Journal
DEVELOPMENT
Volume 142, Issue 21, Pages 3791-3800Publisher
COMPANY BIOLOGISTS LTD
DOI: 10.1242/dev.127191
Keywords
Germ cells; Spermatogenesis; Epigenetic regulation; X inactivation; Male fertility; Meiosis
Categories
Funding
- National Institutes of Health [HD60858]
- National Science Foundation Louis Stokes Alliances for Minority Participation - Bridge to the Doctorate grant [1249284]
- National Institutes of Health /National Institute of General Medical Sciences Minority Biomedical Research Support - Research Initiative for Scientific Enhancement grant [GM6065]
- National Institute on Minority Health and Health Disparities from the National Institutes of Health [G12MD007591]
- Division Of Human Resource Development
- Direct For Education and Human Resources [1249284] Funding Source: National Science Foundation
Ask authors/readers for more resources
Past studies have indicated that transcription of all X-linked genes is repressed by meiotic sex chromosome inactivation (MSCI) during the meiotic phase of spermatogenesis in mammals. However, more recent studies have shown an increase in steady-state levels of certain X-linked miRNAs in pachytene spermatocytes, suggesting that either synthesis of these miRNAs increases or that degradation of these miRNAs decreases dramatically in these cells. To distinguish between these possibilities, we performed RNA-FISH to detect nascent transcripts from multiple miRNA genes in various spermatogenic cell types. Our results show definitively that Type I X-linked miRNA genes are subject to MSCI, as are all or most X-linked mRNA genes, whereas Type II and III X-linked miRNA genes escape MSCI by continuing ongoing, active transcription in primary spermatocytes. We corroborated these results by co-localization of RNA-FISH signals with both a corresponding DNA-FISH signal and an immunofluorescence signal for RNA polymerase II. We also found that X-linked miRNA genes that escape MSCI locate non-randomly to the periphery of the XY body, whereas genes that are subject to MSCI remain located within the XY body in pachytene spermatocytes, suggesting that the mechanism of escape of X-linked miRNA genes from MSCI involves their relocation to a position outside of the repressive chromatin domain associated with the XY body. The fact that Type II and III X-linked miRNA genes escape MSCI suggests an immediacy of function of the encoded miRNAs specifically required during the meiotic stages of spermatogenesis.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available