白细胞介素研究进展简介

本文简要介绍1988至1989两年内新发现的白细胞介素,以及白介素和相应受体在生化性质、生理功能、相互作用、调控机制等方面研究的新进展。     

免疫毒素的纯化

本文采用Ultrogel AcA 34凝胶柱纯化单克隆抗体和蓖麻毒素的结合物。结合物与游离毒素的分离较Sephadex G150柱好。继而利用蓖麻毒素B链能与半乳糖基结合的特性,用酸化Sepharose 4B柱进一步纯化结合物;达到完全除去游离抗体,使免疫毒素对靶细胞的特异性毒性提高20倍。     

庆丰链霉菌细菌素

本文报道了庆丰链霉菌斜面培养物上出现的空斑,排除了由于噬菌体污染而引致的可能性：发现和证实可不经诱导而自发产生的细菌素物质,并能对该菌本身产生抑制生长;斜面上出现的空斑与这种细菌素产生的关系进行了探讨;对于放线菌中确定细菌素的问题进行了讨论。     

一株产生链黑菌素的链霉菌新种

在寻找抗肿瘤抗菌素过程中,从西双版纳土壤分离到一株放线菌74—3527,经鉴定为一链霉菌新种,其代谢产物经光谱分析及核磁共振谱鉴别,与链黑菌素基本一致,故定名为链黑菌素链霉菌Streptomyces streptonigrinus n. sp. Yan et al., 1977. 本文报道这个新种的形态、培养特征、生理生化特性和与相近已知种的比较。     

带背飞虱属的厘订

带背飞虱属(Himeunka Matsumura et lshihara,1945)隶属于同翅目,飞虱科(Delphacidae),系据日本模式种所成立,至目前为止世界记录只有一种,笔者等在国内共采得三种,其中包括模式种及二新种。此属原描述很简单,其后lshihara(1949)在“Revision of the Araeopidae of Japan,Ryukyu Islands and Formosa(Hemiptera)”著作中,对此属的再描述也欠明确,模式种的描述亦复如此,尤其是雄性外生殖器未作解剖描绘,由此已引起误解。(1977)在.6:855—869上发表的Delphacidae(Homoptera,Auchenorrhycha)     

Antisense EDRF1 gene inhibited GATA-1 transcription factor DNA-binding activity in K562 cells

Our previous studies showed that EDRF1 influenced expression of α-globin mRNA and synthesis of hemoglobin in K562 cells and modulated self-renewal of K562 cells. To illuminate the function of EDRF1 in K562 cells, sense and antisense EDRF1 constructs were prepared and transfected into K562 cells. By using microarray and dot blot assay, 60 cytokine receptors and some oncogenes sharing important functions in cell proliferation and differentiation were investigated. The results of this study demonstrated that IL-6 receptor, GM-CSF receptor, c-Jun/c-Fos, c-Myc and c-kit genes were regulated by antisense EDRF1 expression. The regulation was confirmed by RNA blot assay. GATA-1 mRNA expression was modulated by EDRF1 gene transfection. Electrophoretic mobility shift assay suggested that the DNA-binding activity of GATA-1 was remarkably inhibited in K562 cells expressing EDRF1 antisense gene. DNA binding activity of NF-E2 was at the same level as control experiment. Therefore EDRF1 may play a role in erythroid proliferation and differentiation by affecting the interaction between GATA-1 and its cis-elements.     

为什么等位基因有时在减Ⅱ时分离?

答:这是因为在减数分裂中第一次分裂的四分体时期,同源染色体的非姊妹染色单体间交叉互换对应片段,使位于这部分的基因从一条染色体上移到另一条染色体上,结果使不同染色体上的等位基因就存在于一条染色体的两个染色单体上,在第二次分裂中,着丝点分裂,基因就随两个染色单体的分开而分离。见下图。