Epigenetics: the study of heritable changes in gene expression and other genomic functions without altering the underlying DNA sequence.
While controversial, epigenetics does appear to offer potentially significant value to livestock genetic programs. Epigenetic studies show that not all genetic information is in the DNA sequence as a significant portion is found in modifications on the epigenome, particularly in DNA methylation (DNAm). It makes sense that manipulating both DNA and methylation of the epigenomes could add significant value to overall livestock genetics efforts. What doesn’t make sense is that such has yet to be explored on any appreciable scale.
In the scientific article “Epigenetics: A New Challenge in the Post-Genomic Era of Livestock,” author Oscar Gonzalez- Recio, of the Departamento de Mejora Genética Animal, Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria in Madrid, Spain, explains the significance in variations in methylation patterns between individuals, even, if not especially, between those that are genotypically identical and what that can mean to breeders and farmers. The article explains the impact thusly:
“…the environment may affect the methylation pattern of up to three generations cohabiting under the same specific circumstances at a given time t during pregnancy: the productive female, the fetus, and the fetus’ germ cells. Hence, what happens to an animal during its lifetime may have consequences in future generations.”
Certainly the article does a good job in spelling out the science, but this SciShow video serves as excellent (and fun) crib notes, well, on humans, but the same concept applies to farm animals and crops as well.
While epigenetics is increasingly popular in genetic studies of cancer and other human diseases, it has yet to gain much attention in livestock genetic studies although the potential benefits in veterinary medicine alone are enticing. Gonzalez- Recio explains in the article that:
“Farms could use epigenetic information to reduce disease incidence and the use of antibiotics in animal production. Personalized medicine using methylation on DNA is currently carried out on cancer research in humans (Peedicayil, 2008; Gomez and Ingelman-Sundberg, 2009), and seems to be a promising strategy for veterinary medicine as well.”
While some farming operations may be unsettled at the thought that they may need to change the environment not only for the current animals' welfare but for future offspring three generations deep, they can likely see profits exceed the costs of doing so, according to Gonzalez- Recio.
“For instance, animals with concentrate and uni-feed diet systems are expected to be differently methylated than animals in a less intensive system based on a pasture feeding systems. It will be important to detect what practices are associated to favorable methylation patterns that affect disease resistance and other economically important traits. Finding this missing causality would assist in rising animals under favorable circumstances and reduce unfavorable methylation patterns.”
Among those “other economically important traits” are likely to be higher profits for epigenetically "certified" livestock and genetic material sales and improved public relations that can lead to better acceptance of meat products and fewer incidents of animal activist protests.
That is, of course, if anyone actually starts looking hard at epigenetics for livestock. It certainly looks to be the next promising frontier.