Genetic Adaptation of C. elegans to Environment Changes I: Multigenerational Analysis of the Transcriptome

Abstract

Abrupt environment changes can elicit an array of genetic effects. However, many of these effects can be overlooked by functional genomic studies conducted in static laboratory conditions. We studied the transcriptomic responses of Caenorhabditis elegans under single generation exposures to drastically different culturing conditions. In our experimental scheme, P0 worms were maintained on terrestrial environments (agar plates), F1 in aquatic cultures, and F2 back to terrestrial environments. The laboratory N2 strain and the wild isolate AB1 strain were utilized to examine how the genotype contributes to the transcriptome dynamics. Significant variations were found in the gene expressions between the \"domesticated\" laboratory strain and the wild isolate in the different environments. The results showed that 20% - 27% of the transcriptional responses to the environment changes were transmitted to the subsequent generation. In aquatic conditions, the domesticated strain showed differential gene expression particularly for the genes functioning in the reproductive system and the cuticle development. In accordance with the transcriptomic responses, phenotypic abnormalities were detected in the germline and cuticle of the domesticated strain. Further studies showed that distinct groups of genes are exclusively expressed under specific environmental conditions, and many of these genes previously lacked supporting biochemical evidence.