How do chloroplasts replicate?
The survival of an autotrophic cell requires that mutiple copies of the plastid genome are reproduced with high fidelity and that these replicated chromosomes are efficiently distributed to the next chloroplast generation. Though Ris and Plaut reported the presence of DNA in chloroplasts over 40 years ago, we still know very little about plastid DNA synthesis. The goal of our study is to analyze the events associated with chloroplast DNA replication and its dispersal to daughter plastids. We are using qPCR to probe the temporal expression of chloroplast-encoded genes that are implicated in DNA replication and division in synchronous Heterosigma cultures. Future studies will use confocal microscopy to document the replication of DNA “beads” on the ring-shaped nucleoid of this organelle and the localization of division proteins.
