可遗传与非可遗传构件应用与转基因动物食品安全评价介绍

近年来基因工程技术不断发展,转基因生物及其产品如雨后春笋般不断涌现,随之而来的转基因食品安全问题也逐渐引起关注和重视。可遗传与非可遗传构件的应用作为生产转基因动物的方法,其存在的潜在风险与巨大的发展前景共存。作者就可遗传与非可遗传构件应用及与转基因动物食品安全评价的关系进行了介绍和讨论,并对其未来的发展做出展望。     

Visual landmark‐directed scatter‐hoarding of Siberian chipmunks Tamias sibiricus

Spatial memory of cached food items plays an important role in cache recovery by scatter‐hoarding animals. However, whether scatter‐hoarding animals intentionally select cache sites with respect to visual landmarks in the environment and then rely on them to recover their cached seeds for later use has not been extensively explored. Furthermore, there is a lack of evidence on whether there are sex differences in visual landmark‐based food‐hoarding behaviors in small rodents even though male and female animals exhibit different spatial abilities. In the present study, we used a scatter‐hoarding animal, the Siberian chipmunk, Tamias sibiricus to explore these questions in semi‐natural enclosures. Our results showed that T. sibiricus preferred to establish caches in the shallow pits labeled with visual landmarks (branches of Pinus sylvestris, leaves of Athyrium brevifrons and PVC tubes). In addition, visual landmarks of P. sylvestris facilitated cache recovery by T. sibiricus. We also found significant sex differences in visual landmark‐based food‐hoarding strategies in Siberian chipmunks. Males, rather than females, chipmunks tended to establish their caches with respect to the visual landmarks. Our studies show that T. sibiricus rely on visual landmarks to establish and recover their caches, and that sex differences exist in visual landmark‐based food hoarding in Siberian chipmunks.     

Resistance patterns and detection of aac(3)-IV gene in apramycin-resistant Escherichia coli isolated from farm animals and farm workers in northeastern of China

The aminoglycoside apramycin has been used widely in animal production in China since 1999. This study was aimed to investigate the resistance pattern of apramycin-resistant Escherichia coli isolated from farm animals and farm workers in northeastern of China during 2004–2007 and to determine whether resistance to apramycin was mediated by plasmid containing the aac(3)-IV gene and the mode for the transfer of genetic information between bacteria of farm animals and farm workers. Thirty six E. coli isolates of swine, chicken, and human origins, chosen randomly from 318 apramycin-resistant E. coli isolates of six farms in northeastern of China during 2004–2007, were multi-resistant and carried the aac(3)-IV gene encoding resistance to apramycin. Conjugation experiments demonstrated that in all 36 cases, the gene encoding resistance to apramycin was borne on a mobilisable plasmid. Homology analysis of the cloned aac(3)-IV gene with the sequence (accession no. X01385) in GenBank showed 99.3% identity at a nucleotide level, but only with a deletion of guanosine in position 813 of the gene in all 36 cases. The results indicted that resistance to apramycin in these isolates was closely related to aac(3)-IV gene. Therefore, the multi-resistance of E. coli could complicate therapeutic practices for enteric infections in both farm animals and human.     

大鼠骨肉瘤模型的建立

为建立大鼠骨肉瘤动物模型的方法, 用30只6周龄SD大鼠随机分为3组,将大 鼠骨肉瘤细胞系UMR 106分别以105,106, 107个数量注入大鼠股外侧皮下。接种后,每 周观察肿瘤生长情况,测量肿瘤直径,绘制肿 瘤生长曲线,连续5周。第6周取肿瘤病理 材料,常规切片,HE染色,光镜下观察。结果 105个细胞及106个细胞组肿瘤生长情况不 佳;107个细胞组肿瘤发生率达到100%。说 明大鼠骨肉瘤细胞系UMR 106具有较强的 致瘤性,应用该细胞系建立的动物模型为骨 肉瘤综合治疗奠定了动物实验基础。     

Prevalence and antimicrobial resistance of Klebsiella species isolated from clinically ill companion animals

BackgroundKlebsiella spp. is an important conditional pathogen in humans and animals. However, due to the indiscriminate use of antibiotics, the incidence of antimicrobial resistance has increased.ObjectivesThe purpose of this study was to investigate antimicrobial resistance in strains of Klebsiella strains and the phylogenetic relatedness of extended-spectrum cephalosporin (ESC)-resistance among Klebsiella strains isolated from clinically ill companion animals.MethodsA total of 336 clinical specimens were collected from animal hospitals. Identification of Klebsiella species, determination of minimum inhibitory concentrations, detection of ESC resistance genes, polymerase chain reaction-based replicon typing of plasmids by conjugation, and multilocus sequence typing were performed.ResultsForty-three Klebsiella strains were isolated and, subsequently, 28 were identified as K. pneumoniae, 11 as K. oxytoca, and 4 as K. aerogenes. Eleven strains were isolated from feces, followed by 10 from ear, 7 from the nasal cavity, 6 from urine, 5 from genitals, and 4 from skin. Klebsiella isolates showed more than 40% resistance to penicillin, cephalosporin, fluoroquinolone, and aminoglycoside. ESCresistance genes, CTX-M groups (CTX-M-3, CTX-M-15, and CTX-M-65), and AmpC (CMY-2 and DHA-1) were most common in the K. pneumoniae strains. Some K. pneumoniae carrying CTX-M or AmpC were transferred via IncFII plasmids. Two sequence types, ST709 and ST307, from K. pneumoniae were most common.ConclusionsIn conclusion, this is the first report on the prevalence, ESCresistance genotypes, and sequence types of Klebsiella strains isolated from clinically ill companion animals. The combination of infectious diseases and antimicrobial resistance by Klebsiella in companion animals suggest that, in clinical veterinary, antibiotic selection should be made carefully and in conjunction with the disease diagnosis.     

加权基因共表达网络分析在畜禽研究中的应用

为了解加权基因共表达网络分析(Weighted gene co-expression network analysis,WGCNA)方法在畜禽中的应用研究,本文对近年来国内外通过WGCNA方法对牛、羊、猪、禽等畜禽进行研究的相关文献进行了整理与分析,总结了WGCNA方法应用的一般分析流程、策略及畜禽WGCNA的研究现状。结果表明:WGCNA是一种系统生物学的方法,可分析转录组、蛋白组、代谢组、DNA甲基化和单细胞转录组等高通量数据,解析分子间调控的表达模式,确定关键调控因子;在畜禽的研究中,WGCNA方法已经广泛应用在生长性状、繁殖性状、抗病性状和品质性状等复杂性状的优势功能因子的挖掘。综上,WGCNA方法对分析组学数据具有较强的优势,可为畜禽重要经济性状的挖掘,阐明性状生物学机制提供助力。     

肾虚肝郁证迟发性性腺功能减退症大鼠模型的建立与评价

目的 建立“肾虚肝郁证”迟发性性腺功能减退症（Late onset hypogonadism,LOH）动物模型,并对其进行评价。方法 以中医理论“房劳过度伤肾”、“郁久伤肝”为指导,采用“退役种鼠（40周龄）+复合情志刺激+孤养”方法,建立“肾虚肝郁证”LOH动物模型,与正常组（8周龄）比较,以血清总睾酮、悬尾实验、睾丸间质细胞超微结构、睾酮合成相关酶以及Caspase-3 mRNA和蛋白表达为指标。结果 模型组大鼠出现一系列典型的LOH精神、心理、体能改变,与正常组比较,模型组大鼠血清总睾酮水平明显降低,悬尾不动时间显著延长,睾丸组织Caspase-3 mRNA和蛋白表达增强,睾酮合成相关酶类固醇激素合成急性调节蛋白（Steroidogenic Acute Regulatory Protein,StAR）^[13]、细胞色素胆固醇侧链裂解酶（Cytochrome P450 side-chain cleavage,P450scc）^[14]、3β-羟甾脱氢酶（3beta-hydroxysteroid dehydrogenase,3β-HSD）mRNA和蛋白表达下降,差异均有统计学意义（P<0.01）;模型组睾丸间质变少,睾丸间质细胞线粒体数量减少,出现水肿,线粒体嵴消失。结论 “退役种鼠+复合情志刺激+孤养”方法复制“肾虚肝郁证”LOH模型切实可行,有较高的实用价值。     

芽孢杆菌作为微生物饲料添加剂的功能及其应用

芽孢杆菌具有促进动物肠道发育、平衡肠道菌群、提高动物免疫和生产性能等功能,被开发作为动物饲料微生态制剂。文章综述了微生物饲料添加剂芽孢杆菌的作用机理、国内应用现状、存在问题及其发展前景等,以期为其在饲料中合理应用提供参考。     

Influence of cropping system and nitrogen input on soil fauna and microorganisms in a Swedish arable soil

Summary The development of a number of components was analysed in an agro-ecosystem study with four cropping regimens, barley without and with N fertilization, grass ley, and lucerne. A great variation in N inputs (1–39 g N m^-2 year^-1) and cropping systems produced a variation in primary production (260–790 g C m^-2 year^-1) and input of organic material to the soil (150–270 g C m^-2 year^-1). This was reflected in variations of total soil animal biomass (1.6–5.1 g C m^-2) and in variations in the abundance of various animal groups, nematodes (5.6–9.8×10⁶m^-2), micro- (2.6–4.8×10^-4 m^-2), and macroarthropods (0.9–4.2×10³ m^-2). In contrast, total bacteria, fungi, flagellates, and amoebae varied quite independently of the organic matter input. Mineralization processes covaried more with C and N inputs and total animal biomass than with microbial biomass. it is suggested that the rather constant microbial biomass was a result of an adjustment in the grazing pressure of microbial-feeding animals to the level of microbial production.Dedicated to the late Prof. Dr. W. Kühnelt     

限制动物跨省区流动的关键措施

限制动物跨省区流动是控制动物疫病传播的关键措施。通过采取无规定动物疫病区管理措施,防疫条件分级管理,建立指定通道,加强动物贩运经纪人资质管理等措施,可以有效限制动物跨省流动,保证养殖业安全和动物产品安全。