, Volume 166, Issue 1–2, pp 8–20

Microtubules of the flagellar apparatus are active during prey capture in the chrysophycean algaEpipyxis pulchra

  • R. A. Andersen
  • R. Wetherbee


The flagellar apparatus ofEpipyxis pulchra (Chrysophyceae) and its role in phagotrophy is described. Prior to feeding, the cell elongates forming a basal stalk, and the flagellar apparatus moves away from the contractile vacuole/nucleus complex. In feeding cells the flagellar apparatus consists of a striated rhizoplast, cytoplasmic microtubules nucleated from the short flagellum basal body, three microtubular roots (R1, R3 with tubulesa-f, R4) and cytoplasmic microtubules nucleated from R1 and R3 roots. The microtubules of the R3 root split forming a small and a large loop under the short flagellum; thea microtubule forms the inner, smaller loop and thef microtubule forms the outer loop. After looping under the short flagellum, thea andf microtubules join and extend deep into the cell along a complex layered structure involving microtubules, the rhizoplast and a mitochondrion. When a food particle is captured between the flagella, the cell forms a feeding cup to engulf the particle. The rim of the developing cup forms as the distal end of thef microtubule slides up the complex layered structure, increasing the size of its loop under the short flagellum. Vesicles fuse between the loops of thea andf microtubules, increasing the surface area and depth of the cup. When the cup is fully formed, the food particle is moved into the cup. Thef tubule returns to its normal position, closing the cup and forming a food vacuole.


Cytoskeleton Flagellar apparatus Microtubular roots Morphogenesis Phagocytosis 


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Copyright information

© Springer-Verlag 1992

Authors and Affiliations

  • R. A. Andersen
    • 1
  • R. Wetherbee
    • 2
  1. 1.Bigelow Laboratory for Ocean SciencesUSA
  2. 2.School of BotanyUniversity of MelbourneMelbourne

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