QUICK SEARCH:   [advanced] Author: Keyword(s):
Home     Help     Feedback     Subscriptions     Archive     Search     Table of Contents

This Article Summary Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Forsell, J. Articles by Holmqvist, B. Search for Related Content PubMed PubMed Citation Articles by Forsell, J. Articles by Holmqvist, B.

Expression of pineal ultraviolet- and green-like opsins in the pineal organ and retina of teleosts

Johan Forsell¹, Peter Ekström¹, Iñigo Novales Flamarique^2,* and Bo Holmqvist^3,4,

¹ Department of Zoology, University of Lund, Lund, Sweden,
² Institute of Marine Research, Austevoll Aquaculture Research Station, N-5392 Storebø, Norway,
³ Department of Pathology, University of Lund, Sölvegatan 25, 22185, Lund, Sweden and
⁴ Department of Molecular Biology, University of Bergen, Bergen, Norway
^* Present address: Department of Biological Sciences, Simon Fraser University, 8888 University Drive, Burnaby, British Columbia, Canada V5A 1S6

View larger version (149K): [in a new window]   Fig. 1. (A) Immunoreactive opsin in the pineal organ (arrow) of the halibut embryo. Note the undifferentiated lateral eyes (e). (B) Herring embryo, with opsin-immunoreactive pineal cells (arrow), at an earlier developmental stage than the halibut in A. (C) Parasagittal section through the brain of a halibut embryo showing the generally low level of differentiation. The earliest differentiated neuronal cell bodies and axonal pathways are immunoreactive for acetylated -tubulin (arrows). Note the absence of immunoreactivity in the optic tectum (ot). (D) Axonal connections (arrowheads) between the pineal organ (pin) and deep brain regions in the halibut embryo; pc, posterior commissure. (E) Expression of ultraviolet-opsin mRNA in the pineal organ of the halibut embryo. (F) Expression of ultraviolet-opsin mRNA in the pineal organ of the halibut larva. (G) The adult pineal organ of halibut (transverse section at the level of the end-vesicle) displays a large number of photoreceptors expressing green-opsin mRNA; bv, blood vessel; asterisk, lumen of the pineal organ. (H) Photoreceptors in the ventral retina of the halibut larva express ultraviolet-opsin mRNA (arrows). Scale bar: A, 50µm; B, 140µm; C, 80µm; D 30µm; E,F, 12µm; G, 40µm; H, 15µm.

View larger version (190K): [in a new window]   Fig. 2. Pineal photoreceptors displaying hybridisation with the HPO1 (green-opsin) probe (arrows). Sagittal sections of the pineal organ of (A) cod larva, (B) early herring larva, (C) adult cichlid (Labidochromis cearuleus), (D) haddock larva, (E) adult zebrafish and (F) Atlantic salmon parr. Scale bar: A,C–F, 15µm; B, 9µm.

View larger version (187K): [in a new window]   Fig. 3. Hybridisation of retinal photoreceptors with the HPO4 (ultraviolet-opsin) probe (A,C,E–H) and with the HPO1 (green-opsin) probe (I–K). (A,C) In zebrafish, HPO4 hybridisation is restricted to short single cones (arrows); these cones, which form rows with long single cones, are the most vitreally located cone types, as observed histologically (B,D; arrows). (E) In Atlantic salmon parr, HPO4 hybridisation is restricted to single corner cones (arrows); note that these cones face the partitioning membranes of adjacent double cones (arrowheads). (F) The same corner cones are labelled by HPO4 in the salmon alevin. (G) In the cichlid Labidochromis cearuleus, HPO4 hybridises to single cones (arrows), as is the case in the other cichlid species investigated Pseodotropheus spp. and Archocentrus nigrofasciatus. (H) In turbot larva, as in halibut larva (see Fig.1H), HPO4 hybridises to single photoreceptors in the ventral portion of the retina (arrows). (I) Intense HPO1 hybridisation in the retinal photoreceptor layer of cod larva. (J) In the same cod retina, no hybridisation is observed with the HPO1 sense probe applied to a section adjacent to that shown in I. (K) HPO1 hybridisation in the retinal photoreceptor layer of the herring larva. dc, double cone; lc, long single cone; onl, outer nuclear layer; rpe, retinal pigment epithelium. Scale bar: A,B,E,F,H, 12µm; C,D, 18µm; G, 15µm; I–K, 21µm.