Red Algal Adelphoparasites
My interests here are principally related to the developmental similarities between the adelphoparasite and its host’s life history stages, and how these evolutionary adaptations are conserved across both other adelphoparasite and alloparasites (those parasites infecting more distantly related taxa) in red algae. In a approach utilizing next gen sequencing, observations, and biological manipulations, we intend to understand the genetic underpinnings that have allowed these multiple evolutionary events of parasitism in the red algae.
Red algal parasites are ideal model organisms for investigating the origins of a parasitic life-style for two important reasons. First, many red algal parasites share an immediate common ancestor with their host, earning them the title adelphoparasites (adelphose is the Greek term for “kin”). Because of this sister-species relationship between parasite and host, the cellular and genomic changes occurring early in the evolution of a parasite, as well as information on host/parasite co-evolutionary dynamics can be assessed through direct comparison of adelphoparasites and their hosts. Additionally, red algal parasites have an interesting infection mechanism, which resembles mitotic amplification of a fertilization event found in the normal triphasic life history of floridiophyte red algae. I believe this mechanism, unique to the red algae, has allowed for the large number of independent evolutions of parasites with the lineage.
National Science Foundation Porphyra/Algal genome Research Coordination Network
Asexual and sexual reproduction is widespread throughout many clades in the tree of life. Theories on the advantage of sexual reproduction hypothesize that sexual offspring have adaptive advantages due to genetic recombination, even though sexual reproduction generally results in lower recruitment potential compared to asexual reproduction. Conversely, models predict that asexuals can out-compete sexuals in most environments because these organisms do not need to produce both male and female offspring and do not break up favorable allelic combinations. Nevertheless, sexual reproduction persists and asexual lineages often die out over time. This suggests that there may be a penalty to asexual reproduction. My involvement in the RCN allows me to further my research into the genetic basis for asexual reproduction, and its evolution in the obligately asexual P. umbilicalis population in Maine, USA within the context of the genetic diversity demonstrated in this population.
The Porphyra RCN supports establishment of the strong research network and bioinformatics’ resources needed to analyze the Porphyra umbilicalis genome. Analyses of the Porphyra genome will include comparative studies using genomes of sister and derived groups of algae (e.g., other red algae, green algae, haptophytes, dinoflagellates). Such studies will improve our understanding of cellular evolution (e.g., endosymbiosis and endosymbiotic gene transfer). This research goal is aided by the breadth of scientific expertise within the RCN. Learn more about the Porphyra RCNhere.