陕西富硒与非富硒地区山羊组织硒含量和GPX-7基因表达的比较

为了探讨陕西紫阳县(富硒地区)山羊各组织中微量元素硒的含量和谷胱甘肽过氧化酶7(Glutathione Peroxidase 7,GPX-7)基因的表达情况,以及组织中的硒沉积量对GPX-7基因表达的影响。利用原子荧光光谱法对年龄相仿、体质量相近的紫阳县双安镇(n=7)和广成镇(n=7)和宝鸡市陈仓区白山羊体内硒含量进行了测定;同时运用实时荧光定量PCR(qRT-PCR)相对定量技术测定GPX-7基因mRNA的相对表达量。紫阳双安镇山羊硒含量显著高于紫阳广成镇(P0.05),同时紫阳县均显著高于宝鸡陈仓区(P0.05);但是紫阳双安镇与紫阳广成镇山羊肺脏中硒含量差异不显著(P0.05)。GPX-7基因在各组织器官中广泛表达,但是不同地区的山羊表现出不同的组织差异性。紫阳双安镇山羊心脏、脾脏、肾周脂肪和背最长肌组织中mRNA水平与紫阳广成镇差异不显著(P0.05),但是紫阳地区均显著高于宝鸡陈仓区(P0.05)。在肺脏、肾脏、股二头肌和淋巴组织中,来自不同地区的山羊GPX-7基因mRNA的表达量地差异均两两显著(P0.05),其中紫阳广成镇山羊肺脏的表达量显著高于其他两个地区(P0.05)。由此可见,山羊各组织器官中微量元素硒的沉积量和GPX-7基因mRNA的表达量表现出较为一致的地域趋势,即紫阳双安镇紫阳广成镇宝鸡陈仓区,这表明微量元素硒上调GPX-7基因的表达,但是具有组织差异性。     

The impact of weight loss on circulating cytokines in Beagle dogs

Chronic low-grade inflammation in obesity is characterized by an increased production of pro-inflammatory and chemotactic cytokines that are contributing to insulin resistance and related co-morbidities. Cytokines act in networks and exhibit pleiotropic effects so we investigated the circulating levels of a wide array of cytokines (pro and anti-inflammatory, chemotactic and growth factors) in a canine model of weight loss. The dogs served as their own control in order to study the impact of weight loss independent of potential confounding factors, such as history of excess weight or gender. While low-grade inflammation had been previously investigated in obese dogs by measuring changes in adipokines, acute phase proteins and key pro-inflammatory cytokines, to the best of our knowledge this is the first study to evaluate how weight loss impacts a wide array of circulating cytokines.Eighteen overweight Beagle dogs were recruited (six spayed females and 12 neutered males), and none of them were grossly obese according to the body condition score (BCS). All the dogs reached an ideal weight by the end of the program. Parameters were assessed before (baseline), at mid-point (month 3) and at end-point (month 6). Plasma GM-CSF, IL-2, Il-4, IL-6, IL-7, IL-8, IL-10, IL-15, IL-18, IFNγ, IP-10, TNFα, monocyte chemotactic protein 1 (MCP-1), keratinocyte chemokine (KC) were measured with canine multiplex immunoassays. Fat mass was assessed by dual energy X-ray absorption (DEXA).Several cytokines decreased throughout the weight loss program (p < 0.01) and were correlated with the percentage of fat measured by DEXA (p < 0.05): chemotactic (MCP-1), growth factors (GM-CSF, IL-7 and IL-2), and pro-inflammatory (KC and IL-18). We could not show trends for several cytokines, possibly because their level may be lower than the assay sensitivity: anti-inflammatory (IL-4 and IL-10), and pro-inflammatory (IL-6 and TNFα).In conclusion, while our findings for several pro-inflammatory and chemotactic cytokines are in accordance with human and rodent studies, we may have identified additional cytokines, such as growth factors, related to obesity-induced low-grade inflammation. Considering the weight loss was enabled by an adjusted diet, the role of this association of cytokines in insulin resistance and related co-morbidities needs to be clarified. Our results could help better understand the cytokine biology in dogs, and as such are relevant for further elucidating the relationship between immune function and metabolism/nutrition.     

microRNA let-7调控动物个体发育的研究进展

microRNA(miRNA)是一类广泛存在于多细胞动物中的进化保守的大小为18~25nt的非编码小分子RNA,可以通过与靶基因mRNA的非编码区(3′UTR)结合导致mRNA降解,或阻断mRNA翻译而调节基因表达。let-7是在线虫中发现的具有转录后调节功能的小分子RNA,具有高度的保守性,研究发现,let-7参与动物个体多个器官组织的发育过程。作者综述了近年来let-7参与调控脑、神经系统、心肺系统和肌肉发育等组织器官的研究成果,初步阐述了let-7调控组织器官发育的作用机制,以期为进一步探索let-7在动物体内的功能奠定基础。     

基于改进YOLO v7的轻量化樱桃番茄成熟度检测方法

为在自然环境下自动准确地检测樱桃番茄果实的成熟度,实现樱桃番茄果实自动化采摘,根据成熟期樱桃番茄果实表型特征的变化以及国家标准GH/T 1193—2021制定了5级樱桃番茄果实成熟度级别(绿熟期、转色期、初熟期、中熟期和完熟期),并针对樱桃番茄相邻成熟度特征差异不明显以及果实之间相互遮挡问题,提出一种改进的轻量化YOLO v7模型的樱桃番茄果实成熟度检测方法。该方法将MobileNetV3引入YOLO v7模型中作为骨干特征提取网络,以减少网络的参数量,同时在特征融合网络中加入全局注意力机制(Global attention mechanism, GAM)模块以提高网络的特征表达能力。试验结果表明,改进的YOLO v7模型在测试集下的精确率、召回率和平均精度均值分别为98.6%、98.1%和98.2%,单幅图像平均检测时间为82 ms,模型内存占用量为66.5 MB。对比Faster R-CNN、YOLO v3、YOLO v5s和YOLO v7模型,平均精度均值分别提升18.7、0.2、0.3、0.1个百分点,模型内存占用量也最少。研究表明改进的YOLO v7模型能够为樱桃番茄果实的自...     

基于改进YOLO v7的生猪群体体温热红外自动检测方法

针对当前生猪规模化养殖过程中基于热红外技术的生猪体温测量效率低的问题,提出了一种基于改进YOLO v7的生猪群体体温检测方法。改进YOLO v7算法在Head层引入VoV-GSCSP结构,降低网络结构复杂度;使用内容感知特征重组(Content-aware reassembly of features,CARAFE)替换模型原始上采样算子,提高特征图放大后的品质,强化生猪头部区域有效特征;引入感受野增强模块（Receptive field enhancement module,RFE）,增强特征金字塔对生猪头部特征的提取能力。本文改进YOLO v7算法对于生猪头部的检测精确率为87.9%,召回率为92.5%,平均精度均值（Mean average precision,mAP）为94.7%。与原始YOLO v7相比,精确率提高3.6个百分点,召回率提高7.0个百分点,mAP提高3.6个百分点。该方法首先自动检测生猪头部区域,再利用头部最大温度与耳根温度的高相关性,最终自动获取生猪体温。温度提取平均绝对误差仅为0.16℃,检测速度为222f/s,实现了生猪群体体温的实时精准检测。综合上述试验结果表明,该方法能够自动定位生猪群体的头部区域,满足生猪群体体温测定的高效和高精度要求,为群养生猪体温自动检测提供了有效的技术支撑。     

Frozen bread dough: Effects of freezing storage and dough improvers

This review focuses on the effects of freezing storage on the microstructure and baking performance of frozen doughs, and provides an overview of the activities of dough improvers, including emulsifiers, hydrocolloids and other improvers used in frozen dough applications. The overall quality of bread baked from frozen dough deteriorates as the storage of the dough at sub-zero temperatures increases due to several factors which are discussed. Lipid-related emulsifiers such as diacetyl tartaric acid esters of mono and diglycerides and sucrose esters employed as anti-staling agents, dough modifiers, shortening sparing agents, and as improvers for the production of high-protein bread have also been employed in frozen doughs. Hydrocolloids are gaining importance in the baking industry as dough improvers due to their ability to induce structural changes in the main components of wheat flour systems during breadmaking steps and bread storage Their effects in frozen doughs is discussed. Other dough improvers, such as ascorbic acid, honey and green tea extract, are also reviewed in the context of frozen doughs.     

甘薯响应蔓割病病原菌侵染的IbWRKY7基因克隆与表达分析

为探究IbWRKY7基因在甘薯响应蔓割病病原菌侵染过程中的表达模式,以高抗蔓割病品种‘鄂薯11’为供试材料,克隆到1个新的WRKY家族基因IbWRKY7,进行生物信息学分析;并对‘鄂薯11’和蔓割病敏感品种‘栗子香’在蔓割病病原菌侵染后IbWRKY7基因的表达模式进行分析。结果显示,IbWRKY7的CDS序列全长为945 bp,编码314个氨基酸;推测其编码不稳定的亲水性蛋白,蛋白分子质量为33.92 kU,pI 9.82,含有1个WRKY七肽保守序列和1个C₂HC型锌指结构。IbWRKY7基因上游2 000 bp的启动子区域内存在多种类型的顺式作用元件,如植物激素应答元件Myb、胁迫响应元件MYC和MYB等。多序列比对及系统进化树分析结果表明,IbWRKY7蛋白与日本牵牛花InWRKY7和三裂叶薯ItWRKY7亲缘关系最近。亚细胞定位预测显示IbWRKY7蛋白定位于细胞核。实时荧光定量PCR结果表明,与蔓割病病原菌侵染0 h相比,侵染2、4、12、24、48、72、96和120 h后,‘鄂薯11’的IbWRKY7基因表达量均显著提高(P<0.05);而‘栗子香’的IbWRKY7基因表达量除侵染24 h外的其他7个时间点均显著高于0 h。侵染2~48 h,‘鄂薯11’的IbWRKY7基因表达量显著高于‘栗子香’。双因素方差分析结果表明,不同品种和侵染时间点的IbWRKY7基因表达量均存在显著差异。综上,甘薯IbWRKY7基因上游2 000 bp的启动子区域含有12种激素应答和胁迫应答相关的顺式作用元件。IbWRKY7具有WRKY家族的典型结构特征,属于第Ⅲ类WRKY蛋白,氨基酸序列与同源物种相似度高,进化上高度保守。IbWRKY7基因受蔓割病病原菌侵染诱导表达,且在不同蔓割病抗性的甘薯品种中表达量差异显著。     

不同猪种5-羟色胺受体基因的表达及其与肉质的相关性分析

为研究5-羟色胺（5-HT）受体基因在不同猪种的表达及其与肉质的关系,试验选取淳安花猪与杜长大三元猪各12头,同时饲喂,达上市体重时分别屠宰,测定胴体、肉质性状及肌肉、脂肪中的5-HT受体基因表达量。结果表明：淳安花猪、杜长大三元猪的平均屠宰体重分别为88.1、102.4kg;淳安花猪的板油率、背膘厚、肌内脂肪等指标均显著高于杜长大三元猪（P〈0.05）;屠宰率、眼肌面积杜长大三元猪显著高于淳安花猪（P〈0.05）。5-HT2A、5-HT7受体基因在2个猪种脂肪组织中的表达量均显著高于肌肉组织（P〈0.05）,杜长大三元猪的肌肉中5-HT2A、5-HT7表达量显著低于淳安花猪（P〈0.05）,而脂肪中表达量两猪种间差异不显著。5-HT2A、5-HT7受体基因表达量与屠宰肉质指标之间基本呈负相关,尤其是肌肉中的5-HT2A表达量,呈较强负相关（杜长大三元猪）或显著负相关（淳安花猪）。研究初步认为,5-HT受体基因在中外猪种之间存在表达差异,并与屠宰肉质性状具有相关性。     

Dramatic Changes of Matrix Metalloproteinases-7 and Lysozyme in the Ulcerative Colitis of Mice Induced by Dextran Sulfate Sodium

Ulcerative colitis （UC） is a lifelong illness with profound emotional and social impacts, and could cause serious damage to large intestine, especially in colon. However, the pathogenesis of UC remained unclear. The present study attempts to find out the role of matrix metalloproteinases-7 （MMP-7） and lysozyme in the pathogenesis of UC through a mice model induced by dextran sulfate sodium （DSS）. The UC model was evaluated both by disease activity index （DAI） and the intestinal histopathology. The results show that there is a high correlation between the DAI score and the pathological changes of colon. Interleukin-6 （IL-6） serum levels and large intestinal fluids levels in UC mice are always higher than that of the control groups, which might be associated with the degree of the inflammation damage in the colon. The change tendency of the MMP-7 mRNA and protein expressions are both up-regulated firstly and then down-regulated from 1 to 5 d in the colon, but only the MMP-7 protein is up-regulated at 7 d again. The up-regulated MMP-7 levels in the early stage of UC may play a protective role through the activated defensins, while the down-regulated levels in the mid-later stage of UC may be connected with the severe lesions in the colon. However, the up-regulated MMP-7 levels in the later stage of UC in the colon may also contribute to the tissue repair or be served as a marker to CRC （colorectal cancer）. The distribution of lysozyme protein indicates that there may be Paneth-like cells in the colon. Both the changes of MMP-7 and lysozyme in the small intestine may play a protective role for the safe environment of the whole gut, especially to the colon of UC.