Mitochondrial differentiation during spermatogenesis in the brown alga, Fucus distichus L.

Mitochondrial differentiation and development within Fucus sperm is characterized by a series of internal rearrangements and mass acquisitions relating to overall form and organelle disposition within the mature sperm cell. Moreover, it seems clear that these changes are essential to the functional mode of these free swimming cells in a hazardous environment. Among the more notable structural changes are: increase in the number of cristae, density changes of the matrix and cristae spaces, enhanced membrane staining, appearance and disappearance of inclusions, cristae alignment and reorientation and, of special interest, the formation of intracristal components within all cristae of mature sperm. The intracristal comuonent appears to signal functional capacity for these cells, and its ubiquitous nature marks it f0r taxonomic importance for this group of algae as well. Collectively, these changes represent multiple transformations of the mitochondria in Fucus sperm cell development.