1. Replicating kinetoplast DNA networks from both Crithidia fasciculata and Leishmania tarentolae have an equilibrium density in ethidium bromide— CsQ which is less than that of covalently closed non-replicating networks. After a few hours of chase, these networks assume the covalently closed posi-. tion in the gradient. 2. Pulse-labeled minicircles isolated, from sonicated networks band in the...

In trypanosomatids, the kinetoplast is the portion of the single mitochondrion that is connected to the basal body and contains the kDNA, a network composed by circular and interlocked DNA. The kDNA packing is conducted by Kinetoplast Associated Proteins (KAPs), which are similar to eukaryotic histone H1. In symbiont-harboring trypanosomatids (SHTs) such as Angomonas deanei and Strigomonas culi...

The mitochondrial DNA in kinetoplastid protozoa is contained in a single highly condensed structure consisting of thousands of minicircles and approximately 25 maxicircles. The disk-shaped structure is termed kinetoplast DNA (kDNA) and is located in the mitochondrial matrix near the basal body. We have previously identified a mitochondrial DNA ligase (LIG kbeta) in the trypanosomatid Crithidia ...

Kinetoplast-mitochondrial vesicles from Leishmania tropica promastigotes were prepared by subjecting the particulate fractions from cell lysates to floatation ultracentrifugation in renografin gradients. They formed a distinct band with a density of 1.19 to 1.22 g/ml and appeared homogeneous as judged by phase microscopy. They showed succinate-cytochrome c reductase activity as well as the inco...

Leishmania actin (LdACT) is an unconventional form of eukaryotic actin in that it markedly differs from other actins in terms of its filament forming as well as toxin and DNase-1-binding properties. Besides being present in the cytoplasm, cortical regions, flagellum and nucleus, it is also present in the kinetoplast where it appears to associate with the kinetoplast DNA (kDNA). However, nothing...

The unitary nature of the chondriome of two species of trypanosomatids, Blastocrithidia culicis and Trypanosoma cruzi, has been demonstrated by utilizing serial thick-sectioning techniques combined with high voltage electron microscopy. Profiles of mitochondrial elements seen in thin sections and suspected to be parts of a continuum were confirmed by serial thick sectioning (0.25-0.50 mum thick...

Kinetoplast DNA networks were isolated from stationary-phase culture forms of Phyromonas davidi. The networks banded in CsCl at a density of 1.699 g/ml and consisted of covalently closed circular molecules. The networks were sensitive to shear forces and exhibited several discrete sedimenting components in neutral and alkaline sucrose. Closed monomeric minicircles were isolated from sonicated n...