Sequence and transfection of BoLA-DRB3 cDNAs

Bovine MHC (BoLA-) DRB3 alleles encoded by the DH8A, DH22A and DH24A class II haplotypes were cloned from cDNA and characterized by sequence analysis. Comparison with other full-length DRB3 sequences suggested that DRB3 alleles may have evolved through multiple lineages. All three BoLA-DRB3 alleles were shown to express on the surface of transfected cells, and the transfectants were used to define or confirm the class II specificity of a panel of monoclonal antibodies.     

水压转染法在小鼠不同肝叶的表达效率

为了解水压转染法(hydrodynamics-based transfection,HDT)在小鼠肝脏不同肝叶的转染效率,将容量为小鼠体重的10%,绿色荧光蛋白基因质粒pEGFP-C1含量为35μg/只的生理盐水溶液以0.4 mL/s的速度从小鼠尾静脉注射,于注射后不同时间取小鼠各肝叶制备冰冻切片,在荧光显微镜下观察,计数各肝叶的绿色荧光蛋白表达情况。结果显示注射后12 h,绿色荧光蛋白阳性细胞比例最高,从24 h起表达量逐渐减少,至48 h时各肝叶均基本难以检测出绿色荧光蛋白阳性细胞。在12 h观察各肝叶的转染效率如下:右叶、蒂状叶的绿色荧光蛋白阳性细胞约为22%,左叶、中叶、尾状叶约为15%取材部位不同会造成数据分析的极显著差异。     

用于哺乳动物细胞转染的高纯度质粒DNA的制备

目的：建立简便高效、成本低廉和安全无污染的高纯度质粒提取方法。方法：在乙酸铵方法的基础上加以改进,主要改进之处在于增加了用聚乙二醇纯化质粒的步骤,并对溶液Ⅱ和溶液Ⅲ的成分和具体实验参数也做了合理的改进,以最少的步骤,充分去除了残存杂质,保证了质粒的超纯状态。结果：用本方法提取的质粒与用QIAGEN plasmid midi Kit提取的质粒在理化指标上没有差别,对哺乳动物胞具有同样的转染效率。结论：本方法可完全取代QIAGEN公司的试剂盒用于提取超纯质粒。     

Turtle Lung Cells Produce a Melanization-Stimulating Activity That Promotes Melanocytic Differentiation of Avian Neural Crest Cells

We found previously that neural crest cells in turtle embryos migrated into the lung buds and melanocytes were located in the lungs. The finding suggested to us that the lungs provide a stimulatory factor(s) to the differentiation of neural crest cells into melanocytes. We have established lung cell lines to facilitate analysis of the interactions of neural crest cells with the environment in melanocyte development. One cell line, TLC-2, was found to produce a putative melanization-stimulating activity (MSA), which promoted the melanocyte differentiation in vitro of avian neural crest cells. The TLC-2-derived MSA was different from that of basic fibroblast growth factor (bFGF), α-melanocyte stimulating hormone (α-MSH), and steel factor (SLF). Its molecular weight was estimated to be within the range of 150 kD. Our findings suggest that MSA may be a novel factor exercising a positive control over melanocyte differentiation.