CIS-ACTING SEQUENCES RESPONSIBLE FOR ANTERIOR LOCALIZATION OF BICOID MESSENGER-RNA IN DROSOPHILA EMBRYOS
CIS-ACTING SEQUENCES RESPONSIBLE FOR ANTERIOR LOCALIZATION OF BICOID MESSENGER-RNA IN DROSOPHILA EMBRYOS
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DOI：
10.1038/336595a0
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发表时间：
1988-12-08
期刊：
影响因子：
64.8
通讯作者：
STRUHL, G
中科院分区：
文献类型：
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作者：
MACDONALD, PM;STRUHL, G
黑腹果蝇的前体模式在很大程度上是由bicoid（bcd）基因的蛋白质产物所指定的，bcd基因作为一种分级的形态原，其表达峰值位于胚胎的前极1 -5。梯度的形成依赖于卵子发生过程中bcd信使RNA在卵细胞前极的预先定位6，7。在这里，我们证明了床mRNA的一个离散部分是必要的前定位的bcd转录，并足以导致本地化的异源转录。在bcdmRNA的3'端非翻译部分，负责定位的序列似乎跨越约625个碱基对的间隔，并包括能够形成广泛二级结构的区域。转录本从mbcdare主要合成，如果不是唯一的，在护士细胞，然后运输到卵母细胞的连接在前瞻性的前极6，7。我们的研究结果支持proposal 2 thatbcd成绩单被选择性地识别和捕获，因为他们进入卵母细胞的前端，并建议，这一定位过程是由锚定的序列特异性受体介导的卵母细胞的细胞质。
The anterior body pattern ofDrosophila melanogasteris specified in large part by the protein product of thebicoid (bcd)gene which functions as a graded morphogen with its peak of expression at the anterior pole of the embryo1–5. Formation of the gradient is dependent on prior localization ofbcdmessenger RNA at the anterior pole of the egg cell during oogenesis6,7. Here we demonstrate that a discrete portion of the bed mRNA is necessary for anterior localization of thebcdtranscript and is sufficient to cause localization of heterologous transcripts. The sequences responsible for localization appear to span an interval of about 625 base pairs in the 3' untranslated portion of thebcdmRNA and to include regions capable of forming extensive secondary structure. Transcripts frombcdare synthesized predominantly, if not exclusively, in the nurse cells and then transported to the oocyte by connections at the prospective anterior pole6,7. Our findings support the proposal2thatbcdtranscripts are selectively recognized and trapped as they enter the anterior tip of the oocyte, and suggest that this localization process is mediated by anchored sequence-specific receptors in the oocyte cytoplasm.