无量山乌骨鸡肝脏组织发育特征及脂蛋白脂酶基因表达研究

Development Characteristics of Liver Tissue and Expression of Lipoprotein Lipase Gene in Wuliangshan Black-boned Chicken

【目的】明确无量山乌骨鸡肝脏组织发育过程中脂质沉积和脂酶活性的变化特征以及与脂蛋白脂酶(lipoprotein lipase,LPL)基因表达的相关性。【方法】以1(D1)、42(D42)、84(D84)、126(D126)日龄共4个阶段的无量山公鸡和母鸡为研究对象,测定体重和肝脏组织重量并计算肝脏指数,HE石蜡切片染色鉴定肝脏组织的形态学变化,采用甘油三酯(triglyceride,TG)检测试剂盒(单试剂GPO-PAP法)检测肝脏组织中TG含量,采用比色法检测LPL和肝酯酶(hepaticlipase,HL)活性,采用实时荧光定量PCR检测肝脏组织中LPL基因mRNA表达量,采用Pearson相关性分析确定LPL基因表达量和肝脏组织各指标之间的相关性。【结果】无量山乌骨鸡公鸡和母鸡在不同生长阶段肝脏重差异均显著(P<0.05),D42和D84肝脏指数分别与D1和D126相比差异显著(P<0.05);公鸡和母鸡肝脏组织中TG含量均在D84时出现峰值;母鸡LPL和HL活性在D126时达到顶峰且显著高于其他阶段(P<0.05),公鸡LPL和HL活性在D42时达到顶峰,公母鸡总脂酶活性分别在D42和D126时达到顶峰且显著高于其他阶段(P<0.05);公鸡和母鸡肝脏组织LPL基因mRNA表达的峰值分别在D42和D1,且母鸡LPL基因mRNA表达量在D1、D42和D126共3个发育阶段均与HL活性呈显著相关(P<0.05)。【结论】无量山乌骨鸡肝脏组织重量、肝脏指数、TG含量、脂酶含量和LPL基因mRNA表达量在不同发育阶段变化较大,而成鸡脂酶活性主要受性别影响,母鸡中LPL基因mRNA表达量与HL活性显著相关。结果为进一步研究无量山乌骨鸡肝脏脂肪代谢调控机制提供科学依据。

【Objective】The aim of this study was to study the changes of lipid deposition and lipase activity during the development of liver of Wuliangshan Black-boned chicken and its correlation with lipoprotein lipase(LPL)gene expression.【Method】In this study,four stages of roosters and hens at 1(D1),42(D42),84(D84)and 126 days of age(D126)were used as the research objects.The body weight and liver weight were measured and the liver index was calculated.HE staining was used to identify the morphological changes of liver.The content of triglyceride(TG)in liver was detected by TG detection kit(single reagent GPO-PAP method).Colorimetric method was used to detect LPL and hepaticlipase(HL)activities.Real-time quantitative PCR was used to detect LPL gene mRNA expression.Pearson correlation analysis was used to determine the correlation between LPL gene expression and liver indexes.【Result】There were significant differences in liver weight between roosters and hens at different growth stages(P<0.05).The liver indexes of D42 and D84 were significantly different from those of D1 and D126(P<0.05).TG content in the liver tissues of both roosters and hens peaked at D84.The activities of LPL and HL in hens reached the peak at D126 and were significantly higher than those at other stages(P<0.05),and the activities of LPL and HL in roosters reached the peak at D42.The total esterase activity of roosters and hens reached the peak at D42 and D126 respectively and were significantly higher than that at other stages(P<0.05).The peak of LPL mRNA expression in liver of roosters and hens were at D42 and D1 respectively,and the expression of LPL gene mRNA in hens was significantly correlated with HL activity at three developmental stages of D1,D42 and D126(P<0.05).【Conclusion】The liver weight,liver index,TG content,lipase content and LPL gene mRNA expression of Wuliangshan Black-boned chicken varied greatly at different developmental stages.The lipase activity of adult chickens were mainly affected by gender,and the expression of LPL gene mRNA in hens was significantly correlated with HL activity.This results provided a scientific basis for further study on the regulation mechanism of liver fat metabolism in Wuliangshan Black-boned chicken.