我国两个不同地区猪繁殖和呼吸综合征病毒分离株ORF5基因序列比例

To elucidate the characteristics of molecular epidemiology of PRRSV in China, the nucleotide sequence of open reading frame 5 (ORF5) coding regions from two wild PRRSV strains, J1 and S1, isolated in northern and mid-eastern regions of China was determined by RT-PCR. Comparison showed that only 4 different bases between J1 and S1 strains resulted in 3 amino acid (aa. )changes in their deduced proteins. There were 3 and 2 different aa. between the deduced aa. sequences of J1, S1 strains and the American prototype ATCC virus VR2332 respectively, while there existed 16 and 15 aa. changes between the 2 isolates and the modified live vaccine strains derived from VR2332. The putative protein molecular weight, isoelectric point, signal region, glycosylation site and possible transmembrane helices of ORF5 of each strains were similar to that of VR2332 strain. These results showed that the two isolates belong to the same genotype and they may come from USA.

姬松茸新菌株J_3的细胞生物学鉴定与菌盖不同部位微量元素含量分析

利用扫描电镜和X射线能谱仪对姬松茸菌株J3与原菌株J1子实体的菌盖皮、菌盖内和菌褶中常见的微量元素S、P、Ca、K、Fe、Cu和Zn进行了测定,计算了它们的相对重量百分比。利用扫描及透射电境观察姬松茸菌株J3与原菌株J1菌丝体、子实体的表面和内部结构。结果表明菌盖皮、菌盖内和菌褶均含上述各种微量元素,但含量各不相同;姬松茸J3菌丝表面有明显竹节状,在菌丝的外部形态特征上不同于原菌株J1。此外,姬松茸J3细胞壁厚,而出现重度质壁分离;姬松茸菌株J3子实体中淀粉粒、线粒体均比原菌株J1多。由此,说明姬松茸J3与原菌株J1在细胞学特性存在一定差异。

^(60)Co诱变姬松茸突变株J_3与原菌株J_1的比较研究

通过姬松茸60Co辐射诱变育种获得突变株J3,测定并比较研究了60Co辐射诱变姬松茸突变株J3与原菌株J1 子实体的产质量,氨基酸、微量元素和重金属镉含量的变化。结果表明,突变株J3子实体的产量、儿童氨基酸、鲜味氨基酸、甜味氨基酸、必需氨基酸、支链氨基酸和芳香族氨基酸以及微量元素Fe、Mn、Ti和Mo含量均高于原菌株J1;而重金属镉(Cd)含量仅为原菌株J1的36．19％,克服了姬松茸镉含量超标的问题,具有一定的开发价值。