A Novel Cysteine Knot Protein for Enhancing Sperm Motility That Might Facilitate the Evolution of Internal Fertilization in Amphibians.
A Novel Cysteine Knot Protein for Enhancing Sperm Motility That Might Facilitate the Evolution of Internal Fertilization in Amphibians.
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DOI：
10.1371/journal.pone.0160445
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发表时间：
2016
期刊：
影响因子：
3.7
通讯作者：
Watanabe A
中科院分区：
文献类型：
--
作者：
Yokoe M;Takayama-Watanabe E;Saito Y;Kutsuzawa M;Fujita K;Ochi H;Nakauchi Y;Watanabe A
体内受精确保了四足脊椎动物在陆地上的成功繁殖，尽管这种繁殖模式是如何进化的尚不清楚。在这里，我们鉴定了一个新的编码精子运动启动物质(SMIS)的基因，它是通过Edman降解分离的蛋白和随后的逆转录聚合酶链式反应来实现鳄鱼内部受精的关键蛋白。SMIS基因编码150个氨基酸的序列，包括半胱氨酸结(CK)基序。在任何模式生物的数据库中都没有与SMI有很大相似性的基因。SMI的活性部位位于CK基序第2环的C-末端区域。一种合成肽，包括结合到中间部分的活性部位序列，并启动/增强果胶精子的圆周运动，这允许穿透专门用于该物种内部受精的卵冻。合成的多肽与树蛙的整个精子结合，增强了旋转运动，适合于推动精子通过专用于树栖繁殖的卵衣基质，而与东亚钳蝎精子的头部和尾部结合，增强了振动运动，适合于精子通过淡水中专用于该物种繁殖的卵凝胶穿透。抗Sm活性部位的多克隆抗体可与褐家鼠卵被基质特异性结合。这些结果表明，两栖动物生殖方式的多样化伴随着卵衣的特化和精子运动能力的适应以穿透特化的卵衣，而SMIS作为无尾两栖类的精子活力增强剂，可能有助于自适应地优化精子活力，从而建立内部受精。
Internal fertilization ensures successful reproduction of tetrapod vertebrates on land, although how this mode of reproduction evolved is unknown. Here, we identified a novel gene encoding sperm motility-initiating substance (SMIS), a key protein for the internal fertilization of the urodele Cynops pyrrhogaster by Edman degradation of an isolated protein and subsequent reverse transcription polymerase chain reaction. The SMIS gene encoded a 150 amino-acid sequence including the cysteine knot (CK) motif. No gene with substantial similarity to the SMIS was in the data bank of any model organisms. An active site of the SMIS was in the C-terminal region of the 2nd loop of CK motif. A synthetic peptide including the active site sequence bound to the midpiece and initiated/enhanced the circular motion of C. pyrrhogaster sperm, which allows penetration of the egg jelly specialized for the internal fertilization of this species. The synthetic peptide bound to whole sperm of Rhacophorus arboreus and enhanced the rotary motion, which is adapted to propel the sperm through egg coat matrix specialized for arboreal reproduction, while it bound to the tip of head and tail of Bufo japonicus sperm, and enhanced the vibratory motion, which is suited to sperm penetration through the egg jelly specialized for the reproduction of that species in freshwater. The polyclonal antibody against the active site of the SMIS specifically bound to egg coat matrix of R. arboreus. These findings suggest that diversification of amphibian reproductive modes accompanies the specialization of egg coat and the adaptation of sperm motility to penetrate the specialized egg coat, and SMIS acts as the sperm motility enhancer of anurans and urodeles that might facilitate to adaptively optimize sperm motility for allowing the establishment of internal fertilization.
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影响因子：
3.7
作者：
Boschert V;van Dinther M;Weidauer S;van Pee K;Muth EM;Ten Dijke P;Mueller TD
通讯作者：
Mueller TD
影响因子：
4.8
作者：
Axelsson, MAB;Asker, N;Hansson, GC
通讯作者：
Hansson, GC
影响因子：
56.9
作者：
MORISAWA, M;SUZUKI, K
通讯作者：
SUZUKI, K
影响因子：
0.9
作者：
Ukita, M;Itoh, T;Onitake, K
通讯作者：
Onitake, K
DOI：
10.1530/jrf.0.0810495
发表时间：
1987-11-01
期刊：
JOURNAL OF REPRODUCTION AND FERTILITY
影响因子：
--
作者：
ASHIZAWA, K;WISHART, GJ
通讯作者：
WISHART, GJ