Meeting Abstract
P3.75 Sunday, Jan. 6 Piwi genes and their expression in the ctenophore Pleurobrachia bachei: Quest for ancestral master regulators of non-coding RNAs in animals. BOSTWICK, C.J.*; WINTERS, G.C.; DABE, E.C.; BOBKOVA, Y.; CITARELLA, M.R.; KOHN, A.B.; SWALLA, B.J.; MOROZ, L.L.; University of Florida; University of Florida; University of Florida; University of Florida; University of Florida; University of Florida; University of Washington ; University of Florida bostwick@ufl.edu
In the short time since their discovery, the function and properties of non-coding RNAs (ncRNAs) have been the subject of intense research focus. These species of RNAs are not translated into protein, but serve other roles in the development and regulation of an organism’s genome. Piwi proteins are a subfamily of the Argonaute family of proteins, which bind small ncRNAs and have been implicated as being one of the chief protein components of transcriptional and post-transcriptional gene silencing. Moreover, Piwi proteins and their ncRNAs (known as piRNAs) have also been shown to play a role in the epigenetic modification of the genome. We have discovered two Piwi genes in the genome of the pelagic ctenophore, Pleurobrachia bachei. Comparative genomic analysis to a variety of metazoan Piwi sequences provided evidence that the P. bachei Piwi genes are indeed homologous to those of other metazoans. The Piwi mRNA was expressed in the tentacle bulbs, comb tips, aboral organ, and gonads of P. bachei. However, the expression of each Piwi within these body structures differed slightly. We also found both Piwi transcripts expressed in the embryonic stages of P. bachei in transcriptome sequencing projects, indicating a role for Piwi during the development and maturation of P. bachei. Further experiments utilizing RT-PCR showed both Piwi RNAs being transcribed in the majority of embryonic stages from one cell to twenty-four hour old embryos. This suggests that, in ctenophores, Piwi is expressed in both the germline and in stem cells and is likely involved in the process of cellular differentiation.
