Algae. 2000; 15(3): 149-153.

Mitochondrial Dynamics in Red Algae. 2. Monosporogenesis in Audouinella botryocarpa (Acrochaetiales)

David J. Garbary, Pei Zuchang

The shape, number and distribution of mitochondria were examined during monosporogenesis in Audouinella botryocarpa using fluorescence microscopy and staining with DiOC sub(6) (3) and DASPEI. Mitochondria are variable in shape and range from spherical to ovoid or irregular. There is an increase mitochondrial number during sporogenesis from about 75 to 200, and mitochondrial number is closely correlated with sporangial size (r = 0.90). Mitochondria are evenly distributed in monosporangial initials. At least ten, large mitochondrial complexes occur early in sporangial development, and these are evenly scattered throughout the cell. Subsequently, these complexes decrease and become restricted to the central portion of monosporangia. Just prior to spore release about one half of the mitochondria remain aggregated in this region. Patterns of mitochondrial distribution and abundance likely reflect changes in metabolic demands and in nuclear/cytoplasmic interactions during sporogenesis.