Effect of liquid cultivations on N2 and AB1 strains of C. elegans

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. Overall design: To induce an adaptive response and observe its sustained effects on the following generation, the P0 generation C. elegans was grown on bacteria-seeded agar plates, the F1 generation in liquid, and the F2 generation back on agar. We carried out three sets of experiments with different food sources and animal strains. For the first experiment, the F1 generation N2 strain was grown in axenic CeHR Medium. To examine the effect of dietary changes in the liquid cultures, we cultured F1 generation N2 strain in bacterial S-Medium for the second experiment. Finally, the adaptive response differences were investigated by growing F1 generation AB1 strain in CeHR Medium. For each generation, RNA-seq was performed on young adult animals to determine the transcriptional responses

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Çelen İ, Doh JH, Sabanayagam CR