Molecular relationships between closely related strains and species of nematodes

Abstract

Electrophoretic comparisons have been made for 24 enzymes in theBergerac andBristol strains ofCaenorhabditis elegans and the related species,Caenorhabditis briggsae. No variation was detected between the two strains ofC. elegans. In contrast, the two species,C. elegans andC. briggsae exhibited electrophoretic differences in 22 of 24 enzymes. A consensus 5S rRNA sequence was determined forC. elegans and found to be identical to that fromC. briggsae. By analogy with other species with relatively well established fossil records it can be inferred that the time of divergence between the two nematode species is probably in the tens of millions of years. The limited anatomical evolution during a time period in which proteins undergo extensive changes supports the hypothesis that anatomical evolution is not dependent on overall protein changes.