A new translational repression element and unusual transcriptional control regulate expression of don juan during Drosophila spermatogenesis
A new translational repression element and unusual transcriptional control regulate expression of don juan during Drosophila spermatogenesis
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DOI：
10.1016/s0925-4773(01)00577-9
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发表时间：
2002-01-01
影响因子：
2.6
通讯作者：
Renkawitz-Pohl, R
中科院分区：
文献类型：
--
作者：
Blümer, N;Schreiter, K;Renkawitz-Pohl, R
果蝇DonJuan(DJ)基因编码一种仅在雄性生殖系中表达的碱性蛋白，在结构上与连接子组蛋白H I相似。唐胡安位于两个不同的亚细胞结构中：在染色质凝聚阶段的细胞核中，以及后来从精子细胞个体化开始的线粒体衍生物中。Don Juan基因是在初级精母细胞中转录的，其上游的23bp与下游的序列结合在一起。在减数分裂阶段和精子细胞的早期阶段，don Juan mRNA在翻译上被抑制了几天。对未进行减数分裂的雄性不育突变体的分析表明，DJ mRNA从翻译抑制中的释放与减数分裂无关。在凝胶滞留分析中，DJ前导末端的60个核苷酸与从睾丸提取的蛋白质形成四个主要的复合体，但不与卵巢的蛋白质提取物形成复合体。转化研究证明，在体内，DJ mRNA该区域内的35bp对于提供翻译抑制是必不可少的。紫外光交联研究表明，一个62 kDa的蛋白质特异性地结合到5(‘)非翻译区内的同一区域。DJ翻译抑制元件tre不同于先前描述的MST(3)Cgp基因Fan-百合所有成员的翻译控制元件TCE。此外，在几个雄性不育突变体中的表达研究表明，在精子形态发生过程中，don Juan mRNA比MST(3)CGP mRNAs在发育阶段更早被翻译。这证明了精子发生中休眠mRNAs的翻译激活发生在不同的时间点，这是每个基因所特有的，这是协调精子形态发生的基本特征。(C)2002爱思唯尔科学爱尔兰有限公司。保留所有权利。
The Drosophila don juan (dj) gene encodes a basic protein that is expressed solely in the male germline and shows structural similarities to the linker histone H I. Don Juan is located in two different subcellular structures: in the nucleus during the phase of chromatin condensation and later in the mitochondrial derivatives starting with spermatid individualization. The don juan gene is transcribed in primary spermatocytes under the control of 23 bp upstream in combination with downstream sequences. During meiotic stages and in early spermatid stages don juan mRNA is translationally repressed for several days. Analysis of male sterile mutants which fail to undergo meiosis shows that release of dj mRNA from translational repression is independent of meiosis. In gel retardation assays 60 nucleotides at the end of the dj leader form four major complexes with proteins that were extracted from testes but not with protein extracts from ovaries. Transformation studies prove that in vivo 35 bp within that region of the dj mRNA is essential to confer translational repression. UV cross-linking studies show that a 62 kDa protein specifically binds to the same region within the 5(') untranslated region. The dj translational repression element, TRE, is distinct from the translational control element, TCE, described earlier for all members of the Mst(3)CGP gene fan-Lily. Moreover, expression studies in several male sterile mutants reveal that don juan mRNA is translated in earlier developmental stages during sperm morphogenesis than the Mst(3)CGP mRNAs. This proves that translational activation of dormant mRNAs in spermatogenesis occurs at different time-points which are characteristic for each gene, an essential feature for coordinated sperm morphogenesis. (C) 2002 Elsevier Science Ireland Ltd. All rights reserved.