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Plants rely heavily on innate immunity toward pathogens due to the fact that many of them do not contain specialized adaptive immune system cells. In order to mount proper immune responses, plants must come up with several broad defense mechanisms. One such mechanism in these plants, nucleotide-binding domain & leucine-rich repeat (NLR) proteins, are key players when it comes to intracellular immune-related functions. While the biological functions and protein structure of NLR genes are similar across species, variation in NLR gene numbers and sequences among closely related plant taxa can play a key role in diversification and the evolution of reproductive isolating barriers. In this study, we examine variation in NLR genes within Hawaiian Metrosideros (Myrtaceae), an incipient adaptive radiation of woody taxa that show partial isolating barriers. By using NLR annotating software tools, examining the number of NLR genes through code, mapping these genes to their respective chromosomes, and looking at synteny between taxa, we hope to glean insight into the evolution of NLRs in Metrosideros and how variation of these NLR-mediated mechanisms may potentially confer reproductive isolation within taxa. Preliminary results suggest that pubescent Metrosideros taxa may have a greater number of NLR sequences than glabrous taxa while also varying in their distribution across chromosomes. Future synteny analysis will provide a framework for examining variation of these homologous genes and help to establish if gene order is a significant factor of NLR variation among different species.

Publication Date

Fall 11-15-2021




Metrosideros; NLR; Reproductive Isolation; Annotation; Incipient Radiation

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2000 KB


Faculty Mentor: Elizabeth Stacy, Ph.D.


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Evolutionary Analysis of NLR Genes in Metrosideros through Comparative Genomics