15个鸡群体IL-2基因的遗传变异分析

为了深入研究鸡IL-2基因的多态性及为鸡抗病育种提供理论依据,本研究以IL-2基因为研究对象,采用直接测序的方法对11个中国地方鸡品种、3个引进鸡品种和1个培育鸡品种共448个个体该基因的遗传变异进行了分析。通过DNA池和直接测序技术,共发现了13个突变位点。对所有个体的一段包含5个SNPs的区域进行分析,发现不同等位基因在15个鸡群体间分布存在显著差异,表明不同品种间IL-2基因具有丰富的遗传变异资源,可为抗病基因的选择提供素材;群体遗传学指标分析表明,H系京星黄鸡的遗传多样性最低,这与其品种形成过程一致,其他品种多样性差异不大;单倍型分析共发现23种单倍型,其中H1(CAACG)、H2(CAATT)、H4(TGTTG)、H9(TGTTG)、H11(TATCG)和H16(CATCG)为中国地方鸡品种特有或优势单倍型,可能与抗病能力相关。     

生物钟基因在绒山羊皮肤中表达模式的比较

文章旨在研究绒山羊皮肤生物钟基因clock、tim、per1和cry1的表达模式,进而分析其在绒山羊皮肤组织中的作用及相互关系。生物钟基因形成一个转录-翻译反馈环,通过钟基因在绒山羊皮肤生长周期进行高表达,激活per1和cry1基因的转录-转化过程,从而在mRNA和蛋白水平的调控下进行有节律的表达。结果表明,这些生物钟基因在绒山羊皮肤中的表达量依次为:clocktimper1cry1;皮肤次级毛囊兴盛期,高振幅clock、per1、tim、cry1的节律表达分别出现在一天中的04∶00、08∶00、08∶00、16∶00;皮肤次级毛囊休止期,这些基因的高振幅节律表达分别出现在一天中的08∶00、04∶00、04∶00、16∶00。另外,cry1、per1基因的表达在生物钟基因正反馈循环中被激活,tim基因的表达在生物钟基因的负反馈循环中被激活。因此,clock、tim、per1和cry1调控下运行的钟基因反馈环是绒毛生长呈周期性现象的基础。     

Effect of Heat Shock Protein-90 (HSP-90) mRNA Expression in Intestinal Tissuse of Chickens Infected with E.necatrix

The 90 chickens were randomly divided into control group, E.necatrix one time infection group and E.necatrix two times infection group.We used duplex PCR method to test the expression changes of HSP-90 mRNA in intestinal tissue of chickens infected with E.necatrix and researched the effects of it comprehensively and systematically.The results were showed that after 0 to 14 days the expression of HSP-90 mRNA in intestinal tissues of 14-day-old chickens infected with E.necatrix presented a upward trend though it was lower than the control chickens.These chickens were infected with E.necatrix again at 28 days, HSP-90 mRNA expressions of duodenum, jejunum and ileum decreased and then increased.However, it always showed a downward trend in appendix.When 28 days chickens were infected with high-does E.necatrix once, HSP-90 mRNA expressions of duodenum, jejunum and appendix were in a declining curve.While it was increased originally and then decreased in ileum.This study indicated that HSP-90 mRNA expressions in intestinal tissue of chickens infected with E.necatrix were inhibited at first, and the expression quantity was closely related to the degrees of intestinal tissue damage.     

Advance on Foot-and-mouth Disease Virus

Foot-and-mouth disease (FMD) is an acute,febrile and highly contagious animal disease caused by foot-and-mouth disease virus (FMDV),and has been recognized as the most important constraint to international trade in animals and animal products.An outstanding feature for FMDV infection is that the FMDV infected animals may remain as a carrier state,some of the animals exposed to FMDV may have a long term asymptomatic infection.This article will review the advance of FMDV in the following aspects,epidemiology,etiology and pathogenesis.     

枸杞多糖对雏鸡新城疫免疫效果的影响

为了研究枸杞多糖对雏鸡的免疫调节作用,将400羽1日龄雏鸡随机分为A、B、C、D共4组。7日龄时,分别给予A、B组雏鸡灌服10 mg/kg和20 mg/kg的枸杞多糖各5 m L,C、D组灌服同等剂量的生理盐水。给药的同时,A、B、C组滴鼻和点眼免疫新城疫Ⅳ系疫苗,D组不作处理。分别于7、14、21、28和35日龄时,采用微量法HI试验测定各组雏鸡新城疫抗体效价。分别于免疫后的第7、14、21、28和35天,计算各组雏鸡的免疫器官指数。试验结果显示,A、B组的新城疫抗体效价和各免疫器官指数明显高于C、D组,提示枸杞多糖对鸡新城疫疫苗的免疫效果具有明显的增强作用,且能够促进雏鸡中枢及外周免疫器官的发育。     

动物运输应激源与应激反应影响因子研究进展

动物的运输是畜牧业的重要生产环节,但运输活动带来的动物福利问题也越来越受到关注。开展动物运输应激源和应激反应影响因子的研究,对深入认识动物运输应激本质和提出解决方案乃至相关立法具有重要意义。论文对前人开展的动物运输应激源(拥挤、禁食禁水、气温、装卸、颠簸等)的分离研究和应激反应影响因子(运输距离和运输时间、年龄和经验、性情、恐惧信息素)的研究进行了回顾整理,并分析了争议的原因,为动物运输应激领域研究提供参考或指出新的研究方向。     

Why cuckoos should parasitize parrotbills by laying eggs randomly rather than laying eggs matching the egg appearance of parrotbill hosts?

The coevolutionary interaction between cuckoos and their hosts has been studied for a long time, but to date some puzzles still remain unsolved. Whether cuckoos parasitize their hosts by laying eggs randomly or matching the egg morphs of their hosts is one of the mysteries of the cuckoo problem. Scientists tend to believe that cuckoos lay eggs matching the appearance of host eggs due to selection caused by the ability of the hosts to recognize their own eggs.In this paper, we first review previous empirical studies to test this mystery and found no studies have provided direct evidence of cuckoos choosing to parasitize host nests where egg color and pattern match. We then present examples of unmatched cuckoo eggs in host nests and key life history traits of cuckoos, e.g. secretive behavior and rapid egg-laying and link them to cuckoo egg laying behavior. Finally we develop a conceptual model to demonstrate the egg laying behaviour of cuckoos and propose an empirical test that can provide direct evidence of the egg-laying properties of female cuckoos. We speculate that the degree of egg matching between cuckoo eggs and those of the host as detected by humans is caused by the ability of the hosts to recognize their own eggs, rather than the selection of matching host eggs by cuckoos. The case of Common Cuckoos(Cuculus canorus) and their parrotbill hosts(Paradoxornis alphonsianus), where it has been shown that both have evolved polymorphic eggs(mainly blue and white), was used to develop a conceptual model to demonstrate why cuckoos should utilize parrotbill hosts by laying eggs randomly rather than laying eggs matching the appearance of host eggs.In conclusion, we found no evidence for the hypothesis that cuckoos lay eggs based on own egg color matching that of the parrotbill-cuckoo system. We argue theoretically that laying eggs matching those of the hosts in this system violates a key trait of the life history of cuckoos and therefore should be maladaptive.     

刨花长度及板坯铺装结构对麦秸板性能的影响

以长秸秆刨花、短秸秆刨花为原料,分别制备单层定向、三层定向和非定向等三种不同铺装结构的秸秆刨花板,研究刨花长度与板坯铺装结构对麦秸板性能的影响。结果表明,按本试验设定工艺参数制备的试板,性能均可达到LY/T 2141-2013《定向结构麦秸板》干状承载型板材的要求。实际生产中,可依据目标产品的应用领域,选择适宜的刨花长度和板坯结构。     

森林旅游景区生态安全要素及其景观感知传递性分析

剖析森林旅游景区生物资源等要素的生态安全状态及其相应的景观感知,以及它们之间的传递关系,建立森林旅游景区生态安全与景观感知安全传递关系模型。通过对景区生态安全各要素的分析发现,在景区开发、游客干扰等人类活动的干扰下,我国一些森林旅游景区水体、土壤、空气、声音环境受到严重污染,动植物生长生存条件发生退化,并对游客的景观感知产生了显著的负面影响。对景区生态安全与景观感知安全的传递性分析表明,景观感知安全是人类活动对自然资源的影响转移到自身的一种反映,它对景区生态安全状态有一定的预知作用。在此基础上,结合景区生态安全与景观感知安全之间的传递关系,和对景区生态安全构念的分析,建立了包括生物生存环境安全和生物资源安全要素在内的森林旅游景区生态安全结构,及其与景观感知安全之间的传递关系模型。     

10种常绿阔叶树种理化性质的研究

常绿阔叶树种是森林的主要植物种类,具有含水率高的特点。选择石栎Lithocarpus glaper、拟赤杨Alniphyllum tortunei、冬青Ilex chinensis、樟树Cinnamomum philippinense、木荷Schima superba、罗浮栲Castanopsis fabri、山杜英Elaeocarpus decipiens、甜槠Castanopsis eyrei、苦槠Castanopsis sclerophylla、油茶Camellia oleifera 10种常绿阔叶树种,采集不同树种的树叶、树枝和树皮,烘干粉碎后在室内进行理化性质的测定分析,以不同树种器官的含水率、热值、燃点、木质素、粗纤维、粗灰分、粗脂肪7个指标作为评价因素,对10个树种的抗火性进行聚类分析,结果表明:抗火性强的是冬青;抗火性较强的有3种,由强到弱依次是油茶、山杜英、拟赤杨;抗火性一般的有2种,由强到弱依次是苦槠、石栎;抗火性较弱的有4种,由强到弱依次是木荷、樟树、甜槠、罗浮栲。研究结果能为防火树种的筛选提供理论依据。