The chromatoid body of male germ cells: Similarity with processing bodies and presence of Dicer and microRNA pathway components

TLDR

The chromatoid body is a perinuclear, cytoplasmic structure in male germ cells whose function has remained unclear. We demonstrate that chromatoid bodies are RNA‑processing bodies enriched in Dicer, Ago proteins, and microRNAs, interact with the germ cell–specific helicase MVH, and function as intracellular hubs of the microRNA pathway, underscoring their role in postmeiotic male germ cell differentiation.

Abstract

The chromatoid body is a perinuclear, cytoplasmic cloud-like structure in male germ cells whose function has remained elusive. Here we show that the chromatoid body is related to the RNA-processing body of somatic cells. Dicer and components of microRNP complexes (including Ago proteins and microRNAs) are highly concentrated in chromatoid bodies. Furthermore, we show that Dicer interacts with a germ cell-specific chromatoid body component, the RNA helicase MVH (mouse VASA homolog). Thus, chromatoid bodies seem to operate as intracellular nerve centers of the microRNA pathway. Our findings underscore the importance of posttranscriptional gene regulation and of the microRNA pathway in the control of postmeiotic male germ cell differentiation.