The genus Volvox is comprised of several species of communal multcellular chlorophytes which exhibit a series of interesting morphogenetic events during their developmental cycle. In Volvox carteri, the inversion event is interesting in that after several rounds of cell division from a single cell, the glycoprotein lled, spheroidal plakea completely inverts itself thorough of series of highly c...

Hydrogen gas functions as a key component in the metabolism of a wide variety of microorganisms, often acting as either a fermentative end-product or an energy source. The number of organisms reported to utilize hydrogen continues to grow, contributing to and expanding our knowledge of biological hydrogen processes. Here we demonstrate that Volvox carteri f. nagariensis, a multicellular green a...

Volvox carteri, Differentiation, Embryogenesis, Cell Lineages, Pattern Formation Asexual spheroids of the multicellular green alga Volvox are composed of two types of cells: non-flagellated reproductive gonidia and Chlamydomonas-\ike flagellated somatic cells. They are committed by a differentiating cleavage during embryogenesis. The gonidia of the adult spheroids form a symmetrical pattern con...

Inversion is a dominant aspect of morphogenesis in Volvox. In this process, the hollow, spheroidal Volvox embryo turns inside-out through a small opening called the phialopore to bring flagella from its inner to its outer surface. Analyses of intact, sectioned, and fragmented embryos by light, scanning electron, and transmission electron microscopy, suggest that shape changes preprogrammed into...

The sex-inducing pheromone of Volvox carteri is a glycoprotein that triggers development of males and females at a concentration below 10(-16) M. Evidence is presented for the existence of a novel mechanism of signal amplification operating within the extracellular matrix of this multicellular organism. A family of 70 kDa matrix glycoproteins denoted pherophorins bear a C-terminal domain being ...

We present an apparatus optimized for tracking swimming micro-organisms in the size range of 10-1000 microm, in three dimensions (3Ds), far from surfaces, and with negligible background convective fluid motion. Charge coupled device cameras attached to two long working distance microscopes synchronously image the sample from two perpendicular directions, with narrow band dark-field or bright-fi...