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A DEAD-box RNA helicase mediates meiotic silencing by unpaired DNA

Victor T Sy1, Erin C Boone1, Hua Xiao1

  • 1Division of Biological Sciences, University of Missouri, Columbia, MO 65211, USA.

G3 (Bethesda, Md.)
|April 13, 2023
PubMed

Insights

Meiotic silencing by unpaired DNA (MSUD) in Neurospora crassa involves a new gene, sad-9. This gene, encoding a DEAD-box RNA helicase, is crucial for sexual development and MSUD regulation.

Area of Science:

  • Genetics
  • Molecular Biology
  • RNA Interference

Background:

  • Neurospora crassa undergoes sexual reproduction where unpaired genes are silenced via meiotic silencing by unpaired DNA (MSUD).
  • MSUD is an RNA interference (RNAi) pathway that targets transcripts of unpaired genes during meiosis.

Purpose of the Study:

  • To identify novel genes involved in the MSUD pathway.
  • To elucidate the function of identified genes in sexual development and gene silencing.

Main Methods:

  • Reverse genetic screen to identify MSUD-related genes.
  • Characterization of gene function through analysis of sexual development and MSUD activity.

Main Results:

  • Identified sad-9, a gene encoding a DEAD-box RNA helicase, as essential for MSUD.
  • SAD-9 is crucial for sexual development and does not affect vegetative growth.
  • SAD-9, with SAD-2, recruits SMS-2 Argonaute to the perinuclear region, the site of MSUD.

Conclusions:

  • SAD-9 is a key component of the MSUD pathway in Neurospora crassa.
  • The SAD-9/SAD-2 complex facilitates the recruitment of SMS-2 to initiate MSUD in the perinuclear region.
Keywords:
Neurospora crassaDEAD-box RNA helicaseRNA interference (RNAi)genome defensemeiotic silencing by unpaired DNA (MSUD)

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