Genetic legacy of last glaciation influences reindeer's seasonal
migrations
Proportion of northern ancestry influences migratory behavior

Date:
February 10, 2022
Source:
PLOS
Summary:
Caribou (known as reindeer in Europe) make one of the longest
seasonal migrations of land animals, but an individual's propensity
to migrate depends on its genetic ancestry, researchers report.



FULL STORY ========================================================================== Caribou (known as reindeer in Europe) make one of the longest seasonal migrations of land animals, but an individual's propensity to migrate
depends on its genetic ancestry, Maria Cavedon at the University of
Calgary in Canada and colleagues report in a study publishing Feb. 10
in the open-access journal PLOS Genetics.


==========================================================================
The researchers used GPS tracking and DNA sequencing to investigate the
genetic factors influencing migratory behavior in 139 female reindeer
(Rangifer tarandus)living in tundra or woodland habitats across western
North America.

They identified over 50 genetic mutations associated with migratory
behavior, of which 27 were located in genes involved in brain activity,
fat and energy metabolism, body development, or hormone production. The sequences clustered into northerly and southerly subpopulations,
descended from ancestral caribou that were trapped either side of the
Rocky Mountains during the last glaciation. Despite generations of hybridization since the glaciation ended around 11,000 years ago, the researchers found that caribou with a greater proportion of genes from
northern ancestry were more likely to migrate longer distances. Migratory individuals travelled nearly 250 kilometers on average, ten times
further than sedentary reindeer. These results indicate an evolutionary
legacy from the last glaciation, when northerly caribou populations
had to migrate to survive in harsh tundra environments, while southerly populations living in forests were more sedentary.

The study is the first to investigate the genes influencing migration
in an endangered terrestrial mammal. Seasonal migrations allow animals
to track moving resources or avoid harsh conditions, but they also make
them particularly vulnerable to habitat fragmentation. Ancestral genes
for migration could be lost forever if the descendants of northern
lineages are driven extinct, but conserving key habitats in their
seasonal migration routes could help to preserve the genes underpinning
the world's longest terrestrial migration, the authors say.

"Wide-ranging animals, including migratory species, are significantly threatened by the effects of habitat fragmentation and habitat loss,"
Cavedon adds. "We examined migratory behavior of GPS-collared endangered caribou in western North America and carried out genomic scans for the
same individuals.

We detected genes associated with migratory behavior, and we determined
that propensity to migrate depended upon the evolutionary history
of caribou. If, as we report, migratory behavior is influenced
by genes, caribou could be further impacted by the loss of the
migratory trait in some isolated populations already at low numbers." ========================================================================== Story Source: Materials provided by PLOS. Note: Content may be edited
for style and length.


========================================================================== Journal Reference:
1. Maria Cavedon, Bridgett vonHoldt, Mark Hebblewhite, Troy Hegel,
Elizabeth
Heppenheimer, Dave Hervieux, Stefano Mariani, Helen Schwantje, Robin
Steenweg, Jessica Theoret, Megan Watters, Marco Musiani. Genomic
legacy of migration in endangered caribou. PLOS Genetics, 2022;
18 (2): e1009974 DOI: 10.1371/journal.pgen.1009974 ==========================================================================

Link to news story: https://www.sciencedaily.com/releases/2022/02/220210154227.htm

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