شناسه هاي افزوده :
پوركاظمي، محمد ، همكارطرح , كاظمي، رضوان اله ، همكارطرح , يزداني، محمدعلي ، همكارطرح , پوردهقاني، محمد ، همكارطرح , حسن زاده صابر، محمد ، همكارطرح , پورعلي فشتمي، حميدرضا ، همكارطرح , يوسفي جوردهي، ايوب ، همكارطرح , عزيززاده پرمهر، ليلا ، همكارطرح , يگانه، هوشنگ ، همكارطرح
چكيده انگليسي :
Compensatory growth is the phase of rapid growth, greater than normal, which occurs upon adequate re-feeding following a period of under nutrition. The present study was conducted to assess the metabolic and endocrine response of Persian sturgeon (Acipenser persicus) during compensatory growth and in the same rearing condition over an 8 week. After acclimation to experimental conditions (1 week), 375 juvenile Persian sturgeon (mean weight, 108.06±0.28g, mean ± S.E., n=25 fish/ tank) were randomly distributed between 15 circular, 1000-L, cement holding tanks with a flow-through system. Sturgeons were allocated to one of five feeding treatment: Control (C, continuous feeding), W1 (1 week starvation), W2 (2 weeks starvation), W3 (3 weeks starvation) and W4 (4 weeks starvation), followed by a single 4 weeks re-feeding to satiation. Biometric measurements, and blood and tissue sampling for biochemical and molecular analyses were taken in the middle and at the end of the experimental period. Morphological factors including body weight, specific growth rate (SGR), condition factor (CF), weight gain (WG), hepatosomatic index (HSI), significantly decreased during starvation. Body weight significantly decreased in fasting treatments (W1, W2, W3, and W4) compare to C groups. But after re-feeding, growth increased and weight loss compensated in different groups, partly. However, sturgeons in W1 treatment reached the same weight as the control fish, and showed higher SGR, indicating that complete compensatory growth had occurred. Although the specific growth rate in W2, W3 and W4 fish was greater than that in control fish after re-feeding, but fish did not reached the same body weight as control fish at the end of re-feeding period and showed partial compensation only. During fasting, HSI decreased but after re-feeding it increased significantly that indicated the role of liver reserves including glycogen and lipid as a store of energy during starvation. Plasma levels of glucose and insulin during starvation and re-feeding did not significantly change, it seems, that Persian sturgeon is able to maintain blood glucose during food deprivation periods suggesting non-carbohydrate source dietary in sturgeon. Plasma total lipid and triglyceride, were found to increase during starvation period and it decreased following re-feeding. Possibly due to the role of lipids as a preferred nutrients for mobilization in Persian sturgeon during starvation.
IGF-I cDNA cloning and sequencing in Persian sturgeon, resulted an open reading frame, encoding a 162 amino acid composed of 5 (B, C, A, D, and E) domains. Nucleotide and peptide sequence of IGF-I in Persian sturgeon had high sequence identities with other sturgeon’s species including sterlet, Russian and Siberian sturgeon and beluga. The present study resulted that nutritional status influenced IGF-I mRNA expression pattern in the liver and white muscle. IGF-I mRNA expression in liver increased during starvation, before decreasing after re-feeding. Furthermore, IGF-I expression in muscle was different and decreased following starvation and increased by re-feeding. However, changes in the expression of IGF-I mRNA were not significantly different among any of the treatment in both tissues.
It can be deduced that IGF-I mRNA expression in liver as an endocrine and in muscle as paracrine/autocrine does not have a key role in induced compensatory growth in Persian sturgeon.
كليدواژه :
رشد جبراني , پارامترهاي بيوشيميايي , متابوليت ها , رژيم هاي غذايي , تاسماهي ايراني , فاكتور رشد شبه انسوليني يك
