Figure 4.

In vivo effect of actinomycin on at-RA induced spinule formation. (A) Preincubation (15, 60, and 120 min) with actinomycin (200 μM) did not block the effects of at-RA (0.5 μM). Open bars represent the data from dark-adapted control retinae that received an injection of at-RA, and hatched bars represent data from the retinae that in addition were preincubated with actinomycin (n = 2 animals for each time point). (B) In vivo effect of actinomycin on the expression of rod transducin Gαt₁ and c-jun in the carp retina. Immunoblots of SDS/10% PAGE gels on which aliquots (60 μg of protein each) of homogenates of dark-adapted controls (D) and actinomycin-treated retinas (2 hr in vivo preincubation; Act) were separated. The expression patterns of a 39-kDa anti-Gαt₁- and a 39-kDa anti-c-jun-immunoreactive protein are shown.