title: The Draft Genome and Transcriptome of the Atlantic Horseshoe Crab,Limulus polyphemus.
abstract: The horseshoe crab,Limulus polyphemus, exhibits robust circadian and circatidal rhythms, but little is known about the molecular mechanisms underlying those rhythms. In this study, horseshoe crabs were collected during the day and night as well as high and low tides, and their muscle and central nervous system tissues were processed for genome and transcriptome sequencing, respectively. The genome assembly resulted in 7.4 × 105contigs with N50 of 4,736, while the transcriptome assembly resulted in 9.3 × 104contigs and N50 of 3,497. Analysis of functional completeness by the identification of putative universal orthologs suggests that the transcriptome has three times more total expected orthologs than the genome. Interestingly, RNA-Seq analysis indicated no statistically significant changes in expression level for any circadian core or accessory gene, but there was significant cycling of several noncircadian transcripts. Overall, these assemblies provide a resource to investigate theLimulusclock systems and provide a large dataset for further exploration into the taxonomy and biology of the Atlantic horseshoe crab.
authors.affiliation: Hubbard Center for Genome Studies, University of New Hampshire, Durham, NH 03824, USA.
authors.forename: Stephen D
authors.identifier: 0000-0002-4383-3972
authors.initials: SD
authors.lastname: Simpson
authors.affiliation: Hubbard Center for Genome Studies, University of New Hampshire, Durham, NH 03824, USA.
authors.forename: Jordan S
authors.initials: JS
authors.lastname: Ramsdell
authors.affiliation: Department of Biological Sciences, University of New Hampshire, Durham, NH 03824, USA.
authors.forename: Winsor H
authors.initials: WH
authors.lastname: Watson Iii
authors.affiliation: Department of Biological Sciences, MSC#64, Plymouth State University, Plymouth, NH 03264, USA.
authors.forename: Christopher C
authors.initials: CC
authors.lastname: Chabot