| dc.description.abstract | One of the earliest samples of Caenorhabditis elegans was isolated in Bergerac, France. Early estimates indicated that a Bergerac strain had a high copy-number of the transposable element Tc1 and also displayed diminished fitness compared to lower Tc1 bearing counterparts. In this study, to clarify the extent of phenotypic disruption caused by high TE copy number, four fitness traits (developmental rate, longevity, survivorship, and productivity) were analyzed in three Bergerac strains (RW7000, RW6999, and CB4851) and compared to a wildtype N2 control. All three Bergerac strains were shown to have significantly reduced fitness compared to the control for all traits measured with specific traits displaying significant differences between Bergerac strains. To understand the molecular basis for these differences, whole-genome sequencing was completed on each Bergerac strain. The Tc1 copy-number for each strain was estimated using the McClintock meta-pipeline, and Tc1 copy-number was shown to be negatively correlated with fitness values. A genomic analysis of the location of Tc1 insertions and the genes disrupted by Tc1 has revealed the probable cause of low fitness in these strains, while also reinforcing the target site preferences of Tc1. This study sets the stage for a search for mutations associated with Tc1 proliferation, a comparison of the relative amount of RNA transcripts in the Bergerac strains, and long-term experimental evolution at high population sizes, which will reveal the causes and consequences of Tc1 proliferation and the genetic basis for adaptive, compensatory evolution. | |
