Asymmetric Introgression in a Spotted Salamander Hybrid Zone

Benjamin B. Johnson, Thomas A. White, Christopher A Phillips, Kelly R. Zamudio

Research output: Contribution to journalArticle

Abstract

Before the establishment of reproductive isolation, deeply diverged intraspecific lineages can experience complex genetic and behavioral interactions as they come into secondary contact. Divergent selective and demographic processes mediate gene flow among lineages, resulting in hybrid zones with complex biogeographic structure. Discordance in the biogeographic patterns of autosomal and maternally inherited loci provides a useful window to infer the processes mediating admixture and introgression across hybrid zones. Here, we sampled 489 genotypes across a hybrid zone between 2 phylogeographic lineages of the spotted salamander, Ambystoma maculatum, and characterize discordant patterns of nuclear and mitochondrial introgression across the contact boundary. Our results indicate asymmetric introgression of nuclear DNA beyond the contact boundary from the western to eastern lineage, with introgression of eastern mitochondrial DNA into the western lineage. We discuss alternative mechanisms for this pattern and attribute this result to neutral patterns of population expansion of the western lineage into the east in combination with female mate choice for larger-bodied western males. Our results underscore the complexity of interacting mechanisms that give rise to reproductive asymmetries in the earliest stages of the speciation process.

Original languageEnglish (US)
Pages (from-to)608-617
Number of pages10
JournalJournal of Heredity
Volume106
Issue number5
DOIs
StatePublished - Jan 1 2015

Fingerprint

Urodela
Ambystoma
Reproductive Isolation
Behavioral Genetics
Gene Flow
Mitochondrial DNA
Genotype
Demography
DNA
Population

Keywords

  • Cline
  • hybrid zone
  • hybridization
  • mate choice
  • mitonuclear discordance

ASJC Scopus subject areas

  • Biotechnology
  • Molecular Biology
  • Genetics
  • Genetics(clinical)

Cite this

Asymmetric Introgression in a Spotted Salamander Hybrid Zone. / Johnson, Benjamin B.; White, Thomas A.; Phillips, Christopher A; Zamudio, Kelly R.

In: Journal of Heredity, Vol. 106, No. 5, 01.01.2015, p. 608-617.

Research output: Contribution to journalArticle

Johnson, Benjamin B. ; White, Thomas A. ; Phillips, Christopher A ; Zamudio, Kelly R. / Asymmetric Introgression in a Spotted Salamander Hybrid Zone. In: Journal of Heredity. 2015 ; Vol. 106, No. 5. pp. 608-617.
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