Increased gene dosage and mRNA expression from chromosomal duplications in Caenorhabditis elegans

Abstract

Isolation of copy number variations and chromosomal duplications at high frequency in the laboratory suggested that Caenorhabditis elegans tolerates increased gene dosage. Here, we addressed if a general dosage compensation mechanism acts at the level of mRNA expression in C. elegans. We characterized gene dosage and mRNA expression in 3 chromosomal duplications and a fosmid integration strain using DNA-seq and mRNA-seq. Our results show that on average, increased gene dosage leads to increased mRNA expression, pointing to a lack of genome-wide dosage compensation. Different genes within the same chromosomal duplication show variable levels of mRNA increase, suggesting feedback regulation of individual genes. Somatic dosage compensation and germline repression reduce the level of mRNA increase from X chromosomal duplications. Together, our results show a lack of genome-wide dosage compensation mechanism acting at the mRNA level in C. elegans and highlight the role of epigenetic and individual gene regulation contributing to the varied consequences of increased gene dosage.

Nonlinear readout of spatial cues underlies robustness of asymmetric cell division

“…However, dosage compensation of individual autosomal genes is less well understood. Systematic transcriptional analysis suggests the degree of compensation can vary substantially at the level of individual genes, though the vast majority show no or only partial compensation (Malone et al, 2012; Ragipani et al, 2022).…”

Comparative genomics and the salivary transcriptome of the redbanded stink bug shed light on its high damage potential to soybean

“…These novel functions can be retained if they confer a fitness benefit that makes an organism better adapted to its environment (Pearce et al 2017). In addition to providing fuel for evolutionary novelties, an increase in gene dosage can lead to higher expression levels of a gene family, thus increasing the likelihood of translation of those proteins (Ragipani et al 2022). Along with this, changes in gene expression at particular loci can facilitate an organism’s adaptation to its surroundings (López-Maury et al 2008; Nourmohammad et al 2017).…”