Salinity Effects in the Expression of Hormone Receptor in Marine Black Porgy, Acanthopagrus schlegeli

• Main Authors: Yu-ming Chang, 張育銘
• Other Authors: Ching-Fong Chang
• Format: Others
• Language: zh-TW
• Published: 2004
• Online Access: http://ndltd.ncl.edu.tw/handle/67003946111071309571

碩士 === 國立臺灣海洋大學 === 水產養殖學系 === 92 === The objectives of the present study were to investigate the possible roles of prolactin (PRL), growth hormone (GH), prolactin receptor (PRLR), glucocorticoid receptor (GR), growth hormone receptor (GHR) and Na+/K+-ATPase α-subunit (NKA) in the osmoregulation of black porgy. The cDNA of PRL, GH, GR, GHR, PRLR and NKA were cloned, and the quantitative PCR measurement of the respective genes was developed. Total RNA of pituitary, gill, intestine and kidney was extracted and cDNA was synthesized by reverse transcriptase. The changes in the expression of hormone mRNA and hormone receptor mRNA of black porgy, when transferred from fresh water (FW) to seawater (SW) and also from SW to FW, were studied in the chronic and acute response effects in the salinity adaptation. In the pituitary, prolactin expression increased significantly when the fish were transferred from SW to FW, while GH transcripts had no significant change. PRLR mRNA transcripts were increased in gill and kidney in FW-adapted black porgy as compared to the SW-adapted fish. NKA mRNA levels decreased in gill and kidney, and increased in intestine when environmental salinity was increased from FW to SW. GR transcripts increased in gill, intestine and kidney when FW-adapted fish were transferred to SW. GHR transcripts in intestine and kidney but not in the gill increased when SW-adapted black porgy was transferred to FW. No clear changes were observed in the profiles of GHR in relation to the environmental salinity in fish. Administration of different doses of steroids by injection, showed that pituitary PRL transcripts were up-regulated by cortisone but not cortisol, dexamethosone and estradiol-17 β. PRLR and NKA transcripts in gill, but only NKA in kidney increased by cortisol injection. GR transcripts were down-regulated by cortisol in intestine and kidney, while GHR transcripts were decreased in kidney. The current data reveals that cortisol played an important role in osmoregulation. The expression of prolactin receptor and growth hormone receptor gene showed a correlation to the adaptation to FW, while glucocorticoid receptor gene expression showed a correlation to SW adaptation in an euryhaline marine black porgy.