杉木单染色体的显微分离及体外扩增

染色体微分离及体外扩增是传统细胞生物学和现代分子生物学相结合而发展起来的一项新技术.自1981年Scalenghe等[1]首次在果蝇唾腺染色体上取得成功后,该技术很快在人及动物分子遗传学研究中得到广泛应用,并取得很多重要的结果.     

Resveratrol Downregulates Cyp2e1 and Attenuates Chemically Induced Hepatocarcinogenesis in SD Rats

Cyp2e1 plays an important role in chemically induced hepatocarcinogenesis. Resveratrol (REV) is known to prevent diethylnitrosamine (DEN)-induced hepatocarcinogenesis, but its effects on this process induced by DEN and 2-acetylaminofluorene (2-AAF) and the role of Cyp2e1 remain unclear. In this study, glutathione S-transferase placental form (GST-P)-positive foci were used as a marker of hepatocarcinogenesis. REV or diallyl disulfide (DADS, an inhibitor of Cyp2e1) significantly reduced both the area and number of GST-P-positive foci induced by DEN and 2-AAF. Treatment with REV or DADS also markedly decreased the expression of Cyp2e1 in the rat liver. By immunohistochemical staining of serial liver sections, we found that the expression of Cyp2e1 in GST-P-positive foci showed three distinct patterns: decreased in GST-P foci, increased in GST-P foci when compared with surrounding liver tissue and mixed type. The number of GST-P foci with increased Cyp2e1 expression was greater than the number of GST-P foci with decreased Cyp2e1. Protein levels of GST-P and Cyp2e1 were also higher in foci compared with surrounding liver tissue. REV or DADS significantly reduced the expression of GST-P and Cyp2e1 in both foci and surrounding liver tissue. Taken together, these results suggested that REV has a significant inhibitory effect on chemically induced hepatocarcinogenesis, which may be attributed to downregulation of Cyp2e1.     

银杏第1染色体DNA文库的构建

观察了50个银杏根尖的染色体,发现在约半数根尖中,最大的1对染色体(第1染色体)随体有差异,其中1条随体较大而明显,另1条则很小.采用玻璃针分离法,通过显微操作系统成功地分离了随体较为明显的那条第1染色体.将分离到的单条染色体去蛋白,Sau3A酶切,并在染色体DNA片段两端加上Sau3A人工接头,进行2轮PCR扩增,得到了大小为300-3000bp的扩增片段.用第2轮PCR产物构建质粒文库,得到了约含有75000个重组子的该染色体DNA文库.随机挑取66个重组子进行分析,发现插入片段大小主要分布在500-2000bp,平均为800bp.该文库为银杏第1染色体特异探针的筛选、遗传图谱的构建、重要基因的克隆以及性染色体的鉴别等研究提供了基础.     

Pseudorabies virus infection in mink: a host-specific pathogenesis

Pseudorabies virus (PRV) is an alphaherpesvirus that causes a neurological disease in many wild and domestic animals. The neuropathology elicited by PRV is quite consistent regardless of the host with the only exception of mink, in which it is characterized by a vasculopathy rather than by an encephalitis. In this study, we aimed to investigate the underlying pathogenic mechanism(s) of PRV infection in mink by using immunohistochemistry and laser capture microdissection (LCM) on material from naturally and experimentally infected animals. The inflammatory reaction induced by PRV was minimal or absent not only in the nervous system, where we identified a low number of macrophages and a few T lymphocytes, but also in the primary replication site, the oropharyngeal mucosa; however, the number of PRV-infected cells detected by immunohistochemistry was extremely high both in the peripheral mucosa and in the nervous tissue. On the other hand, the vascular pathology included parenchymal hemorrhages of various degrees and, in specific cortical areas of the brain, fibrinoid degeneration of the capillary walls. Detection of viral antigens by immunohistochemistry revealed infection of endothelial cells of capillaries situated both in the oropharyngeal mucosa and in the brain stem; the presence of PRV DNA in vessels was further demonstrated by PCR performed on LCM samples of brain capillaries. These results can be interpreted as supporting the idea that the different pathology of the disease in mink may be the consequence of an increased endotheliotropism of PRV in this species. Infection of the vessel wall may then lead to vascular pathology and impairment in endothelial cell function, resulting in a weak immune response to infection.     

杨树花药激光显微切割体系的建立

鉴于以往对于杨树雄配子发育的分子调控机制的研究都基于整个花药甚至整个花序的取材,无法提供细胞特异性的表达信息,本研究建立了冷冻切片技术和激光显微切割技术联用分离杨树花药中不同发育时期的小孢子和花粉细胞的技术体系,并对其RNA进行了提取和检测。结果显示RNA的纯度、完整度均达到线性扩增的要求。这可以为更精确地研究杨树雄性生殖细胞发育的分子调控机制甚至为全面解析杨树雄配子发育的调控机制提供丰富的信息。      

染色体微切割、微克隆技术及其在植物上的应用

染色体显微切割、微克隆技术是由细胞遗传学通往分子遗传学研究的直接桥梁。本文就其概念、发展现状、应用前景以及在植物染色体研究中存在的困难等进行了综述。     

Differential expression of cell cycle regulators p21, p27 and p53 in metastasizing canine mammary adenocarcinomas versus normal mammary glands

The cyclin dependent kinase inhibitors p21 and p27 are important regulators of cell cycle progression. To analyze their role in the malignant progression of canine mammary tumors expression levels of p27 and p21 and its major regulator p53 were compared in simple adenomas, adenocarcinomas of the mammary gland and lymph node metastases with normal mammary gland. Laser microdissection of tissue samples and real-time PCR were used for quantification of mRNA expression levels. p21 was overexpressed in adenocarcinomas, whereas adenomas and metastases expressed p21 more heterogeneously. Comparison of p21 expression in adenocarcinomas and their metastases revealed a significant decrease in expression in metastases. In contrast, p27 expression was reduced in the adenocarcinomas but heterogeneously expressed in adenomas and metastases. Taken together the results suggest that loss of p21 overexpression is associated with tumor metastasis while reduced cell cycle inhibition by p27 is associated with malignant progression.     

植物染色体微分离、微切割与微克隆技术的研究进展

介绍了染色体微分离、微切割与微克隆技术的发展历史;综述了植物染色体微分离、微切割和微克隆技术的研究进展及其应用与展望。     

激光捕获显微切割技术的研究进展

介绍了激光捕获显微切割系统（LCM）的原理、发展历程和主要应用,并对目前利用LCM技术存在的瓶颈作了分析和展望。     

染色体显微切割和微克隆技术研究进展

本文对染色体显微切割和微克隆技术的初创、应用和发展前景作文献回顾。