@article{add0a89b51254d7fb3b55e103b26cebd,
title = "Opsin repertoire and expression patterns in horseshoe crabs: Evidence from the genome of limulus polyphemus (arthropoda: Chelicerata)",
abstract = "Horseshoe crabs are xiphosuran chelicerates, the sister group to arachnids. As such, they are important for understanding the most recent common ancestor of Euchelicerata and the evolution and diversification of Arthropoda. Limulus polyphemus is the most investigated of the four extant species of horseshoe crabs, and the structure and function of its visual system have long been a major focus of studies critical for understanding the evolution of visual systems in arthropods. Likewise, studies of genes encoding Limulus opsins, the protein component of the visual pigments, are critical for understanding opsin evolution and diversification among chelicerates, where knowledge of opsins is limited, and more broadly among arthropods. In the present study, we sequenced and assembled a high quality nuclear genomic sequence of L. polyphemus and used these data to annotate the full repertoire of Limulus opsins. We conducted a detailed phylogenetic analysis of Limulus opsins, including using gene structure and synteny information to identify relationships among different opsin classes. We used our phylogeny to identify significant genomic events that shaped opsin evolution and therefore the visual system of Limulus. We also describe the tissue expression patterns of the 18 opsins identified and show that transcripts encoding a number, including a peropsin, are present throughout the central nervous system. In addition to significantly extending our understanding of photosensitivity in Limulus and providing critical insight into the genomic evolution of horseshoe crab opsins, this work provides a valuable genomic resource for addressing myriad questions related to xiphosuran physiology and arthropod evolution.",
keywords = "Evolution, Limulus polyphemus, Opsin, Photoreceptors, Xiphosuran",
author = "Battelle, {Barbara Anne} and Ryan, {Joseph F.} and Kempler, {Karen E.} and Saraf, {Spencer R.} and Marten, {Catherine E.} and Warren, {Wesley C.} and Minx, {Patrick J.} and Montague, {Michael J.} and Green, {Pamela J.} and Schmidt, {Skye A.} and Lucinda Fulton and Patel, {Nipam H.} and Protas, {Meredith E.} and Wilson, {Richard K.} and Porter, {Megan L.}",
note = "Funding Information: The Limulus genome project was conceived by N.P. and R.K.W. and completed at the McDonnell Genome Institute at Washington University School of Medicine by W.C.W., P.M., M.J.M. and L.F. with critical input from P.J.G., S.A.S., M.E.P. and B.-A.B. The project was supported by the National Human Genome Research Institute [2U54HG00307909 to R.K.W.], and the National Science Foundation [MCB1021636 to P.J.G.]. Analyses of Limulus opsins and their expression was conceived by B.-A.B., J.F.R. and M.L.P. and executed at the University of Florida{\textquoteright}s Whitney Laboratory for Marine Bioscience and the University of Hawaii, Manoa by B.-A.B., J.F.R., M.L.R., K.E.K., S.R.S., and C.E.M. The study was supported by the National Science Foundation [IOS 1146175 and DBI 0648969 to B.-A.B.], startup funds from the University of Florida DSP Research Strategic Initiatives #00114464 and University of Florida Office of the Provost Programs to J.F.R., and startup funds from the University of Hawaii, Manoa to M.L.P. S.R.S was a National Science Foundation Research Experience for Undergraduates trainee at the Whitney Laboratory [DBI 0648969]. The article was prepared by B.-A.B., J.F.R., M.L.P. and M.J.M. with critical input from each of the authors. The authors thank Terence Murphey at NCBI for genome annotation. Publisher Copyright: The Author 2016.",
year = "2016",
month = may,
doi = "10.1093/gbe/evw100",
language = "English",
volume = "8",
pages = "1571--1589",
journal = "Genome Biology and Evolution",
issn = "1759-6653",
number = "5",
}