title: Molecular cloning of PEPCK and stress response of black porgy (Acanthopagrus schlegeli) to increased temperature in freshwater and seawater.
abstract: Stress responses to increased temperature in black porgy reared in freshwater (FBP) and seawater (SBP) were examined via endocrinological and blood physiological methods. A rise in temperature increased plasma cortisol levels, which were significantly higher in FBP compared to SBP. The stimulated expression of phosphoenolpyruvate carboxykinase (PEPCK) mRNA in liver might result from the high cortisol level, and this explains the observed higher plasma glucose levels in FBP versus SBP. Full-length cDNA sequence for PEPCK was determined by 3' and 5' RACE procedures. PEPCK cDNA clone was found to contain 2563 nucleotides including an open reading frame that encodes 624 amino acids. While aspartate aminotransferase (AST) and alanine aminotransferase (ALT) of FBP increased with temperature, there was no change in SBP. In FBP, T(3) were 2.3+/-0.3 ng/ml at 20 degrees C and significantly decreased to 1.0+/-0.3 ng/ml at 30 degrees C. On the other hand, in SBP, it were 3.1+/-0.5 ng/ml at 20 degrees C but significantly increased to 5.2+/-0.4 ng/ml at 30 degrees C. When comparing osmolality at the temperature of 30 degrees C and of 20 degrees C, the difference was found to be greater for FBP than SBP. Accordingly, the results suggest that FBP suffers greater stress than SBP with increased temperature, and provide stress responses and osmoregulatory abilities against stressors in black porgy that could differ depending on salinities.
authors.affiliation: Division of Marine Environment & Bioscience, Korea Maritime University, Busan 606-791, Republic of Korea.
authors.forename: Cheol Young
authors.initials: CY
authors.lastname: Choi
authors.forename: Byung Hwa
authors.initials: BH
authors.lastname: Min
authors.forename: Pil Gue
authors.initials: PG
authors.lastname: Jo
authors.forename: Young Jin
authors.initials: YJ
authors.lastname: Chang
mesh_terms: D000410:Alanine Transaminase / Q000097:blood; D000595:Amino Acid Sequence; D000818:Animals; D001219:Aspartate Aminotransferases / Q000097:blood; D001786:Blood Glucose / Q000032:analysis; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000235:genetics; D005618:Fresh Water; D006358:Hot Temperature; D006854:Hydrocortisone / Q000097:blood; D010473:Perciformes / Q000097:blood* / Q000235:genetics*; D019764:Phosphoenolpyruvate Carboxykinase (ATP) / Q000737:chemistry / Q000235:genetics*; D010949:Plasma / Q000737:chemistry; D012333:RNA, Messenger / Q000032:analysis / Q000235:genetics; D012623:Seawater; D013312:Stress, Physiological / Q000097:blood* / Q000235:genetics / Q000503:physiopathology; D013997:Time Factors; D014284:Triiodothyronine / Q000097:blood
chemical_list: D001786:Blood Glucose; D018076:DNA, Complementary; D012333:RNA, Messenger; D014284:Triiodothyronine; D001219:Aspartate Aminotransferases; D000410:Alanine Transaminase; D019764:Phosphoenolpyruvate Carboxykinase (ATP); D006854:Hydrocortisone