Individuality is a complex trait, yet a series of stages each advantageous in itself can be shown to exist allowing evolution to get from unicellular individuals to multicellular individuals. We consider several of the key stages involved in this transition: the initial advantage of group formation, the origin of reproductive altruism within the group, and the further specialization of cell typ...

Volvox barberi is a multicellular green alga forming spherical colonies of 10,000-50,000 differentiated somatic and germ cells. We observed that in culture, these actively self-organized just few minutes into flocks contained as many 100 moving rotating collectively for hours. The formed two-dimensional, irregular, active crystals, is, geometric lattices within which individual rotated separate...

Here, we report our analysis of a mutant of Volvox carteri, InvB, whose embryos fail to execute inversion, the process in which each Volvox embryo normally turns itself inside-out at the end of embryogenesis, thereby achieving the adult configuration. The invB gene encodes a nucleotide-sugar transporter that exhibits GDP-mannose transport activity when expressed in yeast. In wild-type embryos, ...

The alga Volvox carteri represents one of the simplest multicellular organisms. Its extracellular matrix (ECM) is modified under developmental control, e.g. under the influence of the sex-inducing pheromone that triggers development of males and females at a concentration below 10(-16) M. A novel ECM glycoprotein (pherophorin-S) synthesized in response to this pheromone was identified and chara...

Five species of freshwater green algae, including three strains of Botryococcus braunii (two A Race, one B Race), Eudorina unicocca and Volvox aureus, were cultured under controlled conditions in media containing different concentrations of deuterium. The hydrogen isotopic ratios of lipids in the algae, including alkadienes, botryococcenes, heptadecenes, fatty acids, and phytadiene, were measur...

BACKGROUND Bacteria of the family Rickettsiaceae are principally associated with arthropods. Recently, endosymbionts of the Rickettsiaceae have been found in non-phagotrophic cells of the volvocalean green algae Carteria cerasiformis, Pleodorina japonica, and Volvox carteri. Such endosymbionts were present in only C. cerasiformis strain NIES-425 and V. carteri strain UTEX 2180, of various strai...

Sequence analysis based on multiple isolates representing essentially all genera and species of the classic family Volvocaeae has clarified their phylogenetic relationships. Cloned internal transcribed spacer sequences (ITS-1 and ITS-2, flanking the 5.8S gene of the nuclear ribosomal gene cistrons) were aligned, guided by ITS transcript secondary structural features, and subjected to parsimony ...