Isolation and characterisation of chemotactic mutants of Chlamydomonas reinhardtii obtained by insertional mutagenesis.

The swimming behaviour of the green flagellated protist Chlamydomonas reinhardtii is influenced by several different external stimuli including light and chemical attractants. Common components are involved in both the photo- and chemo-sensory transduction pathways, although the nature and organisation of these pathways are poorly understood. To learn more about the mechanism of chemotaxis in Chlamydomonas, we have generated nonchemotactic strains by insertional mutagenesis.

Study of Molecular Karyotypes in Amoeboaphelidium protococcarum,the Endotrophic Parasite of Chlorophycean alga Scenedesmus.

On the basis of the pulsed field gel electrophoresis(PFGE) technique, molecular karyotypes in Amoeboaphelidiumprotococcarum (the endotrophic parasite of chlorophycean algae, whichcombines protozoon- and fungus-type characters) were determined. Molecularkaryotypes in the strains X1, X5, and X31, which differ in the host range andoriginate from Western, Central, and Eastern Euro-Asia respectively,demonstrate the intrageneric polymorphism-from 7 to 13 chDNA bands-with theestimated molecular size of 0.3-2.

Isolation and Characterization of Chemotaxis Mutants of Chlamydomonas reinhardtii.

Zoospores of Chlamydomonas reinhardtii exhibit chemotaxis towards maltose, sucrose, xylose, mannitol, and ammonium. Ten independent mutants defective in chemotaxis towards sugars have been isolated. These mutants form five phenotypic classes.