Phylogenetic analysis of the genus Anaplasma in Southwestern China based on 16S rRNA sequence

To identify the species within the genus Anaplasma circulating among ruminants in the Southwest of China, we performed the phylogenetic analysis of the 16S rRNA gene of two Anaplasma isolates from cattle and seven from goats. The two sequences obtained from cattle strains belonged to the A. marginale cluster, whereas the other seven sequences from caprine strains formed two Anaplasma spp. clusters, which diverged earlier than the clusters of A. marginale, A. centrale and A. ovis. These results indicate that there are at least two Anaplasma species circulating among ruminants in Southwestern China.     

具有抗菌活性红树林土壤放线菌BH0951的分离和鉴定

以广西北海红树林高盐泥样为材料,采用高氏1号培养基对其中的菌株进行分离纯化,通过抗菌试验筛选出1株放线菌BH0951,该菌株的发酵产物具有较强的抗菌活性,其最适生长温度为28℃,最适生长pH值为7.0。提取其总DNA,采用通用引物对其16S rDNA进行PCR扩增,并对扩增产物进行序列测定。结果表明,BH0951为链霉菌属（Streptomyces aurantiogriseus）AY999773的变种。     

两系杂交稻绿敏S/L24在安徽霍山示范表现及高产栽培技术

绿敏S/L24是安徽省农业科学院水稻研究所育成的两系杂交稻新组合,从产量、农艺性状、生育期、抗性及米质等方面阐述了绿敏S/L24的特征特性,并从播种、育秧、肥水管理及病虫害防治等方面总结了其高产栽培技术。     

免疫乳对断奶仔猪免疫功能的影响

[目的]研究免疫乳对断奶仔猪免疫功能的影响。[方法]将30头断奶仔猪随机分为3组,即抗大肠杆菌免疫乳组、抗沙门氏菌免疫乳组和对照组,10头/组,分别饲喂抗体滴度均为28抗大肠杆菌免疫乳、抗沙门氏菌免疫乳和普通常乳。饲喂方法为经口灌服,20ml/次,2次/d,持续2周。2周后,测定血清中总蛋白、白蛋白、球蛋白、IgA、IgM和IgG含量、血清抗体水平和淋巴细胞转化率。[结果]免疫乳能显著提高断奶仔猪血清中总蛋白、白蛋白、球蛋白、IgA、IgM和IgG的含量,血清中抗体水平以及淋巴细胞转化率（P〈0.05）。[结论]口服免疫乳可明显增强仔猪免疫力。     

Sortase anchored proteins of Streptococcus uberis play major roles in the pathogenesis of bovine mastitis in dairy cattle

Streptococcus uberis, strain 0140J, contains a single copy sortase A (srtA), encoding a transamidase capable of covalently anchoring specific proteins to peptidoglycan. Unlike the wild-type, an isogenic mutant carrying an inactivating ISS1 insertion within srtA was only able to infect the bovine mammary gland in a transient fashion. For the first 24 h post challenge, the srtA mutant colonised at a similar rate and number to the wild type strain, but unlike the wild type did not subsequently colonise in higher numbers. Similar levels of host cell infiltration were detected in response to infection with both strains, but only in those mammary quarters infected with the wild type strain were clinical signs of disease evident. Mutants that failed to express individual sortase substrate proteins (sub0135, sub0145, sub0207, sub0241, sub0826, sub0888, sub1095, sub1154, sub1370, and sub1730) were isolated and their virulence determined in the same challenge model. This revealed that mutants lacking sub0145, sub1095 and sub1154 were attenuated in cattle. These data demonstrate that a number of sortase anchored proteins each play a distinct, non-redundant and important role in pathogenesis of S. uberis infection within the lactating bovine mammary gland.     

“3S”技术在草地鼠虫害监测与预测中的应用

日益严重的草地鼠虫害,己成为引发草原退化、沙化、水土流失的重要因素之一,并威胁我国草地畜牧业的可持续发展。"3S"技术作为一种综合性技术手段,具有探测范围广、信息量大、成本低、受地面条件限制和人为因素影响小等特点,可实现对各种空间信息和环境信息的快速、机动、准确、可靠的收集、处理与更新。这一技术与地面调查资料的结合,不仅加快了对草地资源的宏观监测速度,而且能够快速、准确地反映草地鼠虫害的变化动态。结合鼠虫害发生的特点,重点概述了运用"3S"技术对草地鼠虫害进行监测的原理、方法及存在的问题,并分析了该领域未来的研究重点和"3S"技术的应用前景。     

几株家蚕蛹油降解细菌的分离鉴定与降解能力测定

利用稀释培养法从缫丝废水中分离到5株可降解家蚕蛹油的细菌,采用紫外分光光度法测定了其对家蚕蛹油的降解能力,H73、H23、H1、H5和H43菌株在72 h内对家蚕蛹油的降解率分别达到76.36%、62.04%、60.58%、53.85%和51.20%。通过形态特征、生理生化特性测定和16S rDNA序列系统发生分析对各菌株进行鉴定,其中H23、H1和H43为芽孢杆菌属(Bacillus sp.),H5为微杆菌属(Microbacterium sp.),H73为肠杆菌属(Enterobacter sp.)。     

自花结实鸭梨品种自交亲和分子机理研究

对鸭梨及其自花结实变异品种-金坠梨和魏县阎庄自花结实鸭梨的S基因进行了研究。通过对3个品种基因组DNA进行S基因特异性PCR扩增,扩增产物经2%琼脂糖凝胶电泳检测发现,在370 bp左右均扩增出了1条带,但不能区分2个S等位基因;经8%聚丙烯酰胺凝胶电泳检测发现,鸭梨和金坠梨在370 bp左右有2条带,而魏县阎庄自花结实鸭梨只有1条带,表明魏县阎庄自花结实鸭梨系鸭梨的1个S基因发生了变异,从而导致自交亲和;进一步研究表明,魏县阎庄自花结实鸭梨S1基因正常,系S21基因发生了变异,导致自交亲和;金坠梨和鸭梨谱带无差别,自交亲和机理可能是调控S基因表达的修饰基因发生了变异,导致自交亲和。     

肠艾美尔球虫纯种分离及18S rDNA部分序列测定

采用单卵囊分离技术,分离肠艾美尔球虫。根据GenBank中发表的肠艾美尔球虫18SrDNA序列,设计一对引物,建立PCR方法对其基因片段扩增并测序、比对。结果成功分离肠艾美尔球虫,PCR扩增出清晰条带,大小为528bp,最低能检出27个孢子化卵囊。该序列测定结果与Genebank发表的肠艾美尔球虫18SrDNA比对,相似性达98.5%。     

日本血吸虫谷胱甘肽硫转移酶原核表达载体的构建及序列分析

为构建带有组氨酸标签(his-tag)的日本血吸虫谷胱甘肽硫转移酶(sjGST)表达载体。以载有sjGST基因的载体PGEX-KG为模板,PCR扩增sjGST基因,并在进行酶切和基因测序后将其克隆到pET28a载体上。运用生物学软件与具有代表性的血吸虫GST基因进行比对并对可能的表达产物进行分析。结果表明,PCR产物与3种sjGST基因有99%的同源性。重组载体构建成功。