Michael P. Murtaugh, Principal Investigator

Porcine Peyer’s Patch Expressed Sequences Associated With Disease Resistance

Peyer’s patches (PPs) are specialized immune tissues lining the small intestine of vertebrate species. Their anatomical location, their ability to sample microorganisms and molecules from the gut environment, and their organized lymphoid architecture have led to the hypothesis that PPs provide immune surveillance at enteric portals of pathogen entry, are both inductive and effector sites of immune resistance, and mediate oral tolerance to food antigens and commensal bacteria. Despite this critical role in host defense against enteric pathogens while preventing immune responses to food, detailed information about the biochemical and molecular mechanisms by which the PP executes its functions is lacking in all vertebrate species. Moreover, the absence of deoxyribonucleic acid (DNA) sequence information underlying PP biochemical functions interferes with the use of genetic selection to improve animal health and production. These researchers hypothesize that PP expresses genes with specialized functions to maintain mucosal immunity and resistance to enteric disease. To address this hypothesis, the researchers are cataloging the functional activities of the PP by identification of expressed sequences and localizing genomic regions involved in differential resistance to enteric disease by microsatellite linkage disequilibrium in a commercial swine resource population.

A PP molecular catalog, or transcriptome, will provide a foundation for long-term research programs to enhance the understanding of PP biology. Identification of genomic regions that segregate with enteric disease resistance will, with the help of comparative mammalian gene maps, result in the association of candidate PP expressed sequences with differential disease resistance. The findings will help to nominate PP expressed genes with roles in enteric disease resistance and further the development of genetic selection tools for livestock disease resistance.