Atypical mitochondria in the lung of newts, Triturus alpestris, Laur

Abstract

Mitochondria with atypical cristae were found in the pulmonary cells of laboratory-kept newts, Triturus alpestris Laur. The relative number of atypical mitochondria increased with the time spent by the animals under laboratory conditions. The atypical mitochondria are plate shaped and contain two to six parallel cristae, their membrane being regularly undulated and interconnected by electron-dense lamellae inclined at an angle of approx 45° to the plane of cristae. In some sections oblique to the plane of cristae a tetragonal pattern can be seen. Our electron microscopic observations suggest that atypical cristae do not contain helical structures observed in other atypical mitochondria and the regular, oblique striae represent sections through the electron-dense lamellae bridging both membranes of crista. The occasionally observed tetragonal pattern seems to appear as a result of optical superposition of the arrays of such lamellae from two adjacent cristae.