37. Ellis, E. A. and R. M. Brown, Jr. 1972.
Freeze etch electron microscopy of the lichen, Parmelia caperata.
Trans. Amer. Microscop. Soc. 91:411-421.
37. Abstract
Freeze-etch ultrastructure of Parmelia
caperata (L.) Ach. Trans. Amer. Micros. Soc. 91: 411-421.
Freeze-etch preparations of the foliose lichen Parmelia caperata
(L.) Ach. indicate that the technique can be applied advantageously
to ultrastructural studies of the lichen association. The preservation
of fine structure confirms in most respects the image observed
after chemical fixation. The ultrastructural image presented
by freeze-etching is superior in many cases to that produced by
chemical fixation plasmalemma and stacking of the thylakoids in
the algal chloroplast, comparable to the grana of higher plants,
were demonstrated. Freeze-etching revealed the crystals of lichen
substances and invaginations in the phycobiont plasmalemma, details
normally not observed in sectioned material. The freeze-etch
technique presents an independent physical method for elucidating
lichen ultrastructure and should be coupled with conventional
chemical fixation techniques for further investigations of the
lichen association.