Mitochondria behaviour during microsporogenesis in Cosmos bipinnatus

Using a combination of E. M. electron microscopic cytochemistry and experiments with inhibitors (N, DNP, Actinomycin D), mitochondria behaviour during microsporogenesis in Cosmos bipinnatus was examined. In male cells, mitochondrial populations, underwent compre-hensive dedifferentiation, such that the possibility of discontinuity of the organelle line was considered. The number of mitochondria increases dramatically during the early, meiotic a prophase, with the accompanying production of profiles, which indicate that many of these newly produced orgarletles degenerate. It is, suggested that the degeneration observed may result from the lack of nulear-encoded regulatory molecules reaching the organelles. The association of mitochondria and nuclear envelopes in postmeiotic cells of Cosmos is the most likely evidence of direct ATP injection into the nucleus or a sign that information carrying molecules are being exported from the nucleus and passed, to the organelles. Unfortunately, experiments using inhibitors suggest that this may not necessarily be the case.