DOI: 10.5061/dryad.v3s00
title: Data from: The evolution of complexity in the visual systems of stomatopods: insights from transcriptomics

description: Stomatopod crustaceans have complex visual systems containing up to 16
 different spectral classes of photoreceptors, more than described for any
 other animal. A previous molecular study of this visual system focusing on
 the expression of opsin genes found many more transcripts than predicted
 on the basis of physiology, but was unable to fully document the expressed
 opsin genes responsible for this diversity. Furthermore, questions remain
 about how other components of phototransduction cascades are involved.
 This study continues prior investigations by examining the molecular
 function of stomatopods’ visual systems using new whole eye 454
 transcriptome datasets from two species, Hemisquilla californiensis and
 Pseudosquilla ciliata. These two species represent taxonomic diversity
 within the order Stomatopoda, as well as variations in the anatomy and
 physiology of the visual system. Using an evolutionary placement algorithm
 to annotate the transcriptome, we identified the presence of nine
 components of the stomatopods’ G-protein-coupled receptor (GPCR)
 phototransduction cascade, including two visual arrestins, subunits of the
 heterotrimeric G-protein, phospholipase C, transient receptor potential
 channels, and opsin transcripts. The set of expressed transduction genes
 suggests that stomatopods utilize a Gq-mediated GPCR-signaling cascade.
 The most notable difference in expression between the phototransduction
 cascades of the two species was the number of opsin contigs recovered,
 with 18 contigs found in retinas of H. californiensis, and 49 contigs in
 those of P. ciliata. Based on phylogenetic placement and fragment overlap,
 these contigs were estimated to represent 14 and 33 expressed transcripts,
 respectively. These data expand the known opsin diversity in stomatopods
 to clades of arthropod opsins that are sensitive to short wavelengths and
 ultraviolet wavelengths and confirm the results of previous studies
 recovering more opsin transcripts than spectrally distinct types of
 photoreceptors. Many of the recovered transcripts were phylogenetically
 placed in an evolutionary clade of crustacean opsin sequences that is
 rapidly expanding as the visual systems from more species are
 investigated. We discuss these results in relation to the emerging
 pattern, particularly in crustacean visual systems, of the expression of
 multiple opsin transcripts in photoreceptors of the same spectral class,
 and even in single photoreceptor cells.
description: Fasta file of
 Pseudosquilla ciliata phototransduction contigs from retinal
 transcriptomeThis data file contains
 60 contigs identified as transcripts potentially involved in
 phototransduction. The contig sequences are from 454 sequencing, assembled
 using Newbler v2.3, and identified using targeted BLAST and phylogenetic
 methods. Retinal tissue was taken from a single individual of
 Psuedosquilla ciliata, collected adjacent to the Isla Magueyes Marine
 Laboratory, Puerto Rico (17.9687, -67.0488) in a sandy patch-reef
 lagoon.Pciliata_contigs.fas.txtFasta file of Hemisquilla californiensis phototransduction contigs from retinal transcriptomeThis data file contains 22 contigs identified as transcripts potentially involved in phototransduction. The contig sequences are from 454 sequencing, assembled using Newbler v2.3, and identified using targeted BLAST and phylogenetic methods. Retinal tissue was taken from a single male individual of Hemisquilla californiensis, collected by dreading off the coast of Orange County, California, USA.Hcaliforniensis_contigs.fas.txt