Gene Expression of Somatolactin and Proopiomelanocortin in relation to Environmental Stress in Black Porgy, Acanthopagrus schlegeli

• Main Authors: Yuan-Fang Wang, 王元芳
• Other Authors: Ching-Fong Chang
• Format: Others
• Language: zh-TW
• Published: 2004
• Online Access: http://ndltd.ncl.edu.tw/handle/68737199879037702528

碩士 === 國立臺灣海洋大學 === 水產養殖學系 === 92 === The objective of the present study was to examine the stimulatory effect of stressors on the somatolactin and proopiomelanocortin gene expression in the pituitary of black porgy, Acanthopagrus schlegeli. The nucleotide sequences of SL and POMC mRNA were determined in pituitary, and specific primers were designed for real-time PCR to measure SL and POMC gene expression in response to stress. Slight cold stress (19.5 ℃→14 ℃) resulted in an increase in SL gene expression after 24 hrs treatment. Response to low dose cortisol injection (0.5 μg/g BW) was measured immediately after administration of the hormone and the result showed that SL gene expression was increased significantly. Similarly, SL gene expression also showed a significant increase in response to sex steroid injection. These results suggest that SL may be associated with reproduction. Under different salinities, the SL gene expression decreased when BP was transferred from FW to SW on the 4th day, indicating that SL gene expression may also be related to FW adaptation. POMC gene expression increased significantly during cold stress, but gene expression of POMC was not significantly different between low and high dose of cortisol treatment. Different salinities or injection with different sex steroids did not cause any significant change in POMC expression. In the present study, the major physiological functions of SL remain unclear. But SL may be associated with environmental adaptation. In HPI axis, stressor can influence hypothalamus to secrete CRH which in turn acts upon pituitary to secrete ACTH. Thus, POMC may play an important role in stress response and also in homeostatic balance.