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Gene expression analyses suggest that more than 1000–2000 genes are expressed predominantly in mouse and human testes. Although functional analyses of hundreds of these genes have been performed, there are still many testis-enriched genes whose functions remain unexplored. Analyzing gene function using knockout (KO) mice is a powerful tool to discern if the gene of interest is essential for sperm formation, function, and male fertility in vivo. In this study, we generated KO mice for 12 testis-enriched genes, 1700057G04Rik, 4921539E11Rik, 4930558C23Rik, Cby2, Ldhal6b, Rasef, Slc25a2, Slc25a41, Smim8, Smim9, Tmem210, and Tomm20l, using the clustered regularly interspaced short palindromic repeats /CRISPR-associated protein 9 (CRISPR/Cas9) system. We designed two gRNAs for each gene to excise almost all the protein-coding regions to ensure that the deletions in these genes result in a null mutation. Mating tests of KO mice reveal that these 12 genes are not essential for male fertility, at least when individually ablated, and not together with other potentially compensatory paralogous genes. Our results could prevent other laboratories from expending duplicative effort generating KO mice, for which no apparent phenotype exists. [ABSTRACT FROM AUTHOR]

HASPIN is a nuclear serine-threonine kinase originally identified in the mouse testis. Its 193 bp DNA promoter element (hereafter, 193PE) regulates bidirectional, synchronous gene expression in the germ cells of male mice. Recent studies have shown that Haspin is also expressed in trace amounts in somatic cells; HASPIN also functions in oocytes. Haspin expression is regulated by the tissue-specific methylation of Haspin genomic DNA regions, including somatic cells. This study investigated relationship between 193PE and DNA methylation by examining methylation status of transgenic mice carrying 193PE and a reporter gene. In somatic (liver) cells carrying the reporter gene, 193PE induced methylation as well as trace expression of the reporter gene. In the testis, 193PE induced hypomethylation and intense reporter gene expression. Expression of HASPIN in an egg was assessed using human chorionic gonadotrophin to induce ovulation in female transgenic mice. The results showed that 193PE induced tissue-specific methylation, which resulted in reporter gene expression in a mouse egg.

HASPIN acts in chromosome segregation via histone phosphorylation. Recently, HASPIN inhibitors have been shown to suppress growth of various cancer cells. Pancreatic cancer has no symptom in the early stages and may progress before detection. So, the 5-year survival rate is low. Here, we reported that administration of the HASPIN inhibitor, CHR-6494, to mice bearing pancreatic BxPC-3-Luc cancer cells significantly suppressed growth of BxPC-3-Luc cells. CHR-6494 might be a useful agent for treating pancreatic cancer., Competing Interests: There is no conflict of interest in this study., (Copyright© by Royan Institute. All rights reserved.)

Aim: To characterize mouse capping protein alpha3 (CPalpha3) during spermatogenesis and sperm maturation., Methods: We produced rat anti-CPalpha3 antiserum and examined the expression of CPalpha3 in various mouse tissues using Western blot analysis and the localization of CPalpha3 in testicular and epididymal sperm using immunohistochemical analyses. We also examined how the localization of CPalpha3 and beta-actin (ACTB) in sperm changed after the acrosomal reaction by performing immunohistochemical analyses using anti-CPalpha3 antiserum and anti-actin antibody., Results: Western blot analysis using specific antiserum revealed that CPalpha3 was expressed specifically in testes. Interestingly, the molecular weight of CPalpha3 changed during sperm maturation in the epididymis. Furthermore, the subcellular localization of CPalpha3 in sperm changed dynamically from the flagellum to the post-acrosomal region of the head during epididymal maturation. The distribution of ACTB was in the post-acrosomal region of the head and the flagellum. After inducing the acrosomal reaction, the CPalpha3 and ACTB localization was virtually identical to the localization before the acrosomal reaction., Conclusion: CPalpha3 might play an important role in sperm morphogenesis and/or sperm function., ((c) 2008, Asian Journal of Andrology, SIMM and SJTU. All rights reserved.)