Profiling Genome-Wide Methylation Patterns in Cattle Infected with Ostertagia ostertagi

Area of Science:

• Epigenetics
• Animal Science
• Immunology

Background:

• DNA methylation (DNAm) is a key epigenetic mechanism regulating gene expression and genomic imprinting.
• Gastrointestinal (GI) nematode infections pose significant challenges to livestock health and productivity.
• Understanding host responses to parasitic infections at an epigenetic level is crucial for improving animal health strategies.

Purpose of the Study:

• To investigate the impact of Ostertagia ostertagi infection on host DNA methylation patterns in cattle.
• To identify tissue-specific and shared differentially methylated positions (DMPs) and regions (DMRs) associated with nematode infection.
• To explore the relationship between DNA methylation changes and immune responses in infected cattle.

Main Methods:

• Holstein steers were infected with Ostertagia ostertagi or served as controls.
• Epigenome-wide profiling was conducted on abomasal fundus, pylorus, draining lymph nodes, and duodenum tissues using a mammalian methylation array.
• Analysis focused on 31,107 cattle CpGs across 5082 genes to identify differential methylation.

Main Results:

• Infection induced distinct, tissue-specific DNA methylation patterns.
• A total of 389 shared and 2770 tissue-specific DMPs were identified, with many in immune-related genes, particularly in draining lymph nodes and abomasal fundus.
• Differentially methylated regions (DMRs) were observed across all sampled tissues, with a notable prevalence of hypomethylation in draining lymph nodes and fundus, and hypermethylation in pylorus and duodenum.

Conclusions:

• DNA methylation plays a significant role in the host's response to GI nematode infection in cattle.
• The identified DMPs and DMRs in immune-related genes suggest DNAm is involved in modulating host immunity against parasites.
• This study provides insights into the epigenetic regulatory landscape of cattle infected by GI nematodes, potentially informing future disease management strategies.