甘蔗幼叶切段培养中的体细胞胚胎发生

本文从形态学和组织学方面研究了甘蔗幼叶胚性愈伤组织发生及体细胞胚胎的形成过程。甘蔗幼叶片切段培养于含2.4—D1.5mg/1的MS培养基上,4—6天后切段开始形成愈伤组织,约10天后愈伤组织表面出现白色颗粒状结构。将含有白色颗粒状结构的愈伤组织转移至不含激素的培养基中,7—10天后可见有小植株长出。组织学和形态学观察表明,甘蔗离体再生植株是通过体细胞胚胎发生途径。     

棕色固氮菌缺失nifZ基因的突变种固氮酶MoFe蛋白的纯化和性质

采用 52℃下加热 6 min,后经 DEAE- 52、Sephacryls S- 2 0 0和 Q- Sepharose等柱层析方法 ,分离纯化了棕色固氮菌 (Azotobacter vinelandii)缺失 nif Z基因突变种固氮酶 Mo Fe(Δnif Z Mo Fe)蛋白 ,其纯度达到电泳纯。Δnif Z Mo Fe蛋白的固氮活性为 2 83nmol C2 H2 还原 / (min·mg蛋白 ) ,远低于野生种 Mo Fe蛋白。Δnif Z Mo Fe蛋白对氧更敏感 ;热稳定性略低于野生种。Δnif Z Mo Fe蛋白的可见光吸收光谱与野生种 Mo Fe蛋白极为相似。其圆二色谱和磁圆二色谱在 450～ 550 nm与野生种 Mo Fe蛋白显著不同 ,表明其 P- cluster及其周围环境与野生种 Mo Fe蛋白有所差异。这亦可能是造成缺失 nif Z突变种 Mo Fe蛋白固氮活性低的原因。     

应用流式细胞仪研究抗IL-8单抗对IL-8激活人颗粒细胞活力的中和作用(英文)

以IL-8免疫的BALB/C小鼠脾细胞与Sp2/0或653小鼠骨髓瘤细胞融合构建了淋巴细胞杂交瘤克隆I8-S2和I8-63。ELISA叠加试验(ELISA Additivity Test)表明这两杂交瘤克隆分泌的单抗分别识别IL-8分子的不同表位。IL-8能激活人颗粒细胞,引起细胞内Ca~(2 )浓度([Ca~(2 )]_i)上升。通过流式细胞仪分析[Ca~(2 )]_i的变化,发现两个克隆单抗对IL8激活细胞的活力具有不同的中和作用。克隆I8-S2具有很强的中和作用,而克隆18-63则不然。上述结果提示IL-8的激活细胞活力局限于该分子的某表位。     

src-specific immunity in inbred chickens bearing v-src DNA- and RSV-induced tumors

Serological data identify a single major histocompatibility complex (MHC) class I locus in cattle. Molecular data, however, demonstrate the presence of at least two cattle MHC (BoLA) class I loci. To investigate the number of transcribed BoLA class I genes, we amplified cattle cDNA by using a single MHC class I-specific primer that hybridized to a conserved region of exon 4 and a non-specific 3 primer. Six BoLA class I cDNAs have been cloned and sequenced from a Bos taurus bull heterozygous for BoLA class I serological antigens, demonstrating the presence of a minimum of three loci. Sequence comparisons suggested that one of these cDNAs may be an unexpressed allele or the product of a nonclassical locus.The nucleotide sequence data reported in this paper have been submitted to the GenBank nucleotide sequence database and have been assigned the accession numbers U01186 and U01187.     

The genetic characterisation of novel multi-addition doubled haploid lines derived from triticale x wheat hybrids

Two novel 46-chromosome doubled haploid lines, W66 and M17, derived from separate hexaploid triticale x bread wheat crosses, were characterised using cytological and biochemical markers. Both lines were shown to be relatively stable cytologically, over 11 and 8 generations of selfing, respectively. By examining mitotic and meiotic chromosomes, the stabilities of the two lines were shown to be similar with frequencies of 2n=46 in 74.2–85.5% of cells. However, over selfed generations, the rye chromosomes were shown to have lost some of their heterochromatin, which made it difficult to establish their continued presence using cytological techniques, such as C-banding alone. Cytological evidence from pairing studies, C-banding, and fluorescence in-situ hybridization, showed that both M17 and W66 are wheat/rye multi-addition lines with rye chromosome constitutions of 1R+6R, and 1R+4R, respectively. These conclusions were confirmed by isozyme and storage-protein analysis.     

黄桃罐头产品质量Fuzzy综合鉴评

本文根据FuzzZ数学理论,运用多级模型的综合评判法,对国内20种黄桃罐头产品质量进行了优劣鉴评。并将其划分为一、二、三、四4个等级。从而为罐头产品质量鉴评,准确地汰劣遴优提供新方法。