Calmodulin is involved in the occurrence of extracellular Ca2+-dependent full-type hyperactivation in boar ejaculated spermatozoa incubated with cyclic AMP analogs
Calmodulin is involved in the occurrence of extracellular Ca2+-dependent full-type hyperactivation in boar ejaculated spermatozoa incubated with cyclic AMP analogs
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DOI：
10.1111/asj.13552
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发表时间：
2021-01-01
影响因子：
2
通讯作者：
Harayama，Hiroshi
中科院分区：
文献类型：
--
作者：
Wada，Atsushi;Harayama，Hiroshi
在哺乳动物中，超激活是精子与卵母细胞在体内受精所必需的。在公猪、公牛和小鼠的精子中可以观察到两种类型的超活化“全型和非全型模式”。我们有一个假设，即全型超活化是一种生理（体内）模式，并正在阐明其分子基础。本研究的目的是通过Western印迹和间接免疫荧光检测猪精子鞭毛中的钙调素，并研究细胞外Ca 2+和钙调素拮抗剂“W-7和W-5（W-5;一种较弱的拮抗剂）”对猪精子中全型超活化发生的影响。钙调素被特异性检测为头部鞭毛和顶体后区的17-kDa抗原。在3.42 mM CaCl 2孵育120-180 min的样品中可以有效地诱导全型超活化，并且W-7和W-5以浓度依赖性方式显著降低。W-7对全型超激活的抑制作用强于W-5。这些观察结果表明鞭毛钙调蛋白参与了猪精子细胞外Ca 2+依赖性全型超活化的发生。这是细胞内Ca 2+敏感分子可以在全型超活化中发挥作用的第一个迹象。
In mammals, hyperactivation is essential for sperm fertilization with oocytes in vivo. Two types of hyperactivation “full‐type and nonfull‐type patterns” can be observed in the spermatozoa from boars, bulls, and mice. We have a hypothesis that the full‐type hyperactivation is a physiological (in vivo) pattern and are elucidating its molecular bases. The aims of this study were to detect calmodulin in boar sperm flagella by Western blotting and indirect immunofluorescence and to investigate effects of extracellular Ca2+and calmodulin antagonists “W‐7 and W‐5 (W‐5; a less potent antagonist)” on the occurrence of full‐type hyperactivation in boar spermatozoa. Calmodulin was specifically detected as the 17‐kDa antigen in the flagella and postacrosomal region of the heads. Full‐type hyperactivation could be induced effectively in the samples incubated with 3.42 mM CaCl2for 120–180 min, and it was significantly reduced in the concentration‐dependent manners of W‐7 and W‐5. Suppressing effects of W‐7 on the full‐type hyperactivation were stronger than those of W‐5. These observations indicate that flagellar calmodulin is involved in the occurrence of extracellular Ca2+‐dependent full‐type hyperactivation in boar spermatozoa. This is the first indication of the intracellular Ca2+‐sensing molecule which can function in the full‐type hyperactivation.