组织型纤溶酶原激活剂（t—PA）工程细胞系遗传特性及成瘤性分析

组织型纤溶酶原激活剂(t-PA)因其在防止血栓形成中起重要作用而受到人们的重视。但由于t-PA在血液中半衰期很短,作为溶栓药,一时难于推广。为了延长半衰期、增强其特异活性,本组构建了t-PA突变体并在CHO-dhfr~-细胞中获得了高效表达。我们在细胞培养基中加入秋水仙素,通过低张、固定、染色,进行染色体分析,结果表明,t-PA工程细胞系染色体条数为20条,畸变类型有异着丝粒。四倍体、裂隙、断片,畸变率为15％,属于正常范围。同时我们对该细胞系进行成瘤性试验,选用4周龄裸鼠作为试验鼠,以Hela细胞为阳性对照,CHO-dhfr~-细胞为阴性对照,试验表明:t-PA工程细胞及表达产物对裸鼠均无成瘤性。     

Lack of association of bovine MHC class I alleles with carcass and reproductive traits

The present study was carried out to examine whether a relationship between bovine major histocompatibility complex (BoLA) class I alleles and carcass traits or reproductive performance exists in Braunvieh and Fleckvieh A1 (artificial insemination) bulls. The influence of BoLA class I (BOLA-A) alleles on deregressed breeding values for net growth rate, carcass index and thigh volume was assessed in Braunvieh crosses and Fleckvieh bulls with a gene substitution model. The reproductive traits: non-return rate and interval between first and last insemination of daughters (female fertility), as well as non-return rate of inseminated cows (male fertility), were only investigated in Fleckvieh animals. No influence of the BOLA-A region on the traits evaluated could be demonstrated. An improper, i.e. less restrictive analysis would have led to spurious results.     

New cellulose synthesizing complexes (terminal complexes) involved in animal cellulose biosynthesis in the tunicateMetandrocarpa uedai

Summary Subcellular compartments comprising the endomembrane system in filamentous fungi are poorly characterized with most showing significant morphological differences from eukaryotic cells. For example, many filamentous fungi lack stacked Golgi-body cisternae, but contain Golgi equivalents — single cisternae or tubules which appear to serve the same functions. To help identify fungal endomembrane compartments and interrelationships between them we used a pharmacological agent, brefeldin A, known to affect specific endomembrane organelles in other organisms, most prominently the Golgi apparatus. At 10 g/ml brefeldin A, radial hyphal growth of the rice blast pathogenMagnaporthe grisea on solid agar medium was reduced by 96% over an initial 48 h, but recovered and was reduced by only 20% over a subsequent 72 h exposure. Light microscopic examination of individual living hyphae showed that apical elongation generally halted within 1 min after exposure to brefeldin A. Acute effects of 14 g/ml brefeldin A were characterized ultrasiructurally in cells prepared by freeze substitution. These included the appearance of two types of cisternae with unusual morphology, associated with ca. 45 nm diameter vesicles, as well as the unexpected persistence and increase in complexity of the Golgi equivalents. Also observed were (1) reduced numbers of apicale vesicles and disruption of Spitzenkörper organization, (2) apical clusters of 30–35 nm diameter microvesicles and associated tubular arrays, (3) dilation of rough endoplasmic reticulum, (4) packets of membrane-bounded electron-opaque cell wall inclusions, and (5) altered morphology of some vacuolar compartments. The distribution of concanavalin A binding sites, previously mapped to particular endomembrane compartments, was documented to aid the interpretation of these results. We conclude that brefeldin A effects on cells ofM. grisea differ from those reported with plant and animal cells, perhaps reflecting underlying differences in the endomembrane systems among these eukaryotes.Abbreviations BFA brefeldin A - ConA concanavalin A - ER endoplasmic reticulum - PDA potato dextrose agar - RER rough endoplasmic reticulum     

Colchicine-mediated chromosome doubling during anther culture of maize (Zea mays L.)

Efficient methods of chromosome doubling are critical for the production of microspore-derived, doubled-haploid (=DH) plants, especially if, as in maize anther culture, spontaneous chromosome doubling occurs infrequently. In the present study, colchicine (5–1000 mg/l) was added to the induction medium and maize anthers were incubated in the colchicine-containing medium for different durations (1–7 days). In order to improve overall anther culture response, the culture temperature was adjusted to 14°C during the first 7 days. Colchicine applied at low concentration, i.e. 5 mg/l (7 days), or for short duration, i.e. 1–3 days (250 mg/l), showed beneficial effects on the formation of embryolike structures (=ES) and thus led to increased plant production, but was comparatively ineffective regarding chromosome doubling. Optimal doubling effects were observed when anthers had been exposed to culture medium containing 250 and 1000 mg/l of colchicine (7 days); in these treatments the doubling index (=DI), defined as the quotient of the number of DH plants and the number of totally regenerated plants in a specific treatment, rose to 0.56 and 0.53, respectively, compared to 0.20 in the untreated control. However, colchicine administered at concentrations higher than 250 mg/l seemed to be detrimental to general plant production; thus, in spite of a high DI, the overall DH plant production was even lower than in the control treatment. Maximum DH plant production for three different genotypes was accomplished with culture medium containing 250 mg/l of colchicine (7 days). With the best-responding genotype (ETH-M 36) a DH plant production of 9.9 DH plants/100 anthers was accomplished, i.e. a 7-fold increase compared to the non-treated anthers. This is the first report on efficient chromosome doubling in anther culture by subjecting anthers to colchicinecontaining induction medium during a post-plating cold treatment. Chromosome doubling as described here becomes an integral part of the maize anther culture protocol and thus represents a rapid and economical way to produce DH plants.     

Isolation and identification of Triticum aestivum L. em. Thell. cv Chinese Spring-T. peregrinum Hackel disomic chromosome addition lines

Analyses of RFLPs, isozymes, morphological markers and chromosome pairing were used to isolate 12 Triticum aestivum cv Chinese Spring (genomes A, B, and D)-T. peregrinum (genomes S^v and U^v) disomic chromosome addition lines. The evidence obtained indicates that each of the 12 lines contains an intact pair of T. peregrinum chromosomes. One monosomic addition line, believed to contain an intact 6S^v chromosome, was also isolated. A CS-7U^v chromosome addition line was not obtained. Syntenic relationships in common with the standard Triticeae arrangement were found for five of the seven S^v genome chromosomes. The exceptions were 4S^v and 7S^v. A reciprocal translocation exists between 4S¹ and 7S¹ in T. longissimum and evidence was obtained that the same translocation exists in T. peregrinum. In contrast, evidence for syntenic relationships in common with the standard Triticeae arrangements were found for only one U^v chromosome of T. peregrinum.; namely, chromosome 2U^v. All other U^v genome chromosomes are involved in at least one translocation, and the same translocations were found in the U genome of T. umbellulatum. Evidence was also obtained indicating that the centromeric regions of 4U and 4U^v are homoeologous to the centromeric regions of Triticeae homoeologous group-6 chromosomes, that the centromeric regions of 6U and 6U^v are homoeologous to the centromeric regions of group-4 chromosomes, and that 4U and 4U^v are more closely related overall to Triticeae homoeologous group-6 chromosomes than they are to group-4 chromosomes.     

大鼠肝癌模型CBRH—3的建立及其生物学特性

用ＤＥＮＡ诱发近交系Ｗｉｓｔａｒ大鼠,经三个月后得原发性肝癌,移植于同品系幼鼠,从而建立了 一株染色体众数正常,ＡＥＰ阳性的大鼠移植性肝癌模型,命名为ＣＢＲＨ－３,病理鉴定为肝细胞型肝 癌。至今已传至６０余代,目前生长稳定。     

Carbohydrate and amino acid metabolism during batch culture of a human lymphoblastoid cell line,BTSN6

This work presents data on the carbohydrate and amino acid metabolism of a lymphoblastoid cell line producing an IgG1 antibody. In static culture, it was observed that lactate levels were significantly lowered when the cells were cultured on galactose as a carbon source. The use of carbohydrate substitution may be useful in lowering lactate levels, if it is established that this component is toxic to the cells. In addition, carbohydrate substitution may be used to modify glycosylation patterns and hence pharmacokinetic properties of glycoproteins.The amino acids glutamine and tryptophan were shown to be limiting in batch culture on this medium (DR, a 1:1 mixture of DMEM and RPMI, with 4mM glutamine). Amino acids produced included alanine, proline and glutamate. Serine was consumed to exhaustion, which was followed by a depletion of extracellular glycine. Amino acid metabolism, specific antibody productivity and specific growth rate were shown to be functions of the inoculation density in stirred flask culture. The results have implications for the design of media for both low and high density antibody manufacture by these cell lines.     

Rapid authentication of animal cell lines using pyrolysis mass spectrometry and auto-associative artificial neural networks

Summary Pyrolysis mass spectrometry (PyMS) was used to produce biochemical fingerprints from replicate frozen cell cultures of mouse macrophage hybridoma 2C11-12, human leukaemia K562, baby hamster kidney BHK 21/C13, and mouse tumour BW-O, and a fresh culture of Chinese hamster ovary CHO cells. The dimensionality of these data was reduced by the unsupervised feature extraction pattern recognition technique of auto-associative neural networks. The clusters observed were compared with the groups obtained from the more conventional statistical approaches of hierarchical cluster analysis. It was observed that frozen and fresh cell line cultures gave very different pyrolysis mass spectra. When only the frozen animal cells were analysed by PyMS, auto-associative artificial neural networks (ANNs) were employed to discriminate between them successfully. Furthermore, very similar classifications were observed when the same spectral data were analysed using hierarchical cluster analysis. We demonstrate that this approach can detect the contamination of cell lines with low numbers of bacteria and fungi; this approach could plausibly be extended for the rapid detection of mycoplasma infection in animal cell lines. The major advantages that PyMS offers over more conventional methods used to type cell lines and to screen for microbial infection, such as DNA fingerprinting, are its speed, sensitivity and the ability to analyse hundreds of samples per day. We conclude that the combination of PyMS and ANNs can provide a rapid and accurate discriminatory technique for the authentication of animal cell line cultures.     

中国马兜铃属植物的细胞分类学初步研究

本文报道了中国马兜铃属１２种植物的染色体数目和核型分析,发现并确定了ｘ＝８为本属染色体基数之一。本属染色体的共同特征是：小型;以中部（ｍ）,近中部（ｓｍ）着丝点染色体为主;核型类型为１Ａ,２Ａ,３Ａ,１Ｂ,２Ｂ;随体一般处在染色体的长臂上。     

拉萨郊区藏族跖纹主线走向分析

本文用茚三酮－味精法采集跖纹,体视显微镜下追踪跖纹主线走向,分析了２５０（男女各１２５人）拉萨效区藏族健康人的跖纹样本。结果显示：Ａ线主要走向１区,其次是７区;Ｂ线亦多止于１区和７区;Ｃ线主要止于和９区;Ｄ线止于１区 频率最高;Ｅ线主要走向１３区;Ｐ三叉缺失较多。Ｐｚ＾ｄ线止共位置较高（１３区和１１区）,而Ｐ＾ｆ线止区较低（７区）。在民族和人种间进行了比较,提示藏族践纹主线走向有自己的特点,又呈现