Bobcats (Lynx rufus) are vulnerable to population decline due to road accidents and the loss and fragmentation of their habitat. To aid in their conservation, researchers use various genetic tools to study the movement and genetic diversity of bobcat populations.
Epigenetics, which deals with heritable changes in gene expression without a change to the underlying nucleotide sequence, may allow for a better understanding of how bobcats are adapting to changing environmental conditions.
DNA methylation is a type of epigenetic modification in which a methyl group is added to a nucleotide, potentially inhibiting gene expression.
Methylation levels are influenced by many factors including age, habitat, maternal diet, and developmental stage. Levels can also vary between individuals and among different tissues within an individual.
In a recent paper published in Genome, Bonnie Cantrell and colleagues set out to study epigenetic changes in bobcats by quantifying DNA methylation in 30 animals caught by trappers. The experiment is a first attempt to study interactions between genes and the environment in wildlife, says co-author Stephanie McKay.
The researchers used DNA extracted from the bobcats’ livers to determine the percentage of global DNA methylation, which they then looked at in relation to the age, sex, and weight of the individual from which it came. The bobcats used in the study ranged from younger than a year to 12 years old and weighed between 3.2 and 13.6 kg.
The authors found that methylation in the livers ranged from 0.46% to 2.76%, with an average of 1.65%, but found no correlation between methylation levels and either age or weight.
“The lack of a correlation between methylation and age or sex could be the byproduct of a limited sample size, the tissue that was used, or the resolution of the method,” says McKay. While she says she would have liked to have found a correlation, McKay asserts that, “these findings reinforce the need for further epigenetics research in wildlife.”
McKay explains that for a similar study conducted by her lab in beef cattle, they knew what and how often the animals ate and what environmental conditions they lived in. For their study on bobcats, they did not have this information.
The group plans to continue working on epigenetics in wildlife.
“Next steps include performing additional analysis with more animals, different tissues, and higher-resolution methods, like whole genome bisulfite sequencing, which would allow us to examine similarities and (or) differences between animals at a single base resolution,” McKay says.
“Another possible next step would be generating a DNA methylation clock in bobcats to determine chronological and biological age [or the age cells are functioning at].”
Read the paper: A novel understanding of global DNA methylation in bobcat (Lynx rufus) in Genome.
