Variation in Major Histocompatibility Complex diversity in invasive cane toad populations

Mette Lillie*, Sylvain Dubey, Richard Shine, Katherine Belov

*Corresponding author for this work

Research output: Contribution to journalArticle

2 Citations (Scopus)

Abstract

Context The cane toad (Rhinella marina), a native species of central and southern America, was introduced to Australia in 1935 as a biocontrol agent after a complex history of prior introductions. The population rapidly expanded and has since spread through much of the Australian landmass, with severe impacts on the endemic wildlife, primarily via toxicity to predators. The invasion process has taken its toll on the cane toad, with changes in the immunological capacity across the Australian invasive population. Aims To investigate the immunogenetic underpinnings of these changes, we studied the diversity of the Major Histocompatiblity Complex (MHC) genes in introduced cane toad populations. Methods We studied the diversity of two MHC genes (the classical class I UA locus and a class II DAB locus) and compared these with neutral microsatellite markers in toads from the Australian site of introduction and the Australian invasion front. We also included toads from Hawai'i, the original source of the Australian toads, to infer founder effect. Key results Diversity across all markers was low across Australian and Hawai'ian samples, consistent with a reduction in genetic diversity through multiple founder effects during the course of the successive translocations. In Australia, allelic diversity at the microsatellite markers and the UA locus was reduced at the invasion front, whereas all three alleles at the DAB locus were maintained in the invasion-front toads. Conclusions Loss of allelic diversity observed at the microsatellite markers and the UA locus could be the result of drift and bottlenecking along the invasion process, however, the persistence of DAB diversity warrants further investigation to disentangle the evolutionary forces influencing this locus. Implications Through the use of different molecular markers, we provide a preliminary description of the adaptive genetic processes occurring in this invasive population. The extremely limited MHC diversity may represent low immunogenetic competence across the Australian population, which could be exploited for invasive species management.

Original languageEnglish
Pages (from-to)565-572
Number of pages8
JournalWildlife Research
Volume44
Issue number6/7
DOIs
Publication statusPublished - 2017
Externally publishedYes

Keywords

  • Bufo marinus
  • genetic drift
  • MHC
  • microsatellite markers
  • range expansion

Fingerprint Dive into the research topics of 'Variation in Major Histocompatibility Complex diversity in invasive cane toad populations'. Together they form a unique fingerprint.

  • Cite this