Differential activity of Ras1 during patterning of the Drosophila dorsoventral axis

• Published in: Genetics (Austin) Vol. 144; no. 4; pp. 1545 - 1557
• Main Authors: Schnorr, J.D, Berg, C.A
• Format: Journal Article
• Language: English
• Published: United States Genetics Soc America 01.12.1996; Genetics Society of America
• Subjects: Alleles; Animals; Base Sequence; Chromosome Mapping; compound eyes; DNA Transposable Elements - genetics; Drosophila - embryology; Drosophila - genetics; Drosophila - metabolism; Drosophila melanogaster; embryogenesis; epistasis; excision alleles; Eyes & eyesight; female fertility; Gene Expression Regulation, Developmental; Genes; Genes, ras; genetic change; genetic excision; Genetics; guanosinetriphosphatase; Insects; Investigations; Molecular Sequence Data; mutagenesis; mutants; nucleotide sequences; oogenesis; ova; phenotype; Proteins; pyrophosphatases; ras Proteins - genetics; ras Proteins - metabolism; ras1 gene; structural genes; transgenic animals; transposons
• ISSN: 0016-6731; 1943-2631; 1943-2631
• DOI: 10.1093/genetics/144.4.1545

In Drosophila, the Ras1 gene is required downstream of receptor tyrosine kineses for correct eye development, embryonic patterning, wing vein formation, and border cell migration. Here we characterize a P-element allele of Ras1, Ras1 5703, that affects viability, eye morphogenesis, and early and late stages of oogenesis. Flies transheterozgyous for Ras1 5703 and existing EMS-induced Ras1 alleles are viable and exhibit a range of eye and eggshell defects. Differences in the severity of these phenotypes in different tissues suggest that there are allele-specific effects of Ras1 in development. Analysis of rescue constructs demonstrates that these differential phenotypes are due to loss of function in Ras1 alone and not due to effects on neighboring genes. Females mutant at the Ras1 locus lay eggs with reduced or missing dorsal eggshell structures. We observe dominant interactions between Ras1 mutants and other dorsoventral pathway mutants, including Egfr(top) and gurken. Ras1 is also epistatic to K10. Unlike Egfr(top) and gurken mutants, however, Ras1 females are moderately fertile, laying eggs with ventralized eggshells that can hatch normal larvae. These results suggest that Ras1 may have a different requirement in the patterning of the eggshell axis than in the patterning of the embryonic axis during oogenesis.