混合线性模型下猪群间遗传联系的度量

采用关联指数(IC)和决定系数(CD)两种方法,度量混合线性模型遗传评估下 猪群体间的遗传关联性。结果表明,加拿大安大略省的大约克夏猪、长白猪、杜洛克猪和汉普夏猪4个主要品种群体间具有良好的遗传联系。CD法既组合了数据结构和信息量,又考虑了预测误差方差和遗传变异性,是一个选择判断遗传评估精度的好方法。 Abstract:Two criteria for the measures of genetic connectedness in mixed linear model of genetic evaluation are used:the degree of connectedness(IC)and the generalized coefficient of determination(CD).The results indicated that the data of four dominant swine breeds:Yorkshire,Landrace,Duroc and Hampshire in Ontario,Canada are well connected.The CD,which combines data structure and amount of information and also accounts for both prediction error variance and genetic variability,is a good method to select for judging the precision of a genetic evaluation.     

Improved resolution of O-methylalditol acetates by gas-liquid chromatography on capillary columns with blended coatings of OV-17 and OV-225

Dithiocarbamate chitosan was obtained by treating chitosan with carbon disulfide in a mixture of ammonia and methanol, and was studied by infrared spectrometry. Dithiocarbamate chitosan having a sulfur content of 7.8% was used to extract metal ions in high yield from acc, neutral, and alkaline solutions.     

The many roles of small RNAs in leaf development

Leaf development involves many complex genetic interactions,signals between adjacent cells or between more distant tissues and consequent changes in cell fate.This review describes three stages in leaf development where regulation by small RNAs have been used to modulate gene expression patterns.     

Factors affecting the accuracy of urine-based biomarkers of BSE

Background  

Transmissible spongiform encephalopathy diseases are untreatable, uniformly fatal degenerative syndromes of the central nervous system that can be transmitted both within as well as between species. The bovine spongiform encephalopathy (BSE) epidemic and the emergence of a new human variant of Creutzfeldt-Jakob disease (vCJD), have profoundly influenced beef production processes as well as blood donation and surgical procedures. Simple, robust and cost effective diagnostic screening and surveillance tools are needed for both the preclinical and clinical stages of TSE disease in order to minimize both the economic costs and zoonotic risk of BSE and to further reduce the risk of secondary vCJD.     

Evaluation of zona pellucida birefringence intensity during in vitro maturation of oocytes from stimulated cycles

Background  

This study evaluated whether there is a relationship between the zona pellucida birefringence (ZP-BF) intensity and the nuclear (NM) and cytoplasmic (CM) in vitro maturation of human oocytes from stimulated cycles.     

Motile sperm organelle morphology examination (MSOME): intervariation study of normal sperm and sperm with large nuclear vacuoles

Background  

Although the motile sperm organelle morphology examination (MSOME) was developed only as a selection criterion, its application as a method for classifying sperm morphology may represent an improvement in evaluation of semen quality, with potential clinical repercussions. The present study aimed to evaluate individual variations in the motile sperm organelle morphology examination (MSOME) analysis after a time interval.     

Characterization of 13 newly isolated strains of anaerobic, cellulolytic, thermophilic bacteria

Characteristics of 13 newly isolated thermophilic, anaerobic, and cellulolytic strains were compared with previously described strains of Clostridium thermocellum: ATCC 27405 and JW20 (ATCC 31549). Colony morphology, antibiotic sensitivity, fermentation end-products, and cellulose degradation were documented. All 13 strains were sensitive to erythromycin (5 μg/ml) and chloramphenicol (25 μg/ml), and all strains but one were sensitive to kanamycin (20 μg/ml). Polymerase chain reaction (PCR) amplification using primers based on gene sequences from C. thermocellum ATCC 27405 was successful for all 13 strains in the case of the hydrogenase gene and 11 strains in the case of phosphotransacetylase/acetate kinase genes. Ten strains amplified a product of the expected size with primers developed to be specific for C. thermocellum 16SrRNA primers. Two of the 13 strains did not amplify any product with the PCR primers designed for the phosphotransacetylase/acetate kinase and 16SrRNA primers. A MboI-like GATC- recognizing restriction activity was present in all of the five strains examined. The results of this study have several positive implications with respect to future development of a transformation system for cellulolytic thermophiles. Journal of Industrial Microbiology & Biotechnology (2001) 27, 275–280. Received 12 September 2000/ Accepted in revised form 20 November 2000     

Expression and purification of the recombinant diphtheria fusion toxin DT388IL3 for phase I clinical trials

A genetically engineered fusion toxin targeted to acute myeloid leukemia (AML) blasts was designed with the first 388 amino acid residues of diphtheria toxin with an H-M linker fused to human interleukin-3. The cDNA was subcloned in the pRK bacterial expression plasmid and used to transform BLR (DE3) Escherichia coli. A single transformed colony was grown in Superbroth with ampicillin; bacteria were centrifuged at an OD(650) of 1.3; master cell bank aliquots of bacteria in 30% glycerol/Superbroth were frozen and stored at -80 degrees C. Master cell bank bacteria were diluted 1500-fold into Superbroth and recombinant protein was induced with 1 mM IPTG at an OD(650) of 0.6. After two additional hours of fermentation, inclusion bodies were isolated, washed, and denatured in guanidine hydrochloride and dithioerythritol. Recombinant protein was refolded by diluted 100-fold in cold buffer with arginine and oxidized glutathione. After dialysis, purified protein was obtained after anion-exchange, size exclusion on FPLC, and polymyxin B affinity chromatography. The final material was filter sterilized, aseptically vialed, and stored at -80 degrees C. Seventy-five 3-L bacterial culture preparations were made and pooled for the AT-1 batch (568 mL) and twenty-four 3-L bacterial culture preparations were made and pooled for the AT-2 batch (169 mL). The final product was characterized by Coomassie Plus protein assay, Coomassie-stained SDS-PAGE, limulus amebocyte lysate endotoxin assay, human AML TF/H-ras cell cytotoxicity assay, sterility, tandem mass spectroscopy, IL3 receptor binding affinity, ADP ribosylation activity, inhibition of normal human CFU-GM, disulfide bond analysis, immunoblots, peptide mapping, stability, HPLC TSK3000, N-terminal sequencing, E. coli DNA contamination, C57BL/6 mouse toxicity, cynomolgus monkey toxicity, and immunohistochemistry. Yields were 25.7+/-5.6 mg/L bacterial culture of denatured fusion toxin. After refolding and chromatography, final yields were 20+/-11% or 5 mg/L. Vialed product was sterile. Batches were in 0.25 M sodium chloride/5 mM Tris, pH 8, and had protein concentrations of 1.8-1.9 mg/mL. Purity by SDS-PAGE was 99+/-1%. Aggregates by HPLC were <1 %. Potency revealed a 48 h IC(50) of 6-8 pM on TF/H-ras cells. Endotoxin levels were 1 eu/mg. The remaining chemical and biologic assays confirmed the purity, composition, and functional activities of the molecule. The LD(10) in mice was 250 microg/kg/day every other day for six doses. The MTD in monkeys was 60 microg/kg/day every other day for six doses. Drug did not react with tested frozen human tissue sections by immunohistochemistry. There was no evidence of loss of solubility, proteolysis aggregation, or loss of potency over 6 months at -80 and -20 degrees C. Further, the drug was stable at 4 and 25 degrees C in the plastic syringe and administration tubing for 24 h and at 37 degrees C in human serum for 24 h. The synthesis of this protein drug should be useful for production for clinical phase I/II clinical trials and may be suitable for other diphtheria fusion toxins indicated for clinical development.