Unusual Axonemes of Hexapod Spermatozoa

Dallai, Romano; Lupetti, Pietro; Mencarelli, Caterina

doi:10.1016/s0074-7696(06)54002-1

Cited by 46 publications

(41 citation statements)

References 173 publications

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“…Thus, a simple central tube, rather than a complex cartwheel, could be the highly conserved structure managing the process of procentriole assembly in many organisms. Until now, the very few exceptions to the universal 9-fold symmetry concern primarily basal bodies that nucleate aberrant axonemes [Dallai et al, 2006]. However, it is unclear whether these abnormal axonemes reflect the structure of odd centrioles or if they are the result of large modifications occurring during the initial stages of spermatid differentiation.…”

Section: Resultsmentioning

confidence: 99%

Centriole symmetry: A big tale from small organisms

Riparbelli

Dallai

Mercati

et al. 2009

Cell Motil. Cytoskeleton

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Centrioles are microtubule-based cylindrical organelles with a 9-fold symmetry. They are essential for axoneme formation in cilia and flagella and for centrosome organization. In the basal hexapods Acerentomon microrhinus, we discovered unusually large centrioles composed of 14 doublet microtubules that serve as templates for cilia and flagella and organize mitotic and meiotic spindles. These observations challenge the long-standing view that centriole symmetry is highly conserved among eukaryotes. Strikingly, daughter centrioles contain a transient cartwheel that is lost after maturation. The length of radial spokes is like that found in 9-fold cartwheels, whereas the diameter of the hub varies according to the dimensions of the centriole cylinder. This suggests that the hub may dictate the master plan for centriole geometry. Finally, the finding that 14-doublet centrioles arise from 9-doublet mothers points to an alternative model for centriole assembly.

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Section: Resultsmentioning

confidence: 99%

Centriole symmetry: A big tale from small organisms

Riparbelli

Dallai

Mercati

et al. 2009

Cell Motil. Cytoskeleton

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show abstract

“…For instance, in many insect spermatozoa outer-doublet microtubules have an associated singlet microtubule (i.e. a '9+9+2' axoneme) (Dallai et al 2006), whereas in spermatozoa from some arachnids three singlet central microtubules are seen (a '9+3' axoneme) (Michalik et al 2003). In marine picoplankton of the genus Micromonas only a short 9+2 axoneme of ~1 µm length is built, but the central pair then extends for ~4 µm beyond the termination of the outer-doublet microtubules (Omoto and Witman 1981).…”

Section: Moderation Of Axoneme Structurementioning

confidence: 99%

Eukaryotic Flagella: Variations in Form, Function, and Composition during Evolution

2014

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“…Motile flagella in arthropods are restricted to sperm cells (Nielsen, 2001), but some taxa, including Acari (represented in our study by Ixodes ricinus) and Branchiopoda (here represented by Daphnia pulex) have aflagellated sperm (Morrow, 2004). Insects generally retain sperm flagella, but they are structurally unusual in most taxa, for example by including supernumerary microtubules (Dallai et al, 2006;Mencarelli et al, 2008). Also the way of assembly of the sperm flagellum is unusual in at least some insect species (e.g., in Drosophila, where it was studied in detail), because it does not rely on IFT (which is employed in the formation of the immotile sensory cilia only; AvidorReiss et al, 2004;Mencarelli et al, 2008).…”

Section: The Phyletic Pattern Of Rjl Suggests a Flagellum-associated mentioning

confidence: 77%