Plants and animals carry DNA in their mitochondria, in addition to the majority of genes that are carried on nuclear chromosomes. In flowering plants the mitochondrial DNA (mtDNA) is often inherited from the mother only, such that the copies of mtDNA within an individual are identical. Recent studies of the plant Silene vulgaris showed that inheritance of mtDNA is sometimes from both the mother and father, resulting in a heterogeneous mix of mtDNA molecules in the offspring (heteroplasmy). This study will investigate the frequency of non-maternal inheritance of mtDNA through experimental crosses of S. vulgaris conducted in the greenhouse, and document the frequency and magnitude of heteroplasmy in natural populations, using the tools of molecular biology.
The results will be of value to population biologists because mtDNA is used as a genetic marker in many types of studies, under the assumption of maternal inheritance. This assumption has only been tested directly in relatively few species, and the consequences of non-maternal inheritance are not well understood. The results will also interest applied biologists whose goal is to develop lines of economically important plants that produce a high proportion of females for breeding purposes, given that sex determination in plants is often traced to mitochondrial genes.
