RECOMBINATION IN RELATION TO ULTRAVIOLET SENSITIVITY IN CHLAMYDOMONAS REINHARDI

Howard Rosen ¹ and W. T. Ebersold ¹

¹ Department of Botanical Sciences, University of California, Los Angeles, California 90024

A mutant strain of Chlamydomonas reinhardi which is UV sensitive as a result of a single-gene chromosomal mutation has also been found to exhibit reduced recombination. In crosses homozygous for the mutant allele, a reduction in recombination frequency was demonstrated in two different linkage groups and in three different genetic backgrounds. Thus a single mutation affecting UV sensitivity also has a possible effect on recombination. Such a mutant could be analogous to the rec^- mutants discovered in E. coli and as such be useful in the study of recombination mechanisms. Three additional UV-sensitive isolates were tested. Recombination was not altered in these mutant strains.