Effects ef ions on the orientation of cortical microtubu]es (MTs) in spirogyra cells were studied. After depotymerization with amiprophos-methyl (APM), MTs were atlowed to reorganize in NaCl sollltions of yarious concentrations. As the conce"tration of NaCl increased, the frequency of ce]ls that had oblique MTs increased. When ce]ls in NaCl solution vvere transferred into artificia) pond water ...

The problems of heredity are intimately related to the two critical stages in the life cycle of the higher organisms, the reduction divisions of sporogenesis in plants and of gametogenesis in animals, and the cytological processes of fertilization. The first of these has received much attention and is generally considered to be closely correlated with the segregation of the factors which determ...

Cytokinesis in the green alga Spirogyra (Zygnemataceae) is characterized by centripetal growth of a septum, which impinges on a persistent, centrifugally expanding telophase spindle, leading to a phragmoplast-like structure of potential phylogenetic significance (Fowke, L. C., and J. D. Pickett-Heaps. 1969. J. Phycol. 5:273-281). Combining fluorescent tagging of the cytoskeleton in situ and vid...

INTRODUCTION We evaluated periphytic algal and microbial communities to assess the influence of human and cattle impact on Sierra water quality. METHODS 64 sites (lakes and streams from Lake Tahoe to Sequoia National Park, California) were sampled for suspended indicator bacteria and algae following standardized procedures. The potential for nonpoint pollution was divided into three categorie...

Ecological investigation of two riverine wetlands of Goalpara district, Assam, India was carried out in relation to planktonic productivity from 2006 to 2008. The physico chemical parameters were found fluctuating with the growth of both phytoplankton and zooplankton. Both the beel was dominated by Chlorophyceae throughout the year amongst which Ulothrix and Spirogyra were found as dominating s...