PDF(Pubmed)
Abstract：
A low-calcium microenvironment is imperative for spermatozoa maturation within the epididymis. Our previous work has shown that γ-glutamyl carboxylase (GGCX), the carboxylation enzyme of the matrix Gla protein (MGP), plays an essential role in epididymal calcium homeostasis and sperm maturation in rats and that the GGCX SNP mutation rs699664 was associated with asthenozoospermia (AZS) in humans. Here, we investigated the expression patterns of GGCX and MGP in the mouse epididymis and generated GgcxK325Q knock-in (KI) mice. We also tested the effects of this mutation on epididymal calcium homeostasis, sperm function, and male fertility in GgcxK325Q-/- mice. The results showed that both GGCX and MGP were enriched in all regions of the mouse epididymis, especially in the initial segment of the epididymis. Double immunofluorescence staining revealed that GGCX colocalized with MGP in the epithelial cells of the initial segment and caput regions as well as in the lumen of the corpus and cauda regions of the mouse epididymis. However, the GgcxK325Q-/- mice were fertile with normal epididymal morphology, sperm functions, and epididymal calcium concentration. Overall, our findings revealed that the GgcxK325Q mutation does not exert any discernible effect on male fertility in mice.
摘要：
低钙微环境对于附睾内的精子成熟至关重要。我们以前的工作表明，γ-谷氨酰羧化酶(GGCX)，基质Gla蛋白（MGP）的羧化酶，在大鼠附睾钙稳态和精子成熟中起重要作用，GGCXSNP突变rs699664与人类弱精子症（AZS）有关。这里,我们研究了GGCX和MGP在小鼠附睾中的表达模式，并产生了GgcxK325Q敲入（KI）小鼠。我们还测试了这种突变对附睾钙稳态的影响，精子功能，GgcxK325Q-/-小鼠的雄性生育力。结果表明，GGCX和MGP在小鼠附睾的所有区域均富集，尤其是在附睾的初始部分。双重免疫荧光染色显示，GGCX与MGP共定位在小鼠附睾的初始节段和帽区域的上皮细胞以及体和尾区域的内腔中。然而,GgcxK325Q-/-小鼠可育，附睾形态正常，精子功能，和附睾钙浓度。总的来说,我们的研究结果表明,GgcxK325Q突变对小鼠雄性生育力没有明显影响.
