Molecular cloning and characterization of two putative appetite regulators in winter flounder (Pleuronectes americanus): preprothyrotropin-releasing hormone (TRH) and preproorexin (OX).
cDNAs encoding for preproTRH and preproorexin were cloned in winter flounder, a species that undergoes a period of natural fasting during the winter. For both peptides, the deduced amino acid structure of the hormone precursor shows 30-70% similarities with their homologs in other fish species. RT-PCR studies show that these peptides are present not only in the brain, but also in several peripheral tissues, including gastrointestinal tract and testes. Fasting induced increases in both preproorexin and preproTRH expressions in the hypothalamus, but did not affect their expression levels in the telencephalon/preoptic area. In addition, the mRNA expressions of both preproorexin and preproTRH were higher in the winter than in the summer in both hypothalamus and telencephalon/preoptic area. Our results suggest that orexin and thyrotropin-releasing hormone (TRH) might have a role in the seasonal regulation of food intake in winter flounder.
Buckley
Colleen
C
Department of Biology/Biochemistry, Memorial University of Newfoundland, St. John's, NL, A1B 3X9, Canada.
MacDonald
Erin E
EE
Tuziak
Sarah M
SM
Volkoff
Hélène
H
D000595:Amino Acid Sequence; D000818:Animals; D001069:Appetite Regulation / Q000502:physiology*; D003001:Cloning, Molecular; D018076:DNA, Complementary; D005260:Female; D029941:Fish Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D005432:Flounder / Q000235:genetics / Q000378:metabolism*; D005508:Food Deprivation; D005786:Gene Expression Regulation; D007031:Hypothalamus / Q000378:metabolism; D047908:Intracellular Signaling Peptides and Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D008297:Male; D008969:Molecular Sequence Data; D009479:Neuropeptides / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D000068797:Orexins; D009928:Organ Specificity; D010802:Phylogeny; D011498:Protein Precursors / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D012333:RNA, Messenger / Q000378:metabolism; D011994:Recombinant Proteins / Q000737:chemistry; D012621:Seasons; D016415:Sequence Alignment; D013687:Telencephalon / Q000378:metabolism; D013973:Thyrotropin-Releasing Hormone / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*
D018076:DNA, Complementary; D029941:Fish Proteins; D047908:Intracellular Signaling Peptides and Proteins; D009479:Neuropeptides; D000068797:Orexins; D011498:Protein Precursors; D012333:RNA, Messenger; D011994:Recombinant Proteins; C063596:prepro-thyrotropin-releasing hormone; D013973:Thyrotropin-Releasing Hormone