Host–parasite genotype (Gh x Gp) interactions and identification of genetic mechanisms underlying the host-parasite interface in liver fluke (Fasciola hepatica) infected dairy cows

• Applicants: Dr. Katharina May; Professorin Christina Strube, Ph.D.
• Subject Area: Animal Breeding, Animal Nutrition, Animal Husbandry ; Veterinary Medical Science
• Term: since 2021
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 455792432

The objective of the present research proposal is to study host-parasite interactions between the parasitic agent Fasciola hepatica and dairy cows as their hosts, considering the genome of both interaction partners. To date, studies addressing endoparasite resistance in farm animals have focused either on the host genome or on the parasite genome, but neglected possible genotype-by-genotype interactions between both species. Hence, for the first time, interactions will be modelled considering cow genotypes (Gh) and F. hepatica genotypes (Gp). In this regard, we will phenotype slaughtered F. hepatica infected and non-infected cows from dairy herds with a positive F. hepatica infection status for a broad range of infection traits including faecal egg counts, worm burden, morphometric worm patterns, antigen/antibody titres in faeces/serum, blood parameters and liver tissue damage. Beside infection traits for studying genomics of resistance, we will consider cow yield deviations for milk production traits to infer tolerance mechanisms in dependency of infection intensity. For genotyped cows, we will focus on transcriptomic RNA-seq analyses to investigate gene expression profiles between F. hepatica infected and non-infected cows. We will analyse the effect of Gh, Gp and Gh x Gp interactions on i) infection and production traits via mixed model and genome-wide association analyses and on ii) gene expression profiles to identify genomic regions influencing host resistance to F. hepatica. As a novelty, we additionally focus on F. hepatica glycomic analyses to infer variations in tegumental fluke proteins in dependency of Gp, Gh x Gp and environmental descriptors. The combination of ‘omic’ tools with innovative genomic model analyses considering the host and parasite genome and their interactions provides a novel and unique approach to infer genetic and immunological mechanisms in cattle in response to F. hepatica infections.

• DFG Programme: Research Grants