The Spin1 interactor, Spindoc, is dispensable for meiotic division, but essential for haploid spermatid development in mice

In mammals, germline development undergoes dramatic morphological and molecular changes and is epigenetically subject to intricate yet exquisite regulation. Which epigenetic players and how they participate in the germline developmental process are not fully characterized. Spin1 is a multifunctional epigenetic protein reader that has been shown to recognize H3 K4me3-R8me2a histone marks, and more recently the non-canonical bivalent H3 K4me3-K9me3/2 marks as well. As a robust Spin1-interacting cofactor, Spindoc has been identified to enhance the binding of Spin1 to its substrate histone marks, thereby modulating the downstream signaling; However, the physiological role of Spindoc in germline development is unknown. We generated two Spindoc knockout mouse models through CRISPR/Cas9 strategy, which revealed that Spindoc is specifically required for haploid spermatid development, but not essential for meiotic divisions in spermatocytes. This study unveiled a new epigenetic player that participates in haploid germline development.

Automated summary

This study identified a new epigenetic player named Spindoc that is essential for haploid spermatid development, but not necessary for meiotic divisions in spermatocytes. This discovery sheds light on the role of Spindoc in germline development and its interaction with Spin1 in modulating downstream signaling.