Dynein-2 affects the regulation of ciliary length but is not required for ciliogenesis in Tetrahymena thermophila.
Eukaryotic cilia and flagella are assembled and maintained by the bidirectional intraflagellar transport (IFT). Studies in alga, nematode, and mouse have shown that the heavy chain (Dyh2) and the light intermediate chain (D2LIC) of the cytoplasmic dynein-2 complex are essential for retrograde intraflagellar transport. In these organisms, disruption of either dynein-2 component results in short cilia/flagella with bulbous tips in which excess IFT particles have accumulated. In Tetrahymena, the expression of the DYH2 and D2LIC genes increases during reciliation, consistent with their roles in IFT. However, the targeted elimination of either DYH2 or D2LIC gene resulted in only a mild phenotype. Both knockout cell lines assembled motile cilia, but the cilia were of more variable lengths and less numerous than wild-type controls. Electron microscopy revealed normally shaped cilia with no swelling and no obvious accumulations of material in the distal ciliary tip. These results demonstrate that dynein-2 contributes to the regulation of ciliary length but is not required for ciliogenesis in Tetrahymena.
Rajagopalan
Vidyalakshmi
V
Department of Biology, Harvey Mudd College, Claremont, CA 91711, USA.
Subramanian
Aswati
A
Wilkes
David E
DE
Pennock
David G
DG
Asai
David J
DJ
D000818:Animals; D030801:Animals, Genetically Modified; D001692:Biological Transport / Q000502:physiology; D002352:Carrier Proteins / Q000235:genetics / Q000378:metabolism; D002923:Cilia / Q000502:physiology / Q000648:ultrastructure; D029721:Drosophila Proteins / Q000235:genetics / Q000378:metabolism; D004398:Dyneins / Q000145:classification / Q000235:genetics / Q000378:metabolism*; D005407:Flagella / Q000378:metabolism / Q000648:ultrastructure; D005786:Gene Expression Regulation; D006801:Humans; D051379:Mice; D008969:Molecular Sequence Data; D010587:Phagocytosis / Q000502:physiology; D010641:Phenotype; D010802:Phylogeny; D020033:Protein Isoforms / Q000145:classification / Q000235:genetics / Q000378:metabolism*; D015800:Protozoan Proteins / Q000145:classification / Q000235:genetics / Q000378:metabolism*; D016808:Tetrahymena thermophila / Q000166:cytology / Q000378:metabolism
D002352:Carrier Proteins; C118054:DYH2 protein, Tetrahymena thermophila; D029721:Drosophila Proteins; D020033:Protein Isoforms; D015800:Protozoan Proteins; D004398:Dyneins