Changes in polar bear genome activity may allow adaptation to warmer temperatures 

A recent study suggests warming temperatures may be driving changes in transposable element activity and gene expression in a subpopulation of polar bears. 

Southeastern Greenland is home to a subpopulation of polar bears. The temperatures in this region are higher and more variable than in other areas, matching the future conditions predicted for the rest of the Arctic Circle due to global warming.  

Scientists from UEA compared blood samples from these southeastern polar bears and a northeastern population to look for activity of transposable elements, also called ‘jumping genes’ or mobile genetic elements. Transposable elements are DNA sequences that can copy themselves and insert into the genome. By doing so they can change gene expression. Scientists suspect transposable elements may play an important role in allowing species to adapt to rapidly changing environmental conditions. 

Analysis of 12 northeastern polar bear genomes and 5 southeastern found the southeastern bears had differences in transposable element activity compared to the northeastern. Further statistical analysis showed these differences were linked with temperature. These results build on previous observations of temperature affecting transposable element activity in species such as Arabidopsis, C. elegans and Drosophila. These ‘model species’ are used frequently in the study of genetics.  

The study on genetic expression in polar bears also found 27 differentially expressed genes in the southeastern population. 10 of these overlapped with transposable elements and seemed linked to temperature. 

Genes involved in metabolism and responding to stress were more active in the southeastern population. Importantly, there was increased expression of stress proteins – also referred to as heat-shock proteins – involved in responding to a variety of stressors such as high temperatures. These proteins act as molecular chaperones, helping to fold newly formed proteins into the correct structure and refolding or breaking down damaged proteins.  

There was also an increase in the expression of flippases, which are responsible for transporting lipids within cell membranes, and are important for maintaining membrane structure and function when temperature fluctuates. The study also found changes in gated channel and chloride channel expression, proteins that allow cells to respond to many different stressors including heat.  

Researchers have concluded that the differences in transposable element activity and the increased activity of stress proteins may be an adaptation to the higher temperatures in southeastern Greenland. Lead researcher Dr Alice Godden, speaking to the UEA communications office, said this finding “shows, for the first time, that a unique group of polar bears in the warmest part of Greenland are using ‘jumping genes’ to rapidly rewrite their own DNA”. She went on to explain that this might allow rapid adaptation to climate change, meaning a greater understanding of the genetic activity of these bears could be vital for conservation.  

By Eloise Trawick, January 27, 2026.

Edited by Marina Milsum.