Meeting Abstract

P1.151  Friday, Jan. 4  Epigenomic Signatures in Basal Metazoans: DNA Methyltransferase in Pleurobrachia bachei DABE, E.C.*; KOHN, A.B.; BOBKOVA, Y.; KOCOT, K.; CITARELLA, M.; BOSTWICK, C.J.; WINTERS, G.C.; SWALLA, B.J.; MOROZ, L.L.; University of Florida,Whitney Lab for Marine Biosciences, Marineland, FL; University of Washington, Seattle,WA edabe2@ufl.edu

DNA methylation is an epigenetic modification crucial to cell differentiation and development. In the majority of bilaterians 5-methylcytosine DNA methylation occurs at CpG sites and islands controlling gene transcription. Contrary to Drosophila and C. elegans that have lost this machinery, possibly due to their compact genome sizes and short life cycle, here we show that the phylum Ctenophora has conserved methylation machinery. Using the data from the recently sequenced genome of Pleurobrachia bachei we cloned DNA 5-cytosine methyltransferase (DNMT) and characterized its expression in major developmental stages and adult ctenophores.Distinctive mRNA expression in the digestive system, (stomach, pharynx and mouth), tentacles and unique patterns in between ciliated comb rows in adult Pleurobrachia collectively suggest that DNMT mRNA expression levels are both cell-specific and noticeable in areas of high proliferation. Next using colorimetric ELISA assay for methylated DNA we directly showed that DNA methylation does occur in the Pleurobrachia genome, although it was significantly lower than in the molluscan (Aplysia) and mammalian (Ratus) nervous tissues. Combined, our data suggest that the small genome of the ctenophore Pleurobrachia bachei has functional DNA methylation machinery, possibly involved in epigenetic control of somatic cell divisions and regulation of mRNA expression at zones of proliferation.