【目的】选育能够适应猫胃肠环境且具有良好肠道定殖能力的猫源青春双歧杆菌菌株。【方法】从长寿猫和普通猫的粪便中分离出青春双歧杆菌,通过生长量测试和小鼠寿命试验选育得到原始菌株QC-Y(寿命延长率达33.85%),经鉴定该菌为青春双歧...【目的】选育能够适应猫胃肠环境且具有良好肠道定殖能力的猫源青春双歧杆菌菌株。【方法】从长寿猫和普通猫的粪便中分离出青春双歧杆菌,通过生长量测试和小鼠寿命试验选育得到原始菌株QC-Y(寿命延长率达33.85%),经鉴定该菌为青春双歧杆菌。QC-Y经辐射诱变后,通过生长量测试、胃肠耐受性驯化和评价选育得到QC-Y-09。【结果】QC-Y-09的生长量、耐受性评分分别是QC-Y的55.667倍和5.66倍,其对猫胃肠环境的耐受能力具有良好的遗传稳定性。第10代QC-Y-09菌株在人工胃液、肠液、无氧和微氧环境中的存活率分别为18.80%、41.60%、93.26%和48.39%,分别达到0代的62.67%、108.53%、97.92%和94.40%。猫肠道定殖试验表明,QC-Y-09在猫体内的定殖能力显著优于QC-Y和人源青春双歧杆菌。停止饲喂菌剂7 d后,QC-Y-09组猫粪便中青春双歧杆菌活菌仍有4.37 lg CFU/g,分别比QC-Y组和人源组高1.74 lg CFU/g和3.02 lg CFU/g。此外,QC-Y-09对猫换粮应激具有较好的缓解作用,能降低猫换粮应激率85.71%。SNP分析结果表明QC-Y-09在基因层面与QC-Y有显著差异,主要富集在核糖体结构和氨基酰基-tRNA生物合成的通路上。【结论】本研究选育的猫源青春双歧杆菌QC-Y-09菌株能够有效适应猫胃肠环境并在猫肠道中良好定殖,这为青春双歧杆菌在猫用功能性食品中的应用提供了重要的理论和实践基础。展开更多
Psychological studies on human subjects show that contrast detection learning promote learner＇s sensitivity to visual stimulus contrast. The underlying neural mechanisms remain unknown. In this study, three cats （Fe...Psychological studies on human subjects show that contrast detection learning promote learner＇s sensitivity to visual stimulus contrast. The underlying neural mechanisms remain unknown. In this study, three cats （Felis catus） were trained to perform monocularly a contrast detection task by two-altemative forced choice method. The perceptual ability of each cat improved remarkably with learning as indicated by a significantly increased contrast sensitivity to visual stimuli. The learning effect displayed an evident specificity to the eye employed for learning but could partially transfer to the naive eye, prompting the possibility that contrast detection learning might cause neural plasticity before and after the information from both eyes are merged in the visual pathway. Further, the contrast sensitivity improvement was evident basically around the spatial frequency （SF） used for learning, which suggested that contrast detection learning effect showed, to some extent, a SF specificity. This study indicates that cat exhibits a property of contrast detection learning similar to human subjects and can be used as an animal model for subsequent investigations on the neural correlates that mediate learning-induced contrast sensitivity improvement in humans.展开更多
文摘【目的】选育能够适应猫胃肠环境且具有良好肠道定殖能力的猫源青春双歧杆菌菌株。【方法】从长寿猫和普通猫的粪便中分离出青春双歧杆菌,通过生长量测试和小鼠寿命试验选育得到原始菌株QC-Y(寿命延长率达33.85%),经鉴定该菌为青春双歧杆菌。QC-Y经辐射诱变后,通过生长量测试、胃肠耐受性驯化和评价选育得到QC-Y-09。【结果】QC-Y-09的生长量、耐受性评分分别是QC-Y的55.667倍和5.66倍,其对猫胃肠环境的耐受能力具有良好的遗传稳定性。第10代QC-Y-09菌株在人工胃液、肠液、无氧和微氧环境中的存活率分别为18.80%、41.60%、93.26%和48.39%,分别达到0代的62.67%、108.53%、97.92%和94.40%。猫肠道定殖试验表明,QC-Y-09在猫体内的定殖能力显著优于QC-Y和人源青春双歧杆菌。停止饲喂菌剂7 d后,QC-Y-09组猫粪便中青春双歧杆菌活菌仍有4.37 lg CFU/g,分别比QC-Y组和人源组高1.74 lg CFU/g和3.02 lg CFU/g。此外,QC-Y-09对猫换粮应激具有较好的缓解作用,能降低猫换粮应激率85.71%。SNP分析结果表明QC-Y-09在基因层面与QC-Y有显著差异,主要富集在核糖体结构和氨基酰基-tRNA生物合成的通路上。【结论】本研究选育的猫源青春双歧杆菌QC-Y-09菌株能够有效适应猫胃肠环境并在猫肠道中良好定殖,这为青春双歧杆菌在猫用功能性食品中的应用提供了重要的理论和实践基础。
基金Supported by Natural Science Foundation of Anhui Province(070413138)the foundation of Key Laboratory of Anhui Province and the Key Research Foundation from Education Department of Anhui Province(KJ2009A167)
文摘Psychological studies on human subjects show that contrast detection learning promote learner＇s sensitivity to visual stimulus contrast. The underlying neural mechanisms remain unknown. In this study, three cats （Felis catus） were trained to perform monocularly a contrast detection task by two-altemative forced choice method. The perceptual ability of each cat improved remarkably with learning as indicated by a significantly increased contrast sensitivity to visual stimuli. The learning effect displayed an evident specificity to the eye employed for learning but could partially transfer to the naive eye, prompting the possibility that contrast detection learning might cause neural plasticity before and after the information from both eyes are merged in the visual pathway. Further, the contrast sensitivity improvement was evident basically around the spatial frequency （SF） used for learning, which suggested that contrast detection learning effect showed, to some extent, a SF specificity. This study indicates that cat exhibits a property of contrast detection learning similar to human subjects and can be used as an animal model for subsequent investigations on the neural correlates that mediate learning-induced contrast sensitivity improvement in humans.
