RT Journal Article
SR Electronic
T1 A Screen for Genes That Function Downstream of Ras1 During Drosophila Eye Development
JF Genetics
JO Genetics
FD Genetics Society of America
SP 315
OP 329
VO 143
IS 1
A1 Karim, Felix D.
A1 Chang, Henry C.
A1 Themen, Marc
A1 Wassarman, David A.
A1 Laverty, Todd
A1 Rubin, Gerald M.
YR 1996
UL http://www.genetics.org/content/143/1/315.abstract
AB Cell-fate specification of the R7 photoreceptor cell is controlled by the sevenless receptor tyrosine kinase (SevRTK) and Ras1, the Drosophila homologue of mammalian H-ras, K-ras and N-ras oncogenes. An activated form of Ras1 expressed under control of the sevenless enhancer/promoter (sev-Ras1v12) induces production of supernumerary R7 photoreceptor cells, which causes the eye to become rough in appearance. To isolate mutations in genes functioning downstream of Ras1, we carried out a screen for dominant suppressors and enhancers of this rough eye phenotype. Approximately 850,000 mutagenized flies were screened, and 282 dominant suppressors and 577 dominant enhancers were isolated. Mutations in the Drosophila homologues of Raf, MEK, MAPK, type I Geranylgeranyl Transferase and Protein Phosphatase 2A were isolated, as were mutations in several novel signaling genes. Some of these mutant genes appear to be general signaling factors that function in other Ras1 pathways, while one seems to be more specific for photoreceptor development. At least two suppressors appear to function either between Ras1 and Raf or in parallel to Raf.