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Updated: Sep 25, 2025

Manipulation of Ploidy in Caenorhabditis elegans
Published on: March 15, 2018
The X chromosome in C. elegans sex determination and dosage compensation
1Department of Molecular and Cell Biology, Howard Hughes Medical Institute, University of California, 16 Barker Hall, Berkeley, CA 94720-3204, USA.
Abstract:
Abnormalities in chromosome dose can reduce organismal fitness and viability by disrupting the balance of gene expression. Unlike imbalances in chromosome dose that cause pathologies, differences in X-chromosome dose that determine sex are well tolerated. Dosage compensation mechanisms have evolved in diverse species to balance X-chromosome gene expression between sexes. Mechanisms underlying nematode X-chromosome counting to determine sex revealed how small quantitative differences in molecular signals are translated into dramatically different developmental fates. Mechanisms underlying X-chromosome dosage compensation revealed the interplay between chromatin modification and three-dimensional chromosome structure imposed by an X-specific condensin complex to regulate gene expression over vast chromosomal territories. In a surprising twist of evolution, this dosage-compensation condensin complex also regulates lifespan and tolerance to proteotoxic stress.
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