Establishment and Analysis of Actin-like 7b deficient mice – a tool to study male factor infertility.

配子形成过程中的缺陷可能会阻碍成功受精，导致不育。不孕症在临床上被定义为“一种生殖系统疾病，其定义是在无保护措施的常规性交12个月或更长时间后，未能实现临床怀孕。已有多种因素被描述为导致男性不育，包括遗传异常和环境影响。然而，在37-58%的病例中，男性不育的确切原因仍不清楚。为了开发潜在的男性不育治疗策略或预测应用人工生殖技术(ART)的成功与否，有必要对参与雄配子形成的基因和途径进行详细的了解。其中，肌动蛋白样蛋白7b(ACTL7b)被描述为仅在圆形和细长的精子细胞中特异地在睾丸中表达。有趣的是，在一组日本男性不育患者中，发现了ACTL7b的4个多态，提示ACTL7b可能在生育中起作用。此外，在沼泽水牛精子发生重要基因的筛查中发现了ACTL7b，似乎与控制羊肉产仔数有关。利用CRISPR-Cas9介导的受精卵基因编辑，我们已经删除了Actl7b基因。初步结果支持ACTL7b是精子发生所必需的假说。缺乏Actl7b的雄性动物是不育的，在精子发生过程中表现出发育停滞。为了充分了解所观察到的表型，我们现在建议用经典的组织学、免疫组织化学、马萨诸塞州的方法对ACTL7b缺陷小鼠进行详细的分析。SPEC和CoIP分析。有了这一点，我们能够准确地描述ACTL7b在精子发生和一般男性因素不育的背景下的功能和作用。

Defects during gamete formation may impede successful fertilization, resulting in infertility. Infertility is clinically defined as “a disease of the reproductive system defined by the failure to achieve a clinical pregnancy after 12 months or more of regular unprotected sexual intercourse. Multiple factors have been described to cause male infertility including genetic aberrations as well as environmental influences. Still, in 37-58% of cases the exact cause for male infertility remains unknown. To develop potential treatment strategies for male infertility or predict the success when applying Artificial Reproduction Technologies (ART), it is necessary to get a detailed understanding of the genes and pathways involved in male gamete formation. Among others, the actin-like protein 7b (ACTL7b) is described to be specifically expressed in testes in round and elongated spermatids only. Interestingly in a cohort of Japanese infertile male patients, 4 polymorphisms in ACTL7b were detected, suggesting a potential role of ACTL7b in fertility. Further, ACTL7b was detected in a screen for genes important for spermatogenesis in swamp buffalo and seems to be involved in controlling litter size in mutton. We have deleted the Actl7b gene using CRISPR-Cas9 mediated gene editing in zygotes. Preliminary results support the hypothesis of ACTL7b being required for spermatogenesis. Male animals deficient for Actl7b are infertile and show a developmental arrest during spermiogenesis. In order to fully understand the phenotype observed, we propose now a detailed analysis of the ACTL7b deficient mice using classical histology, immunohistochemistry, Mass. Spec and CoIP analyses. With this we are able to precisely describe the function and role of ACTL7b in the context of spermiogenesis in particular and male factor infertility in general.