Sex-specific alternative splicing of RNA from the transformer gene results from sequence-dependent splice site blockage.
Sex-specific alternative splicing of RNA from the Drosophila transformer gene involves competition between two 3' splice sites. In the absence of Sex-lethal activity (as in males), only one site functions; in the presence of Sex-lethal activity (as in females), both sites function. Information for sex-specific splice site choice is contained within the intron itself. Deletions of the splice site used in males lead to Sex-lethal-independent use of the otherwise female-specific site. The relative amounts of unspliced and spliced RNA derived from these mutant genes do not change with changes in Sex-lethal activity. Specific nucleotide changes in the non-sex-specific splice site do not affect splicing activity but eliminate Sex-lethal-induced regulation. A deletion removing material between the two splice sites does not eliminate sex-specific regulation, while a deletion of the female splice site leads to a female-specific increase in unspliced RNA. These results are consistent with a model in which female-specific factors block the function of the non-sex-specific 3' splice site.
Sosnowski
B A
BA
Molecular Biology and Virology Laboratory, Salk Institute, San Diego, California 92138.
Belote
J M
JM
McKeown
M
M
D000818:Animals; D002874:Chromosome Mapping; D004252:DNA Mutational Analysis; D004331:Drosophila melanogaster / Q000235:genetics*; D005260:Female; D005786:Gene Expression Regulation; D007438:Introns; D008297:Male; D012326:RNA Splicing; D012260:Ribonucleases; D012733:Sex Differentiation
D012260:Ribonucleases