Mnemiopsis leidyi (Warty comb jelly) Assembly and Gene Annotation

About Mnemiopsis leidyi

Mnemiopsis leidyi, the warty comb jelly or sea walnut, is a ctenophore, originally native to western Atlantic coasts but now found throughout Europe and Asia, in waters of varying salinity and temperature. M. leidyi has a lobed body and four rows of cilia by which it moves. It can grow up to 12 cm long and 2.5 cm wide, making them the largest animals that move by means of cilia. In the absence of predators (e.g. Beroe ovata, another ctenophore) this comb jelly can drastically deplete fish populations, because it feeds on fish eggs, larvae and plankton.

The phylogenetic position of M. leidyi has been long debated, with recent studies positioning ctenophores as the sister group to porifera, placozoa, cnidaria and bilateria. The study of key biological processes, like regeneration and axial patterning, and its phylogenetic importance make the comb jelly an important model for evolutionary and developmental studies.

Picture credit (Creative Commons BY-SA 3.0): Steven G. Johnson 2008

Assembly

Mnemiopsis leidyi was the first published ctenophore genome, and was sequenced and assembled by the National Human Genome Research Institute (NHGRI) [1]. The assembly was sequenced to 12x coverage using Roche 454 and Illumina GA-II mate-pair sequencing technology and assembled with the Phusion assembler software.

Annotation

Gene models were predicted using ab initio and homology-based methods (FGENESH, AUGUSTUS HMMgene, GenomeScan, PASA, BLASTP results) which were combined using EVidenceModeler (EVM) into a consensus gene set. Non-coding RNA genes were added using the Ensembl Genomes pipeline, and BLAST hits and protein features have been computed. Additional data is available at the NHGRI Mnemiopsis Genome Project Portal.

References

1. The genome of the ctenophore Mnemiopsis leidyi and its implications for cell type evolution.
   Ryan JF, Pang K, Schnitzler CE, Nguyen AD, Moreland RT, Simmons DK, Koch BJ, Francis WR, Havlak P, et al. 2013. Science. 342:1242592.

More information

General information about this species can be found in Wikipedia.