a genome-wide over-expression screen identifies genes involved in phagocytosis in the human protozoan parasite, entamoeba histolytica全基因组表达屏幕识别基因吞噬人类原生动物寄生虫,痢疾阿米巴.pdfVIP

A Genome-Wide Over-Expression Screen Identifies Genes Involved in Phagocytosis in the Human Protozoan Parasite, Entamoeba histolytica 1 1 2 2¤ 1 Ada V. King , Brenda H. Welter , Amrita B. Koushik , Lindsay N. Gordon , Lesly A. Temesvari * 1 Department of Biological Sciences, Clemson University, Clemson, South Carolina, United States of America, 2 Department of Genetics and Biochemistry, Clemson University, Clemson, South Carolina, United States of America Abstract Functional genomics and forward genetics seek to assign function to all known genes in a genome. Entamoeba histolytica is a protozoan parasite for which forward genetics approaches have not been extensively applied. It is the causative agent of amoebic dysentery and liver abscess, and infection is prevalent in developing countries that cannot prevent its fecal-oral spread. It is responsible for considerable global morbidity and mortality. Given that the E. histolytica genome has been sequenced, it should be possible to apply genomic approaches to discover gene function. We used a genome-wide over- expression screen to uncover genes regulating an important virulence function of E. histolytica, namely phagocytosis. We developed an episomal E. histolytica cDNA over-expression library, transfected the collection of plasmids into trophozoites, and applied a high-throughput screen to identify phagocytosis mutants in the population of over-expressing cells. The screen was based on the phagocytic uptake of human red blood cells loaded with the metabolic toxin, tubercidin. Expression plasmids were isolated from trophozoites that survived exposure to tubercidi