The Harderian gland is a sparsely characterized immune tissue known to play an important role in local immunity.The function of the Harderian gland, however, is not clearly defined.Measuring the expression of all genes using RNA-seq enables the identification of genes, pathways, or networks of interest.Our relative RNA-seq expression analysis compared the chicken Harderian gland transcriptome H-Brake Input Assembly to other important primary and secondary immune tissues including the bursa of Fabricius, thymus, and spleen of non-challenged birds.A total of 2,386 transcripts were identified as highly expressed in the Harderian gland.
Gene set enrichment showed the importance of G-protein coupled receptor signaling and several immune pathways.Among the genes highly expressed in the Harderian gland were 48 miRNAs, a category of genetic elements involved in regulation of gene expression.Several identified miRNAs have immune related Ball - Glove Baseball Catcher - Senior functions.This analysis gives insight to the unique immune processes inherent in the Harderian gland.