Evidence for the expression of actomyosin in the infective stage of the sporozoan protist Eimeria

Cell Biol Int Rep. 1992 Apr;16(4):377-81. doi: 10.1016/s0309-1651(06)80143-8.


A high-speed supernatant extract was obtained from infective oocysts of Eimeria tenella homogenised in a sucrose-low ionic strength buffer. Immunoblotting showed this soluble, micropore-filtered preparation (designated E1) to be rich in actin. E1 underwent superprecipitation on addition of ATP but not its non-hydrolysable analogue AMP.PMP--behaviour typical of an actomyosin solution. The superprecipitate fluoresced strongly in the presence of rhodamine-phalloidin (indicative of the presence of F-actin) and electron microscopy of negatively-stained preparations of this flocculent matter confirmed the abundance of filamentous material within it. This is the first demonstration of a functional actomyosin isolated from a member of the economically important phylum Apicomplexa.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Actins / analysis
  • Actomyosin / analysis*
  • Adenosine Triphosphate / pharmacology
  • Adenylyl Imidodiphosphate / pharmacology
  • Animals
  • Chemical Precipitation
  • Eimeria tenella / chemistry*
  • Eimeria tenella / ultrastructure
  • Immunoblotting
  • Microscopy, Electron
  • Phalloidine
  • Rhodamines


  • Actins
  • Rhodamines
  • Phalloidine
  • Adenylyl Imidodiphosphate
  • Adenosine Triphosphate
  • Actomyosin