Open AccessScanning electron microscopy of the nuclei and nucleoli in Tetrahymena
Author(s) -
LEICK V.,
BRO B.,
LIMADEFARIA A.
Publication year - 1979
Publication title -
hereditas
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.819
H-Index - 50
eISSN - 1601-5223
pISSN - 0018-0661
DOI - 10.1111/j.1601-5223.1979.tb01309.x
Subject(s) - macronucleus , nucleolus , biology , scanning electron microscope , tetrahymena pyriformis , tetrahymena , transmission electron microscopy , microscopy , materials science , optics , ciliate , microbiology and biotechnology , genetics , nanotechnology , cytoplasm , physics
The macronucleus and the micronucleus of Tetrahymena thermophila have been analysed by transmission and scanning electron microscopy using different methods of fixation. The micronucleus is frequently found located in a concave depression of the macronucleus. There is good agreement between the observations made with transmission and scanning electron microscopy with respect to the size and shape of the two types of nuclei. The nucleoli have been isolated from the macronucleus and analysed in the scanning electron microscope. Three types of fixatives have been used; osmium, formaldehyde and acetic‐alcohol. All three produced similar results. There is also good agreement between the size and shape of the nucleoli observed with the transmission and scanning electron microscopy. The nucleoli appear in the scanning electron microscope as single units or as compound structures consisting of two to three elements. They have a structure with indentations similar to those found in Acheta . In both Tetrahymena and Acheta there is amplification of ribosomal DNA. The arrangement of the DNA copies within the nucleolus of the two species is compared and correlated with the amplification process.