Spem2, short for SPEM family member 2, is a novel testis-enriched gene. It is essential for spermiogenesis, the process crucial for producing haploid spermatozoa with normal morphology, structure, and function, and male fertility. Its role likely involves pathways related to sperm individualization, cytoplasm shedding, and acrosome formation [1].

Mice with Spem2 deficiency (Spem2-null) developed male infertility due to spermiogenesis impairment. There were insufficient sperm individualization, failure of excess cytoplasm shedding, and acrosome formation defects in Spem2-null sperm. Sperm counts and motility were significantly reduced. In vivo, these sperm could not fertilize oocytes, possibly because of impaired migration from the uterus to the oviduct, and in vitro fertilization could not rescue male infertility, suggesting defective sperm-egg interaction. Also, SPEM2 interacted with ZPBP, PRSS21, PRSS54, PRSS55, ADAM2, and ADAM3 and was required for their processing and maturation in epididymal sperm [1].

In conclusion, Spem2 is an essential regulator of spermiogenesis and fertilization in mice, potentially in mammals including humans. The study of Spem2-null (KO) mouse models has revealed its critical role in male fertility-related processes, providing insights that could be valuable for future treatment of human male infertility and development of non-hormonal male contraceptives [1].

References:

1. Li, Chaojie, Shen, Chunling, Xiong, Wenfeng, Fei, Jian, Wang, Zhugang. 2024. Spem2, a novel testis-enriched gene, is required for spermiogenesis and fertilization in mice. In Cellular and molecular life sciences : CMLS, 81, 108. doi:10.1007/s00018-024-05147-w. https://pubmed.ncbi.nlm.nih.gov/38421455/