@article {381,
	title = {Silencing of a putative inner arm dynein heavy chain results in flagellar immotility in Trypanosoma brucei.},
	journal = {Mol Biochem Parasitol},
	volume = {175},
	year = {2011},
	month = {2011 Jan},
	pages = {68-75},
	abstract = {The Trypanosoma brucei flagellum controls motility and is crucial for cell polarity and division. Unique features of trypanosome motility suggest that flagellar beat regulation in this organism is unusual and worthy of study. The flagellar axoneme, required for motility, has a structure that is highly conserved among eukaryotes. Of the several dyneins in the axonemal inner arm complex, dynein f is thought to control flagellar waveform shape. A T. brucei gene predicted to encode the dynein f alpha heavy chain, TbDNAH10, was silenced using RNA interference in procyclic T. brucei cells. This resulted in immotile flagella, showing no movement except for occasional slight twitches at the tips. Cell growth slowed dramatically and cells were found in large clusters. Microscopic analysis of silenced cultures showed many cells with detached flagella, sometimes entangled between multiple cells. DAPI staining showed an increased frequency of mis-positioned kinetoplasts and multinucleate cells, suggesting that these cells experience disruption at an early cell cycle stage, probably secondary to the motility defect. TEM images showed apparently normal axonemes and no discernable defects in inner arm structure. This study demonstrates the use of RNAi as an effective method to study very large genes such as dynein heavy chains (HCs), and the immotility phenotype of these dynein knockdowns suggests that an intact inner arm is necessary for flagellar beating in T. brucei. Since analogous mutants in Chlamydomonas reinhardtii retain motility, this phenotype likely reflects differences in requirements for motility and/or dynein assembly between the two organisms and these comparative studies will help elucidate the mechanisms of flagellar beat regulation.},
	keywords = {Cell Nucleus, Dyneins, Flagella, Locomotion, Microscopy, Electron, Transmission, Organelles, Protozoan Proteins, RNA Interference, Trypanosoma brucei brucei},
	issn = {1872-9428},
	doi = {10.1016/j.molbiopara.2010.09.005},
	author = {Springer, Amy L and Bruhn, David F and Kinzel, Kathryn W and Rosenthal, No{\"e}l F and Zukas, Randi and Klingbeil, Michele M}
}
@article {380,
	title = {Three mitochondrial DNA polymerases are essential for kinetoplast DNA replication and survival of bloodstream form Trypanosoma brucei.},
	journal = {Eukaryot Cell},
	volume = {10},
	year = {2011},
	month = {2011 Jun},
	pages = {734-43},
	abstract = {Trypanosoma brucei, the causative agent of human African trypanosomiasis, has a complex life cycle that includes multiple life cycle stages and metabolic changes as the parasite switches between insect vector and mammalian host. The parasite{\textquoteright}s single mitochondrion contains a unique catenated mitochondrial DNA network called kinetoplast DNA (kDNA) that is composed of minicircles and maxicircles. Long-standing uncertainty about the requirement of kDNA in bloodstream form (BF) T. brucei has recently eroded, with reports of posttranscriptional editing and subsequent translation of kDNA-encoded transcripts as essential processes for BF parasites. These studies suggest that kDNA and its faithful replication are indispensable for this life cycle stage. Here we demonstrate that three kDNA replication proteins (mitochondrial DNA polymerases IB, IC, and ID) are required for BF parasite viability. Silencing of each polymerase was lethal, resulting in kDNA loss, persistence of prereplication DNA monomers, and collapse of the mitochondrial membrane potential. These data demonstrate that kDNA replication is indeed crucial for BF T. brucei. The contributions of mitochondrial DNA polymerases IB, IC, and ID to BF parasite viability suggest that these and other kDNA replication proteins warrant further investigation as a new class of targets for the development of antitrypanosomal drugs.},
	keywords = {Cell Survival, Cells, Cultured, DNA Replication, DNA, Kinetoplast, DNA-Directed DNA Polymerase, Humans, Membrane Potential, Mitochondrial, Mitochondria, Parasitemia, RNA Interference, Trypanosoma brucei brucei, Trypanosomiasis, African},
	issn = {1535-9786},
	doi = {10.1128/EC.05008-11},
	author = {Bruhn, David F and Sammartino, Mark P and Klingbeil, Michele M}
}
