Evidence for Alternative Splicing of a Dopamine D2 Receptor in a Teleost
Previous attempts at identifying an alternatively spliced dopamine (DA) D2 receptor in teleosts have proven unsuccessful. We provide evidence of a splicing event of a goldfish D2 (gfD2b1) receptor in the neuroendocrine brain of adult goldfish that produces a spliced short isoform (gfD2b1S). We also...
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Published in | Physiological and biochemical zoology Vol. 84; no. 2; pp. 135 - 146 |
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Main Authors | , , |
Format | Journal Article |
Language | English |
Published |
United States
University of Chicago Press
01.03.2011
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Subjects | |
Online Access | Get full text |
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Summary: | Previous attempts at identifying an alternatively spliced dopamine (DA) D2 receptor in teleosts have proven unsuccessful. We provide evidence of a splicing event of a goldfish D2 (gfD2b1) receptor in the neuroendocrine brain of adult goldfish that produces a spliced short isoform (gfD2b1S). We also identify an additional novel D2b paralog (gfD2b2) that does not appear to be alternatively spliced in adult fish during the reproductive cycle. Relatively high mRNA levels of gfD2b1S were observed in the neuroendocrine brain and pituitary of sexually immature fish compared with sexually regressing fish. Real-time RT-PCR revealed that intraperitoneal injection of either SCH 23390 or sulpiride—D1- or D2-specific antagonists, respectively—decreased mRNA levels of gfD2b1S by 3.9-fold without affecting the unspliced isoforms. We suggest that the expression of the spliced D2 receptor modulates the inhibitory tone of DA throughout the reproductive cycle. The deduced amino acid sequence of gfD2b1S lacks 29 amino acids in the same region as the short isoform of mammalian D2. We propose that the gfD2b1S splice variant is the teleost ortholog of mammalian D2S. The hypothesis that D2 receptor splicing is a relatively recent innovation in higher tetrapods is not supported by our results. |
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Bibliography: | ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23 |
ISSN: | 1522-2152 1537-5293 |
DOI: | 10.1086/658290 |