Ultrastructure of cell division inAgardhiella subulata(Gigartinales, Rhodophyta)

Abstract

The fine structure of cell division in Agardhidla subulata is consistent with the basic pattern observed for most multicellular red algae.Unusual features include complete microtubule-filled tunnels through the nucleus (prophase), a nucleus-associated organelle penetrated by the outer membrane of the nuclear envelope (prophase) and a metaphase-anaphase polar region that appears in thin section as two large gaps separated by a central intact fragment of nuclear envelope. The only other red alga in which the latter two features have been detected is Lomentaria baileyana (Rhodymeniales). This study is the first complete ultrastructural description of cell division in a member of the Gigartinales. In addition, it provides information on features that may be useful as taxonomic indicators for members of the Gigartinales and the Rhodymeniales.