NSF Postdoctoral Fellowship in Biology FY 2019: What?s in a name? Linking type specimens, reproductive mode, and genetics in Pteridaceae

Picard Kathryn T, Washington DC

Investigators

Abstract

This action funds an NSF Postdoctoral Research Fellowship in Biology for FY 2019, Research Using Biological Collections. The fellowship supports research and training of the fellow that will utilize biological collections in innovative ways. Tied to each species name is a reference (type) specimen. Type specimens are critically important for biologists for identifying new species and inferring relationships between species. However, due to poor DNA quality in preserved specimens, there are few type specimens for which genetic data are available. This poses a significant challenge to scientists studying evolution in groups of organisms with unclear species boundaries or complex evolutionary histories. Ferns are particularly noteworthy for their similar morphologies and complicated genetic makeup, all of which can obscure evolutionary relationships. To address this problem, the fellow will use advances in DNA sequencing technology to generate gene sequence data from decades- and centuries-old type specimens of ferns to estimate the role of genome changes and hybridization as drivers of fern species diversity. The results of this research will not only provide new molecular tools and important life history data for the fern community, but will also contribute to the emerging discipline of museum genomics, helping to unlock the wealth of biodiversity data contained within natural history collections. In the initial phase of the research, the fellow will use spore analysis to determine reproductive mode and estimate ploidy level for the 500+ type specimens in the diverse fern family Pteridaceae at the US National Herbarium. In the second phase of the project, the fellow will extract DNA from all type specimens and use custom DNA hybridization probes to enrich for two important chloroplast genes (the barcode loci rbcL and matK) and 25 low- to single-copy nuclear genes. This phylogenomic dataset will be used to (1) infer a family-wide phylogeny for the Pteridaceae; (2) confirm the ploidy level of each type specimen; and (3) identify speciation events driven by whole-genome duplications and hybridization. This research will be hosted at the US National Herbarium at the National Museum of Natural History. The fellow will receive training in phylogenomics, computational biology, molecular biology and microscopy. The fellow will also direct a science communication workshop series for graduate students and postdoctoral scholars. Workshop participants and the fellow will develop classroom activities based on their research, which will be brought to K-12 schools in the Washington, DC metro area through 'Meet a Scientist' events. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.