Spermatogenesis is normal in Tex33 knockout mice

Zhendong Zhu; Xin Zhang; Wentao Zeng; Shuqin Zhao; Jianli Zhou; Zuomin Zhou; Mingxi Liu

doi:10.7717/peerj.9629

Spermatogenesis is normal in Tex33 knockout mice

PeerJ. 2020 Jul 29:8:e9629. doi: 10.7717/peerj.9629. eCollection 2020.

Authors

Zhendong Zhu^#¹, Xin Zhang^#¹, Wentao Zeng², Shuqin Zhao², Jianli Zhou², Zuomin Zhou¹, Mingxi Liu¹

Affiliations

¹ Department of Histology and Embryology, Nanjing Medical University, Nanjing, China.
² Animal Core Facility of Nanjing Medical University, Nanjing Medical University, Nanjing, China.

^# Contributed equally.

Abstract

Testis expressed gene 33 (Tex33) is a recently reported testis-specific gene and it is evolutionarily conserved in vertebrates. The Tex33 expression is found in cytoplasm of round spermatids in Mus musculus. However, the in vivo function of Tex33 remains unknown. In this study, we made a 62bp in frame deletion on Exon2 of Tex33 gene by CRISPR/Cas9 in C57B/L6 mouse, which cause frame shift mutation of Tex33 gene. Tex33 ^-/-adult male were fertile, and there is no significant change on litter size compared with male wildtype (Tex33 ^+/+) adult. Besides, no overt differences were found in testis/body weight ratios, testicular/epididymal tissue morphology, sperm counts, sperm morphology and spermatozoa motility in adult Tex33^-/- male mice (N = 3), in comparison with Tex33 ^+/+ adult (N = 3). TUNEL assay also indicates the germ cells apoptosis ratio was not significantly changed in adult Tex33^-/- adult male mouse testis (N = 3), compared with adult Tex33^+/+ male (N = 3). Importantly, the first wave of elongating spermatids formation happens in 5w old mice. We find that the first wave of spermiogenesis is not disrupted in both 5-week-old Tex33^+/+ and Tex33 ^-/-male mouse testes and three hallmarks of spermatogenesis, PLZF,γ-H2AX and TNP1, are all detectable in seminiferous tubule. All results indicate that Tex33 is a redundant gene to spermatogenesis. This study can help other researchers avoid repetitive works on redundant genes.

Keywords: Male infertility; Mouse; NIRH and SYT domain; Spermatogenesis; Tex33.

Grants and funding

This work was supported by the National Key Research and Development Program of China 2016YFA0500902 (to Mingxi Liu), the Natural Science Foundation of China (31771651 and 31571538 to Zuomin Zhou, 31571536, 31771654, and 31530047 to Mingxi Liu), the Natural Science Fund for Colleges and Universities in Jiangsu Province 16KJA310003 (to Mingxi Liu), the Natural Science Foundation of Jiangsu Province (Grants No. BK20190081 to Mingxi Liu), and the Qing Lan Project (to Mingxi Liu). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.