Skip to main content
NCBI home page
Genetics logoLink to Genetics
. 1992 Mar;130(3):547–554. doi: 10.1093/genetics/130.3.547

The Genetic Analysis of Snf: A Drosophila Sex Determination Gene Required for Activation of Sex-Lethal in Both the Germline and the Soma

H K Salz 1
PMCID: PMC1204872  PMID: 1551576

Abstract

Our analysis demonstrates that snf is a positive regulator of Sex-lethal in both the germline and the soma. In the germline, unregulated expression of Sex-lethal can bypass the requirement for snf(+) gene function, implying that snf is required for Sex-lethal activity in the germline. This conclusion is supported by the finding that the Sex-lethal transcription pattern is abnormal in a snf mutant background. In the soma, activation of Sex-lethal appears to be sensitive to snf gene dosage only when the probability of Sex-lethal activation has been otherwise reduced. We also show that the activity of one of the constitutive Sex-lethal alleles (Sxl(M1)) is sensitive to snf gene dosage, demonstrating that, in spite of its constitutive behavior in some assays, Sxl(M1) is still subject to some regulation. In spite of snf's role in the somatic activation of Sex-lethal, no lethal alleles of snf were isolated in a screen of ~25,000 chromosomes. The observation that the existing snf mutations present a lethal phenotype only in certain genetic backgrounds suggests that snf is required, but is not essential, for the activation of Sex-lethal in the soma. In contrast, snf does appear to be essential for activation of Sex-lethal in the germline, as evidenced by its female-sterile phenotype.

Full Text

The Full Text of this article is available as a PDF (2.1 MB).

Selected References

These references are in PubMed. This may not be the complete list of references from this article.

  1. Bell L. R., Horabin J. I., Schedl P., Cline T. W. Positive autoregulation of sex-lethal by alternative splicing maintains the female determined state in Drosophila. Cell. 1991 Apr 19;65(2):229–239. doi: 10.1016/0092-8674(91)90157-t. [DOI] [PubMed] [Google Scholar]
  2. Bell L. R., Maine E. M., Schedl P., Cline T. W. Sex-lethal, a Drosophila sex determination switch gene, exhibits sex-specific RNA splicing and sequence similarity to RNA binding proteins. Cell. 1988 Dec 23;55(6):1037–1046. doi: 10.1016/0092-8674(88)90248-6. [DOI] [PubMed] [Google Scholar]
  3. Cline T. W. Evidence that sisterless-a and sisterless-b are two of several discrete "numerator elements" of the X/A sex determination signal in Drosophila that switch Sxl between two alternative stable expression states. Genetics. 1988 Aug;119(4):829–862. doi: 10.1093/genetics/119.4.829. [DOI] [PMC free article] [PubMed] [Google Scholar]
  4. Eberl D. F., Hilliker A. J. Characterization of X-linked recessive lethal mutations affecting embryonic morphogenesis in Drosophila melanogaster. Genetics. 1988 Jan;118(1):109–120. doi: 10.1093/genetics/118.1.109. [DOI] [PMC free article] [PubMed] [Google Scholar]
  5. Elkins T., Zinn K., McAllister L., Hoffmann F. M., Goodman C. S. Genetic analysis of a Drosophila neural cell adhesion molecule: interaction of fasciclin I and Abelson tyrosine kinase mutations. Cell. 1990 Feb 23;60(4):565–575. doi: 10.1016/0092-8674(90)90660-7. [DOI] [PubMed] [Google Scholar]
  6. Erickson J. W., Cline T. W. Molecular nature of the Drosophila sex determination signal and its link to neurogenesis. Science. 1991 Mar 1;251(4997):1071–1074. doi: 10.1126/science.1900130. [DOI] [PubMed] [Google Scholar]
  7. Gans M., Audit C., Masson M. Isolation and characterization of sex-linked female-sterile mutants in Drosophila melanogaster. Genetics. 1975 Dec;81(4):683–704. doi: 10.1093/genetics/81.4.683. [DOI] [PMC free article] [PubMed] [Google Scholar]
  8. Hodgkin J. Sex determination compared in Drosophila and Caenorhabditis. Nature. 1990 Apr 19;344(6268):721–728. doi: 10.1038/344721a0. [DOI] [PubMed] [Google Scholar]
  9. Komitopoulou K., Gans M., Margaritis L. H., Kafatos F. C., Masson M. Isolation and Characterization of Sex-Linked Female-Sterile Mutants in DROSOPHILA MELANOGASTER with Special Attention to Eggshell Mutants. Genetics. 1983 Dec;105(4):897–920. doi: 10.1093/genetics/105.4.897. [DOI] [PMC free article] [PubMed] [Google Scholar]
  10. Maine E. M., Salz H. K., Cline T. W., Schedl P. The Sex-lethal gene of Drosophila: DNA alterations associated with sex-specific lethal mutations. Cell. 1985 Dec;43(2 Pt 1):521–529. doi: 10.1016/0092-8674(85)90181-3. [DOI] [PubMed] [Google Scholar]
  11. Mohler J. D. Developmental genetics of the Drosophila egg. I. Identification of 59 sex-linked cistrons with maternal effects on embryonic development. Genetics. 1977 Feb;85(2):259–272. doi: 10.1093/genetics/85.2.259. [DOI] [PMC free article] [PubMed] [Google Scholar]
  12. Mével-Ninio M., Terracol R., Kafatos F. C. The ovo gene of Drosophila encodes a zinc finger protein required for female germ line development. EMBO J. 1991 Aug;10(8):2259–2266. doi: 10.1002/j.1460-2075.1991.tb07762.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
  13. Nöthiger R., Jonglez M., Leuthold M., Meier-Gerschwiler P., Weber T. Sex determination in the germ line of Drosophila depends on genetic signals and inductive somatic factors. Development. 1989 Nov;107(3):505–518. doi: 10.1242/dev.107.3.505. [DOI] [PubMed] [Google Scholar]
  14. Oliver B., Perrimon N., Mahowald A. P. Genetic evidence that the sans fille locus is involved in Drosophila sex determination. Genetics. 1988 Sep;120(1):159–171. doi: 10.1093/genetics/120.1.159. [DOI] [PMC free article] [PubMed] [Google Scholar]
  15. Oliver B., Perrimon N., Mahowald A. P. The ovo locus is required for sex-specific germ line maintenance in Drosophila. Genes Dev. 1987 Nov;1(9):913–923. doi: 10.1101/gad.1.9.913. [DOI] [PubMed] [Google Scholar]
  16. Pauli D., Mahowald A. P. Germ-line sex determination in Drosophila melanogaster. Trends Genet. 1990 Aug;6(8):259–264. doi: 10.1016/0168-9525(90)90208-n. [DOI] [PubMed] [Google Scholar]
  17. Perrimon N., Mohler D., Engstrom L., Mahowald A. P. X-linked female-sterile loci in Drosophila melanogaster. Genetics. 1986 Jul;113(3):695–712. doi: 10.1093/genetics/113.3.695. [DOI] [PMC free article] [PubMed] [Google Scholar]
  18. Salz H. K., Cline T. W., Schedl P. Functional changes associated with structural alterations induced by mobilization of a P element inserted in the Sex-lethal gene of Drosophila. Genetics. 1987 Oct;117(2):221–231. doi: 10.1093/genetics/117.2.221. [DOI] [PMC free article] [PubMed] [Google Scholar]
  19. Salz H. K., Maine E. M., Keyes L. N., Samuels M. E., Cline T. W., Schedl P. The Drosophila female-specific sex-determination gene, Sex-lethal, has stage-, tissue-, and sex-specific RNAs suggesting multiple modes of regulation. Genes Dev. 1989 May;3(5):708–719. doi: 10.1101/gad.3.5.708. [DOI] [PubMed] [Google Scholar]
  20. Samuels M. E., Schedl P., Cline T. W. The complex set of late transcripts from the Drosophila sex determination gene sex-lethal encodes multiple related polypeptides. Mol Cell Biol. 1991 Jul;11(7):3584–3602. doi: 10.1128/mcb.11.7.3584. [DOI] [PMC free article] [PubMed] [Google Scholar]
  21. Slee R., Bownes M. Sex determination in Drosophila melanogaster. Q Rev Biol. 1990 Jun;65(2):175–204. doi: 10.1086/416718. [DOI] [PubMed] [Google Scholar]
  22. Steinmann-Zwicky M., Schmid H., Nöthiger R. Cell-autonomous and inductive signals can determine the sex of the germ line of drosophila by regulating the gene Sxl. Cell. 1989 Apr 7;57(1):157–166. doi: 10.1016/0092-8674(89)90181-5. [DOI] [PubMed] [Google Scholar]

Articles from Genetics are provided here courtesy of Oxford University Press

RESOURCES