Phycoplast

Schematic representation of the types of cell division in various green algae: 1) Phycoplast formation with a separation groove (for example Chlamydomonas ); 2) separation groove and existing spindle apparatus (for example Klebsormidium ); 3) Phycoplast and cell plate formation ( e.g. Fritschiella ); 4) spindle apparatus and phragmoplast with cell plate formation ( e.g. coleochaete )

As phycoplast (from Greek. Phykos = "Tang", "seaweed" and plastos = "formed") a particular orientation is microtubules during cell division of the Chlorophyceae , the largest group within the green algae referred to. With them, the spindle apparatus , which is usually perpendicular to the plane of separation, disintegrates and a new microtubule structure is formed, arranged parallel to the new cell wall of the individual cells. Cell division takes place via a separation furrow and, as a rule, no temporary cell plate is created.

In contrast to this, the microtubules of the streptophytina , i.e. all multicellular plants as well as the chandelier algae , are arranged perpendicular to the new cell wall. This is called accordingly by phragmoplast that builds through the fusion of the tubules a temporary cell plate that can interrupt the spindle apparatus during cell division and dissolves again with the separation of the daughter cells. The phragmoplast can accordingly be regarded as a derived feature, which represents an apomorphism of the streptophytina and thus justifies their combination.

literature

• Keywords "Phycoplast" and "Phragmoplast" in: Herder-Lexikon der Biologie. Spektrum Akademischer Verlag GmbH, Heidelberg 2003, ISBN 3-8274-0354-5