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Updated: Jul 30, 2026

Manipulation of Ploidy in Caenorhabditis elegans
07:54

Manipulation of Ploidy in Caenorhabditis elegans

Published on: March 15, 2018

Crossing over during Caenorhabditis elegans meiosis requires a conserved MutS-based pathway that is partially

J Zalevsky1, A J MacQueen, J B Duffy

  • 1Department of Developmental Biology and Department of Genetics, Stanford University School of Medicine, Stanford, California 94305, USA.

Genetics
|November 5, 1999
PubMed

Insights

The him-14 gene is crucial for homologous chromosome crossovers during Caenorhabditis elegans meiosis. This gene, a MutS family member, plays a specialized role in promoting crossovers, unlike its function in DNA mismatch repair.

Area of Science:

  • Genetics
  • Molecular Biology
  • Cell Biology

Background:

  • Homologous chromosome crossover is essential for accurate meiotic segregation.
  • The him-14 gene in Caenorhabditis elegans is implicated in crossover formation.
  • Crossover formation ensures proper chromosome pairing and alignment during meiosis.

Purpose of the Study:

  • To investigate the role of the him-14 gene in homologous chromosome crossover during meiosis.
  • To determine the specific stage at which him-14 functions.
  • To understand the mechanism by which him-14 promotes crossover formation.

Main Methods:

  • Genetic analysis of him-14 mutants in Caenorhabditis elegans.
  • Cytological examination of meiotic chromosome pairing and synapsis.
  • Temperature-shift experiments to define the functional timing of him-14.

Main Results:

  • Loss of him-14 function severely reduces crossing over and leads to missegregation.
  • Homologs are paired and aligned in him-14 mutant pachytene nuclei, indicating him-14 is not required for synapsis.
  • him-14 functions during the pachytene stage and encodes a germline-specific MutS family protein with a specialized role in crossover promotion.

Conclusions:

  • him-14 is essential for most, if not all, crossovers in C. elegans meiosis.
  • Unlike yeast, C. elegans relies heavily on the him-14 pathway for crossover formation.
  • A model proposing HIM-14 interferes with Holliday junction branch migration is discussed.

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