The antifreeze protein genes of the winter flounder, Pleuronectus americanus, are differentially regulated in liver and non-liver tissues.
The synthesis of winter flounder (Pleuronectus americanus) antifreeze protein (AFP) mRNAs in the liver is seasonally regulated by the pituitary gland. With the recent discovery that AFP mRNAs are also present in several non-liver tissues, the aim of the present investigation was to compare the regulatory mechanisms of AFP genes in liver and non-liver tissues. Northern blot analyses indicate that the level of liver AFP mRNA undergoes a several hundred fold difference between the winter and summer months, while AFP mRNAs from gills and kidneys exhibit only a modest 5-10 fold seasonal variation. As expected, the liver AFP mRNA in the hypophysectomized fish was increased by over 40 fold. However, no significant increase was observed for the non-liver AFP mRNAs upon hypophysectomy. These investigations suggest that AFP mRNAs in liver and non-liver tissues are differentially regulated.
Gong
Z
Z
Hospital for Sick Children, Department of Clinical Biochemistry, University of Toronto, Canada.
King
M J
MJ
Fletcher
G L
GL
Hew
C L
CL
D000818:Animals; D021301:Antifreeze Proteins; D015152:Blotting, Northern; D005432:Flounder / Q000378:metabolism*; D005615:Freezing; D005786:Gene Expression Regulation; D005880:Gills / Q000378:metabolism; D006023:Glycoproteins / Q000096:biosynthesis* / Q000235:genetics; D007016:Hypophysectomy; D007668:Kidney / Q000378:metabolism; D008099:Liver / Q000378:metabolism*; D009928:Organ Specificity; D012333:RNA, Messenger / Q000096:biosynthesis; D012016:Reference Values; D012621:Seasons
D021301:Antifreeze Proteins; D006023:Glycoproteins; D012333:RNA, Messenger