共查询到20条相似文献，搜索用时 593 毫秒
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减蛋综合征病毒全基因组DNA文库的构建及物理图谱分析 总被引：1，自引：0，他引：1
Ｅ Ｄ Ｓ Ｖ Ａ Ａ２ 株纯化 Ｄ Ｎ Ａ 经 Ｈｉｎｄ Ⅲ、 ＰｓｔⅠ和 Ｓｐｈ Ⅰ水解后, 分别提取 Ｄ Ｎ Ａ 片段并克隆至ｐ Ｂｌｕｅｓｃｒｉｐｔ Ｋ Ｓ（ ＋ ） 和ｐ Ｇ Ｅ Ｍ３ Ｚｆ （ ＋ ） 载体, 构建了 Ｅ Ｄ Ｓ Ｖ 全基因文库。根据 Ｅ Ｄ Ｓ Ｖ Ｄ Ｎ Ａ 片段和基因组 Ｄ Ｎ Ａ 电泳迁移率计算, Ｅ Ｄ Ｓ Ｖ 基因组大小为３２９ｋｂ , 通过克隆片段酶谱鉴定, 杂交建立了 Ｅ Ｄ Ｓ Ｖ 限制性内切酶 Ｈｉｎｄ Ⅲ、 Ｐｓｔ Ⅰ和 Ｓｐｈ Ⅰ的物理图谱。 相似文献
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Exploratory spatial relative risk mapping 总被引：2，自引：0，他引：2
Berke O 《Preventive veterinary medicine》2005,71(3-4):173-182
The many faces of disease mapping include maps of disease case locations, regional counts of cases, and disease risk. Another approach is that of mapping the relative risk. Previous methods to map the relative risk were based on regression models of relative risk, given information about geographical locations and established risk factors. However, spatial epidemiological investigations are often exploratory with limited knowledge about the putative risk factors. Indeed, often the primary motivation for the analysis is to identify unknown geographically varying risk factors.
An exploratory approach to mapping the spatial relative risk is to scale the risk map using the background risk in the unexposed (or less-exposed) population. Exposure to unknown spatial risk factors is defined via specific cluster analysis. Identification of spatial disease clusters separates the population into those inside and those outside high risk areas (the exposed and unexposed populations). This exploratory approach to relative risk mapping gives the investigator an impression about the importance and geographical distribution of the unknown spatial risk factors.
Two examples illustrate the exploratory relative risk mapping approach using a spatial point data set on pseudorabies in pig-herds and a regional count data set on small fox tapeworm infections in red foxes. 相似文献
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畜禽基因定位的现状和展望 总被引：3，自引：2，他引：1
本文对畜禽基因定位的内容、方法和现状进行了综述。提出了基因定位中存在的主要问题是定位精度不高，方法有待进一步完善。我国开展此项工作应将重点放大中国畜禽特有性状和重要经济性状上。 相似文献
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在早期的QTL定位研究中,研究者所关注的主要是QTL检出效率的高低。随着QTL定位研究的不断深入,研究者们发现：即使是在QTL检出效率很高的情况下,其定位的精确性仍然可能很低。就目前的定位精度来看,虽然基本可以满足实施标记辅助选择的要求,但还远远不能满足分子克隆技术所能达到的操作程度。因此有必要寻找新的定位策略以达到QTL精细定位的目的。本文简要综述了QTL精细定位新策略-传递不平衡检测（TDT）的概念及发展、原理与方法及其在QTL精细定位中的应用。 相似文献
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对奶牛产奶性能的５个性状（泌乳量、乳脂率、乳脂量、蛋白率和蛋白量）以及２个重要的次级性状（乳房炎发病率和繁殖力）ＱＴＬ作图的方法和进展进行综述，并讨论了奶牛ＱＴＬ定位中存在的问题。 相似文献
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原位杂交技术及其在动物基因定位上的应用进展 总被引：3，自引：0，他引：3
原位杂交技术是８０年代发展起来的一门新的生物技术。目前,在动物基因定位研究方面已得到广泛应用。本广文系统综述了该技术及其在动物基因定位研究方面的应用进展情况。 相似文献
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J. Aldenhoven A. Spötter & O. Distl 《Zeitschrift für Tierzüchtung und Züchtungsbiologie》2007,124(1):39-41
The 7000‐rad INRA‐University of Minnesota porcine Radiation Hybrid panel was used to localize the FGFR2 gene on Sus scrofa chromosome 14 (SSC14). An insertion/deletion mutation of approximately 240 bp was detected in the porcine FGFR2 gene. This mutation consists of a repeat motif of 48 bp. In a short and long variant of this polymorphism, the motif was repeated either six or 11 times. The mutation was shown to follow a Mendelian mode of inheritance in 10 families including 48 pigs of Large White × Duroc origin. 相似文献
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积雪在全球水文和气候变化中扮演着十分重要的角色。利用遥感技术进行积雪监测已有40多年的研究历史, 在雪盖制图、雪深反演、冰雪反照率等方面发展了一系列的算法及产品。其中,光学遥感以其高时空分辨率的特点在积雪监测中得到了非常广泛的应用。随着对地观测系统（Earth Observation System,EOS）的发展,以及国产环境卫星的陆续升空,越来越多的遥感数据被应用于积雪监测,遥感技术势必在积雪监测领域发挥更加重要的作用,为模拟地球辐射平衡、地表水文研究、全球变化等提供丰富的数据资料。 相似文献
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Mami UEMURA Hitomi IGARASHI Aisa OZAWA Naoki TSUNEKAWA Masamichi KUROHMARU Masami KANAI-AZUMA Yoshiakira KANAI 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2015,77(5):587-591
In early embryogenesis, the posteroventral foregut endoderm gives rise to the
budding endodermal organs including the liver, ventral pancreas and gallbladder during
early somitogenesis. Despite the detailed fate maps of the liver and pancreatic
progenitors in the mouse foregut endoderm, the exact location of the gallbladder
progenitors remains unclear. In this study, we performed a DiI fate-mapping analysis using
whole-embryo cultures of mouse early somite-stage embryos. Here, we show that the majority
of gallbladder progenitors in 9–11-somite-stage embryos are located in the lateral-most
domain of the foregut endoderm at the first intersomite junction level along the
anteroposterior axis. This definition of their location highlights a novel entry point to
understanding of the molecular mechanisms of initial specification of the gallbladder. 相似文献
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AFLP是一种新的分子遗传标记技术，它结合了RFLP和PCR技术的优点，具有RFLP的稳定性和PCR的高效性，被称为“最有威力的分子遗传标记”或“下一代分子标记”。相对于国外而言，我国在这方面的研究还比较少。本文综述了扩增片段长度多态性(AFLP)这种遗传标记的原理、技术特点、技术发展及其在动物遗传多样性、种质鉴定、遗传图谱构建、基因定位和标记辅助育种等研究中的应用。 相似文献
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应用反转录聚合酶链反应检测鸡传染性支气管炎病毒核酸的研究 总被引：1，自引：0，他引：1
根据国外报道的鸡传染性支气管炎病（ＩＢＶ）Ｇｒａｙ株的纤突蛋白（Ｓ１）核苷酸序列，自行设计合成了Ｓ１蛋白主要抗原决定簇基因两侧的１对引物，跨幅为１．０ｋｂ。用该引物对从内蒙古、天津、山东等地分离的３株ＩＢＶ进行ＲＮＡ提取，反转录后ＰＣＲ，经琼脂糖凝胶电泳结果表明，３株毒株均获得了与预期一致的ＰＣＲ产物；此外，ＩＢＶＰＣＲ灵敏度的测定结果表明，ＰＣＲ方法可检测出１０ｐｇ的模板，ＰＣＲ酶切结果为，ＨａｅⅢ、ＴａｇⅠ酶对３株ＰＣＲ产物均有１个酶切位点，而ＭｓＰⅠ酶无酶切位点 相似文献
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In many farm animal populations, high‐density single nucleotide polymorphism (SNP) genotypes are becoming available on a large scale, and routine estimation of breeding values is implemented for a multiplicity of traits. We propose to apply the basic principle of the quantitative transmission disequilibrium test (QTDT) to estimated Mendelian sampling terms. A two‐step procedure is suggested, where in the first step additive breeding values are estimated with a mixed linear model and the Mendelian sampling terms are calculated from the estimated breeding values. In the second step, the QTDT is applied to these estimated Mendelian sampling terms. The resulting test is expected to yield significant results if the SNP is in sufficient linkage disequilibrium and linkage with quantitative trait loci (QTL). This principle is illustrated with a simulated data set comprising 4665 individuals genotyped for 6000 SNP and 15 true QTL. Thirteen of the fifteen QTL were significant on a genome‐wide 0.1% error level. Results for the empirical power are derived from repeated samples of 1000 and 3000 genotyped individuals, respectively. General properties and potential extensions of the methodology are indicated. Owing to its computational simplicity and speed, the suggested procedure is well suited to scan whole genomes with high‐density SNP coverage in samples of substantial size and for a multiplicity of different traits. 相似文献
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《Strength and Conditioning Journal》2020,73(1):30-52
Spatial variability in terrain, vegetation, and other features affect cattle and wildlife distribution on mountainous grazing lands of the western United States. Yet we have a poor understanding of how this spatial variability influences risk of wolf-cattle encounters and associated depredation. This knowledge gap severely limits our capacity to prevent or mitigate wolf-cattle conflict. Research addressing this problem was conducted in 2009−2011 at four study areas in western Idaho to evaluate models and mapping tools for predicting spatial risk of wolf-cattle encounters. Lactating beef cows grazing these study areas were instrumented with Global Positioning System (GPS) collars and tracked at 5-min intervals throughout the summer grazing season. Resource selection function (RSF) models, based on negative binomial regression, were developed from these GPS data and used to map the relative probability of cattle use in each study area. A wolf RSF model originally developed by Ausband et al. (2010) was applied to map study-area habitat types in terms of their relative suitability as wolf rendezvous sites. Spatial relationships between cattle and wolf selectivity patterns were used to classify and map wolf-cattle encounter risk to 5 classes (very high to very low) across each study area during the wolf rendezvous period (15 June−15 August). Validation analyses using GPS-based, wolf-cattle encounter observations (n = 200) revealed 84% of observed encounters occurred in areas of high- or very high−encounter risk (class 4 or 5). About 75% of confirmed wolf depredations recorded among three of four study areas were located in areas of high or very high risk. This new predictive understanding of wolf-cattle encounter risk will greatly aid livestock producers, resource managers, and policy makers in more effectively applying husbandry practices, allocating mitigation resources, and developing conflict mitigation plans and policies applicable throughout the mountainous western United States and potentially other regions of the world where wolves and cattle come into conflict. 相似文献
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使用PCARC／INFO软件进行草地资源系列制图的方法研究 总被引：2，自引：1，他引：1
通过使用ＰＣＡＲＣ／ＩＮＦＯ软件，对草地资源系列制图的研究，本文较为详细地探讨了使用该系统进行划时资源系制图的方法，步骤和精度。 相似文献
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The effect on power and precision of including the causative SNP amongst the investigated markers in Quantitative Trait Loci (QTL) mapping experiments was investigated. Three fine mapping methods were tested to see which was most efficient in finding the causative mutation: combined linkage and linkage disequilibrium mapping (LLD); association mapping (MARK); a combination of LLD and association mapping (LLDMARK). Two simulated data sets were analysed: in one set, the causative SNP was included amongst the markers, while in the other set the causative SNP was masked between markers. Including the causative SNP amongst the markers increased both precision and power in the analyses. For the LLD method the number of correctly positioned QTL increased from 17 for the analysis without the causative SNP to 77 for the analysis including the causative SNP. The likelihood of the data analysis increased from 3.4 to 13.3 likelihood units for the MARK method when the causative SNP was included. When the causative SNP was masked between the analysed markers, the LLD method was most efficient in detecting the correct QTL position, while the MARK method was most efficient when the causative SNP was included as a marker in the analysis. The LLDMARK method, combining association mapping and LLD, assumes a QTL as the null hypothesis (using LLD method) and tests whether the ‘putative causative SNP’ explains significantly more variance than a QTL in the region. Thus, if the putative causative SNP does not only give an Identical‐By‐Descent (IBD) signal, but also an Alike‐In‐State (AIS) signal, LLDMARK gives a positive likelihood ratio. LLDMARK detected less than half as many causative SNPs as the other methods, and also had a relatively high false discovery rate when the QTL effect was large. LLDMARK may however be more robust against spurious associations, because the regional IBD is largely corrected for by fitting a QTL effect in the null hypothesis model. 相似文献