A sign of hope (but with caution): rapid changes in the activity of genes associated with heat stress, aging and metabolism have been identified in warmer areas inhabited by polar bears, which use “jumping genes” to “rewrite” our own DNA.
A population of polar bears in Greenland appears to be rapidly altering genetic activity to cope with a warmer environment, in a sign of accelerated adaptation to climate change.
Scientists from the University of East Anglia (United Kingdom) identified the population they describe as “unique” after analyzing blood samples from 17 polar bears: 12 from northeast Greenland, a colder region, and five from the southeast, where temperatures are higher.
The team compared how genes were “on” or “off” in each group, using RNA sequencing, and focused on a particular type of genetic elements known as transposons, often called transposons. “jumping genes.” Transposons are segments of DNA capable of moving within the genome, thus influencing the regulation of other genes. By mapping these patterns, researchers observed striking differences between the two populations, according to the study in Mobile DNA.
In bears living in the southeast, the warmest sector, changes in the activity of genes associated with heat stress, aging and metabolism, which suggests a rapid biological response to environmental conditions.
“Essentially, this means that different groups of bears are having different sections of their DNA change at different rates, and this activity appears to be linked to their specific environment and climate.”explains the main researcher, Alice Goddenem .
For the team, these results represent the first evidence that a group of polar bears in the warmer part of Greenland may be using “jumping genes” to “rewrite” your own DNA as a possible survival mechanism in the face of sea ice loss.
The authors emphasize, however, that the ability to adapt does not eliminate the risk. On the contrary, it may be an indicator of extreme pressure on the species. Godden argues that these bears offer a “genetic blueprint” that helps understand how the polar bear might react quickly to global warming, which could be relevant for guiding conservation efforts. But he warns that we cannot be complacent, and insists on the need to reduce carbon emissions and halt the rise in global temperatures.
The team now intends to extend the analysis to other subpopulations — there are around 20 in the Northern Hemisphere — and calls for the urgency of studying the genome of this species “before it is too late”, quotes .
