Centrosome Structure in Anthoceros Laevis and Marchantia Polymorpha

Berlin and Bowen (2) observed paired centrioles adjacent to nuclei in vegetative hyphae, sporangiophores, and sporangia in the fungus Albugo candida. The centrioles were arranged end-to-end on the same axis "with little or no angle between them." Later these same authors suggested that the centrioles in an end-to-end orientation appeared to be in the process of replication (3) . Turner (11) noted the appearance of centrioles immediately preceding the last division in spermatid mother cells of the bryophyte Reboulia hemisphaerica . Two centrioles were found aligned on a common axis with their proximal ends apposed . He observed that the "hub" of the cartwheel structure appeared to be continuous between the two centrioles. The work presented here considers the significance of an end-to-end orientation of centrioles in two other bryophytes.