Degenerate tetraploidy was established before bdelloid rotifer families diverged

Mol Biol Evol. 2009 Feb;26(2):375-83. doi: 10.1093/molbev/msn260. Epub 2008 Nov 7.


Rotifers of Class Bdelloidea are abundant freshwater invertebrates known for their remarkable ability to survive desiccation and their lack of males and meiosis. Sequencing and annotation of approximately 50-kb regions containing the four hsp82 heat shock genes of the bdelloid Philodina roseola, each located on a separate chromosome, have suggested that its genome is that of a degenerate tetraploid. In order to determine whether a similar structure exists in a bdelloid distantly related to P. roseola and if degenerate tetraploidy was established before the two species separated, we sequenced regions containing the hsp82 genes of a bdelloid belonging to a different family, Adineta vaga, and the histone gene clusters of P. roseola and A. vaga. Our findings are entirely consistent with degenerate tetraploidy and show that it was established before the two bdelloid families diverged and therefore probably before the bdelloid radiation.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Animals
  • Biological Evolution*
  • Heat-Shock Proteins / genetics
  • Helminth Proteins / genetics
  • Histones / genetics
  • Multigene Family
  • Polyploidy*
  • Rotifera / genetics*


  • Heat-Shock Proteins
  • Helminth Proteins
  • Histones