Meeting Abstract

68.1  Wednesday, Jan. 6  The Genome of the Lobate Ctenophore, Mnemiopsis leidyi RYAN, Joseph*; PANG, Kevin; HERRERA-GALEANO, Enrique; MORELAND, Travis; NGUYEN, Anh-Dao; NIH SEQUENCING CENTER, ; MULLIKIN, James; MARTINDALE, Mark; BAXEVANIS, Andreas; National Human Genome Research Institute; University of Hawaii; National Human Genome Research Institute; National Human Genome Research Institute; National Human Genome Research Institute; National Institutes of Health Sequencing Center; National Human Genome Research Institute; University of Hawaii; National Human Genome Research Institute jfryan@mail.nih.gov

Genome sequencing of species from early-branching metazoan phyla such as Porifera, Placozoa, and Cnidaria have provided important insights into the evolution of multicellular animals, the relationship between genomic complexity and morphological complexity, and the molecular basis for the evolution of novel cell types such as epithelia, neurons, muscle, and stem cells. Until now, Ctenophora was the last non-bilaterian animal phyla without a sequenced genome. New sequencing technologies have made de novo genome sequencing affordable, but technological challenges still remain. Here we report the results of the sequencing, annotation, and initial analysis of the 200-megabase genome of the ctenophore Mnemiopsis leidyi. We produced 8,068,590 reads from seven rounds of 454 sequencing, along with 26,864,036 reads from one lane of Illumina transcriptome sequencing, yielding 50x sequencing coverage of the genome. Using the Phusion assembler, 161 megabases of genomic sequence was assembled into 10,106 scaffolds with an N50 scaffold length of 123 KB, the longest scaffold being 597 KB in length. We have compared important developmental and human disease-related gene families from Mnemiopsis with those found in other animal genomes. Our early findings suggest that Mnemiopsis possesses an impressive repertoire of genes involved in patterning, signaling, the immune system, neural development, and other key developmental pathways. Further analysis of the Mnemiopsis genome will continue to shed light on the mechanisms driving metazoan diversity and complexity.