Genetic and biochemical analysis of photolyase mutants ofChlamydomonas reinhardtii |
| |
Authors: | D B Munce J L Cox G D Small D Vl?ek S Podstavková E Miadoková |
| |
Institution: | (1) Department of Biochemistry, University of South Dakota, 57069 Vermillion, SD, USA;(2) Department of Anatomy, Mt. Sinai School of Medicine, 10029 New York, NY, USA;(3) Department of Genetics Faculty of Natural Science, Comenius University, 842 15 Bratislava, Slovakia |
| |
Abstract: | A mutant ofChlamydomonas 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 diploids with one mutation was not significantly different
from extracts of wild-type diploids indicating a lack of gene dosage. The amount of DNA photolyase activity in extracts from
the phr-1-1 phr-1-2 was no greater than found in the phr-1-1 phr-1-1 or phr-1-2 phr-1-2 diploids, confirming a lack of complementation
of the mutations. Analysis of 106 tetrads from a cross ofphr-1-1 arg2×phr-1-2 arg7 indicated thatphr-1-1 andphr-1-2 were mutations in the same gene. |
| |
Keywords: | |
本文献已被 SpringerLink 等数据库收录! |
|