Stress Fibres In Cells From Normal And Dystrophic (bio 146) Hamsters And Identification Of A Desmin-like Protein From Hamster Muscle
Date of Award
Doctor of Philosophy
The BIO 14.6 line of Syrian hamsters has been a useful model system for Duchenne dystrophy since its introduction (Homburger et al., 1962b). To reduce the effects of genetic background in this model system, a control line ('BC') was produced which shares >90% of its genotype with the BIO 14.6 line. These control animals did not differ from random-bred ('RB') control hamsters under the investigative techniques used here.;In this study, stress fibres in cultured fibroblast-like cells from muscle and skin were examined by direct staining and by indirect immunofluorescence using antibodies to the muscle proteins (alpha)-actinin, tropomyosin and M-line protein. No consistent differences in stress fibre patterns were seen among cells derived from RB, BIO 14.6, carrier and BC animals.;Organisms and cells across a broad phylogenetic range respond to a brief elevation in temperature by the new or enhanced synthesis of 'heat-shock proteins' (hsps), which are believed to serve a thermoprotective function. Changes in the cytoskeletal elements in heat-shocked cells have also been reported (Falkner et al., 1981; Thomas et al., 1981). Cultured fibroblasts from RB, BIO 14.6 carrier and BC animals showed synthesis of two hsp groups in response to temperatures above 42(DEGREES)C: a 64 kd doublet (pIs 5.8 and 5.4) and a 25 kd triplet (pIs 6.2, 5.8 and 5.4). These proteins did not show association with the nucleus under the conditions described here. Heat-shock treatment of RB-derived cells induced a change in cytoskeletal morphology; such a change was not seen in BIO 14.6-derived cells.;Antibodies were produced which recognize a 52 kd protein distinct from desmin. These antibodies stained the Z-line when used for immunofluorescence analysis of myofibrils. In preparations from dystrophic animals, however, some myofibrils showed diffuse background staining with conspicuous 'blank' regions at the Z-line. Abnormal Z-line staining was not seen in preparations from younger (7-10 day) dystrophic animals.;Myofibrils from 7-10 day animals frequently showed a fluorescent doublet in the I-Z region. The significance of the developmental shift in the distribution of the 52 kd protein is not clear at this time.
Pollock, Michael Andrew, "Stress Fibres In Cells From Normal And Dystrophic (bio 146) Hamsters And Identification Of A Desmin-like Protein From Hamster Muscle" (1985). Digitized Theses. 1423.