ADAD2 regulates heterochromatin in meiotic and post-meiotic male germ cells via translation of MDC1 (Publication with Expression of Concern. See vol. 135, 2022) (Publication with Expression of Concern. See vol. 135, 2022)

Male germ cells establish a unique heterochromatin domain, the XY-body, early in meiosis. How this domain is maintained through the end of meiosis and into post-meiotic germ cell differentiation is poorly understood. ADAD2 is a late meiotic male germ cell-specific RNA-binding protein, loss of which leads to post-meiotic germ cell defects. Analysis of ribosome association in Adad2 mouse mutants revealed defective translation of Mdc1, a key regulator of XY-body formation, late in meiosis. As a result, Adad2 mutants show normal establishment but failed maintenance of the XY-body. Observed XY-body defects are concurrent with abnormal autosomal heterochromatin and ultimately lead to severely perturbed post-meiotic germ cell heterochromatin and cell death. These findings highlight the requirement of ADAD2 for Mdc1 translation, the role of MDC1 in maintaining meiotic male germ cell heterochromatin and the importance of late meiotic heterochromatin for normal post-meiotic germ cell differentiation.

Automated summary

This study identifies ADAD2 as a late meiotic male germ cell-specific RNA-binding protein that plays a crucial role in maintaining the XY-body formation and post-meiotic germ cell differentiation. Loss of ADAD2 leads to defective translation of Mdc1, resulting in the failure of maintaining the XY-body and ultimately causing abnormal heterochromatin and cell death in post-meiotic germ cells.