Temporal and spatial changes in the expression pattern of multiple red and green subtype opsin genes during zebrafish development

Abstract

SUMMARY Zebrafish have two red, LWS-1 and LWS-2, and four green, RH2-1, RH2-2, RH2-3 and RH2-4, opsin genes encoding photopigments with distinct absorption spectra. Occurrence of opsin subtypes by gene duplication is characteristic of fish but little is known whether the subtypes are expressed differently in the retina, either spatially or temporally. Here we show by in situ hybridization the dynamic expression patterns of the opsin subtypes in the zebrafish retina. Expression of red type opsins is initiated with the shorter-wavelength subtype LWS-2, followed by the longer-wavelength subtype LWS-1. In the adult retina, LWS-2 was expressed in the central to dorsal area and LWS-1 in the ventral and peripheral areas. Expression patterns of green type opsins were similar to those of the red type opsins. The expression started with the shortest wavelength subtype RH2-1 followed by the longer wavelength ones, and in the adult retina, the shorter wavelength subtypes (RH2-1 and RH2-2) were expressed in the central to dorsal area and longer wavelength subtypes (RH2-3 and RH2-4)in the ventral and peripheral areas. These results provide the framework for subsequent studies of opsin gene regulation and for probing functional rationale of the developmental changes by using the power of zebrafish genetics.

Evolutionary changes of multiple visual pigment genes in the complete genome of Pacific bluefin tuna

“…Previous studies demonstrated that the expression pattern of fish opsins might be regulated spatially, as well as temporally, in the retina (31)(32)(33). In the case of zebrafish, shorter-wavelength RH2 proteins are first expressed in the central part of the retina, whereas longer wavelength proteins are expressed later in the peripheral part (34). Similarly, the five RH2 genes of tuna might be differentially expressed in retina, which would contribute to the visual diversification of tuna.…”

Intra-retinal variation of opsin gene expression in the guppy (Poecilia reticulata)

“…It is possible that LWS S180r is expressed in more cone cells or in a different region of the retina at a different life history stage, as only adults were surveyed in this study. Opsin gene expression and regional cone abundance vary during ontogeny in a diversity of fish including cichlids , winter flounder (Mader and Cameron, 2004), salmonids and zebrafish (Takechi and Kawamura, 2005;Allison et al, 2010).…”

“…intra-retinal variation) could be advantageous for fish, given that the light hitting the dorsal retina is of different spectral composition from that hitting the ventral retina, as a result of the filtering properties of water and any dissolved organic solutes or suspended particulates in it that alter the spectral properties of light. Several species of fish have been shown to possess intra-retinal variation in spectral sensitivity, exhibiting different densities and/or distributions of various photoreceptor types, apparently to deal with varied visual tasks (Takechi and Kawamura, 2005;Allison et al, 2006;Veldhoen et al, 2006;Temple et al, 2010;Temple, 2011). This intra-retinal variation in opsin gene expression may also influence the behaviour of species that use colour in mate choice decisions (Temple, 2011).…”

Analysis of the retina in the zebrafish model

“…Green cones (40-45 hpf) Chinen et al (2003), Takechi and Kawamura (2005), Vihtelic et al (1999) NDRG1 RNA probe…”

“…Red cones (40-45 hpf) Chinen et al (2003), Raymond et al (1995), Takechi and Kawamura (2005) Rod opsin Ab (poly) Rods (≤3 dpf) Doerre and Malicki (2001), Vihtelic et al (1999) Rod opsin c…”