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The evolution of complexity in the visual systems of stomatopods: insights from transcriptomics.
Integr Comp Biol. 2013 Jul; 53(1):39-49.IC

Abstract

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.

Authors+Show Affiliations

Department of Biology, University of South Dakota, Vermillion, SD 57069, USA. Megan.Porter@usd.eduNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info available

Pub Type(s)

Journal Article
Research Support, U.S. Gov't, Non-P.H.S.

Language

eng

PubMed ID

23727979

Citation

Porter, Megan L., et al. "The Evolution of Complexity in the Visual Systems of Stomatopods: Insights From Transcriptomics." Integrative and Comparative Biology, vol. 53, no. 1, 2013, pp. 39-49.
Porter ML, Speiser DI, Zaharoff AK, et al. The evolution of complexity in the visual systems of stomatopods: insights from transcriptomics. Integr Comp Biol. 2013;53(1):39-49.
Porter, M. L., Speiser, D. I., Zaharoff, A. K., Caldwell, R. L., Cronin, T. W., & Oakley, T. H. (2013). The evolution of complexity in the visual systems of stomatopods: insights from transcriptomics. Integrative and Comparative Biology, 53(1), 39-49. https://doi.org/10.1093/icb/ict060
Porter ML, et al. The Evolution of Complexity in the Visual Systems of Stomatopods: Insights From Transcriptomics. Integr Comp Biol. 2013;53(1):39-49. PubMed PMID: 23727979.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - The evolution of complexity in the visual systems of stomatopods: insights from transcriptomics. AU - Porter,Megan L, AU - Speiser,Daniel I, AU - Zaharoff,Alexander K, AU - Caldwell,Roy L, AU - Cronin,Thomas W, AU - Oakley,Todd H, Y1 - 2013/05/31/ PY - 2013/6/4/entrez PY - 2013/6/4/pubmed PY - 2013/12/20/medline SP - 39 EP - 49 JF - Integrative and comparative biology JO - Integr Comp Biol VL - 53 IS - 1 N2 - 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. SN - 1557-7023 UR - https://www.unboundmedicine.com/medline/citation/23727979/The_evolution_of_complexity_in_the_visual_systems_of_stomatopods:_insights_from_transcriptomics_ L2 - https://academic.oup.com/icb/article-lookup/doi/10.1093/icb/ict060 DB - PRIME DP - Unbound Medicine ER -