|Guo, Zhengyu - Texas A&M University|
|Gonzalez, Jorge Francisco - University Of Las Palmas De Gran Canaria|
|Hernandez, Julia - University Of Las Palmas De Gran Canaria|
|Mcneilly, Tom - Moredun Research Institute|
|Morrison, Tyler - Moredun Research Institute|
|Yu, Peng - Texas A&M University|
Submitted to: Scientific Reports
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/28/2016
Publication Date: 5/20/2016
Citation: Guo, Z., Gonzalez, J., Hernandez, J.N., Mcneilly, T.N., Morrison, T., Yu, P., Li, R.W. 2016. Possible mechanisms of host resistance to Haemonchus contortus infection in sheep breeds native to the Canary Islands. Scientific Reports. 6:26200. doi: 10.1038/srep26200.
Interpretive Summary: The intestinal worm Haemonchus contortus, a voracious blood feeder, is the most economically important parasite species in small ruminants. The two indigenous breeds of sheep native to the Canary Islands display a distinct difference against this parasite. These two breeds offer a unique opportunity for us to understand the genetic and immunological bases of host resistance to parasitic infection. In this study, we identified greater than 400 biological processes that are implicated in the development of inter-breed differences in parasite resistance using genomics and high-throughput bioinformatics tools. Our findings suggest that identifying molecular mechanisms controlling inter-breed as well as inter-individual differences in parasite resistance has both pragmatic and theoretical implications.
Technical Abstract: The blood feeder parasite Haemonchus contortus appears to be the most economically important helminth species for small ruminant production in many regions of the world. The two sheep breeds native to the Canary Islands display distinctly different resistant phenotypes under both natural and experimental infection. Canaria Hair Breed (CHB) tends to have significantly lower worm burden and delayed and reduced egg production than the susceptible Canaria Sheep (CS). To understand molecular mechanisms underlying host resistance, we compared the abomasal mucosal transcriptome of the two breeds in response to Haemonchus infection using RNAseq technology. The transcript abundance of 711 and 50 genes were significantly impacted by infection in CHB and CS, respectively (false discovery rate <0.05) while 27 genes were significantly affected in both breeds. Likewise, 477 and 16 Gene Ontology (GO) terms were significantly enriched in CHB and CS, respectively (P <1.0 x10-4) . A broad range of mechanisms have evolved in resistant CHB to provide protection against the helminth parasite. Our findings suggest that readily inducible acute inflammation responses, complement activation, accelerated cell proliferation and subsequent tissue repair, and host immunity directly against parasite fecundity all contributed to the development of host resistance to gastrointestinal nematode infection in the CHB breeds.