Differential responses of abomasal transcriptome to Haemonchus contortus infection between Haemonchus-selected and Trichostrongylus-selected merino sheep

Authors: LIU, JING - Collaborator; ZHOU, JIACHANG - Collaborator; ZHAO, SI - Collaborator; XU, XIANGDONG - Collaborator; Li, Congjun - Cj; LI, LI - Collaborator; SHEN, TINGBO - Collaborator; HUNT, PETER - Collaborator; ZHANG, RUNFENG - Collaborator

Submitted to: Parasitology International
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/4/2022
Publication Date: 1/7/2022
Citation: Liu, J., Zhou, J., Zhao, S., Xu, X., Li, C., Li, L., Shen, T., Hunt, P.W., Zhang, R. 2022. Differential responses of abomasal transcriptome to Haemonchus contortus infection between Haemonchus-selected and Trichostrongylus-selected merino sheep. Parasitology International. 87:102539. https://doi.org/10.1016/j.parint.2022.102539.
DOI: https://doi.org/10.1016/j.parint.2022.102539

Interpretive Summary: Haemonchus contortus is the most prevalent and pathogenic gastrointestinal nematode to sheep and goats. The two CSIRO sheep resource flocks were developed for research on host resistance or susceptibility to gastrointestinal nematode infection. To identify features in the host transcriptome and understand the molecular differences underlying host resistance to H. contortus between flocks, we compared the abomasal transcriptomic responses of the resistant or susceptible animals between HSF and TSF flocks. A total of 11 and 903 differentially expressed genes were identified in the innate infection in resistant and susceptible sheep between HSF and TSF flocks respectively, while 52 and 485 genes were identified to be differentially expressed in the acquired infection, respectively. Among them, 294 genes were significantly affected in the susceptible sheep by both the innate and acquired infections between HSF and TSF flocks. Nineteen pathways were significantly enriched in both the innate and adaptive immune responses in susceptible animals, which indicated that these pathways likely contribute to the host resistance. Our results offered a quantitative snapshot of host transcriptomic changes induced by H. contortus infection between flocks with different selective breeding and genetic backgrounds and provided novel insights into molecular mechanisms of host resistance.

Technical Abstract: Haemonchus contortus is the most prevalent and pathogenic gastrointestinal nematode to sheep and goats. The two CSIRO sheep resource flocks, the Haemonchus-selected flock (HSF) and Trichostrongylus-selected flock (TSF) were developed for research on host resistance or susceptibility to gastrointestinal nematode infection. The previous studies mainly focused on the immune differences after H. contortus infection between the resistant and susceptible sheep within each flock. To identify features in the host transcriptome and understand the molecular differences underlying host resistance to H. contortus between flocks with different selective breeding and genetic backgrounds, we compared the abomasal transcriptomic responses of the resistant or susceptible animals between HSF and TSF flocks. A total of 11 and 903 differentially expressed genes were identified in the innate infection in resistant and susceptible sheep between HSF and TSF flocks respectively, while 52 and 485 genes were identified to be differentially expressed in the acquired infection, respectively. Among them, 294 genes were significantly affected in the susceptible sheep by both the innate and acquired infections between HSF and TSF flocks. Moreover, similar expression patterns of the 294 genes were observed, with 273 genes up-regulated and 21 down-regulated significantly in the abomasal transcriptome of the susceptible animals between HSF and TSF flocks. Gene ontology enrichment of the differentially expressed genes identified in this study predicted the likely involvement of extracellular matrix and muscle contraction-related functions in the immune response to H. contortus infection. Nineteen pathways were significantly enriched in both the innate and adaptive immune responses in susceptible animals, which indicated that these pathways likely contribute to the host resistance development to H. contortus infection in susceptible sheep. Biological networks built for the set of genes differentially abundant in susceptible animals identified hub genes of PRKG1, PRKACB, PRKACA, and ITGB1 for the innate immune response, and CALM2, MYL1, COL1A1, ITGB1 and ITGB3 for the adaptive immune response, respectively. Our results offered a quantitative snapshot of host transcriptomic changes induced by H. contortus infection between flocks with different selective breeding and genetic backgrounds and provided novel insights into molecular mechanisms of host resistance.