Fine Structure and Cytochemistry of the Nucleus and the Kinetoplast of Epimastigotes ofTrypanosoma cruzi1

Publisher Website
Google Scholar
Abstract
Ultrastructural cytochemical techniques were used to analyze the nucleus and the kinetoplast of epimastigotes of T. cruzi. With the use of ethanolic phosphotungstic acid, which detects basic proteins, reaction product was seen in the chromatin and at the periphery of the kinetoplast. Thallium alcoholate, which interacts with DNA, stained strongly the whole kinetoplast and the chromatin. With the use of a silver impregnation method that detects acidic nucleolar proteins, silver granules were seen preferentialy located in the central region of the nucleolus. With the EDTA method, which reveals the presence of ribonucleoproteins, staining was observed in the nuclear pores. Also 6-8 nm fibrils, 25 nm and 40 nm granules, which correspond to the perichromatin fibers, interchromatin granules and the perichromatin granules, respectively, were identified in the nucleus. The EDTA method also revealed the presence of 40 nm granules in the kinetoplast. These granules were seen mainly at the 2 extremities of the kinetoplast. Freeze-fracture images indicate that the nuclear membrane contains .apprx. 9 pores/.mu.m2 of nuclear surface area. The mean diameter of the pores was 80 nm. Opimastigotes of T. cruzi probably have a very active nucleus and a high rate of nucleocytoplasmic interchange.