developing eggs. As in the case of other tumorous 
ovary mutations, small proliferating cells fill the 
germarial region of each ovariole. A group of such 
cells is occasionally surrounded by follicle cells to 
form an abnormal cyst, which does not differentiate 
further. This same phenotype results v^hen the 
major gene controlling somatic sex determination. 
Sex-lethal, cannot function in the germline. Female 
germline cells may require the action of Sex-lethal 
as well as tumorous ovary genes to prevent the de- 
velopment of germline cells along male pathways. 
Consistent with this model, morphological similari- 
ties were noted between the proliferating cells in 
PUBLICATIONS 
bgm ovaries and normal spermatocytes. The stel- 
late gene family, a locus normally expressed only in 
the testis, was active in bgm females. The bgm gene 
was cloned, rescued by transformation, and the 
structure of a major transcript characterized. The 
amino terminus showed limited homology to the 
gene ovary tumorous. 
Dr. Spradling is also Staff Member in the Depart- 
ment of Embryology at The Carnegie Institution of 
Washington and Adjunct Professor in the Depart- 
ments of Microbiology and Biology at The Johns 
Hopkins University. 
Books and Chapters of Books 
Spradling, A., and Leys, E. 1988. Slow replication fork movement during Drosophila chorion gene amplifica- 
tion. In Cancer Cells: Eukaryotic DNA Replication (Kelly, T, and Stillman, B., Eds.). Cold Spring Harbor, 
NY: Cold Spring Harbor, vol 6, pp 305-309. 
Articles 
Cooley L., Berg, C, Kelley, R., McKearin, D., and Spradling, A. 1989. Identifying and cloning Drosophila 
genes by single P element insertional mutagenesis. Prog Nucleic Acid Res Mol Biol 36:99-109. 
Cooley, L., Berg, C, and Spradling, A. 1988. Controlling P element insertional mutagenesis. Trends Genet 
4:254-258. 
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