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Updated: Nov 9, 2025

Manipulation of Ploidy in Caenorhabditis elegans
Published on: March 15, 2018
Genome assembly, sex-biased gene expression and dosage compensation in the damselfly Ischnura elegans
Pallavi Chauhan1, Janne Swaegers2, Rosa A Sánchez-Guillén3
1Department of Biology, Lund University, Ecology Building, 223 62 Lund, Sweden.
Abstract:
The evolution of sex chromosomes, and patterns of sex-biased gene expression and dosage compensation, are poorly known among early winged insects such as odonates. We assembled and annotated the genome of Ischnura elegans (blue-tailed damselfly), which, like other odonates, has a male-hemigametic sex-determining system (X0 males, XX females). By identifying X-linked genes in I. elegans and their orthologs in other insect genomes, we found homologies between the X chromosome in odonates and chromosomes of other orders, including the X chromosome in Coleoptera. Next, we showed balanced expression of X-linked genes between sexes in adult I. elegans, i.e. evidence of dosage compensation. Finally, among the genes in the sex-determining pathway only fruitless was found to be X-linked, while only doublesex showed sex-biased expression. This study reveals partly conserved sex chromosome synteny and independent evolution of dosage compensation among insect orders separated by several hundred million years of evolutionary history.
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