New understandings into badger biology, disease and response to climate change are on the horizon, following the completion of the European badger reference genome by scientists at the University of Oxford and the Wellcome Sanger Institute. The work is part of the Darwin Tree of Life project to sequence all species in Britain and Ireland.
The genome, released openly on Wellcome Open Research, will enable researchers to answer new questions about badger biology and evolution, such as how genetics affects their ability to respond to disease and climate change.
Because the European badger is highly-adaptable and able to thrive in diverse habitats, with related species in Eastern Europe, Asia, and Japan, it is a good model species to assess the impacts of climate change.
To create the genome, researchers at the University of Oxford’s Wildlife Conservation Research Unit (WildCRU) collected blood samples from an individual badger plus both of its parents in Wytham Woods, as part of a long-term study examining badger ecology, behaviour and genetics.
DNA from the sampled badgers was extracted, sequenced and these data then reassembled into a complete, high-quality reference genome at the Wellcome Sanger Institute.
Responses to climate change
The badger population in Wytham Woods has been studied in unprecedented detail since 1987, generating a large long-term dataset that has given insights into badger behaviour, climate change responses, reproductive biology, epidemiology, immunology and disease. The badger genome will facilitate further genetic studies into ecology, population biology and evolution of badgers and related mammals.
One project currently underway is investigating whether early-life adversity affects individual badgers in later life and whether this is linked to epigenetic patterns, where gene expression is affected by environmental factors rather than altering the genetic code itself.
“By combining the vast amount of badger population data collected at Wytham since 1987 with the new reference genome, we can start to answer some of these intricate questions. This will also inform the field about the effect of climate change in wildlife populations at a molecular level.”
Ming-Shan Tsai, WildCRU
The European badger has a particularly high density in the United Kingdom, where in recent years it has been subject to a controversial cull aimed at reducing incidence of bovine tuberculosis (bTB) in cattle herds. Though badgers are susceptible to bTB and can transmit it to cattle, there is no conclusive evidence that reducing badger numbers will help to reduce outbreaks in livestock.
“In previous research our team investigated why badgers are so prone to bovine tuberculosis, with the aim of trying to refine a vaccine. But without a badger genome we had to use ferret data as an analogue, which restricted what we could learn. Reference genomes allow you to answer questions you simply couldn’t otherwise, and I’m sure badger researchers will be excited to explore new paradigms in evolutionary ecology using this highly tractable mammal model.”
Chris Newman, WildCRU