Forward Genetic Analysis of the Apicomplexan Cell Division Cycle in Toxoplasma gondii

PLoS Pathogens

Marc-Jan Gubbels¹  Michael W White¹  Josh Radke¹  Maria E Jerome¹  Jayme Flynn²  Margaret Lehmann²  Ben Parrot²  Mani Muthalagi³  Tomasz Szatanek³  Carrie F Brooks³  Boris Striepen³ 

[1] Center for Tropical and Emerging Global Diseases and Department of Cellular Biology, University of Georgia, Athens, Georgia, United States of America;Department of Biology, Boston College, Chestnut Hill, Massachusetts, United States of America;Department of Veterinary Molecular Biology, Montana State University, Bozeman, Montana, United States of America

关键词: Parasitic cell cycles;    Cell cycle;    cell division;    Phenotypes;    Genetic loci;    Toxoplasma gondii;    Parasite replication;    Apicomplexa;    Genomic library construction;   

DOI  :  10.1371/journal.ppat.0040036

学科分类：生物科学（综合）

来源: Public Library of Science

【 摘 要 】

Apicomplexa are obligate intracellular pathogens that have fine-tuned their proliferative strategies to match a large variety of host cells. A critical aspect of this adaptation is a flexible cell cycle that remains poorly understood at the mechanistic level. Here we describe a forward genetic dissection of the apicomplexan cell cycle using the Toxoplasma model. By high-throughput screening, we have isolated 165 temperature sensitive parasite growth mutants. Phenotypic analysis of these mutants suggests regulated progression through the parasite cell cycle with defined phases and checkpoints. These analyses also highlight the critical importance of the peculiar intranuclear spindle as the physical hub of cell cycle regulation. To link these phenotypes to parasite genes, we have developed a robust complementation system based on a genomic cosmid library. Using this approach, we have so far complemented 22 temperature sensitive mutants and identified 18 candidate loci, eight of which were independently confirmed using a set of sequenced and arrayed cosmids. For three of these loci we have identified the mutant allele. The genes identified include regulators of spindle formation, nuclear trafficking, and protein degradation. The genetic approach described here should be widely applicable to numerous essential aspects of parasite biology.

【 授权许可】

CC BY