Global genomic methylation related to the degree of parasitism in cattle

Abstract

The objective of the present study was to characterize a herd of 72 ½ Angus × ½ Nellore heifers, identify the resistant, resilient and susceptible animals to parasites, relate the overall DNA methylation of these animals with the degree of parasitism, evaluated by the egg count per gram of feces (EPG), Haematobia irritans count (horn fly) and Rhipicephalus microplus count (bovine tick). The experiment was carried out in a completely randomized design, containing 72 treatments, with each animal considered a treatment, and 11 repetitions, with each collection within a year considered a repetition. The data obtained from the counts of the evaluated parasites were subjected to statistical analysis using the SISVAR program, to classify heifers according to the degree of parasitism in low (resistant), intermediary (resilient) and high (susceptible) parasite load for infection by nematodes, infestation by ticks and flies. Addition the animals in these three groups, by hierarchical grouping using the GENES program, heifers were classified as to the degree of parasitism by the three parasites along with the DNA methylation content of the animals in each group. A negative relationship was observed between resistance and methylated DNA content in both classifications, with the resistant, resilient, and susceptible animals showing the highest, intermediate, and lowest methylated DNA quantifications, respectively. Thus, the methodologies used herein enabled the classification of 72 heifers according to the degree of collective infection by gastrointestinal nematodes and infestation by ticks and horn flies, thereby establishing a link between the degree of parasitic resistance in cattle and the global methylated DNA quantification.

Effects of DNA Methylation on Gene Expression and Phenotypic Traits in Cattle: A Review

“…The DNA methylation level has a correlation with the environment and disease resistance in cattle (Figures 2 and 9) [15][16][17][37][38][39]. In the study of genomic DNA methylation in blood samples of heat-tolerant bulls and Angus bulls, it was found that heat stress can cause variation in methylation patterns of specific loci, which provides a theoretical basis for further study of the role of DNA methylation in heat tolerance in cattle [132].…”

“…Meanwhile, DNA methylation is time-specific and tissue-specific in the life process of animals and plants, and the degree of DNA methylation varies greatly in different developmental stages. An increasing number of studies have shown that the epigenetics caused by DNA methylation have an important impact on animal reproductive performance [15][16][17][18][19][20][21][22][23][24], growth and development [25][26][27][28][29][30][31][32][33][34][35][36] and disease resistance [15,16,[37][38][39], so the methylation of related sites can be used as a molecular marker in future animal breeding (Figures 2-9). At present, research on DNA methylation has been extended to the use of hybrid advantage in livestock, molecular genetic breeding and clone optimization and has begun to explore the specific functions of DNA methylation in livestock genetic breeding.…”