Biogenesis of the posterior-tail plasma membrane domain of the mammalian spermatozoon: targeting and lateral redistribution of the posterior-tail domain-specific transmembrane protein CE9 during spermiogenesis.
Biogenesis of the posterior-tail plasma membrane domain of the mammalian spermatozoon: targeting and lateral redistribution of the posterior-tail domain-specific transmembrane protein CE9 during spermiogenesis.
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哺乳动物精子后尾质膜结构域的生物发生：精子发生过程中后尾结构域特异性跨膜蛋白CE9的靶向和横向重新分布。
DOI：
10.1006/dbio.1995.1162
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发表时间：
1995
期刊：
影响因子：
--
通讯作者：
Bartles,JR
中科院分区：
文献类型：
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作者：
Cesario,MM;Ensrud,K;Hamilton,DW;Bartles,JR
我们使用免疫过氧化物酶组织化学和共聚焦免疫荧光显微镜来检查大鼠精子发生过程中 CE9 与后尾质膜结构域的区室化有关的事件。我们确定了精子发生的两个主要事件，在这两个事件期间，CE9似乎在细胞内分泌途径的元件内以相对大量的积累。第一阶段涵盖了从前细线期到早期粗线期初级精母细胞的细胞，并且明显表现为内质网和高尔基复合体的强烈细胞内标记。第二阶段包括精子发生步骤 8-12 中的精子细胞，并且明显表现为高尔基复合体的强烈细胞内标记和在精子细胞质内观察到的较小的囊泡结构。在这两次事件之间，CE9 的检测量显着减少。尽管CE9在精子发生前半段的大部分时间都存在于高尔基复合体和顶体系统中，但直到精子发生的第8-9步才在精子细胞尾部检测到。尽管最初从步骤 8-9 开始在整个尾部长度上检测到相对少量的 CE9，但直到精子发生的步骤 11 之后，没有证据表明尾部或精子细胞表面的其他任何地方存在相对大量的 CE9。在精子发生的步骤11和步骤13-14之间，观察到CE9在整个尾部上以相对大量的积累，与其从高尔基复合体的明显损失相一致。然后观察到 CE9 在精子发生和精子形成步骤 13-14 之间的某个时间经历进一步区室化到后尾域。我们的结果表明，CE9 在精子发生的大部分过程中被合成并进入分泌途径，但 CE9 的积累位点随着发育的变化而变化很大。关于后尾质膜域的生物发生，我们的结果表明，CE9在精子发生中后期从高尔基复合体靶向整个尾部的质膜，然后横向重新分布到后尾域，与精子发生后期环带的尾部迁移一致。该途径对哺乳动物精子细胞的后勤能力具有许多重要意义。
We used immunoperoxidase histochemistry and confocal immunofluorescence microscopy to examine the events involved in the compartmentalization of CE9 to the posterior-tail plasma membrane domain during spermatogenesis in the rat. We identified two major episodes of spermatogenesis during which CE9 appeared to accumulate in relatively large amounts intracellularly within elements of the secretory pathway. The first episode encompassed cells from preleptotene through early pachytene primary spermatocytes and was evident as intense intracellular labeling of the endoplasmic reticulum and the Golgi complex. The second episode encompassed spermatids in steps 8-12 of spermiogenesis and was evident as intense intracellular labeling of the Golgi complex and smaller vesicular structures observed within the cytoplasm of the spermatid. Between these two episodes, CE9 was detected in considerably reduced amounts. Although present within the Golgi complex and the acrosomic system throughout much of the first half of spermiogenesis, CE9 was not detected on the tail of the spermatid until steps 8-9 of spermiogenesis. Although detected initially in relatively small amounts along the entire length of the tail beginning at steps 8-9, there was no evidence for the presence of relatively large amounts of CE9 on the tail or anywhere else on the surface of the spermatid until after step 11 of spermiogenesis. Between step 11 and steps 13-14 of spermiogenesis, CE9 was observed to accumulate in relatively large amounts on the whole tail coincident with its apparent loss from the Golgi complex. CE9 was observed to then undergo further compartmentalization to the posterior-tail domain sometime between steps 13-14 of spermiogenesis and spermiation. Our results suggest that CE9 is synthesized and enters the secretory pathway throughout much of spermatogenesis, but that the site of accumulation of CE9 varies considerably as a function of development. With respect to the biogenesis of the posterior-tail plasma membrane domain, our results suggest that CE9 is targeted from the Golgi complex to the plasma membrane of the whole tail during mid to late spermiogenesis and then redistributes laterally into the posterior-tail domain coincident with the caudal migration of the annulus late in spermiogenesis. This proposed pathway has a number of important implications for the logistical capabilities of the mammalian spermatids.