Guppy vision: cone mosaic and visual opsin expression pattern. (A) A square cone-mosaic is present in adults and juveniles. Adult MSP derived λmax values from multiple studies and populations (listed below) are shown for each photoreceptor type: short single cone, SC; accessory, A, and principle, P, double cone, DC; long single cone, LC; rod, R. Unspecified cones (asterisk) are grouped with like values. Colors represent the λmax of each cone opsin (based on Wavelength to RGB v.1.0 software). Not reported (dash). (B) Photoreceptor layer (PL) (below) with tangential cross-section (above) showing juvenile rod and cone mosaic with predominating opsins (based on data from panel A and our expression data). Table summarizing our RT-qPCR expression data for the nine putative cone opsins in the eyes of: juveniles, J; females, F; males, M; all ages and sexes tested, A. Predominantly expressed opsins (underlined) constitute >95% of all visual opsin transcripts (excluding RH1) in Cumaná guppy eyes. Among populations, differential LWS or RH2-1 expression likely occurs (LWS+). Grey background added for clarity. Additional abbreviations: outer segments, OS, are proportional in length and diameter (adult data); inner segment, IS; synaptic terminal, ST; ellipsosome, E; mitochondria, M; nucleus, N. (C) Adult cone-mosaic showing differential DC and LC expression (unknown in juveniles). Median dorsal-ventral section of an adult guppy eye showing cone spatial distribution based on MSP and morphological studies. Decrease in quantity of cone class (or dotted lines) do not reflect exact ratios; lens, L; dorsal, D; ventral, V; optic nerve, ON; optic disc, OD, is devoid of photoreceptors. (D) Cumaná guppy dorsal-ventral retinal tuning to environmental spectra; style adapted from reference . This figure is a composite, based on our RT-qPCR data and references [25,26,28,44-47,50,57,66,89-95].
Laver and Taylor BMC Evolutionary Biology 2011 11:81 doi:10.1186/1471-2148-11-81