Related Experiment Video
Updated: Jul 16, 2026

Genetic Screen for Identification of Multicopy Suppressors in Schizosaccharomyces pombe
Published on: September 13, 2022
Neurospora spore killers Sk-2 and Sk-3 suppress meiotic silencing by unpaired DNA
Namboori B Raju1, Robert L Metzenberg, Patrick K T Shiu
1Division of Biological Sciences, Stanford University, Stanford, CA 94305, USA. nbraju@stanford.edu
Abstract:
In Neurospora crassa, pairing of homologous DNA segments is monitored during meiotic prophase I. Any genes not paired with a homolog, as well as any paired homologs of that gene, are silenced during the sexual phase by a mechanism known as meiotic silencing by unpaired DNA (MSUD). Two genes required for MSUD have been described previously: sad-1 (suppressor of ascus dominance), encoding an RNA-directed RNA polymerase, and sad-2, encoding a protein that controls the perinuclear localization of SAD-1. Inactivation of either sad-1 or sad-2 suppresses MSUD. We have now shown that MSUD is also suppressed by either of two Spore killer strains, Sk-2 and Sk-3. These were both known to contain a haplotype segment that behaves as a meiotic drive element in heterozygous crosses of killer x sensitive. Progeny ascospores not carrying the killer element fail to mature and are inviable. Crosses homozygous for either of the killer haplotypes suppress MSUD even though ascospores are not killed. The killer activity maps to the same 30-unit-long region within which recombination is suppressed in killer x sensitive crosses. We suggest that the region contains a suppressor of MSUD.
More Related Videos
Related Concept Videos
Gene Regulation During Sporulation
Meiosis II
In-vitro Mutagenesis
Endospores and Sporulation
Eukaryotic Transcription Inhibitors
Eukaryotic transcription inhibitors usually contain two distinct domains, a DNA...
Inhibitors of Bacterial DNA Synthesis

