SHEEP ABOMASAL TRANSCRIPTOME AND POSSIBLE MECHANISMS OF HOST RESPONSE TO Haemonchus contortus
feeding, endoparasites, immune response, mRNA sequencing, Ovis aries, resistance.
The presence of gastrointestinal nematodes in sheep production systems throughout the world is a major health problem faced by producers, generating economic losses. The aim of this study was to understand molecular mechanisms underlying host resistance. We compared the abomasal mucosal transcriptome of 17 crossbred ½ Santa Inês and ½ Dorper lambs, previously classified as infected (resistant and susceptible) and uninfected distributed in two feeding system (ad libitum and restrict feed) in response to Haemonchus sp .infection using RNA-Seq technology. The libraries preparation, genome sequencing and sequence analyses were performed at the Laboratory of Animal Biotechnology - ESALQ, Piracicaba, Brazil. The average of reads per sample before and after filtering was 12.522.573 and 9.626.457, respectively, and the average of mapping rate of filtered reads against to Ovis aries Oar_v4.0 reference genome assembly was 79.66%. A total of 421, 1123, 13, 36 and 881 genes was classified as DEG in the tests 1, 2, 3, 4 and 5, respectively. The functional enrichment analysis showed that Gene Ontology terms like signal, immune response, complement system, cell cycle, extracellular matrix and cytokines was significantly enriched (padj.< 0.05). Our findings suggest that in addition to genes that participate directly in the immune system, genes that participate in other biological pathways such as arachidonic acid metabolism, signaling pathway and complement system, for example, are essential in the host's response to Haemonchus contortus, generating a greater sheep resistance. In addition, feeding did not have a significant effect on the gene expression profile, showing that the major difference between gene expressions was due to H. contortus infection.