Volvox offers a unique opportunity to study the segregation of reproductive potential during development of a multicellular organism. At the sixth cleavage division of an asexual embryo of Volvox carteri, strain HK 10, one half of the 32 cells typically cleave unequally to yield 16 large gonidial (reproductive) initials and 16 smaller somatic initials, while the remaining cells divide equally t...

BACKGROUND Volvocine green algae like Pandorina morum represent one of the most recent inventions of multicellularity diverged from their unicellular relatives. The 8-16 celled P. morum alga and its close multicellular relatives constitute a model lineage for research into cellular differentiation, morphogenesis and epithelial folding, sexual reproduction and evolution of multicellularity. Pand...

Colonies of the green alga Volvox are spheres that swim through the beating of pairs of flagella on their surface somatic cells. The somatic cells themselves are mounted rigidly in a polymeric extracellular matrix, fixing the orientation of the flagella so that they beat approximately in a meridional plane, with axis of symmetry in the swimming direction, but with a roughly [Formula: see text] ...

The green flagellate J’olvox is a simple muhicellular organism having only two kinds of cells, somatic and reproductive. The cells are arranged on the periphery of a spheroid. Asexual individu~s of I’olvox carten’ are composed of 2000-4000 somatic cells and about 16 large reproductive cells (gonidia), located in the posterior region of the spheroid. Mature asexual spheroids show a very regular ...