Possible roles of actin and myosin during anaphase chromosome movements in locust spermatocytes
Possible roles of actin and myosin during anaphase chromosome movements in locust spermatocytes
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DOI：
10.1007/s00709-007-0262-y
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发表时间：
2007-10-01
期刊：
影响因子：
2.9
通讯作者：
Forer, Arthur
中科院分区：
文献类型：
--
作者：
Fabian, Lacramioara;Forer, Arthur
本文研究了蝗虫(Locusta Migratoria L.)后期染色体运动的机制。精母细胞可能与鹤蝇精母细胞的描述相似。肌动蛋白和肌球蛋白参与了鹤-蝇精母细胞的后期染色体运动，抑制剂的作用以及肌动蛋白和肌球蛋白在纺锤体中的定位表明了这一点。在这项研究中，我们测试了蝗虫精母细胞纺锤体是否也利用肌动蛋白和肌球蛋白，以及肌动蛋白是否参与了微管的流动。活的蝗虫精母细胞用肌动蛋白(乳杆菌蛋白B和细胞松弛素D)、肌球蛋白(BDM)或肌球蛋白磷酸化(Y-27632和ML-7)的抑制剂处理。我们在后期(单独)添加药物。肌动蛋白抑制剂改变后期：染色体要么完全停止移动，要么减慢，或者有时加速。肌球蛋白抑制剂BDM也会改变后期：在大多数情况下，染色体会急剧减慢或停止。ML-7是一种MLCK的抑制剂，与肌动蛋白抑制剂类似，它会导致染色体停止、减慢或有时加速。Rho-Kinase的抑制剂Y-27632可以显著减缓或停止后期的染色体运动。药物对后期运动的影响是可逆的：大多数半二价体在药物被洗掉后恢复了正常的运动速度。肌动蛋白和肌球蛋白存在于纺锤体中，其位置与它们可能参与力量产生的位置一致。沿着动粒纤维的微管流量是一个肌动蛋白依赖的过程，因为LatB完全消除或显著减少了动粒微管乙酰化的间隙。这些结果表明，肌动蛋白和肌球蛋白参与了蝗虫精母细胞的后期染色体运动。
We tested whether the mechanisms of chromosome movement during anaphase in locust (Locusta migratoria L.) spermatocytes might be similar to those described for crane-fly spermatocytes. Actin and myosin have been implicated in anaphase chromosome movements in crane-fly spermatocytes, as indicated by the effects of inhibitors and by the localisations of actin and myosin in spindles. In this study, we tested whether locust spermatocyte spindles also utilise actin and myosin, and whether actin is involved in microtubule flux. Living locust spermatocytes were treated with inhibitors of actin (latrunculin B and cytochalasin D), myosin (BDM), or myosin phosphorylation (Y-27632 and ML-7). We added drugs (individually) during anaphase. Actin inhibitors alter anaphase: chromosomes either completely stop moving, slow, or sometimes accelerate. The myosin inhibitor, BDM, also alters anaphase: in most cases, the chromosomes drastically slow or stop. ML-7, an inhibitor of MLCK, causes chromosomes to stop, slow, or sometimes accelerate, similar to actin inhibitors. Y-27632, an inhibitor of Rho-kinase, drastically slows or stops anaphase chromosome movements. The effects of the drugs on anaphase movement are reversible: most of the half-bivalents resumed movement at normal speed after these drugs were washed out. Actin and myosin were present in the spindles in locations consistent with their possible involvement in force production. Microtubule flux along kinetochore fibres is an actin-dependent process, since LatB completely removes or drastically reduces the gap in microtubule acetylation at the kinetochore. These results suggest that actin and myosin are involved in anaphase chromosome movements in locust spermatocytes.