title: Evidence for distributed light sensing in the skin of cuttlefish, Sepia officinalis.
abstract: We report that the skin of cuttlefish, Sepia officinalis, contains opsin transcripts suggesting a possible role of distributed light sensing for dynamic camouflage and signalling. The mRNA coding for opsin from various body regions was amplified and sequenced, and gene expression was detected in fin and ventral skin samples. The amino acid sequence of the opsin polypeptide that these transcripts would produce was identical in retina and fin tissue samples, but the ventral skin opsin transcripts differed by a single amino acid. The diverse camouflage and signalling body patterns of cephalopods are visually controlled, and these findings suggest a possible additional mechanism of light sensing and subsequent skin patterning. Cuttlefish, along with a number of other cephalopod species, have been shown to be colour-blind. Since the opsin in the fin is identical to that of the retina (λmax=492 nm), and the ventral transcripts are also unlikely to be spectrally different, colour discrimination by the skin opsins is unlikely. However, spectral discrimination could be provided by involving other skin structures (chromatophores and iridophores), which produce changeable colours and patterns. This 'distributed sensing' could supplement the otherwise visually driven dynamic camouflage system by assisting with colour or brightness matching to adjacent substrates.
authors.affiliation: Marine Biological Laboratory, 7 MBL Street, Woods Hole, MA 02543, USA. lmathger@mbl.edu
authors.forename: Lydia M
authors.initials: LM
authors.lastname: Mäthger
authors.forename: Steven B
authors.initials: SB
authors.lastname: Roberts
authors.forename: Roger T
authors.initials: RT
authors.lastname: Hanlon
mesh_terms: D000818:Animals; D001483:Base Sequence; D049832:Decapodiformes / Q000502:physiology*; D015870:Gene Expression; D008027:Light; D055355:Opsins / Q000235:genetics; D016133:Polymerase Chain Reaction; D012313:RNA / Q000235:genetics; D012867:Skin / Q000378:metabolism; D012879:Skin Physiological Phenomena
chemical_list: D055355:Opsins; D012313:RNA
references.citation: J R Soc Interface. 2009 Apr 6;6 Suppl 2:S149-63
references.pmid: 19091688
references.citation: Biol Rev Camb Philos Soc. 1963 May;38(2):204-40
references.pmid: 4385905
references.citation: J Exp Biol. 2006 May;209(Pt 10):1944-55
references.pmid: 16651559
references.citation: Pigment Cell Res. 2001 Oct;14(5):312-9
references.pmid: 11601652
references.citation: J Exp Biol. 1998 Aug;201(Pt 15):2299-306
references.pmid: 9662500
references.citation: Science. 1980 Jun 13;208(4449):1286-8
references.pmid: 17830814
references.citation: Nature. 1975 Jan 31;253(5490):370-2
references.pmid: 1110782
references.citation: J Exp Biol. 1994 Aug;193(1):1-12
references.pmid: 9317205
references.citation: Pigment Cell Res. 2005 Oct;18(5):360-9
references.pmid: 16162176
references.citation: J Exp Biol. 2010 Jan 15;213(2):249-55
references.pmid: 20038658
references.citation: Exp Dermatol. 2009 Jun;18(6):567-70
references.pmid: 19493002
references.citation: Zoolog Sci. 2006 Sep;23(9):815-9
references.pmid: 17043404
references.citation: Vision Res. 2006 May;46(11):1746-53
references.pmid: 16376404
references.citation: J Exp Biol. 1994 Jun;191(1):247-56
references.pmid: 9317735
references.citation: Am Zool. 1969 May;9(2):429-42
references.pmid: 5362276
references.citation: Nature. 1958 Nov 8;182(4645):1288-90
references.pmid: 13600294