Abstract
A diverse range of eukaryotes show uniparental inheritance of mitochondrial (mt) or chloroplast (cp) DNA, which is based on the preferential degradation of the mt/cpDNA from one of the parents. This process has been extensively studied in the green alga Chlamydomonas reinhardtii but none of the genes that regulate this process have been identified to date.
In this study, we isolated a mutant, biparental (bp) 31, that is defective in the preferential degradation of paternal cpDNA. In addition, bp31 was defective in the formation of zygospores and dynamic alteration in transcriptome upon mating. bp31 has a deletion of ~60kb that includes 12 predicted genes. The mutant phenotype could be rescued by introduction of two of these genes. One of them was a mating type plus specific homeotic gene (GSP1), that is believed to trigger the sexual maturation program. This finding demonstrates the tight link between uniparental inheritance and the sexual program.
