Caenorhabditis phylogeny predicts convergence of hermaphroditism and extensive intron loss

doi:10.1073/pnas.0403094101

Caenorhabditis phylogeny predicts convergence of hermaphroditism and extensive intron loss

Department of Biology, New York University, 100 Washington Square East, New York, NY 10003

Communicated by Morris Goodman, Wayne State University School of Medicine, Detroit, MI, May 3, 2004 (received for review March 3, 2004)

Abstract

Despite the prominence of Caenorhabditis elegans as a major developmental and genetic model system, its phylogenetic relationship to its closest relatives has not been resolved. Resolution of these relationships is necessary for studying the steps that underlie life history, genomic, and morphological evolution of this important system. By using data from five different nuclear genes from 10 Caenorhabditis species currently in culture, we find a well resolved phylogeny that reveals three striking patterns in the evolution of this animal group: (i) Hermaphroditism has evolved independently in C. elegans and its close relative Caenorhabditis briggsae; (ii) there is a large degree of intron turnover within Caenorhabditis, and intron losses are much more frequent than intron gains; and (iii) despite the lack of marked morphological diversity, more genetic disparity is present within this one genus than has occurred within all vertebrates.

Footnotes

↵ † To whom correspondence may be addressed. E-mail: david.fitch{at}nyu.edu or fp1{at}nyu.edu.
Abbreviations: SSU, small subunit; LSU, large subunit; rDNA, rRNA-encoding DNA; RNAP2, largest subunit of the RNA polymerase II gene; Ti/Tv, transition/transversion.
Data deposition: The sequences reported in this paper have been deposited in the GenBank database (accession nos. AY601770-AY601780, AY602167-AY602189, and AY604469-AY604482).