Meeting Abstract

S9-1.6  Saturday, Jan. 7  Tail loss: investigating the Molgula BROWN, C.T.*; LOWE, E; PAVANGADKAR, K; MALISKA, M.E.; SWALLA, B.J.; Michigan State University; Michigan State University; Michigan State University; University of Washington, Seattle; University of Washington, Seattle ctb@msu.edu

The Molgulid clade of ascidians contains multiple species that have at least three times independently lost tails during their larval stage. While the vast majority of the 3,000+ described species of ascidians develop swimming tails, replete with muscles and notochord, fifteen of the one hundred and fifty Molgulid species have lost a larval tail, suggesting that there is some genomic preadaptation for tail loss. Extensive prior investigation of two Molgula, M. occulta (tailless) and M. oculata (tailed), and their hybrids, has demonstrated that the loss of the tail in M. occulta is most likely due to loss of function mutations. We have used deep sequencing (Illumina mRNAseq) to quantitatively investigate the transcriptomes of embryo-stage M. occulta and M. oculata. Quantitative sequencing of hybrids and subsequent allelotyping analysis has also enabled us to begin inferring potential cis-mutations responsible for the loss of the tail developmental program.