title: Intraflagellar transport is essential for mammalian spermiogenesis but is absent in mature sperm.
abstract: Drosophila sperm are unusual in that they do not require the intraflagellar transport (IFT) system for assembly of their flagella. In the mouse, the IFT proteins are very abundant in testis, but we here show that mature sperm are completely devoid of them, making the importance of IFT to mammalian sperm development unclear. To address this question, we characterized spermiogenesis and fertility in the Ift88(Tg737Rpw) mouse. This mouse has a hypomorphic mutation in the gene encoding the IFT88 subunit of the IFT particle. This mutation is highly disruptive to ciliary assembly in other organs. Ift88(-/-) mice are completely sterile. They produce ∼ 350-fold fewer sperm than wild-type mice, and the remaining sperm completely lack or have very short flagella. The short flagella rarely have axonemes but assemble ectopic microtubules and outer dense fibers and accumulate improperly assembled fibrous sheath proteins. Thus IFT is essential for the formation but not the maintenance of mammalian sperm flagella.
authors.affiliation: Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, MA 01605.
authors.forename: Jovenal T
authors.initials: JT
authors.lastname: San Agustin
authors.affiliation: Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, MA 01605 George.Witman@umassmed.edu Gregory.Pazour@umassmed.edu.
authors.forename: Gregory J
authors.initials: GJ
authors.lastname: Pazour
authors.affiliation: Department of Cell and Developmental Biology, University of Massachusetts Medical School, Worcester, MA 01655 George.Witman@umassmed.edu Gregory.Pazour@umassmed.edu.
authors.forename: George B
authors.initials: GB
authors.lastname: Witman
mesh_terms: D000818:Animals; D054468:Axoneme / Q000378:metabolism; D001692:Biological Transport; D002352:Carrier Proteins / Q000378:metabolism; D002923:Cilia / Q000378:metabolism; D008297:Male; D051379:Mice; D008809:Mice, Inbred C3H; D008870:Microtubules / Q000378:metabolism; D013082:Sperm Tail / Q000378:metabolism*; D013091:Spermatogenesis / Q000502:physiology*; D013094:Spermatozoa / Q000378:metabolism / Q000502:physiology*; D013737:Testis / Q000378:metabolism
chemical_list: D002352:Carrier Proteins