EFFECT OF HYPOTHERMIA ON GENE EXPRESSION OF SOME ENZYMES ACTIVITY IN BRAIN OF NILE TILAPIA (OREOCHROMIS
NILOTICUS)
Mohamed F. Dowidar1 ; Mohamed A. Ali2
Mohamed E. Metwaly1 and Susan O. Mohamed2
1Department of Biochemistry Faculty of Vet, Medicine Zagazig University.
2Reproductive physiology and Hatchery Department, Central Laboratory of Aquaculture Research, Abbassa, Sharkia, Egypt.
Received 6/ 2/ 2012 Accepted 3/ 3/ 2012
Abstract
Tilapias are widely recognized as one of the most important fish species for freshwater aquaculture. Temperature is one of the most important factors affecting the metabolism
or Nile tilapia (Oreochromis niloticus).The present study
was conducted to evaluate the effect of low temperature (hypothermia) on some enzymes activity in brain of
(O. niloticus) such as succinate dehydrogenase, pyrovate and lactate temperature was decreased by permanently used colder. Total number of 50 fish were distributed into 5 groups; each group contain 10 fish, group (1) control group reared at optimal temperature (24-26°C) group (2) fish reared at 15°C for 24 hours. Group (3) fish exposed to 15°C for 30 days. Group (4) fish reared at 17°C for 24 hours. Group (5) fish reared at 17°C for 30 days. The brain tissues were kept in liquid nitrogen tank until analysis.
The results revelated that the brain tissues show a significant decrease in succinat dehydrogenase and pyrovate level in the group subjected to hypothermia and this decrease was clear in group 3. While there a significant increase in lactate level in group 3 subjected to hypothermia and this increase was clear in the group subjected to 15°C for 30 days. . The results showed that the brain tissues of O. niloticus show a decrease in the level of Gene expression of Hexokinase enzyme (HK) in group exposed to low temperature at group 3 and 5 when compared to control group. The same results were obtained of Gene expration cytochrome oxidase enzyme (COXII).
Hypothermia has effect on activity and gene expression of metabolic enzymes in brain of Nile tilapia.
Keywords:
Nile tilapia, Oreochromis niloticus, hypothermia, gene expression, enzymes activity, succinate dehydrogenase,pyrovate and lactate, temperature.
