OSBP- and FAN-mediated sterol requirement for spermatogenesis in Drosophila
OSBP- and FAN-mediated sterol requirement for spermatogenesis in Drosophila
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OSBP 和 FAN 介导的果蝇精子发生的甾醇需求
DOI：
10.1242/dev.049312
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发表时间：
2010-11-15
期刊：
影响因子：
4.6
通讯作者：
Huang, Xun
中科院分区：
文献类型：
--
作者：
Ma, Zhiguo;Liu, Zhonghua;Huang, Xun
氧甾醇结合蛋白 (OSBP) 家族的成员参与多种生物过程，包括非囊泡甾醇转运和囊泡运输。 OSBP 与发育和生理过程进行功能整合的机制仍然难以捉摸。在这里，我们报告了模式生物果蝇中 OSBP 功能的体内分析。 Osbp 突变体是雄性不育的，并且在个体化方面表现出缺陷，个体化是每个精子细胞被包装到自己的膜中的过程。 OSBP 的过度表达会导致羽化后行为缺陷，这种缺陷可以通过内质网特异性 VAP 家族蛋白的共表达来抑制。最值得注意的是，FAN（一种睾丸特异性 VAP 蛋白）与 OSBP 在遗传和物理上共同作用，调节个体化过程。在野生型个体化复合体的前缘发现了 OSBP 阳性且富含甾醇的斑点，但在 Osbp 或扇形突变体中没有发现，这表明甾醇运输可能在个体化的膜重塑阶段发挥关键作用。此外，饲喂额外甾醇的Osbp突变体部分恢复了生育能力，这意味着雄性不育是由于甾醇短缺造成的。因此，我们已经确定了果蝇精子发生中 OSBP 和 FAN 介导的甾醇需求。
Members of the oxysterol binding protein (OSBP) family are involved in diverse biological processes, including non-vesicular sterol transport and vesicle trafficking. The mechanisms by which OSBPs integrate functionally with developmental and physiological processes remain elusive. Here, we report the in vivo analysis of OSBP function in the model organism Drosophila. Osbp mutants are male-sterile and exhibit defects in individualization, the process by which each spermatid is packaged into its own membrane. Overexpression of OSBP leads to post-eclosion behaviour defects that can be suppressed by co-expression of endoplasmic reticulum-specific VAP family proteins. Most notably, FAN, a testis-specific VAP protein, acts together with OSBP genetically and physically to regulate the individualization process. OSBP-positive and sterol-enriched speckles are found at the leading edge of the individualization complex in wild type but not in Osbp or fan mutants, suggesting that sterol trafficking might play key roles during the membrane-remodelling phase of individualization. In addition, Osbp mutants that are fed additional sterols partially recover fertility, implying that male sterility is attributable to sterol shortage. Thus, we have identified an OSBP- and FAN-mediated sterol requirement in Drosophila spermatogenesis.