Understanding the molecular basis for sperm function: the sperm connecting piece and sperm motility

精子是将父亲的遗传信息传递给卵母细胞的活动细胞。要发挥作用，精子的形态必须是正常的，精子必须获得运动能力。通常，动物(和人类)男性不育与精子形态和功能异常有关。一种表型，通常观察到的非功能性精子，是由“脆弱的”精子连接件引起的精子头分离。对于养牛业来说，高公牛繁殖力是重要的，也是具有经济后果的。 我们发现并鉴定了一种在动物中保守的精子蛋白p12，它由鸟氨酸脱羧酶抗酶3，Oaz3基因编码。P12调节蛋白磷酸酶的活性，蛋白磷酸酶是精子运动的重要调节因子。在精子尾巴中，p12可能调节精子尾巴的运动，但它也存在于连接件中。小鼠模型显示，缺乏p12会导致脆弱的连接片段表型和异常的尾巴运动。这种表型与在养牛业中所观察到的非常相似。 我们建议研究p12如何参与精子尾部运动的调节和连接部分。 我们将a)分析p12与连接件中的哪些蛋白结合，b)分析p12是否调节连接件蛋白的磷酸化，c)p12与Mypt3的关联对精子尾部的磷酸酶活性和运动调节的重要性，以及d)使用新的p12转基因小鼠模型使用特定的p12突变蛋白来分析p12在精子尾部运动中的作用。 我们的实验将解决养牛业中的一个常见问题，并将提供工具，以装备使用生殖技术诊断精子和优化程序的行业。

Spermatozoa are motile cells that transfer the father's genetic information to the oocyte. To function, sperm morphology must be normal, and sperm must acquire motility. Often, animal (and human) male infertility is related to abnormal sperm morphology and function. One phenotype, commonly observed for non-functional sperm, is sperm head detachment caused by a "fragile" sperm connecting piece. For cattle industry, high bull fertility is important and of economic consequence. We have discovered and characterized a sperm protein, p12 conserved among animal species, encoded by ornithine decarboxylase antizyme 3, Oaz3 gene. p12 modulates protein phosphatase activity, an important regulator of sperm motility. In sperm tails p12 likely regulates sperm tail motility but it is also present in the connecting piece. A mouse model shows that lack of p12 causes a fragile connecting piece phenotype and abnormal tail motility. This phenotype closely resembles observations made in the bovine industry. We propose to investigate how p12 is involved in regulation of sperm tail motility and in the connecting piece. We will a) analyze to which proteins p12 binds in the connecting piece, b) analyze if p12 regulates phosphorylation of connecting piece proteins, c) the importance of the association of p12 with Mypt3 on phosphatase activity in the sperm tail and regulation of motility, and d) analyze p12 function in sperm tail motility using novel transgenic mouse models for p12 using specific p12 mutant proteins. Our experiments will address a common problem in the cattle industry, and will provide tools to equip industry using reproductive technologies to diagnose sperm and optimize procedures.