Genomic consequences of human-mediated translocations in margin populations of an endangered amphibian

Binia De Cahsan, Michael V. Westbury, Sofia Paraskevopoulou, Hauke Drews, Moritz Ott, Günter Gollmann, Ralph Tiedemann

Publications: Contribution to journalArticlePeer Reviewed

Abstract

Due to their isolated and often fragmented nature, range margin populations are especially
vulnerable to rapid environmental change. To maintain genetic diversity and
adaptive potential, gene flow from disjunct populations might therefore be crucial
to their survival. Translocations are often proposed as a mitigation strategy to increase
genetic diversity in threatened populations. However, this also includes the
risk of losing locally adapted alleles through genetic swamping. Human-mediated
translocations of southern lineage specimens into northern German populations of
the endangered European fire-bellied
toad (Bombina bombina) provide an unexpected
experimental set-up
to test the genetic consequences of an intraspecific introgression
from central population individuals into populations at the species range margin.
Here, we utilize complete mitochondrial genomes and transcriptome nuclear data to
reveal the full genetic extent of this translocation and the consequences it may have
for these populations. We uncover signs of introgression in four out of the five northern
populations investigated, including a number of introgressed alleles ubiquitous
in all recipient populations, suggesting a possible adaptive advantage. Introgressed
alleles dominate at the MTCH2 locus, associated with obesity/fat tissue in humans,
and the DSP locus, essential for the proper development of epidermal skin in amphibians.
Furthermore, we found loci where local alleles were retained in the introgressed
populations, suggesting their relevance for local adaptation. Finally, comparisons of
genetic diversity between introgressed and nonintrogressed northern German populations
revealed an increase in genetic diversity in all German individuals belonging
to introgressed populations, supporting the idea of a beneficial transfer of genetic
variation from Austria into North Germany.
Original languageEnglish
Pages (from-to)1623-1634
Number of pages12
JournalEvolutionary Applications
Volume14
Issue number6
DOIs
Publication statusPublished - Jun 2021

Austrian Fields of Science 2012

  • 106012 Evolutionary research
  • 106014 Genomics

Keywords

  • adaptive introgression, admixture, Bombina bombina, genetic rescue, mitogenomes, transcriptomics
  • BELLIED TOADS BOMBINA
  • PHYLOGEOGRAPHY
  • admixture
  • mitogenomes
  • Bombina bombina
  • genetic rescue
  • RESTORATION
  • ADMIXTURE
  • INDIVIDUALS
  • CONSERVATION
  • EVOLUTION
  • SEQUENCE
  • DISEASE RISKS
  • transcriptomics
  • ASSOCIATION
  • adaptive introgression

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