基于RNA-seq方法对始丰微型牛体型形成的调控机制研究

试验旨在探讨始丰微型牛微小体型的遗传机制,应用转录组测序技术分析普通天台黄牛和始丰微型牛在生长发育相关基因上的差异。选择浙江省某保种场约12月龄的健康黄牛15头,公牛组包括2头普通天台黄牛,3头始丰微型牛;母牛组包括4头普通天台黄牛,6头始丰微型牛。采集牛耳组织样品并应用转录组(RNA-seq)测序与生物信息学技术提取差异表达的基因。结果显示,在始丰微型牛组织中,P53信号通路中的胰岛素生长因子结合蛋白基因(IGFBP3)和TGF-β信号通路中的转化生长因子基因(TGFB2)处于下调状态。研究表明,转化生长因子和胰岛素生长因子的表达量下降,抑制了始丰微型牛的生长发育,造成其体型较小。

巧借艺人说唱,抒写兴亡之感——论民间说唱对孔尚任及其戏曲创作的影响

清初民间说唱艺术风行,受文人士大夫爱听说唱并且喜欢品评说唱艺人之风气的濡染,特别是受故里前辈贾凫西的影响,孔尚任不仅喜爱说唱艺术,而且喜欢赋诗撰文描述其耳闻目睹的民间说唱表演。在创作《桃花扇》时,孔尚任则自觉秉承了戏曲史上援引民间说唱入戏的创作传统,有意借用贾凫西的鼓词来开宗明义、卒章显志,并且让说唱艺人柳敬亭、苏昆生深度介入男女主人公的离合故事,一方面发挥牵引、聚合故事情节的纽带作用,另一方面展现其侠肝义胆与气节操守,以"愧天下之士大夫",从而写出了一部具有深邃历史意识与深厚人民情怀的经典作品。

夏季发酵床牛舍与拴系式牛舍环境指标的差异性比较

本试验主要研究了夏季发酵床养殖模式奶牛舍与拴系式养殖模式奶牛舍内环境指标的差异。测定了牛舍的温度、噪声、相对湿度、氨气浓度和细菌密度等环境指标,并分析了其相关性。结果表明,发酵床牛舍的细菌密度为0.10×10~4个/m^3,极显著低于拴系式牛舍的2.33×10~4个/m^3(P<0.01);氨气浓度为3.92mg/m^3,也极显著低于拴系式牛舍的9.68mg/m^3(P<0.01);噪声强度为57.6d B,极显著低于拴系式牛舍的65.3d B(P<0.01);但温湿度、温湿度指数以及其他指标在两种牛舍间没有显著的差异。另外,拴系式牛舍内的温度和噪声存在显著相关关系(Sig.(2-tailed)<0.05)。综上,发酵床牛舍的环境细菌浓度、噪声强度与氨气浓度较低,能够在一定程度上改善奶牛的舒适度。

荧光定量PCR检测原料乳中粘质沙雷氏菌

为建立检测原料乳中粘质沙雷氏菌(S.marcescens)定性定量的检测方法,本研究利用S. marcescens S-核糖基高半胱氨酸酶(luxS)基因片段设计1对特异性引物,设计并建立了S. marcescens luxS基因的SYBR GreenⅠ实时荧光定量PCR的检测方法。结果显示,该方法可特异性检测粘质沙雷氏菌的存在,检测的最低限为6.9×10~2cfu/mL。与其他原料乳中常见的微生物均无交叉反应,比常规PCR的检测限(6.9×10~3cfu/mL)要广。对2015年11月~2016年1月长江下游地区8个牧场的原料乳进行检验,结果表明本检测方法具有较好的敏感性、特异性和实用性。

The Levels of Genetic Differentiation of Small-Tailed Han Sheep and Tan Sheep Populations Using Structural Loci

Using the method of ＂random sampling in typical colonies of the central area of the habitat＂ and several electrophoresis techniques, the variations of 17 structural loci encoding blood proteins in 60 Small-Tailed Han sheep and 73 Tan sheep were examined and compared with those of 14 other sheep populations in China and other countries to investigate their levels of genetic differentiation. The average heterozygosities of Small-Tailed Han sheep and Tan sheep were 0.2360 and 0.2587, respectively. The average polymorphic information content values were 0.1974 and 0.2102, respectively. The average effective numbers of alleles were 1.5723 and 1.5751, respectively. The coefficients of gene differentiation in the four groups （including 4, 6, 13, and 16 sheep populations, respectively） were 0.049323, 0.059987, 0.1728, and 0.201256, respectively, indicating that the degree of gene differentiation at the structural loci was the least in Hu sheep, Tong sheep, Small-Tailed Hart sheep, and Tan sheep; followed by the above-mentioned four sheep populations and two Mongolian sheep populations; and was the highest in sheep populations belonging to the Mongolian sheep group, South Asian sheep, and European sheep. The earlier researchers＇ conclusions that both Small-Tailed Han sheep and Tan sheep evolved from Mongolian sheep were further verified by the results of this study. Hu sheep, Tong sheep, Small-Tailed Han sheep, and Tan sheep were decreasingly affected by the bloodline of Mongolian sheep to different degrees. The relationships among sheep populations were not closely related to the geographical distances among sheep populations.

NH4Cl promotes apoptosis and inflammation in bovine mammary epithelial cells via the circ02771/miR-194b/TGIF1 axis

Excess ammonia(NH_(3))in the circulation of dairy animals can reduce animal health and the quality of products for human consumption.To develop effective prevention and treatment methods,it is essential to examine the molecular mechanisms through which excess NH_(3) may affect the mammary gland.The present study used bovine mammary epithelial cells(BMECs)to evaluate the effects of exogenous NH_(4)Cl on the abundance of circular RNAs(circRNAs)using high-throughput sequencing.Among the identified circRNAs,circ02771 was the most significantly upregulated by exogenous NH_(4)Cl(P<0.05),with a fold change of 4.12.The results of the apoptosis and proliferation assays,transmission electron microscopy,H&E staining,and immunohistochemistry revealed that circ02771 increased apoptosis and inflammation.A double luciferase reporter assay revealed that circ02771 targeted miR-194b,and the overexpression of circ02771(pcDNA-circ02771)reduced(P<0.05)the expression of miR-194b and led to apoptosis and inflammation.Circ02771 also enhanced the expression of transforming growth factor beta-induced factor homeobox 1(TGIF1),which is a target gene of miR-194b.Overall,this study suggests that the circ02771/miR-194b/TGIF1 axis plays a role in mediating the effects of NH_(4)Cl on BMECs.Therefore,this axis provides a novel target to help control hazards within the mammary gland from high circulating NH_(4)Cl levels.

Genetic Structure of Native Sheep Populations in East and South Asia

Variations of structural loci among 4 sheep populations in China were examined by the method of multiloci electrophoresis, and similar data from 11 sheep populations were taken as basic references to analyze the genetic structure of the native sheep populations in East and South Asia. The results showed that the average heterozygosity and effective number of alleles among 15 populations were 0.2746 and 1.559, respectively. Mongolian sheep possessed the largest average heterozygosity and effective number of alleles. Genetic diversity of sheep populations in Mongolia, China, Vietnam, Bangladesh and Nepal was reduced in this order. The coefficients of genetic differentiation were between 0.0126 and 0.3083, with the average of 0.148, demonstrating that genetic variations lay mainly in populations with 85.2% of the total variations. There exists no correlation between geographical distances and genetic distances. Gene flow was smooth among most populations, which led to inconsistency between geographical distances and genetic distances. The 15 native sheep populations in East and South Asia could be divided into two groups： One group included part populations of China and Mongolia, and the other included Yunnan populations of China, and part populations of Nepal and Bangladesh. Other populations did not cluster together and divide into the above-mentioned two groups. Tills study indicated genetic differentiation of the 15 native sheep populations in East and South Asia was relatively low, geographical isolation was not the main reason affecting genetic differentiation, and the fifteen sheep populations could be divided into two groups according to phylogenetic relationships.