Journal Article

introduced and a native vertebrate hybridize to form a genetic bridge to a second native species

Rahel, Frank J, Parchman, Thomas L, Hubert, Wayne A, McDonald, David B, Bower, Michael R

2008

Overview

The genetic impacts of hybridization between native and introduced species are of considerable conservation concern, while the possibility of reticulate evolution affects our basic understanding of how species arise and shapes how we use genetic data to understand evolutionary diversification. By using mitochondrial NADH dehydrogenase subunit 2 (ND2) sequences and 467 amplified fragment-length polymorphism nuclear DNA markers, we show that the introduced white sucker (Catostomus commersoni) has hybridized with two species native to the Colorado River Basin--the flannelmouth sucker (Catostomus latipinnis) and the bluehead sucker (Catostomus discobolus). Hybrids between the flannelmouth sucker and white sucker have facilitated introgression between the two native species, previously isolated by reproductive barriers, such that individuals exist with contributions from all three genomes. Most hybrids had the mitochondrial haplotype of the introduced white sucker, emphasizing its pivotal role in this three-way hybridization. Our findings highlight how introduced species can threaten the genetic integrity of not only one species but also multiple previously reproductively isolated species. Furthermore, this complex three-way reticulate (as opposed to strictly bifurcating) evolution suggests that seeking examples in other vertebrate systems might be productive. Although the present study involved an introduced species, similar patterns of hybridization could result from natural processes, including stream capture or geological formations (e.g., the Bering land bridge).

• Publisher: National Academy of Sciences,National Acad Sciences
• Subject: amplified fragment length polymorphism / Amplified Fragment Length Polymorphism Analysis / Animals / Base Sequence / Bayes Theorem / Biological Sciences / Biological taxonomies / Catostomus commersoni / Catostomus discobolus / Catostomus latipinnis / Cypriniformes / Cypriniformes - genetics / DNA / DNA Primers - genetics / Evolution / Evolutionary biology / Evolutionary genetics / Fish / freshwater fish / Genetic hybridization / genetic markers / Genetics / Genetics, Population / Haplotypes / Hybridity / Hybridization / Hybridization, Genetic / Hybrids / Indigenous species / interspecific hybridization / Introduced species / introgression / Land bridges / mitochondrial DNA / Molecular Sequence Data / NADH dehydrogenase / Native species / nuclear genome / nucleotide sequences / Phylogeny / Population Dynamics / River basins / Sequence Analysis, DNA / Studies / three-way hybridization / Vertebrates / Wyoming