Browsing by Subject "genome evolution"
Now showing 1 - 2 of 2
- Results Per Page
- Sort Options
Item Dual Host-Virus Arms Races Shape an Essential Housekeeping Protein(PLOS Biology, 2013-05-28) Abraham, Jonathan; Choe, Hyeryun; Farzan, Michael; Sawyer, Sara L.; Demogines, AnnTransferrin Receptor (TfR1) is the cell-surface receptor that regulates iron uptake into cells, a process that is fundamental to life. However, TfR1 also facilitates the cellular entry of multiple mammalian viruses. We use evolutionary and functional analyses of TfR1 in the rodent clade, where two families of viruses bind this receptor, to mechanistically dissect how essential housekeeping genes like TFR1 successfully balance the opposing selective pressures exerted by host and virus. We find that while the sequence of rodent TfR1 is generally conserved, a small set of TfR1 residue positions has evolved rapidly over the speciation of rodents. Remarkably, all of these residues correspond to the two virus binding surfaces of TfR1. We show that naturally occurring mutations at these positions block virus entry while simultaneously preserving iron-uptake functionalities, both in rodent and human TfR1. Thus, by constantly replacing the amino acids encoded at just a few residue positions, TFR1 divorces adaptation to ever-changing viruses from preservation of key cellular functions. These dynamics have driven genetic divergence at the TFR1 locus that now enforces species-specific barriers to virus transmission, limiting both the cross-species and zoonotic transmission of these virusesItem Targeted Enrichment: Maximizing Orthologous Gene Comparisons across Deep Evolutionary Time(PLOS One, 2013-07-02) Hedtke, Shannon M.; Morgan, Matthew J.; Cannatella, David C.; Hillis, David M.Estimated phylogenies of evolutionarily diverse taxa will be well supported and more likely to be historically accurate when the analysis contains large amounts of data–many genes sequenced across many taxa. Inferring such phylogenies for non-model organisms is challenging given limited resources for whole-genome sequencing. We take advantage of genomic data from a single species to test the limits of hybridization-based enrichment of hundreds of exons across frog species that diverged up to 250 million years ago. Enrichment success for a given species depends greatly on the divergence time between it and the reference species, and the resulting alignment contains a significant proportion of missing data. However, our alignment generates a well-supported phylogeny of frogs, suggesting that this technique is a practical solution towards resolving relationships across deep evolutionary time.