Reciprocal Introgression Between Golden-Winged Warblers (Vermivora Chrysoptera) and Blue-Winged Warblers (V. Pinus) in Eastern North America

Abstract

<jats:title>Abstract</jats:title> <jats:p>Golden-winged Warblers (Vermivora chrysoptera) and Blue-winged Warblers (V. pinus) are small, brightly colored Neotropical migrant birds that breed in eastern North America. Wherever the two species occur together, they hybridize to a limited degree, producing distinctive hybrid phenotypes. In recent decades, chrysoptera has experienced dramatic population declines across much of its range. Those declines have often been correlated with establishment and increase of pinus in the same areas, but it remains uncertain what, if any, role pinus has played in driving the decline of chrysoptera. In a first attempt at molecular genetic analysis of chrysoptera-pinus population dynamics, Gill (1997) reported cryptic, completely asymmetric, and possibly very rapid introgression of pinus mitochondrial DNA (mtDNA) into chrysoptera, causing what he termed “local cytonuclear extinction” of chrysoptera. As Gill (1997) noted, however, those results were based on relatively small samples from a single area in Pennsylvania. To begin to investigate the generality of Gill’s findings and to establish a baseline for long-term genetic and ecological studies, we intensively sampled one new study area (in southern West Virginia) and also sampled more broadly across two other areas (in Michigan and Ohio) that have experienced pinus invasions and chrysoptera declines. In southern West Virginia, introgression of mtDNA appeared to be roughly symmetrical: 15% (11 of 72) of pinus phenotypes possessed chrysoptera mtDNA, and 12% (17 of 137) of chrysoptera phenotypes possessed pinus mtDNA. Results from much smaller samples from Michigan and Ohio also failed to show any evidence of asymmetric mitochondrial introgression. The results we report here, based on mtDNA and plumage phenotype information for 337 birds representing much of the range of the two species, indicate that previous genetic results and inferences from Pennsylvania may not be broadly applicable to the many areas of contact between chrysoptera and pinus in eastern North America.</jats:p>

Evolution of postzygotic reproductive isolation in galliform birds: analysis of first and second hybrid generations and backcrosses

“…To the contrary, hybrids that result from backcrosses did not show serious inviability problems (at least not more than F1 hybrids), demonstrating that this pathway of flow of genetic material could generate introgression of genes from one species into another, a phenomenon that has been found in several species of birds (e.g. Brumfield et al, 2001;Weckstein et al, 2001;Shapiro et al, 2004;Rheindt & Edwards, 2011).…”

Extensive color polymorphism in the southeast Asian oriental dwarf kingfisher Ceyx erithaca: a result of gene flow during population divergence?

“…The nuclear loci, each containing a majority of intron sites, were from the following genes: glyceraldehyde‐3‐phosphate dehydrogenase (GAPDH, 342 bp), ornithine decarboxylase (ODC, 599 bp), α‐tropomyosin (TROP, 424 bp), myoglobin (MYO, 643 bp) and β‐actin (AlatBact, 421 bp). Sources of primer sequences for the loci were: Hackett (1996) and Shapiro et al (2004) for ND2; Primmer et al (2002) for GAPDH, ODC and TROP; Heslewood et al (1998) and Slade et al (1993) for MYO, and Marks (2008) for AlatBact. For thermocyling, the locus specific annealing temperatures (X°C) were 55°C for ND2 and AlatBact, 58°C for MYO, 60°C for ODC and TROP, and 64°C for GADPH.…”

Complex hybridization dynamics between golden‐winged and blue‐winged warblers (Vermivora chrysoptera and Vermivora pinus) revealed by AFLP, microsatellite, intron and mtDNA markers

“…Two recent studies have further explored the pattern of mitochondrial introgression at five additional sites with various histories of contact and levels of hybridization (Shapiro et al . 2004; Dabrowski et al .…”