IFM(2)2 IS A MYOSIN HEAVY-CHAIN ALLELE THAT DISRUPTS MYOFIBRILLAR ASSEMBLY ONLY IN THE INDIRECT FLIGHT-MUSCLE OF DROSOPHILA-MELANOGASTER
IFM(2)2 IS A MYOSIN HEAVY-CHAIN ALLELE THAT DISRUPTS MYOFIBRILLAR ASSEMBLY ONLY IN THE INDIRECT FLIGHT-MUSCLE OF DROSOPHILA-MELANOGASTER
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DOI：
10.1083/jcb.107.6.2613
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发表时间：
1988-12-01
影响因子：
7.8
通讯作者：
FALKENTHAL, S
中科院分区：
文献类型：
--
作者：
CHUN, MY;FALKENTHAL, S
结合分子和遗传学技术，我们证明了Ifm（2）2是单拷贝肌节肌球蛋白重链基因的等位基因。该等位基因纯合的果蝇在成年人的管状肌中积累野生型水平的mRNA和蛋白质，但在间接飞行肌中不能积累可检测量的肌球蛋白重链mRNA或蛋白质。我们建议，突变干扰基因的转录或剪接的主要转录在间接飞行肌肉，而不是在其他肌肉组织。对这种突变纯合子果蝇的生化和电子显微镜分析表明，在间接飞行肌中，粗丝组装被废除，导致野生型粗丝蛋白的不稳定性。相比之下，细丝和Z盘组件受到轻微影响。我们讨论了肌节组装的工作假设，并定义了一个实验方法来测试这个建议的肌节组装途径的预测。
Using a combination of molecular and genetic techniques we demonstrate that Ifm(2)2 is an allele of the single-copy sarcomeric myosin heavy chain gene. Flies homozygous for this allele accumulate wild-type levels of mRNA and protein in tubular muscle of adults, but fail to accumulate detectable amounts of myosin heavy chain mRNA or protein in the indirect flight muscle. We propose that the mutation interferes with either transcription of the gene or splicing of the primary transcript in the indirect flight muscle and not in other muscle tissues. Biochemical and electron microscopic analysis of flies homozygous for this mutation has revealed that thick filament assembly is abolished in the indirect flight muscle resulting in the instability of wild-type thick filament proteins. In contrast, thin filament and Z disc assembly are marginally affected. We discuss a working hypothesis for sarcomere assembly and defined an experimental approach to test the predictions of this proposed pathway for sarcomere assembly.