Increased Expression of the Na,K-ATPase alpha4 Isoform Enhances Sperm Motility in Transgenic Mice
Increased Expression of the Na,K-ATPase alpha4 Isoform Enhances Sperm Motility in Transgenic Mice
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DOI：
10.1095/biolreprod.110.087064
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发表时间：
2011-01-01
影响因子：
3.6
通讯作者：
Blanco, Gustavo
中科院分区：
文献类型：
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作者：
Jimenez, Tamara;Sanchez, Gladis;Blanco, Gustavo
Na，K ATP酶α 4（ATP 1A 4）亚型特异性地表达于雄性生殖细胞中，并且在精子中高度普遍。尽管已经显示用哇巴因选择性地抑制α 4活性会影响精子运动，但是尚未证实该亚型在精子运动中的作用的更直接的分析。我们设计了在雄性生殖细胞中表达与绿色荧光蛋白融合的大鼠α 4同种型的转基因小鼠，在小鼠鱼精蛋白1启动子的控制下，我们发现大鼠Atp 1a 4转基因在小鼠精子中表达，并且它定位于精子鞭毛。随着α 4同种型表达的增加，来自转基因小鼠的精子显示出比野生型小鼠更高的α 4特异性Na，K-ATP酶活性和荧光标记的哇巴因结合。相反，存在于精子中的另一种Na，KATP酶α同种型ATP酶1A 1（α 1）的表达和活性保持不变。类似于野生型小鼠，表达α 4转基因的小鼠表现出正常的睾丸和精子形态并且在生育力上没有差异。然而，与野生型小鼠相比，来自转基因小鼠的精子显示质膜超极化和更高的总运动性和前向运动性。运动性的其它参数也增加，包括直线，此外，转基因小鼠的精子表现出更强的活动能力，但对孕酮诱导的精子顶体反应没有影响。总之，这些结果为ATP 1A 4亚型在非获能和获能条件下精子运动中的作用提供了新的遗传学证据
The Na,K ATPase alpha4 (ATP1A4) isoform is specifically expressed in male germ cells and is highly prevalent in spermatozoa Although selective inhibition of alpha4 activity with ouabain has been shown to affect sperm motility, a more direct analysis of the role of this isoform in sperm movement has not yet been demonstrated To establish this, we engineered transgenic mice that express the rat alpha4 isoform fused to green fluorescent protein in male germ cells, under the control of the mouse protamine 1 promoter We showed that the rat Atp1a4 transgene is expressed in mouse spermatozoa and that it is localized to the sperm flagellum In agreement with increased expression of the alpha4 isoform, sperm from transgenic mice displayed higher alpha4-specific Na,K-ATPase activity and binding of fluorescently labeled ouabain than wild type mice In contrast, expression and activity of ATP1A1 (alpha1), the other Na,K ATPase alpha isoform present in sperm, remained unchanged Similar to wild-type mice, mice expressing the alpha4 transgene exhibited normal testis and sperm morphology and no differences in fertility However, compared to wild type mice, sperm from transgenic mice displayed plasma membrane hyperpolarization and higher total and progressive motility Other parameters of motility also increased, including straight-line, curvilinear, and average path velocities and amplitude of lateral head displacement In addition, sperm from the transgenic mice showed enhanced sperm hyperactive motility, but no changes in progesterone-induced acrosome reaction Altogether, these results provide new genetic evidence for the role of the ATP1A4 isoform in sperm motility, under both noncapacitating and capacitating conditions