Isolation and characterization of two teleost XXXX genes and their differential expression within the inner retina and brain.

@entity1238 @entity71081 @entity1573 @entity7980 @entity19780 @entity44610
@entity44610 is a newly discovered photopigment that is believed to be involved in the regulation of circadian rhythms in tetrapods. Here we describe the characterization of the first two teleost melanopsins ( @entity71081 and @entity71081 ) isolated from @entity7980 ( @entity7980 ). These two teleost genes belong to a subgroup of melanopsins that also include members from @entity1238 , @entity1573 , and Takifugu. In situ hybridization revealed that @entity71081 and @entity71081 are differentially expressed within the retina and brain. In the larval and adult retina, both melanopsins are expressed in a subset of cells in the inner retina, resembling amacrine and ganglion cells. In addition, @entity71081 is expressed in the horizontal cells, indicating a separate task for this gene. In the brain, the two melanopsins are separately expressed in two major retinal and extraretinal photosensitive integration centers, namely, the suprachiasmatic nucleus ( @entity71081 ) and the habenula ( @entity71081 ). The expression of @entity71081 in the suprachiasmatic nucleus in cod is similar to the @entity44610 expression found in @entity1238 . This suggests a conserved role for this @entity19780 and an involvement in mediation of nonvisual photoreceptive tasks, such as entraining circadian rhythms and/or hypophysiotrophic systems. The differential expression of @entity71081 in the habenula suggests that this gene plays a role similar to that of @entity71081 , in that it is also situated in an area that integrates photic inputs from the pineal as well as other brain regions. Thus, the habenula may be an additional region that mediates photic cues in teleosts.
