Localization of SCP2 and SCP3 protein molecules within synaptonemal complexes of the rat
Localization of SCP2 and SCP3 protein molecules within synaptonemal complexes of the rat
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DOI：
10.1007/s004120050340
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发表时间：
1998-12-01
期刊：
影响因子：
1.6
通讯作者：
Heyting, C
中科院分区：
文献类型：
--
作者：
Schalk, JAC;Dietrich, AJJ;Heyting, C
SCP 2和SCP 3是大鼠联会复合体（SC）的侧向元件（LE）的主要蛋白组分，M（r）为173，000和30，000。我们进行了详细的免疫细胞化学比较的SCP 2和SCP 3在SC内的定位在电子显微镜水平。SCP 2和SCP 3的超微结构定位进行了分析，通过免疫金标记的两种类型的制剂，即表面铺展精母细胞和Lowicryl包埋的大鼠睾丸组织切片。对于每一个使用的抗血清，免疫金标记的SC在表面传播的精母细胞的分布显着不同的部分上的标签的分布。我们将这种差异归因于表面扩散技术造成的人为因素，因此我们依赖切片来精确定位表位。在切片上，用两种抗血清对非重叠的、广泛分离的SCP 3片段获得的标记的分布没有显著差异。在用抗SCP 3血清获得的标记模式和用两种抗SCP 2片段的抗血清中的任一种获得的模式之间存在小但显著的差异;尽管对于所有三种抗血清，免疫金标记的峰与LE的中心重合，但是用抗SCP 2片段的抗血清获得的标记的分布是不对称的，在LE的内侧具有肩部，而用抗SCP 3血清获得的标记分布是对称的。此外，我们观察到由抗SCP 2抗体而非抗SCP 3抗体标记的LE之间的模糊连接。这些模糊桥的标记可能导致用抗SCP 2抗体获得的金标记分布中的肩部。
SCP2 and SCP3 are major protein components of the lateral elements (LEs) of synaptonemal complexes (SCs) of the rat, with M(r)s of 173,000 and 30,000. We performed a detailed immunocytochemical comparison of the localization of SCP2 and SCP3 within SCs at the electron microscopic level. The ultrastructural localization of SCP2 and SCP3 was analyzed by immunogold labeling of two types of preparations, namely surface-spread spermatocytes and ultrathin sections of Lowicryl-embedded testicular tissue of the rat. For each of the antisera used, the distribution of immunogold label over SCs in surface-spread spermatocytes differed significantly from the distribution of label on sections. We attributed this difference to artifacts caused by the surface-spreading technique, and therefore we relied on sections for the precise localization of epitopes. On sections, the distribution of label obtained with two antisera against nonoverlapping, widely separated fragments of SCP3 did not differ significantly. There was a small but significant difference between the labeling pattern obtained with an anti-SCP3 serum and the pattern obtained with either of the two antisera against fragments of SCP2; although for all three antisera the peak of the immunogold label coincided with the center of the LE, the distributions of label obtained with the antisera against fragments of SCP2 were asymmetrical, with a shoulder at the inner side of the LE, whereas the distribution of label obtained with anti-SCP3 serum was symmetrical. Furthermore, we observed fuzzy connections between the LEs that were labeled by anti-SCP2 but not anti-SCP3 antibodies. It is possible that labeling of these fuzzy bridges caused the shoulder in the gold label distributions obtained with anti-SCP2 antibodies.