Gene knockout of Zmym3 in mice arrests spermatogenesis at meiotic metaphase with defects in spindle assembly checkpoint

Xiangjing Hu,Shangying Liao,Chunwei Zheng,Chunsheng Han,Xingxu Huang,Longfei Ma,Xiwen Lin,Yan Ning,Zhen Li,Jian Chen,Bin Shen,Daoqin Zhang,Yanmin Feng

doi:10.1038/cddis.2017.228

Abstract

ZMYM3, a member of the MYM-type zinc finger protein family and a component of a LSD1-containing transcription repressor complex, is predominantly expressed in the mouse brain and testis. Here, we show that ZMYM3 in the mouse testis is expressed in somatic cells and germ cells until pachytene spermatocytes. Knockout (KO) of Zmym3 in mice using the CRISPR-Cas9 system resulted in adult male infertility. Spermatogenesis of the KO mice was arrested at the metaphase of the first meiotic division (MI). ZMYM3 co-immunoprecipitated with LSD1 in spermatogonial stem cells, but its KO did not change the levels of LSD1 or H3K4me1/2 or H3K9me2. However, Zmym3 KO resulted in elevated numbers of apoptotic germ cells and of MI spermatocytes that are positive for BUB3, which is a key player in spindle assembly checkpoint. Zmym3 KO also resulted in up-regulated expression of meiotic genes in spermatogonia. These results show that ZMYM3 has an essential role in metaphase to anaphase transition during mouse spermatogenesis by regulating the expression of diverse families of genes.

Highlights

Mammalian spermatogenesis is a unique cellular developmental process that is intricately regulated by extrinsic and intrinsic factors
Based on a microarray data set reported by Oatley et al.,[5] we found that Zmym[3] mRNAs were down-regulated by glial cell-derived neurotrophic factor (GDNF), which was consistently supported by results from three different probe sets on the microarray
As GFRα1 expression is higher in actual stem cells than in potential stem cells that have undergone slight differentiation,[15] we suspected that the expression of Zmym[3] might be regulated by retinoic acid (RA)

Summary

Introduction

Mammalian spermatogenesis is a unique cellular developmental process that is intricately regulated by extrinsic and intrinsic factors. RNA sequencing analysis of cultured SSCs and isolated spermatocytes shows that many genes are expressed aberrantly.

Results

Conclusion