The influence of ontogeny and light environment on the expression of visual pigment opsins in the retina of the black bream, Acanthopagrus butcheri.
The correlation between ontogenetic changes in the spectral absorption characteristics of retinal photoreceptors and expression of visual pigment opsins was investigated in the black bream, Acanthopagrus butcheri. To establish whether the spectral qualities of environmental light affected the complement of visual pigments during ontogeny, comparisons were made between fishes reared in: (1) broad spectrum aquarium conditions; (2) short wavelength-reduced conditions similar to the natural environment; or (3) the natural environment (wild-caught). Microspectrophotometry was used to determine the wavelengths of spectral sensitivity of the photoreceptors at four developmental stages: larval, post-settlement, juvenile and adult. The molecular sequences of the rod (Rh1) and six cone (SWS1, SWS2A and B, Rh2Aalpha and beta, and LWS) opsins were obtained and their expression levels in larval and adult stages examined using quantitative RT-PCR. The changes in spectral sensitivity of the cones were related to the differing levels of opsin expression during ontogeny. During the larval stage the predominantly expressed opsin classes were SWS1, SWS2B and Rh2Aalpha, contrasting with SWS2A, Rh2Abeta and LWS in the adult. An increased proportion of long wavelength-sensitive double cones was found in fishes reared in the short wavelength-reduced conditions and in wild-caught animals, indicating that the expression of cone opsin genes is also regulated by environmental light.
Shand
Julia
J
School of Animal Biology, University of Western Australia, Crawley, WA 6009, Australia.
Davies
Wayne L
WL
Thomas
Nicole
N
Balmer
Lois
L
Cowing
Jill A
JA
Pointer
Marie
M
Carvalho
Livia S
LS
Trezise
Ann E O
AE
Collin
Shaun P
SP
Beazley
Lyn D
LD
Hunt
David M
DM
D000818:Animals; D001483:Base Sequence; D016000:Cluster Analysis; D017931:DNA Primers / Q000235:genetics; D004777:Environment; D005786:Gene Expression Regulation; D008027:Light; D015591:Microspectrophotometry; D008969:Molecular Sequence Data; D010473:Perciformes / Q000235:genetics / Q000378:metabolism*; D010802:Phylogeny; D012160:Retina / Q000378:metabolism*; D017949:Retinal Cone Photoreceptor Cells / Q000378:metabolism*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D017299:Rod Opsins / Q000235:genetics / Q000378:metabolism*; D017422:Sequence Analysis, DNA
D017931:DNA Primers; D017299:Rod Opsins