A chemoattractant for ascidian spermatozoa is a sulfated steroid
A chemoattractant for ascidian spermatozoa is a sulfated steroid
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DOI：
10.1073/pnas.242470599
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发表时间：
2002-11-12
影响因子：
11.1
通讯作者：
Morisawa, M
中科院分区：
文献类型：
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作者：
Yoshida, M;Murata, M;Morisawa, M
精子在受精前对卵子的趋化作用已在许多动植物中得到证实，一些多肽和小有机化合物已被鉴定为趋化剂。我们以前发现，海鞘类和萨维尼亚类的精子被激活，然后被卵子释放的一个共同因子吸引到卵子。本研究采用柱层析的方法，从肠囊线虫卵子条件培养液中分离纯化了精子激活吸引因子(SAAF)。通过核磁共振和MS/MS分析确定了其分子结构，结果表明SAAF是一种未鉴定的硫化类固醇：3，4，7，26-tetrahydroxycholestane-3，26-disulfate.此外，在层析行为和相对分子质量方面，萨维尼毛虫的SAAF与肠毛虫的SAAF没有区别，这表明同一种化合物可能对两种动物的精子激活和趋化起作用。此外，我们还建立了一种定量分析精子趋化性的方法，并证明了Ciona精子的趋化行为受与SAAF浓度降低相关的“趋化转向”所控制。
Sperm chemotaxis toward eggs before fertilization has been demonstrated in many animals and plants, and several peptides and small organic compounds acting as chemoattractants have been identified. We previously showed that sperm of the ascidians Ciona intestinalis and Gona savignyi are activated and then attracted toward the egg by a common factor released from the egg. In this study, we purified sperm-activating and -attracting factor (SAAF) from the egg-conditioning medium of C intestinalis by using several steps of column chromatography. Determination of the molecular structure by NMR and MS/MS analysis revealed that SAAF is a previously uncharacterized sulfated steroid: 3,4,7,26-tetrahydroxycholestane-3,26-disulfate. Furthermore, it was shown that the SAAF of C. savignyi was indistinguishable from that of C intestinalis in terms of the chromatographic behavior and molecular weight, indicating that the same compound might be responsible for sperm activation and chemotaxis in both the species. Furthermore, we established a method for quantitative analysis of sperm chemotaxis and showed that the chemotactic behavior of Ciona sperm is controlled by the "chemotactic turn" associated with decrease in the concentration of SAAF.