Super-enhancer switching drives a burst in gene expression at the mitosis-to-meiosis transition

• Published in: Nature structural & molecular biology Vol. 27; no. 10; pp. 978 - 988
• Main Authors: Maezawa, So, Sakashita, Akihiko, Yukawa, Masashi, Chen, Xiaoting, Takahashi, Kazuki, Alavattam, Kris G., Nakata, Ippo, Weirauch, Matthew T., Barski, Artem, Namekawa, Satoshi H.
• Format: Journal Article
• Language: English
• Published: New York Nature Publishing Group US 01.10.2020; Nature Publishing Group
• Subjects: 13; 13/100; 14; 38; 38/39; 42; 45; 45/15; 631/136; 631/208/176; Animals; Biochemistry; Biological Microscopy; Biomedical and Life Sciences; Cell Differentiation; Cellular proteins; Enhancer Elements, Genetic; Gene expression; Gene Expression Regulation; Genetic aspects; Identification and classification; Life Sciences; Male; Meiosis; Meiosis - genetics; Membrane Biology; Mice, Inbred C57BL; Mice, Transgenic; Mitosis; Mitosis - genetics; Mutation; Observations; Polycomb-Group Proteins - genetics; Polycomb-Group Proteins - metabolism; Protein Structure; Proto-Oncogene Proteins c-myb - genetics; Proto-Oncogene Proteins c-myb - metabolism; Spermatogenesis; Spermatogenesis - genetics; Spermatogonia - cytology; Spermatogonia - physiology; Trans-Activators - genetics; Trans-Activators - metabolism; X Chromosome - genetics; United States
• ISSN: 1545-9993; 1545-9985; 1545-9985
• DOI: 10.1038/s41594-020-0488-3

Owing to bursts in the expression of thousands of germline-specific genes, the testis has the most diverse and complex transcriptome of all organs. By analyzing the male germline of mice, we demonstrate that the genome-wide reorganization of super-enhancers (SEs) drives bursts in germline gene expression after the mitosis-to-meiosis transition. SE reorganization is regulated by two molecular events: the establishment of meiosis-specific SEs via A-MYB (MYBL1), a key transcription factor for germline genes, and the resolution of SEs in mitotically proliferating cells via SCML2, a germline-specific Polycomb protein required for spermatogenesis-specific gene expression. Before entry into meiosis, meiotic SEs are preprogrammed in mitotic spermatogonia to ensure the unidirectional differentiation of spermatogenesis. We identify key regulatory factors for both mitotic and meiotic enhancers, revealing a molecular logic for the concurrent activation of mitotic enhancers and suppression of meiotic enhancers in the somatic and/or mitotic proliferation phases. The mapping of super-enhancers (SEs) in four stages of spermatogenesis reveals how meiotic enhancers remain ‘poised’ for activation as spermatogonia enter meiosis.