Abstract
Ascidians have the most simple chordate body plan. Ascidians share one curious characteristic in that they produce cellulose. Cellulose is a major component of tunic that surrounds the whole body of ascidians. Recent genome project and phylogenetic analyses of the ascidian, Ciona intestinalis, suggest that (1) ascidians have a gene encoding cellulose synthase, and (2) ascidian may have acquired cellulose synthase through lateral transfer from bacteria. Developmental genetics of Ciona intestinalis with the transposon Minos has generated one mutant for cellulose synthase. This mutant shows abnormal metamorphosis and settlement, suggesting that cellulose is required in the sessile life of this ascidian.
