Developmental expression of a Drosophila actin gene encoding actin I
Developmental expression of a Drosophila actin gene encoding actin I
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编码肌动蛋白 I 的果蝇肌动蛋白基因的发育表达
作者：
E. Zulauf;F. Sánchez;S. Tobin;U. Rdest;B. Mccarthy
黑腹果蝇肌动蛋白基因包括一个分散的多基因家族1,2，共有6个基因，分别位于6个分散的染色体位点（参考文献1,2和未发表的观察结果）。这些基因编码果蝇行动蛋白I， II和iii3,4，它们可以在二维凝胶的等电聚焦维度上分离。肌动蛋白II和III存在于所有组织中，除成体胸腔外，肌动蛋白III是一种不稳定的形态5，而肌动蛋白I是酸性最强的形态，在体内和体外的幼虫肌肉形成过程中都存在3,4。因此，有些行为似乎是受发育调控的。如果一个多基因家族的个体成员在转录水平上受到调控，这意味着基因调控的发育机制可以通过比较基因家族成员来阐明。我们在这里报告了D. melanogaster肌动蛋白基因在79B染色体位点的转录活性模式。我们的研究结果表明，79B肌动蛋白基因编码肌动蛋白I，即幼虫肌肉特异性肌动蛋白，肌动蛋白I最初是作为前体合成的。前体在肌动蛋白II的位置与细胞质肌动蛋白共同迁移，随后乙酰化形成肌动蛋白I。
The Drosophila melanogaster actin genes comprise a dispersed multigene family1,2 of six genes, one at each of six scattered chromosomal loci (refs 1,2 and unpublished observations). These genes encode the Drosophila actins I, II and III3,4, which can be separated in the isoelectric focusing dimension of two-dimensional gels. Actins II and III have been found in all tissues, with actin III an unstable species except in adult thorax5, while actin I, the most acidic form, appears during larval myogenesis both in vivo and in vitro3,4. Some actins therefore seem to be developmentally regulated. If individual members of a multigene family are regulated at the transcriptional level, this implies that developmental mechanisms of gene regulation can be elucidated by comparing gene family members. We report here a pattern of transcriptional activity of the D. melanogaster actin gene at the 79B chromosomal locus. Our results suggest that the 79B actin gene encodes actin I, the larval muscle-specific actin, and that actin I is synthesized initially as a precursor. The precursor co-migrates with cytoplasmic actin at the position of actin II and is subsequently acetylated to form actin I.