Abstract
The evolution of developmental rates may drive morphological change. Caenorhabditis inopinata develops nearly twice as slowly as Caenorhabditis elegans . clk-1 encodes a hydroxylase required for synthesizing ubiquinone, and mutant clk-1 slow growth phenotypes can be rescued by supplying animals with a ubiquinone precursor analogue, 2,4-dihydroxybenzoate. RNA-seq data showing low clk-1 expression raised the possibility that C. inopinata grows slowly because of reduced ubiquinone biosynthesis. C. inopinata did not reveal a clear reduction in the age of maturation when reared on 2,4-dihydroxybenzoate. Further scrutiny of RNA-seq results revealed multiple ubiquinone metabolism genes have low expression in C. inopinata . Divergent clk-1 expression alone may not be a major driver of the evolution of slow development in this species.