梁子湖和淤泥湖团头鲂体脂沉积差异比较
Comparison of body lipid deposition of blunt snout bream (Megalobrama amblycephala) between Liangzi Lake and Yuni Lake

为探讨长江中下游地区梁子湖和淤泥湖团头鲂脂肪沉积和生长发育规律，采用H&E染色观察2个种质资源区团头鲂脂肪和肝脏组织的形态学及脂肪沉积变化，并用qPCR 技术检测脂肪和肌肉组织中LEP、LPL、IGF1和NPY基因表达，初步分析来自2个种质资源区团头鲂在生长和脂肪沉积能力上存在的差异。结果显示，淤泥湖团头鲂的肠系膜脂肪含量是梁子湖的约1.5倍，H&E染色发现，梁子湖团头鲂脂肪和肝脏细胞的脂滴直径比淤泥湖的小；但梁子湖团头鲂肌肉及脂肪组织中的LEP mRNA表达量显著高于淤泥湖的，肌肉组织中IGF1 mRNA的表达量也显著高于淤泥湖的，梁子湖团头鲂脂肪组织LPL mRNA表达量和淤泥湖的相比，无显著差异，2个种质资源区团头鲂NPY的mRNA表达在肌肉和脂肪组织中也没有显著性差异。由此推测，组织中体脂沉积能力及相关基因表达存在差异可能是导致梁子湖和淤泥湖团头鲂生长速度不同的主要原因之一。
To evaluate muscle development and fat deposition of blunt snout bream from Liangzi Lake and Yuni Lake,we detected histomorphological characteristics of the fat and liver,and the variation of fat accumulation by H&E staining,assessed the expression of the genes related to growth rate and lipid metabolism by qPCR.We found that fat accumulation in the mesenteric adipose tissue of blunt snout breams from Yuni Lake was about 1.5 fold of that from Liangzi Lake.H&E staining results showed that the diameter of lipid droplet was shorter in the adipose and liver tissue of blunt snout breams from Liangzi Lake than that from Yuni Lake.The expression of LEP in the muscle and adipose tissue of blunt snout breams from Yuni Lake was prominently lower than that from Liangzi Lake (P<0.05),but IGF1 mRNA level was dramatically higher in the muscle of blunt snout breams from Liangzi Lake (P<0.05).The expression of LPL and NPY showed no significant difference in the muscle and adipose tissues of blunt snout breams from Liangzi and Yuni Lake (P＞0.05).From above,we proposed that the capacity of fat accumulation and key genes’ (LEP and IGF1) expression were different in blunt snout breams from two lakes,which may result to the different growth rates of blunt snout breams between two lakes