Isolation and structure of mitochondria from Ascaris lumbricoides muscle

Abstract

As observed in the electron microscope, particles with an approximate diameter of 0.33 μ were localized predominantly in the central cytoplasmic region of muscle cells from Ascaris lumbricoides var. suis. They also occurred in lesser frequency between bundles of intracellular contractile elements. The presence of tubular cristae which probably originate at the limiting membrane indicates that the particles are mitochondria. Cristae extended only short distances into the matrix and then usually changed their direction in another plane. The presence of lamellar cristae and double outer membranes as described in higher organisms was not observed. In a variety of attempts to obtain the mitochondrial particles of Ascaris muscle in cell-free preparations, it was found that morphological changes were minimal only when dialyzed perienteric fluid was used during the preparative procedure. These particles uniformly contained only few internal tubules and were similar in this respect to particles in situ. It is suggested that the small number of cristae may be related to the essentially anaerobic type of metabolism characteristic for Ascaris.