The use of morphomutants to investigate septum formation and cell separation in Schizosaccharomyces pombe

Cytokinesis in the fission yeast Schizosaccharomyces begins by formation of a medially placed actomyosin ring, continues by progressive development of a septum, and is completed by cleavage of the mature septum to bring about cell separation. The cytological analysis of the Schziosaccharomyces pombe morphomutants sph2-3 and sep1-1 presented here demonstrates that the media l actomyosin ring colocalizes to the leading edge of the centripetally grow ing septum, and cleavage of the septum is triggered by rupture of the mothe r cell wall at the septal basis.