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Quail bronchitis was experimentally reproduced in captive-reared bobwhite quails (Colinus virginianus). Quails were inoculated with 10(6) mean tissue culture infective doses of quail bronchitis virus at 1,3,6, or 9 weeks of age by the intratracheal, intraperitoneal, or subcutaneous route. Clinical signs were minimal, but occasionally birds were ruffled, exhibited open-mouthed breathing, and developed "snicks." Mortality rates of quails inoculated at 1 or 3 weeks ranged from 7% to 87%. Quails inoculated at 6 or 9 weeks of age had mortality rates from 0% to 20%. Mean body weights of survivors that had been inoculated at 3 or 6 weeks were significantly less than those of controls (P less than 0.05). No significant differences in body weight were detected between quails inoculated at 1 or 9 weeks and their uninoculated controls. Antibodies to group I adenovirus were detected by agar gel precipitation in 87.5% of birds that survived infection. 相似文献
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Ziqing Weng Anna Wolc Hailin Su Rohan L.FernANDo Jack C.M.Dekkers Jesus Arango Petek Settar Janet E.Fulton Neil P.O'Sullivan Dorian J.Garrick 《畜牧与生物技术杂志(英文版)》2019,(2)
Background: The frequency of recombination events varies across the genome and between individuals, which may be related to some genomic features. The objective of this study was to assess the frequency of recombination events and to identify QTL(quantitative trait loci) for recombination rate in two purebred layer chicken lines.Methods: A total of 1200 white-egg layers(WL) were genotyped with 580 K SNPs and 5108 brown-egg layers(BL)were genotyped with 42 K SNPs(single nucleotide polymorphisms). Recombination events were identified within half-sib families and both the number of recombination events and the recombination rate was calculated within each0.5 Mb window of the genome. The 10% of windows with the highest recombination rate on each chromosome were considered to be recombination hotspots. A BayesB model was used separately for each line to identify genomic regions associated with the genome-wide number of recombination event per meiosis. Regions that explained more than 0.8% of genetic variance of recombination rate were considered to harbor QTL.Results: Heritability of recombination rate was estimated at 0.17 in WL and 0.16 in BL. On average, 11.3 and 23.2 recombination events were detected per individual across the genome in 1301 and 9292 meioses in the WL and BL,respectively. The estimated recombination rates differed significantly between the lines, which could be due to differences in inbreeding levels, and haplotype structures. Dams had about 5% to 20% higher recombination rates per meiosis than sires in both lines. Recombination rate per 0.5 Mb window had a strong negative correlation with chromosome size and a strong positive correlation with GC content and with CpG island density across the genome in both lines. Different QTL for recombination rate were identified in the two lines. There were 190 and 199 non-overlapping recombination hotspots detected in WL and BL respectively, 28 of which were common to both lines.Conclusions: Differences in the recombination rates, hotspot locations, and QTL regions associated with genomewide recombination were observed between lines, indicating the breed-specific feature of detected recombination events and the control of recombination events is a complex polygenic trait. 相似文献
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Water, Air, & Soil Pollution - 相似文献
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Water, Air, & Soil Pollution - 相似文献
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对元谋干热河谷引种的8种外来树种进行了抗旱性分析，发现水分利用效率从高到低的顺序依次是：窿缘桉、赤桉、柠檬桉、绢毛相思、肯氏相思、厚荚相思、大叶相思、马占相思。水分利用效率越高，对干热环境的适应性越强。8种外来树种适应干热河谷生境的旱性结构的特点是主根深、侧根多、栅栏组织和贮水组织发达、构成等面叶或近等面叶。桉树类树种的蒸腾速率较高，但能生存的主要机理根系分布深，主动供水能力强，补充了地上部分的水分消耗；而相思类则以发达的根系和较高的叶片保水能力来适应干热环境。 相似文献