Cubic membrane structure in amoeba (Chaos carolinensis) mitochondria determined by electron microscopic tomography.

摘要: Abstract Cubic membranes occur in a variety of membrane-bound organelles many cell types. By transmission electron microscopy (TEM) these membrane systems appear to consist highly curved periodic surfaces that fit mathematical models analogous those used describe lipidic cubic phases. For the first time, naturally occurring system has been reconstructed three dimensions by microscopic tomography, and its periodicity directly characterized. Double-tilt tomographic reconstruction mitochondria amoeba, Chaos carolinensis, confirms their cristae (inner infoldings) have structure suggested modeling studies based on thin-section TEM images. Analysis reveals connectivity internal compartments within mitochondria. In regions, matrix is condensed confined continuous, small space between adjacent cristal membranes. The form large, undulating cisternae communicate with peripheral membrane) compartment through narrow tubular segments as seen other types mitochondrial provides an ideal specimen for measuring geometrical distortions biological tomography. It may also prove be useful model correlation cristae–matrix organization activity.