Genetic and biochemical analysis of photolyase mutants of Chlamydomonas reinhardtii

• Published in: Folia microbiologica Vol. 38; no. 6; pp. 435 - 440
• Main Authors: Munce, D.B, Small, G.D. (University of South Dakota, Vermillion (USA). Dept. of Biochemistry), Cox, J.L, Vlcek, D, Podstavkova, S, Miadokova, E
• Format: Journal Article
• Language: English
• Published: Praha Academia 01-12-1993
• Subjects: ADN; ALGAE; Biological and medical sciences; DIPLOIDIA; DIPLOIDIE; Enzymes; Fundamental and applied biological sciences. Psychology; Metabolism; MUTANT; MUTANTES; NOYAU CELLULAIRE; NUCLEO; PIRIMIDINAS; Plant physiology and development; PROPIEDADES OPTICAS; PROPRIETE OPTIQUE; PYRIMIDINE; RADIACION ULTRAVIOLETA; RAYONNEMENT ULTRAVIOLET; SUPERVIVENCIA; SURVIE; Biochemical analysis; Enzymatic activity; Gene; Algae; Chlamydomonas reinhardtii; DNA; Chlorophycophyta; Mutation; Thallophyta
• DOI: 10.1007/BF02814391
• EISSN: 1874-9356
• ISSN: 0015-5632

A mutant of Chlamydomonas reinhardtii phr-1-1 is deficient in the photorepair of pyrimidine dimers in nuclear DNA but not in chloroplast DNA. In this report, a second photoreactivation-deficient strain, phr-1-2, which has a similar phenotype as phr-1-1, is described. To determine if these mutations were in different genes, complementation tests as well as tetrad analysis were performed. Six diploid strains were constructed. The diploid strains containing one mutation exhibited similar UV-light survival curves under photoreactivating conditions as the wild-type diploid, indicating recessive nature of the mutations. No increase in survival was obtained with phr-1-1 phr-1-2 compared with either the phr-1-1 phr-1-1 or phr-1-2 phr-1-2 diploids indicating a lack of complementation. The amount of DNA photolyase activity in cell-free extracts of dipolids with one mutation was not significantly different from extracts of wild-type diploids indicating a lack of gene dosage.