Sex-chromosomes are thought to play an important role in speciation, but few studies of non-model organisms have investigated the relative influence of multiple sex-linked markers on reproductive isolation. We collected 222 individuals along a geographical transect spanning the hybrid zone between Passerina amoena and P. cyanea (Aves: Cardinalidae). Using maximum-likelihood cline fitting methods, we estimated locus-specific introgression rates for 10 z-linked markers. Although the cline width estimates ranged from 2.8 to 584 km, eight of 10 loci had cline widths between 224 and 271 km. We also used coalescent-based estimates of locus-specific divergence times between P. amoena and P. cyanea to test a recently proposed hypothesis of an inverse relationship between divergence time and cline width but did not find a significant association. The narrow width (2.8 km) of the cline estimated from the VLDLR9 locus indicates strong selection retarding introgression of alleles at this locus across the hybrid zone. Interestingly, a mutation in the very low density lipoprotein receptor (VLDLR) gene, in which VLDLR9 is an intron, is known to reduce the egg-laying ability of some chickens, suggesting a possible link between this gene region and reproductive isolation between P. amoena and P. cyanea. These results underscore the importance of sampling multiple loci to investigate introgression patterns across a chromosome or genome and support previous findings of the importance of sex-linked genes in speciation.
Description
Speciation in Passerina buntings: introgression patterns of sex-linked loci identify a candidate gene region for reproductive isolation
%0 Journal Article
%1 wiley0000
%A CARLING, MATTHEW D.
%A BRUMFIELD, ROBB T.
%D 2009
%J Molecular Ecology
%K clines hybrid_zone introgression reproductive_isolation sex_linked speciation
%T Speciation in Passerina buntings: introgression patterns of sex-linked loci identify a candidate gene region for reproductive isolation
%U http://www3.interscience.wiley.com/cgi-bin/fulltext/121681047/HTMLSTART
%X Sex-chromosomes are thought to play an important role in speciation, but few studies of non-model organisms have investigated the relative influence of multiple sex-linked markers on reproductive isolation. We collected 222 individuals along a geographical transect spanning the hybrid zone between Passerina amoena and P. cyanea (Aves: Cardinalidae). Using maximum-likelihood cline fitting methods, we estimated locus-specific introgression rates for 10 z-linked markers. Although the cline width estimates ranged from 2.8 to 584 km, eight of 10 loci had cline widths between 224 and 271 km. We also used coalescent-based estimates of locus-specific divergence times between P. amoena and P. cyanea to test a recently proposed hypothesis of an inverse relationship between divergence time and cline width but did not find a significant association. The narrow width (2.8 km) of the cline estimated from the VLDLR9 locus indicates strong selection retarding introgression of alleles at this locus across the hybrid zone. Interestingly, a mutation in the very low density lipoprotein receptor (VLDLR) gene, in which VLDLR9 is an intron, is known to reduce the egg-laying ability of some chickens, suggesting a possible link between this gene region and reproductive isolation between P. amoena and P. cyanea. These results underscore the importance of sampling multiple loci to investigate introgression patterns across a chromosome or genome and support previous findings of the importance of sex-linked genes in speciation.
@article{wiley0000,
abstract = {Sex-chromosomes are thought to play an important role in speciation, but few studies of non-model organisms have investigated the relative influence of multiple sex-linked markers on reproductive isolation. We collected 222 individuals along a geographical transect spanning the hybrid zone between Passerina amoena and P. cyanea (Aves: Cardinalidae). Using maximum-likelihood cline fitting methods, we estimated locus-specific introgression rates for 10 z-linked markers. Although the cline width estimates ranged from 2.8 to 584 km, eight of 10 loci had cline widths between 224 and 271 km. We also used coalescent-based estimates of locus-specific divergence times between P. amoena and P. cyanea to test a recently proposed hypothesis of an inverse relationship between divergence time and cline width but did not find a significant association. The narrow width (2.8 km) of the cline estimated from the VLDLR9 locus indicates strong selection retarding introgression of alleles at this locus across the hybrid zone. Interestingly, a mutation in the very low density lipoprotein receptor (VLDLR) gene, in which VLDLR9 is an intron, is known to reduce the egg-laying ability of some chickens, suggesting a possible link between this gene region and reproductive isolation between P. amoena and P. cyanea. These results underscore the importance of sampling multiple loci to investigate introgression patterns across a chromosome or genome and support previous findings of the importance of sex-linked genes in speciation.},
added-at = {2009-02-10T00:20:32.000+0100},
author = {CARLING, MATTHEW D. and BRUMFIELD, ROBB T.},
biburl = {https://www.bibsonomy.org/bibtex/28d44afa334cb3f9822298c3b5e2e1255/peter.ralph},
description = {Speciation in Passerina buntings: introgression patterns of sex-linked loci identify a candidate gene region for reproductive isolation},
interhash = {242518b6f398a8912405eacc13876c40},
intrahash = {8d44afa334cb3f9822298c3b5e2e1255},
journal = {Molecular Ecology},
keywords = {clines hybrid_zone introgression reproductive_isolation sex_linked speciation},
timestamp = {2009-02-11T21:50:36.000+0100},
title = {Speciation in Passerina buntings: introgression patterns of sex-linked loci identify a candidate gene region for reproductive isolation},
url = {http://www3.interscience.wiley.com/cgi-bin/fulltext/121681047/HTMLSTART},
year = 2009
}