AFLP analysis of a natural population of native Hawaiian Honeycreepers (Hemignathus virens) reveals candidate markers for tolerance to avian malaria (Plasmodium relictum) (P3066)

Abstract

Abstract A better understanding of host defenses against malaria is important, but most studies have traditionally focused on resistance and/or immunological mechanisms that limit parasite burden. Host tolerance mechanisms are thought to minimize physiological damage caused by both the parasite itself and immunopathology without directly affecting parasite burden. On Hawai`i Island, low elevation populations of amakihi (Hemignathus virens) appear to have recently evolved tolerance mechanisms against avian malaria (Plasmodium relictum). Under comparable parasite loads, low elevation amakihi have lower mortality, greater fitness, lower reticulocyte levels and lower heterophil to lymphocyte ratios than high elevation amakihi. Thus, distinct host defense mechanisms are likely operating in low vs. high elevation amakihi. To search for genes involved in host defense, AFLP analysis was completed. Group significance tests (Bionumerics v 2.0) reveal genetic distinction between groups (p = 0.000). Band frequency comparisons between low and high elevation `amakihi (Fisher’s exact test and Pearson’s chi-square test with Yate’s continuity correction, R v 2.11.1) revealed ten band classes with significantly higher (p < 0.05) frequencies in low vs. high elevation birds and 13 band classes with higher frequencies in high vs. low elevation birds. Isolation and sequencing of these candidate bands is underway and may provide a better understanding of host defense mechanisms in natural populations.