日粮营养对动物基因表达的调控

就目前来看 ,我国动物营养学方面的研究工作基本尚处在机体水平 :即在机体水平上研究各种营养素对机体的作用、在机体内的代谢与平衡、影响机体吸收营养素的因素等问题。分子水平方面的研究还刚刚起步 ,尚处于初级阶段。动物机体的生理病理变化 ,如生长发育、新陈代谢、遗传变异、免疫与疾病等 ,就本质而言 ,都是动物基因表达调控发生了改变的结果 ,许多生理现象的彻底阐明 ,最终需要在基因水平上进行解释 ,所以动物营养学的各方面研究应与分子生物学技术相结合 ,从分子水平上来解释日粮中各种营养素对机体的作用机制、动物机体的生理病理变…     

微量金属元素对基因表达的调控

~~微量金属元素对基因表达的调控$浙江大学动物科学学院!杭州310029@孙德文 $浙江大学动物科学学院!杭州310029@詹勇 $浙江大学动物科学学院!杭州310029@许梓荣     

锌对基因表达的调控研究进展

锌是动物机体组织的一种必需微量元素,人类发现它的存在已有几千年的历史,但其在生物学上的意义直到19世纪才被注意。1934年,Todd等首次证明了锌是高等动物的必     

营养对基因表达的调控作用

运用现代分子生物学的手段和方法，人们已经能够确定日粮中的某些营养物质与基因的表达之间存在着密切的联系。现就日粮中的碳水化合物，蛋白质，脂肪等营养物质对基因表达的作用作一综述。     

营养对基因表达的调控

随着营养学的深入研究 ,发现日粮中的营养成分可以通过多种途径来调控动物基因的表达 ,从而影响动物机体的代谢过程 ,并最终影响动物的生产。本文从分子基因表达的转录及转录后水平方面对日粮中营养成分的生理作用及在生产上的应用作一简单的概述。     

营养物质对基因表达的调控

综述了日粮中常量养分,如碳水化合物、蛋白质、氨基酸和脂肪对动物某些基因表达的调控.这种表达作用可发生在转录水平,也可发生在转录后水平,从而影响机体代谢过程.因此,可通过改变日粮营养组成达到调控动物生产的目的.     

营养对动物基因表达的调控

营养影响动物基因表达。本文在介绍动物基因表达调控机制和营养调控途径的基础上,综述了营养成分如碳水化合物、脂肪和蛋白质等对部分基因表达的调控作用。     

营养对动物基因表达的调控

营养影响动物基因表达。本文在介绍动物基因表达调控机制和营养调控途径的基础上,综述了营养成分如碳水化合物、脂肪和蛋白质等对部分基因表达的调控作用。     

VA对基因表达的调控

随着分子生物学技术和方法的快速发展及其在营养学中的应用,营养素与基因表达的相互作用已成为研究的热点。在介绍VA营养生理功能的基础上,综述了VA对相关基因表达的调控及其主要机制。     

营养物质对基因表达的调控

基因表达是指编码某种蛋白质的基因从转录、mRNA的加工与成熟、RNA的翻译、蛋白质的加工到活性（功能）蛋白质形成的过程。基因表达受到严格的调控,包括转录调控、RNA加工调控、RNA转运调控和翻译调控、mRNA稳定性调控及翻译后的调控。每一个调控点都与养分直接或间接有关。营养和基因表达的一般关系表现为两个方面：一是养分的摄入量影响基因表达;二是基因表达的结果影响养分的代谢途径和代谢效率,并决定营养需要量。     

维生素A对动物基因表达的调控

本文主要综述了维生素A对调节视力的视蛋白基因的表达调控,时糖元异生起关键作用磷酸烯醇式丙酮酸羧激酶(PEPCK)基因的调控,多不饱和脂肪酸合成中△5-去饱和酶基因以及对与生长有关的类胰岛素生长因子(IGF)基因的调控,为研究日粮中维生素A添加对动物营养机理的研究提供理论依据.     

Regulation of gene expression in chickens by heat stress

High ambient temperatures are a critical chal enge in the poultry industry which is a key producer of the animal-based food. To evaluate heat stress levels, various parameters have been used, including growth rates, blood metabolites, and hormones. The most recent advances have explored expression profiling of genes that may play vital roles under stress. A high ambient temperature adversely affects nutrient uptake and is known to modulate the expression of genes encoding for sodium-dependent glucose transporters, glucose transporters, excitatory amino acid transporters, and fatty acidbinding proteins which are responsible for the absorption of macronutrients in the intestine. Various defensive activities are stimulated to protect the cel of different tissues from the heat-generated stress, including expression of early stress response genes coding for heat shock protein(HSP), c-FOS like protein, brain-derived neurotrophic factor(BDNF), and neuronal nitric oxide synthase(n NOS); antioxidant enzyme genes such as superoxide dismutase(SOD), catalase(CAT), and nicotinamide adenine dinucleotide phosphate oxidase(NOX4); and immune-related genes such as cytokines and tol-like receptors(TLRs). The potential role of HSPs in protecting the cel from stress and their presence in several tissues make them suitable markers to be evaluated under heat stress. BDNF and c-FOS genes expressed in the hypothalamus help cel s to adapt to an adverse environment. Heat causes damage to the cel by generating reactive oxygen species(ROS).The NOX4 gene is the inducer of ROS under heat stress, which is in turns control ed by antioxidant enzymes such as SOD and CAT. TLRs are responsible for protecting against pathogenic attacks arising from enhanced membrane permeability,and cytokines help in control ing the pathogen and maintaining homeostasis. Thus, the evaluation of nutrient transporters and defense mechanisms using the latest molecular biology tools has made it possible to shed light on the complex cel ular mechanism of heat-stressed chickens. As the impacts of heat stress on the above-mentioned aspects are beyond the extent to which the reduced growth performance could be explained, heat stress has more specific effects on the regulation of these genes than previously thought.     

多不饱和脂肪酸的营养作用及其基因表达调控

多不饱和脂肪酸(PUFA)是一种重要的营养物质,是所有细胞膜的重要成分,具有重要的生理功能。本文着重论述了PUFA的营养功能和其调控基因表达的分子机制。     

营养因素对比目鱼形变的影响

营养因素是影响比目鱼形变的主要因素。本文介绍了比目鱼的形变并分析了轮虫和桡足动物的主要营养成分的差异,并着重介绍了甲状腺激素、维生素A、脂肪酸和能量对比目鱼着色和眼睛移位的影响。     

影响家蚕表达外源基因效率的几个重要因子的比较研究

本研究以重组病毒rSj14NPV为感染病毒,通过比较纯化蛋白的产量,对家蚕作为生物反应器生产基因工 程产品的适宜蚕品种与相关的重组病毒接种技术进行了比较研究。研究结果表明:871×872、秋风×白玉为表达 Sj14的适宜蚕品种;重组病毒接种量与蛋白表达量有关,适宜接种量为4～5μL/蚕;适宜接种时间以5龄2日龄为 优;以家蚕表达外源基因,最好将重组病毒以家蚕细胞复苏后再接种家蚕以保证获得较高的表达效果。     

Follicular wave dynamics and Growth factors gene expression in Braford heifers

The objectives of the present study were (experiment 1) to characterized development and dynamics of the dominant follicles (DF) and the corpus luteum (CL) to determine patterns of two (W2) and three (W3) follicular waves in beef heifers, and (experiment 2) to determine gene expression of growth factors gene expression in follicular cells of W2 and W3 heifer. Twenty-eight Braford heifers were used. Dominant follicular and CL were monitored daily by ultrasonography to identify the development W2 and W3 in heifers. Pre-ovulatory DF were aspirated on day 19 in W2 and on day 22 in W3 heifers. In W2 and W3, follicular cells (FC) of gene expression of growth differentiation factor 9, bone morphogenetic protein 15 (BMP15), fibroblast growth factor basic, transforming growth factor beta receptor 1, bone morphogenetic protein receptor type IB and fibroblast growth factor receptor 2 were evaluated. The regression of the DF of the first follicular wave and the emergency of the DF of the second follicular wave began later in the heifers W2 than in W3 (p = .02 and p < .01). The regression of the CL began earlier in the W2 than in W3 group (p < .01). Gene expression of growth factors and receptors was similar between groups. However, higher relative levels of BMP15 was observed in W2 group (p = .07). Results propose that wave patterns were regulated by the development time of the DF in the first wave and the life of the CL. Furthermore, higher levels of BMP15 could produce shorter life of CL. The present work suggest that ultrasonography associated with molecular assays could be used as an easy and effective tool to characterize follicular wave patterns.