Immunolocalization of ubiquitin in degenerating insect flight muscle.
Ubiquitin was localized by immunofluorescence microscopy during post-mating histolysis of fibrillar flight muscle in female fire ants, Solenopsis spp. Normal muscles, as well as histolysing muscles from artificially inseminated and haemolymph-injected females contained ubiquitin in association with nuclei, Z-lines, myofilaments and mitochondria. However, the density of the ubiquitin immunoreaction was markedly increased in the nuclei, Z-lines and mitochondria of degenerating tissues 6, 12 and 24 h posttreatment. At these times the heaviest immunoreactivity for ubiquitin was seen in association with the nuclei, Z-lines and mitochondria. Immuno-controls, incubated in the absence of the primary antibody, showed no similar immunostaining. When insemination was preceded by the injection of actinomycin D, muscle degradation was significantly depressed after a 24-h period. Also, ubiquitin immunofluorescence was markedly reduced in tissues pre-treated with actinomycin D. These observations suggest that insemination increases the ubiquitination of specific myofibrillar proteins destined for degradation.
Department of Pathology and Laboratory Medicine, University of Pennsylvania Medical School, Philadelphia 19104.
W L
WL
Davis
B H
BH
Jacoby
D B
DB
Goodman
D000818:Animals; D001000:Ants / Q000737:chemistry*; D003609:Dactinomycin / Q000494:pharmacology; D005260:Female; D006458:Hemolymph / Q000737:chemistry; D007150:Immunohistochemistry; D008297:Male; D008856:Microscopy, Fluorescence; D009132:Muscles / Q000737:chemistry* / Q000648:ultrastructure; D016707:Tissue Fixation; D014452:Ubiquitins / Q000032:analysis*
D014452:Ubiquitins; D003609:Dactinomycin