Lovato T L, Meadows S M, Baker P W, Sparrow J C, Cripps R M
Department of Biology, University of New Mexico, Albuquerque, NM 87131, USA.
Insect Mol Biol. 2001 Aug;10(4):333-40. doi: 10.1046/j.0962-1075.2001.00270.x.
Actin is a ubiquitous and highly conserved eukaryotic protein required for cell motility and locomotion. In this manuscript, we characterize the four muscle actin genes of the insect Drosophila virilis and demonstrate strong similarities between the D. virilis genes and their homologues in Drosophila melanogaster; intron locations are conserved, and there are few amino acid differences between homologues. We also found strong conservation in temporal expression patterns of the muscle actin genes--the homologues of the D. melanogaster genes Act57B and Act87E are expressed throughout the life cycle, whereas the other two D. virilis genes, homologous to Act79B and Act88F are specific to pupal and adult stages. In situ hybridization revealed that each D. virilis gene is expressed in a unique pattern in the muscles of the thorax and abdomen. These muscle-specific patterns of actin isoforms suggest a greater physiological diversity for the adult muscles of insects than has been appreciated to date from their categorization into fibrillar, tubular (non-fibrillar) and supercontractile muscle types.
肌动蛋白是一种普遍存在且高度保守的真核生物蛋白质，是细胞运动和移动所必需的。在本论文中，我们对昆虫粗壮果蝇的四个肌肉肌动蛋白基因进行了表征，并证明了粗壮果蝇基因与其在黑腹果蝇中的同源基因之间存在很强的相似性；内含子位置保守，同源基因之间几乎没有氨基酸差异。我们还发现肌肉肌动蛋白基因的时间表达模式具有很强的保守性——黑腹果蝇基因Act57B和Act87E的同源基因在整个生命周期中都有表达，而粗壮果蝇的其他两个基因，与Act79B和Act88F同源，仅在蛹期和成虫期表达。原位杂交显示，每个粗壮果蝇基因在胸部和腹部肌肉中以独特的模式表达。这些肌动蛋白异构体的肌肉特异性模式表明，昆虫成虫肌肉的生理多样性比迄今为止根据其分为纤维状、管状（非纤维状）和超收缩肌肉类型所认识到的要大。
