Integrative Proteomic and Transcriptomic Analyses Reveal Multiple Post-transcriptional Regulatory Mechanisms of Mouse Spermatogenesis

• DOI: 10.1074/mcp.m112.020123
• Publication Date: 2013-01-17T01:22:43Z
• Authors: Haiyun Gan; Tanxi Cai; Xiwen Lin; Yujian Wu; Xiuxia Wang; Fuquan Yang; Chunsheng Han
• Keywords: Male; Proteomics; 0301 basic medicine; Proteome; Gene Expression Profiling; Molecular Sequence Annotation; Spermatids; Mice; MicroRNAs; 03 medical and health sciences; Testis; Animals; RNA Interference; RNA, Messenger; RNA, Small Interfering; Spermatogenesis; Transcriptome; Oligonucleotide Array Sequence Analysis

Mammalian spermatogenesis consists of many cell types and biological processes and serves as an excellent model for studying gene regulation at transcriptional and post-transcriptional levels. Many key proteins, miRNAs, and perhaps piRNAs have been shown to be involved in post-transcriptional regulation of spermatogenesis. However, a systematic method for assessing the relationship between protein and mRNA expression has not been available for studying mechanisms of post-transcriptional regulation. In the present study, we used the iTRAQ-based quantitative proteomic approach to identify 2008 proteins in mouse type A spermatogonia, pachytene spermatocytes, round spermatids, and elongative spermatids with high confidence. Of these proteins, 1194 made up four dynamically changing clusters, which reflect the mitotic amplification, meiosis, and post-meiotic development of germ cells. We identified five major regulatory mechanisms termed "transcript only," "transcript degradation," "translation repression," "translation de-repression," and "protein degradation" based on changes in protein level relative to changes in mRNA level at the mitosis/meiosis transition and the meiosis/post-meiotic development transition. We found that post-transcriptional regulatory mechanisms are related to the generation of piRNAs and antisense transcripts. Our results provide a valuable inventory of proteins produced during mouse spermatogenesis and contribute to elucidating the mechanisms of the post-transcriptional regulation of gene expression in mammalian spermatogenesis.