Rcd4 is a poorly characterized Drosophila centriole component whose mammalian counterpart, PPP1R35, is suggested to function in centriole elongation and conversion to centrosomes. Here, we show that rcd4 mutants exhibit fewer centrioles, aberrant mitoses, and reduced basal bodies in sensory organs. Rcd4 interacts with the C-terminal part of Ana3, which loads onto the procentriole during interphase, ahead of Rcd4 and before mitosis. Accordingly, depletion of Ana3 prevents Rcd4 recruitment but not vice versa. We find that neither Ana3 nor Rcd4 participates directly in the mitotic conversion of centrioles to centrosomes, but both are required to load Ana1, which is essential for such conversion. Whereas ana3 mutants are male sterile, reflecting a requirement for Ana3 for centriole development in the male germ line, rcd4 mutants are fertile and have male germ line centrioles of normal length. Thus, Rcd4 is essential in somatic cells but is not absolutely required in spermatogenesis, indicating tissue-specific roles in centriole and basal body formation.

中文翻译：

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果蝇 Rcd4 对中心粒复制和纤毛发生的组织特异性要求

Rcd4 是果蝇中心粒的一个尚未充分表征的成分，其哺乳动物对应物 PPP1R35 被认为在中心粒伸长和向中心体的转化中发挥作用。在这里，我们发现 rcd4 突变体表现出较少的中心粒、异常的有丝分裂和感觉器官中基体的减少。Rcd4 与 Ana3 的 C 末端部分相互作用，后者在间期、Rcd4 之前和有丝分裂之前加载到原中心粒上。因此，Ana3 的耗尽会阻止 Rcd4 的募集，但反之则不然。我们发现Ana3和Rcd4都不直接参与中心粒到中心体的有丝分裂转化，但两者都需要加载Ana1，而Ana1对于这种转化至关重要。ana3 突变体是雄性不育的，反映了雄性种系中中心粒发育需要 Ana3，而 rcd4 突变体是可育的并且具有正常长度的雄性种系中心粒。因此，Rcd4 在体细胞中是必需的，但在精子发生中并不是绝对必需的，这表明在中心粒和基体形成中具有组织特异性作用。