最近，一项刊登于国际杂志《Mol Biol Cell 细胞分子生物》上的研究报告中，来自美国弗吉尼亚联邦大学的研究人员在男性不育症研究领域取得了新突破，他们阐明了一种特殊基因在精子鞭毛形成过程中扮演的重要角色，精子鞭毛是推动精子运动的附加物。
研究者揭示了鞭毛运输蛋白IFT20在雄性精子形成过程中所扮演的角色，同时还研究了对精子鞭毛形成重要的基因以及雄性生育力。研究者指出，精子如果没有鞭毛就不能运动。
研究表明，IFT20蛋白对于雄性小鼠的生育力以及精子形成非常重要，而且该蛋白的主要功能就是为精子鞭毛形成来运输蛋白货物。当然研究中研究者还揭开了男性不育的新型遗传因素。在人类中，男性不育占到了所有不育症的40%至50%，而且其影响着大约7%的男性健康，很多不同的医疗条件和其它状况都会引发生育问题，但引发男性不育最常见的问题就是影响男性睾丸发挥作用的问题，很多病因研究者并不清楚，这种问题占到了50%左右的患者，而且遗传因素或许是主要的原因所在。
目前存在两种类型的纤毛：可动纤毛和初级纤毛，可动纤毛在精子、气管上皮细胞以及大脑脑室中广泛存在，其主要的功能就是负责运动；而初级纤毛则主要存在于几乎所有的哺乳动物细胞表面，纤毛在这些细胞中的功能就是作为传感器发挥作用，而且在初级纤毛中还存在多种的信号通路。
鞭毛内运输(intraflagellartransport，IFT)对于纤毛的发育非常重要，纤毛的缺失会导致发育障碍、糖尿病和癌症的出现，目前大约有20种IFT基因，这些基因非常重要以至于如果其在小鼠中被干扰突变的话，就会导致小鼠在成年前发生死亡，如今研究者已经在初级纤毛中研究了IFT基因的功能，但关于可动纤毛却很少有研究进行；尽管在任何哺乳动物细胞中，精子都有着最长的能动纤毛，但目前由于胚胎死亡，几乎没有关于雄性精子细胞发育的相关研究在进行，因此本文中研究者或将成为世界上首个利用条件基因敲除小鼠来阐明IFT基因关键作用的研究团队。
推荐阅读原文：
Intraflagellar transport protein IFT20 is essential for male fertility and spermiogenesis in mice.
Intraflagellar transport (IFT) is a conserved mechanism thought to be essential for the assembly and maintenance of cilia and flagella. However, little is known about its role in mammalian sperm flagella formation. To fill this gap, we disrupted the Ift20 gene in male germ cells. Homozygous mutant mice were infertile with significantly reduced sperm counts and motility. In addition, abnormally shaped elongating spermatid heads and bulbous round spermatids were found in the lumen of the seminiferous tubules. Electron microscopy revealed increased cytoplasmic vesicles, fiber-like structures, abnormal accumulation of mitochondria and a decrease in mature lysosomes. The few developed sperm had disrupted axonemes and some retained cytoplasmic lobe components on the flagella. ODF2 and SPAG16L, two sperm flagella proteins failed to be incorporated into sperm tails of the mutant mice, and in the germ cells, both were assembled into complexes with lighter density in the absence of IFT20. Disrupting IFT20 did not significantly change expression levels of IFT88, a component of IFT-B complex, and IFT140, a component of IFT-A complex. Even though the expression level of an autophagy core protein that associates with IFT20, ATG16, was reduced in the testis of the Ift20 mutant mice, expression levels of other major autophagy markers, including LC3 and ubiquitin were not changed. Our studies suggest that IFT20 is essential for male fertility and spermiogenesis in mice, and its major function is to transport cargo proteins for sperm flagella formation. It also appears to be involved in removing excess cytoplasmic components.