Gardner

Committee

Hugh P. Stanley

Committee

Paul B. Carter

Committee

James T. Bowman

Abstract

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.

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