A PHYSICAL MAP OF THE CHLAMYDOMONAS REINHARDTII NUCLEAR GENOME

Shin, W., Zimmermann, S. & Triemer, R. E. Department of Life Science, Rutgers University, Piscataway, NJ 08854, USA In 1985, Willey and Wibel described the existence of a cytoplasmic pocket formed from the reservoir membrane in Colacium. A band of microtubules derived from the ventral flagellar root (MTR) lined the pocket and a dense fibrillar mesh was associated with the membrane. A comparison of bodonid cytostomes, colorless euglenoid cytostomes, and the reservoir pocket found in Colacium suggested that the three structures were homologous and that photosynthetic euglenoids arose from phagotrophic ancestors. MTR/pockets have since been reported in other photosynthetic euglenoids including Euglena, Eutreptia, Eutreptiella, Cryptoglena, and Tetreutreptia. We now report on MTR/pockets in Lepocinclis, Trachelomonas, Strombomonas and Phacus thereby demonstrating the presence of this complex in representatives of all of the major photosynthetic genera. A comparison of the MTR/complex across genera indicates a reduction in structural complexity that is consistent with recent phylogenetic schemes based on molecular characters.