Regulation of doublesex pre-mRNA processing occurs by 3'-splice site activation.
Sex-specific alternative processing of the doublesex (dsx) pre-mRNA controls somatic sexual differentiation in Drosophila melanogaster. Processing in the female-specific pattern results from the utilization of an upstream 3'-terminal exon and requires the activities of both the transformer (tra) and transformer-2 (tra-2) genes. Use of the more downstream male-specific terminal exons does not require the activities of these genes and is thus considered the default dsx-processing pattern. Here, we used transient expression of dsx pre-mRNAs in the presence or absence of tra and tra-2 gene products in Drosophila tissue culture cells to investigate the molecular mechanism controlling this alternative RNA-processing decision. These studies reveal that female-specific processing of dsx pre-mRNA is controlled by tra and tra-2 through the positive regulation of female-specific alternative 3'-terminal exon use. Delineation of cis-acting sequences necessary for regulation shows that a 540-nucleotide region from within the female exon is both necessary and sufficient for regulation. In addition, utilization of the female-specific 3'-splice site (3'SS) is regulated independently of female-specific polyadenylation. Regulated polyadenylation was obtained only in the presence of splicing, suggesting that activation of female-specific exon use occurs by 3'SS activation.
Ryner
L C
LC
Department of Biological Sciences, Stanford University, California 94305.
Baker
B S
BS
D000818:Animals; D015152:Blotting, Northern; D002478:Cells, Cultured; D004331:Drosophila melanogaster / Q000235:genetics* / Q000254:growth & development; D005091:Exons / Q000235:genetics; D005260:Female; D005786:Gene Expression Regulation / Q000235:genetics*; D008297:Male; D011061:Poly A / Q000235:genetics; D012322:RNA Precursors / Q000235:genetics* / Q000378:metabolism; D012323:RNA Processing, Post-Transcriptional / Q000235:genetics*; D012326:RNA Splicing / Q000235:genetics; D016601:RNA-Binding Proteins / Q000235:genetics*; D012260:Ribonucleases / Q000378:metabolism; D012727:Sex Characteristics; D014162:Transfection / Q000235:genetics
D012322:RNA Precursors; D016601:RNA-Binding Proteins; D011061:Poly A; D012260:Ribonucleases