Epigenetic regulation of SLC11a1 gene in horses infected with cyathostomins

Cyathostomins are the most prevalent nematode parasites of horses worldwide and the SLC11a1 gene has been found to modulate the host immune response against parasite infections. The objective of this work was to determine the DNA methylation profile of the SLC11a1 gene in naturally infected horses (n = 6) and correlate it with the cyathostomin fecal egg count (FEC). In silico analyzes showed two CpG islands, located in the body of the gene and DNA sequencing showed a statistically significant difference between the methylation profile of islands 1 and 2 (P < 0.0001). The data revealed that island 1 was hypermethylated (>95%), while island 2 was hypomethylated (<10%). Although there were no statistical differences in animals with low or high FEC in relation to methylation of island 1 (P = 0.177) or island 2 (P = 0.231), the analysis of island 2 showed a pattern in which samples with higher FEC also presented higher methylation for that island. This data indicates a possible correlation between the cyathostome FEC and the increased methylation of island 2. Animals with a high methylation rate presented a decrease in FEC after 4 months. The preliminary results indicate for the first time the possibility of epigenetic regulation of the SLC11a1 gene in horses. Moreover, it is suggested that methylation of island 2 of the SLC11a1 cascade might indicate the prognostic of parasite infection. Epigenetic processes such as these might be used as biomarkers for identifying individual animals for target treatments and specific breeding purposes.