Life with eight flagella: flagellar assembly and division in Giardia.
Flagellar movement in Giardia, a common intestinal parasitic protist, is crucial to its survival in the host. Each axoneme is unique in possessing a long, cytoplasmic portion as well as a membrane-bound portion. Intraflagellar transport (IFT) is required for the assembly of membrane-bound regions, yet the cytoplasmic regions may be assembled by IFT-independent mechanisms. Steady-state axoneme length is maintained by IFT and by intrinsic and active microtubule dynamics. Following mitosis and before their segregation, giardial flagella undergo a multigenerational division cycle in which the parental eight flagella migrate and reposition to different cellular locations; eight new flagella are assembled de novo. Each daughter cell thus inherits four mature and four newly synthesized flagella.
Dawson
Scott C
SC
Department of Microbiology, One Shields Avenue, UC Davis, Davis, CA 95616, USA. scdawson@ucdavis.edu
House
Susan A
SA
D054468:Axoneme / Q000378:metabolism; D001692:Biological Transport; D002455:Cell Division; D005407:Flagella / Q000378:metabolism*; D005872:Giardia / Q000166:cytology*; D005873:Giardiasis / Q000469:parasitology*; D006801:Humans; D007422:Intestines / Q000382:microbiology*