| Coilia nasus was starved for 20 days when the water temperature was (25.0± 0.82)℃, the effects of starvation on the physiology, biochemistry, the digestive system histology and molecular biology was studied, including the index of body, body composition, body biochemical, digestive enzyme activity, antioxidant capacity, digestive system structure and expression of gene. Six groups were set up in this experiment which was located in the control group, which were hungered for Od, and hunger groups, which were hungered for 2d,5d, 10d,15d,20d. The results were as follows: 1. Effects of starvation stress on the index of body and biochemical composition of Cuilia nasus.After short-term starvation of Coilia nasus (0,2,5,10,15,20), body mass, obese relative, hepatosomatic index, andviserosomatic index; crude fat, crude protein, moisture and crude ash were measured. The results showed that:there was a significant(.P<0.05) trend to decline for hepatosomatic index and andviserosomatic index in the 2nd day, while the effect of obese relative and body weight were not different(P> 0.05)in the 20th day. There was a significant (P< 0.05) trend to decline for the crude fat in the body muscle of the Coilia nasus for 5.99% on the 5th day, while the trend of body contents of crude protein declined in the 15th day. During the period of starvation, there was a significant(P<0.05) trend to increase for contents of moisture in the 10th day while content of crude ash does not change significant y(P> 0.05). 2. Effects of starvation stress on the index of the biochemistry index of blood of Coilia nasus.After short-term starvation of Coilia nasus, the blood glucose, total protein, globulin, albumin, triglycerides, cortisol, cholesterol levels were measured. The results showed that: during the extending of starvation, concentration of serum total protein, globulin, cholesterol and cortisol present a trend of increasing and then decreasing, and serum triglycerides and glucose rapid declined and then maintained a certain level. The concentration of protein, globulin, cholesterol and cortisol increased significantly in the 2nd day (P<0.05) while triglycerides decreased significantly in the 2nd day during the period of starvation (P<0.05) and the concentration of glucose decreased significantly in the 5th day (P<0.05)3. Effects of starvation stress on the index of digestive enzyme activity of Coilia nasus.After short-term starvation of Coilia nasus, the changes of amylase, protease and lipase activity was determined in the Coilia nasus. The results showed that:with the starvation time extending, the protease and lipase activity present a trend of increasing and then decreasing, and the activity of amylase present a downward trend. Statistical analysis results show that the activity of lipase increased significantly (P<0.05) in the 5th day, which rose 274.78%before the falling trend. During the period of starvation, amylase activity present a downward trend, which decreased significantly for 72.13%(P<0.05) in the 20th day. Protease activity present a downward trend after rising, but with no significant change (P>0.05).4. Effects of starvation stress on antioxidant capacity of Coilia nasusAfter short-term starvation of Coilia nasus, the changes of superoxide dismutase (SOD) activity, catalase (CAT) activity and the concentration of malondialdehyde (MDA) was determined in the Coilia nasus. The results showed that:during the period of starvation, SOD, CAT activity and MDA concentration present a rise trend and then decreasing. Statistical analysis results show that the CAT and SOD activity were significantly increased in the 10th day (P<0.05), which increased 126.50% and 301.28% respectively, and then decreased. MDA concentration increased significantly (P<0.05) in the 10th day, which rose to extreme value in the 15th day, with increasing by 207.24%, and it declined in the 20th day.5. Effects of starvation stress on the histological structure of the digestive system of Coilia nasusThis study was carried out to determine the effect of starvation on the histological structure of the digestive system (stomach, esophagus, intestine) of the Coilia nasus which were cultivated with the indoor condition in 20 days. The results show that:with the extension of starvation, the injury of each digestive system organization is different. During the period of starvation, the injury of esophageal is lighter which connective tissue increased and the gap between the muscle layers increased in the 20th day. The injury of stomach and intestinal is similarity in the 10th day without structure changes. The gaps between mesothelial cells become larger which tissue loose and outer layer voids in the 15th day. The impact of this index changed significantly in the 20th day. With the prolonged starvation, there is a different change in lumen diameter, the thickness of the muscle layer, the height epithelium and folds.6. Effects of starvation stress on the cloning and tissue expression of glucocorticoid receptor gene in Coilia nasusThis study was carried out to determine the effect of starvation on a cloning and tissue expression of glucocorticoid receptor (GCR) gene in Coilia nasus which were cultivated with the indoor condition in 20 days. We cloned GCR gene in Coilia nasus by homologous cloning methods, its full-length cDNA is 3121 bp long, with a 2396 bp open reading frame (ORF) that encodes a 792 amino acid protein. The GCR protein of Coilia nasus is predicted to conserve GCR domain, ZnF-C4 domain and HOLI domain. Gene expression is dedcted by qRT-PCR. Coilia nasus GCR was expressed strongly in the muscle and liver, while it is expressed poorly in the brain, gills, spleen, intestine, kidney and head kidney. During starvation, the amount of GCR gene expression in liver showed a significant downward trend which presented an increasing trend and then decreased in muscle. |
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