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Visual Neuroscience (2004), 21 : 223-229 Cambridge University Press
Copyright © 2004 Cambridge University Press
doi:10.1017/S0952523804213281
Published online by Cambridge University Press 05 Apr 2005
 
Visual Neuroscience (2004), 21:3:223-229 Cambridge University Press
Copyright © 2004 Cambridge University Press
doi:10.1017/S0952523804213281
International Colour Vision Society 2003 Symposium

Cone visual pigments of the Australian marsupials, the stripe-faced and fat-tailed dunnarts: Sequence and inferred spectral properties

JESSICA  STRACHAN  a1 a , LING-YU E.  CHANG  a1 a , MATTHEW J.  WAKEFIELD  a2 a3 , JENNIFER A. MARSHALL  GRAVES  a2 and SAMIR S.  DEEB  a1 c1
a1 Departments of Medicine and Genome Sciences, University of Washington, Seattle
a2 Research School of Biological Sciences, The Australian National University, Canberra, Australia
a3 Centre for Bioinformation Science, JCSMR/MSI, The Australian National University, Canberra, Australia

Article author query
strachan j   [Google Scholar] 
chang le   [Google Scholar] 
wakefield mj   [Google Scholar] 
graves jam   [Google Scholar] 
deeb ss   [Google Scholar] 
 

Abstract

Studies of color vision in marsupial mammals have been very limited. Two photoreceptor genes have been characterized from the tammar wallaby, but a third cone pigment was suggested by microspectrophotometric measurements on cone photoreceptors in two other species, including the fat-tailed dunnart, Sminthopsis crassicaudata. To determine the sequence and infer absorption maxima of the cone photoreceptor pigments of S. crassicaudata and the related stripe-faced dunnart (Sminthopsis macroura), we have used evolutionarily conserved sequences of the cone pigments of other species, including the tammar wallaby, to design primers to amplify the S. macroura and S. crassicaudata pigment sequences by the polymerase chain reaction (PCR) using genomic DNA or retinal cDNA as a template. These primers will be useful for amplifying cone opsin coding sequences from a variety of vertebrates. Amplified products were directly sequenced to determine gene structure and coding sequences. The inferred amino acid sequences of the cone visual pigments indicated that both species have middle-wave-sensitive (MWS) pigments with a predicted absorption maximum ([lambda]max) at 530 nm, and ultraviolet-sensitive (UVS) pigments with a predicted [lambda]max at 360 nm. The MWS pigments of the two species differ by two, and UVS by three amino acid positions. No evidence was obtained for a third cone pigment in either species.

(Received September 7 2003)
(Accepted January 16 2004)


Key Words: Cone opsins; Marsupials; Dunnart; Spectral tuning.

Correspondence:
c1 Address correspondence and reprint requests to: Samir S. Deeb, Division of Medical Genetics, BOX 357720, University of Washington, Seattle, WA 98195, USA. E-mail: sdeeb@washington.edu

Footnotes

a Contributed equally to this work.


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