Tex38, testis expressed 38, is a gene that plays a crucial role in sperm morphogenesis, a tightly-regulated differentiation process. It is involved in pathways related to protein S-palmitoylation by interacting with ZDHHC19, a testis-enriched acyltransferase. This interaction is essential for the morphological transformation of spermatids, highlighting its importance in male reproductive biology [1].

In Tex38 knockout (KO) male mice, infertility occurs. Tex38 KO spermatids show excess retention of residual cytoplasm around the head, leading to abnormal sperm morphology with backward head bending. TEX38 interacts and colocalizes with ZDHHC19 at the plasma membrane of spermatids, and they mutually downregulate each other's expression when one is absent. Moreover, mice deficient in ZDHHC19 or with a mutation disabling its palmitoyltransferase activity display similar phenotypes to Tex38 KO mice. This indicates that TEX38-ZDHHC19 complex at the plasma membrane of spermatids is key for spermatid morphological transformation [1].

In conclusion, Tex38 is essential for sperm head morphogenesis through its interaction with ZDHHC19 in the context of protein S-palmitoylation. The Tex38 KO mouse model has been instrumental in revealing its role in male infertility, providing insights into the molecular mechanisms underlying sperm malfunction and potentially guiding future research and treatment strategies in this area [1].

References:

1. Kaneda, Yuki, Lu, Yonggang, Sun, Jiang, Miyata, Haruhiko, Ikawa, Masahito. 2025. TEX38 localizes ZDHHC19 to the plasma membrane and regulates sperm head morphogenesis in mice. In Proceedings of the National Academy of Sciences of the United States of America, 122, e2417943122. doi:10.1073/pnas.2417943122. https://pubmed.ncbi.nlm.nih.gov/40030029/