title: The plastid genomes of nonphotosynthetic algae are not so small after all.
abstract: The thing about plastid genomes in nonphotosynthetic plants and algae is that they are usually very small and highly compact. This is not surprising: a heterotrophic existence means that genes for photosynthesis can be easily discarded. But the loss of photosynthesis cannot explain why the plastomes of heterotrophs are so often depauperate in noncoding DNA. If plastid genomes from photosynthetic taxa can span the gamut of compactness, why can't those of nonphotosynthetic species? Well, recently we showed that they can. The free-living, heterotrophic green algaPolytoma uvellahas a plastid genome boasting more than 165 kilobases of noncoding DNA, making it the most bloated plastome yet found in a heterotroph. In this addendum to the primary study, we elaborate on why theP. uvellaplastome is so inflated, discussing the potential impact of a free-living vs. parasitic lifestyle on plastid genome expansion in nonphotosynthetic lineages.
authors.affiliation: Department of Biology, University of New Brunswick, Fredericton, NB, Canada; CONACyT-Research Fellow, Universidad Autónoma Metropolitana, Iztapalapa, Vicentina, Mexico City, Mexico; Integrated Microbiology Program, Canadian Institute for Advanced Research, Toronto, ON, Canada.
authors.forename: Francisco
authors.initials: F
authors.lastname: Figueroa-Martinez
authors.affiliation: Department of Biology, University of New Brunswick, Fredericton, NB, Canada; Integrated Microbiology Program, Canadian Institute for Advanced Research, Toronto, ON, Canada.
authors.forename: Aurora M
authors.initials: AM
authors.lastname: Nedelcu
authors.affiliation: Department of Biology, University of New Brunswick, Fredericton, NB, Canada; Integrated Microbiology Program, Canadian Institute for Advanced Research, Toronto, ON, Canada.
authors.forename: Adrian
authors.initials: A
authors.lastname: Reyes-Prieto
authors.affiliation: Integrated Microbiology Program, Canadian Institute for Advanced Research, Toronto, ON, Canada; Biology Department, University of Western Ontario, London, ON, Canada.
authors.forename: David R
authors.initials: DR
authors.lastname: Smith
keywords: Chlamydomonas; Polytoma; Polytomella; genome expansion; nonphotosynthetic; plastid DNA