Haoudi A, Rachidi M, Kim M H, Champion S, Best-Belpomme M, Maisonhaute C
Laboratoire de Genetique Cellulaire et Moleculaire, UA 1135 CNRS, Université Pierre and Marie Curie, Paris, France.
Gene. 1997 Sep 1;196(1-2):83-93. doi: 10.1016/s0378-1119(97)00203-5.
Extensive analyses of Drosophila melanogaster retrotransposon transcriptions in cultured cells or during development have been reported, but little is known about their translation during the development of the fly. Analysis of the translational products of the 1731 Drosophila melanogaster retrotransposon in Kc Drosophila cultured cells has been reported, showing the existence of primary products (Gag and Pol) and of processed polypeptides of various sizes. Study of 1731 retrotransposon expression at both levels of transcription and translation during the development of Drosophila melanogaster, is presented. 1731 transcripts were detected by in situ hybridization and 1731 proteins were detected by immunostaining and immunoblotting in embryos and in adult gonads. 1731 transcripts and proteins were detected in the mesoderm and central nervous system during embryonic development, in nurse cells and follicle cells in adult ovaries and in primary spermatocytes in adult testes. Moreover, Western blot analysis of the 1731 proteins with anti-Gag or anti-Pol antibodies in gonads revealed that the 1731 mRNA could be translated differentially according to the expressing tissue: essentially, ovarian translation and/or processing of 1731 products is different from that operating in testes, where the Gag-Pol fusion polyprotein is the most prominent product. Our results indicate that expression of the 1731 mobile element is regulated not only at the transcriptional level but also at the translational level, and that this regulation is different in the two sexes.
关于黑腹果蝇反转录转座子在培养细胞或发育过程中的转录，已有大量分析报道，但对于其在果蝇发育过程中的翻译情况却知之甚少。已有报道对黑腹果蝇1731反转录转座子在Kc果蝇培养细胞中的翻译产物进行了分析，结果显示存在初级产物（Gag和Pol）以及各种大小的加工多肽。本文展示了对黑腹果蝇发育过程中转录和翻译两个水平上1731反转录转座子表达的研究。通过原位杂交检测1731转录本，通过免疫染色和免疫印迹在胚胎和成体性腺中检测1731蛋白。在胚胎发育期间，在中胚层和中枢神经系统中检测到1731转录本和蛋白，在成年卵巢的滋养细胞和卵泡细胞以及成年睾丸的初级精母细胞中也检测到了。此外，用抗Gag或抗Pol抗体对性腺中的1731蛋白进行蛋白质印迹分析表明，1731 mRNA的翻译可能因表达组织而异：本质上，卵巢中1731产物的翻译和/或加工与睾丸中的不同，在睾丸中Gag-Pol融合多蛋白是最主要的产物。我们的结果表明，1731可移动元件的表达不仅在转录水平受到调控，在翻译水平也受到调控，而且这种调控在两性中有所不同。
