REGULATION OF DOUBLESEX PRE-MESSENGER-RNA PROCESSING OCCURS BY 3'-SPLICE SITE ACTIVATION
REGULATION OF DOUBLESEX PRE-MESSENGER-RNA PROCESSING OCCURS BY 3'-SPLICE SITE ACTIVATION
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DOI：
10.1101/gad.5.11.2071
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发表时间：
1991-11-01
影响因子：
10.5
通讯作者：
BAKER, BS
中科院分区：
文献类型：
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作者：
RYNER, LC;BAKER, BS
雌雄同体（dsx）前mrna的性别特异性替代加工控制黑腹果蝇的体细胞性别分化。雌性特有的加工模式源于上游3'端外显子的利用，并且需要变压器（tra）和变压器-2 （tra-2）基因的活性。使用更下游的男性特异性末端外显子不需要这些基因的活性，因此被认为是默认的dsx处理模式。本研究中，我们在果蝇组织培养细胞中，在存在或不存在tra和tra-2基因产物的情况下，使用dsx前mrna的瞬时表达来研究控制这种替代rna加工决策的分子机制。这些研究表明，雌性特异性dsx pre-mRNA的加工是由tra和tra-2通过雌性特异性替代3'端外显子使用的正调控来控制的。对调节所必需的顺式作用序列的描述表明，来自女性外显子的540个核苷酸区域对于调节既是必要的也是充分的。此外，女性特异性3'-剪接位点（3' ss）的利用是独立于女性特异性聚腺苷化调节的。只有在剪接存在的情况下才能获得调节的聚腺苷酸化，这表明女性特异性外显子的激活是通过3'SS激活发生的。
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.