|SCHWARTZ, JOHN - The Pirbright Institute|
|PHILP, REBECCA - The Pirbright Institute|
|Smith, Timothy - Tim|
|HAMMOND, JOHN - The Pirbright Institute|
Submitted to: Immunogenetics
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/29/2017
Publication Date: 10/6/2017
Citation: Schwartz, J.C., Philp, R.L., Bickhart, D.M., Smith, T.P., Hammond, J.A. 2018. The antibody loci of the domestic goat (Capra hircus). Immunogenetics. 70: 317-326. doi: https://doi.org/10.1007/s00251-017-1033-3).
Interpretive Summary: Regions of the genome related to immune function are often poorly characterized in livestock species. This is particularly troubling as U.S. food security needs require that domestic livestock populations maintain a sufficiently diverse immune system repertoire in order to resist diseases that affect production. By fully characterizing genomic regions related to immunity in livestock reference genomes constructed using the latest DNA sequencing technologies, we showed that the newest reference genomes will enable higher resolution analysis of immune genes. This, in turn, will enable the selection of individuals with improved resistance to common pathogens that affect animal productivity.
Technical Abstract: The domestic goat (Capra hircus) is an important ruminant species, both as a source of antibody-based reagents for research and biomedical applications, and as an economically important animal for agriculture, particularly for developing nations that maintain most of the global goat population. Characterization of the loci encoding the goat immune repertoire would be highly beneficial for both vaccine and immune-reagent development. However, in goat and other species whose reference genomes were generated using short-sequence read technologies, the immune loci are poorly assembled as a result of their repetitive nature. Our recent construction of a long read-based goat genome assembly (ARS1) has facilitated characterization of all three antibody loci with high confidence, and with comparative analysis to cattle. We observed broad similarity of goat and cattle antibody-encoding loci, but with notable differences that likely influence formation of the functional antibody repertoire. The goat heavy-chain locus is restricted to only four functional and nearly identical IGHV gene segments, in contrast to the ten observed in cattle. Repertoire analysis indicates that light-chain usage is more balanced in goats, with greater representation of kappa light chains (~20- 30%) compared to cattle (~5%). The present study represents the first characterization of the goat antibody loci, and will help inform future investigations of their antibody responses to disease and vaccination.