title: Stanniocalcin in the euryhaline flounder (Platichthys flesus): primary structure, tissue distribution, and response to altered salinity.
abstract: Stanniocalcin (STC) is a homodimeric glycoprotein hormone that was first discovered in fish, where it is largely produced by a unique endocrine gland, the corpuscles of Stannius (CS). In bony fish, it is thought to be an important regulator of calcium and phosphate uptake from the aquatic environment. This report describes the molecular cloning of STC from euryhaline flounder (Platichthys flesus) CS cDNA and genomic DNA. The flounder STC encodes a prehormone of 251 amino acids (aa) with a signal peptide of 17 aa, followed by another 15 aa sequence before the mature protein of 219 aa. The deduced aa sequence of flounder STC shows 62.9-89.0% similarity and 50.4-83.1% identity with other known fish STC sequences, but only 42.3% identity with mouse STC1, 24.4% identity with fugu and zebrafish STC2, and 22.3% identity with mouse STC2. Primary structural analysis demonstrated that flounder STC gene contains five exons in contrast to the four exons present in mammalian STC gene. RT-PCR revealed the expression of flounder STC mRNA to be widely spread in many tissues and organs, similar to the situation in mammals and other fish. Quantitative PCR (Q-PCR) was conducted to measure relative STC expression levels in the CS, which showed STC mRNA expression levels in seawater-adapted fish CS were about 3-fold higher than in freshwater-adapted fish CS.
authors.affiliation: Faculty of Life Sciences, 3.614 Stopford Building, University of Manchester, UK.
authors.forename: Xiaoming
authors.initials: X
authors.lastname: Hang
authors.forename: Richard John
authors.initials: RJ
authors.lastname: Balment
mesh_terms: D000222:Adaptation, Physiological; D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D003001:Cloning, Molecular; D004247:DNA / Q000737:chemistry; D018076:DNA, Complementary / Q000737:chemistry; D005432:Flounder / Q000235:genetics*; D006023:Glycoproteins / Q000032:analysis / Q000737:chemistry* / Q000235:genetics*; D008969:Molecular Sequence Data; D009994:Osmolar Concentration; D010802:Phylogeny; D012333:RNA, Messenger / Q000032:analysis; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012623:Seawater; D017422:Sequence Analysis, DNA; D017385:Sequence Homology; D012965:Sodium Chloride
chemical_list: D018076:DNA, Complementary; D006023:Glycoproteins; D012333:RNA, Messenger; D012965:Sodium Chloride; C051795:teleocalcin; D004247:DNA