常规PCR、实时定量PCR检测传染性皮下及造血器官坏死病毒的效果分析

对虾传染性皮下及造血器官坏死病毒(IHHNV)可感染世界各地养殖对虾,给对虾养殖业造成严重经济损失。本实验首次采用实时定量PCR法对广西地区的84份凡纳滨对虾样品进行检测,同时以常规PCR检测作对照。实时定量PCR检测阳性率为79·8%,常规PCR检测阳性率为40·5%,表明广西地区养殖的凡纳滨对虾IHHNV的感染率较高。将二者检测均呈阳性的30份样品扩增产物进行序列分析测序,测序结果通过DNA STAR软件包进行分析,并通过NCBI Blast与GenBank中的序列进行比对。结果证明,测定的是IHHNV序列。30份样品的IHHNV序列很保守,可以分为4种类型,仅有两个碱基的位置发生变异。实时定量PCR检测IHHNV,快速、灵敏、准确,特异性好,可以作为检测对虾感染病毒的有效方法。     

Characterization of porcine Trueperella pyogenes by matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS), molecular typing and antimicrobial susceptibility profiling in Sao Paulo State

Trueperella pyogenes can be found as a commensal or pathogenic bacterium among animals causing a variety of pyogenic infections in several species. The agent appears to act primarily as an opportunistic pathogen but may disseminate and produce metastatic abscesses accompanied or not by mastitis, metritis or pneumonia. In this study, 30 porcine T. pyogenes strains were identified by MALDI-TOF MS and 16S rRNA sequencing and further evaluated in relation to their resistance and genetic profiles through broth microdilution and single enzyme AFLP. All strains were susceptible to β-lactams, florfenicol, gentamicin, spectinomycin and tiamulin. The highest resistance rates were observed for sulfonamides, tetracyclines and clindamycin. All isolates could be characterized by SE-AFLP presenting more than 80% of similarity, despite their distinct origins. Four genotypes were detected with the segregation of T. pyogenes ATCC 19411 from Brazilian T. pyogenes strains. No correlation between genotypes and isolates origins and susceptibility profile was observed.     

Polymorphisms in MCT1, CD147, PDK4, and DMRT3 genes in Arabian and Quarter Horses

Monocarboxylate transporter isoform 1 (MCT1) and its ancillary protein, CD147 function to transport H⁺ and lactate ions, retarding systemic acidosis and fatigue. The PDK4 gene is involved in the adenosine triphosphate production, and the DMRT3 gene is involved in the locomotor system. This study investigated polymorphisms of MCT1, CD147, PDK4, and DMRT3 in Arabian and Quarter Horses to associate polymorphisms with performance. Arabian Horses were divided into high performance and untrained horses groups based on success in endurance competition, whereas Quarter Horses were separated by a speed index. Polymorphisms were analyzed by sequencing (MCT1 and CD147), ARMS-PCR (PDK4), and PCR-RFLP (DMRT3). To compare the frequencies of SNPs, the Fisher's exact test was performed in the software R at 5% of significance. The A alleles from the polymorphisms Lys457Gln:1573A>C of MCT1 and Ile51Val:168A>G of CD147 were essentially fixed in both breeds. Only two Arabian from the high performance and one from the untrained horses group appeared AC in MCT1. For the DMRT3 polymorphism (g.22999655C>A:ECA23), all the animals were CC, except one Arabian in the high and two Quarter Horses in the low performance group that were AC. For the PDK4 polymorphism (g.38973231A>G:ECA4), Arabian showed a significantly greater frequency of the G allele than Quarter Horses (P < .01). Considering the kind of exercise practiced by each breed, it is likely that the PDK4 polymorphism influences the pathway to energy production.     

国际棉花基因组测序计划解读

通过对陈增建等2007年发表于美国《植物生理学》的《棉花基因组测序白皮书》等文章的综合理解,来解读国际棉花基因组测序的意义与展望,以及国际基因组织在棉花基因组测序的方法、重点突破方向、目标等方面达成的共识。为棉花种质研究和品种改良提供参考。     

单细胞测序技术及其在畜牧科学研究中的应用

单细胞测序(Single Cell Sequencing)是对单个细胞进行测序后利用生物信息学等手段进行分析的技术,包括单细胞分离、扩增测序和数据分析3个方面,主要应用于肿瘤、胚胎发育、免疫学等方面。随着单细胞测序技术的迅速发展,单细胞测序技术已成为研究细胞发育中基因组、转录组和表观基因组异质性的重要工具。单细胞测序可以获取单个细胞完整的全基因组,克服了大样本量、细胞异质性等问题,为研究细胞间异质性信息和细胞群体之间关系提供了新的研究策略。本文就单细胞测序方法及其在畜牧科学研究中的应用进行综述,并探讨其应用前景。     

琯溪蜜柚果肉过氧化物酶cDNA的克隆及序列分析

以琯溪蜜柚果肉为材料,运用cDNA克隆的方法,克隆得到了琯溪蜜柚果肉过氧化物酶的cDNA的全长,并对得到的序列进行了一些分析,从分子生物学角度对粒化的研究做了初步的探索。结果表明:琯溪蜜柚果肉PODcDNA全长1263bp,有完整的阅读框,编码351个氨基酸。另外5''非翻译区42bp,3''非翻译区168bp(不包含终止密码子TAA),其中包括一个多聚腺苷酸化信号AATAAA,以及一个含24个腺苷酸的poly(A)尾。由琯溪蜜柚果肉PODcDNA推导的氨基酸序列与无花果(Fi-cuscarica)、陆地棉(Gossypiumhirsutum)、杨属植物(Populus)等同源性较高,分别为:58.6%,67.61%,65.24%,67.14%等。     

卡氏住白细胞虫rDNA ITS-2的POR扩增与测序

运用PCR方法扩增了卡氏住白细胞虫rDNA的ITS-2及部分5．8S和28S序列(ITS2 )，并对该序列进行了克隆和测序。采用巨型裂殖体为材料，并根据Saccharomyces cerevisiae rDNA中的5．8S、28S保守序列所设计的通用引物ITS3、ITS4，进行了虫体ITS2 的PCR扩增，将所扩增片段纯化后成功地克隆于pGEM-T easy和PMDl8-T载体的T-T窗口。经双向自动测序显示，该ITS2 片段的大小为270bp；经NCBI Blast联机检索，结果显示，所扩片段中5．8S序列与S．cerevisiae的5．8S序列有部分相同，而ITS-2序列为虫体所特有；同时经wDNA-SIS软件分析，显示该ITS-2序列与S．cerevisiae间同源性相对较远，而与柔嫩艾美耳球虫间同源性相对较近，故而本试验中所测序列为卡氏住白细胞虫的ITS-2特有序列。     

The effect of pharmaceutical waste-fungal biomass,treated to degrade DNA,on the composition of eubacterial and ammonia oxidizing populations of soil

The aim of this work was to study variations in the composition of eubacteria and ammonia-oxidizing populations of soil, both determined by denaturing gradient gel electrophoresis (DGGE), after the addition of a pharmaceutical fungal biomass, treated to degrade its DNA. This waste can be used as an amendment. The fungal biomass waste was added at three rates: 0.05, 0.1, and 1% per dry weight of soil. Control soil, without any amendment, was also investigated. Total DNA was extracted, purified, and amplified by using either universal (eubacteria) or specific (amoA) primers. Amplicons were separated by DGGE. Sequencing was also carried out to better assess the diversity of ammonia oxidizing bacteria. Changes in the composition of eubacterial community were detected after 3 days only in the soil treated with the highest dose, while the ammonia oxidizing population responded more promptly (after 1 day) with evident modifications at level of Nitrosolobus like sequences.     

蓖麻蚕线粒体基因组中nd1及其侧翼tRNA基因的克隆与结构分析

按KoichiroTamura等 (1988)的方法制备出蓖麻蚕线粒体DNA ,用EcoRⅠ和XbaⅠ双酶解后 ,以pSK(+)(Ampr)为载体进行克隆 ,获得 1个 3 3kb的克隆片段。测序结果表明 ,所测序列包括部分 16SrRNA、完整的tRNA Leu ,nd1和tRNA Ser基因。其中 16SrRNA(3’端部分 )、nd1基因与家蚕具有很高的同源性。同时以nd1基因为依据构建了 17种动物的分子进化树 ,显示出蓖麻蚕与家蚕、野蚕有最近的演化关系。根据tRNA Leu和tRNA Ser基因的一级结构 ,推定了可能的二级结构 ,并与家蚕进行了比较。