Changes in hormonal levels can produce alternative
phenotypes.
Juvenile hormone III
plays an importantrole in the
regulation of metamorphosis,
caste determination and age in
bees. In this
work, we examined theultrastructure of
corpora allata cells from stingless
bees (Melipona quadrifasciata) treated with juvenilehormone during development. The
corpora allata cells of M. quadrifasciata queens showed greater activitythan those of
workers. The topical application of
juvenile hormone III altered the cellular ultrastructureand either delayed development (as shown by fewer
mitochondria and greater
chromatin condensation) orenhanced development (looser
chromatin and numerous
mitochondria) when compared to untreated (control)
bees. Our results show that
corpora allata cells differ in their ultrastructural characteristics and that thecessation of
juvenile hormone production by these
cells in M. quadrifasciata is not synchronous.