The Role of Pnut and its Functional Domains in Drosophila Spermatogenesis.
The Role of Pnut and its Functional Domains in Drosophila Spermatogenesis.
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DOI：
10.1134/s2079059717010026
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发表时间：
2017-01
期刊：
影响因子：
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通讯作者：
Fedorova SA
中科院分区：
文献类型：
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作者：
Akhmetova KA;Dorogova NV;Bolobolova EU;Chesnokov IN;Fedorova SA
果蝇果仁蛋白属于间隔蛋白家族，是一种保守的GTP酶，参与胞质分裂和许多其他基本的细胞过程。由于其丝状外观、膜结合和功能，间隔蛋白被认为是细胞骨架的第四组分，与肌动蛋白、微管和中间丝并列。然而，与其他细胞骨架元素相比，对间隔蛋白的研究要少得多。我们之前已经证明，Pnut基因的缺失会导致体细胞有丝分裂的异常。这项工作的目的是研究果仁在果蝇精子发生中的作用。我们设计了一种Pnut RNA干扰的结构，允许异位抑制Pnut的表达。我们分析了果仁RNA干扰对果蝇精子发生的影响。处于精子发生早期的生殖细胞对Pnut的耗竭最为敏感：在这些阶段抑制Pnut的表达会导致男性不育，这是由于精子不能活动。这些不育男性的睾丸没有表现出任何明显的减数分裂缺陷；轴丝和线粒体正常。我们还分析了果仁保守结构域突变对果蝇精子发生的影响。GTPase结构域的突变导致了囊壁延长缺陷。C-末端结构域缺失导致睾丸形态异常。GTPase结构域和C-末端结构域突变的雄性都是不育的，并产生不活动的精子。综上所述，我们发现Pnut参与了精子发生，即精子发生的后期，此时精母细胞发生了主要的形态变化。
The Drosophila Pnut protein belongs to the family of septins, which are conserved GTPases participating in cytokinesis and many more other fundamental cellular processes. Because of their filamentous appearance, membrane association, and functions, septins are considered as the fourth component of the cytoskeleton, along with actin, microtubules, and intermediate filaments. However, septins are much less studied than the other cytoskeleton elements. We had previously demonstrated that the deletion of the pnut gene leads to mitotic abnormalities in somatic cells. The goal of this work was to study the role of the pnut in Drosophila spermatogenesis. We designed a construct for pnut RNA interference allowing pnut expression to be suppressed ectopically. We analyzed the effect of pnut RNA interference on Drosophila spermatogenesis. Germline cells at the earliest stages of spermatogenesis were the most sensitive to Pnut depletion: the suppression of the pnut expression at these stages leads to male sterility as a result of immotile sperm. The testes of these sterile males did not show any significant meiotic defects; the axonemes and mitochondria were normal. We also analyzed the effect of mutations in the Pnut’s conservative domains on Drosophila spermatogenesis. Mutations in the GTPase domain resulted in cyst elongation defects. Deletions of the C-terminal domain led to abnormal testis morphology. Both the GTPase domain and C-terminal domain mutant males were sterile and produced immotile sperm. To summarize, we showed that Pnut participates in spermiogenesis, that is, the late stages of spermatogenesis, when major morphological changes in spermatocytes occur.