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GENOME‐WIDE INVESTIGATION OF REPRODUCTIVE ISOLATION IN EXPERIMENTAL LINEAGES AND NATURAL SPECIES OF NEUROSPORA: IDENTIFYING CANDIDATE REGIONS BY MICROARRAY‐BASED GENOTYPING AND MAPPING
Author(s) -
Dettman Jeremy R.,
Anderson James B.,
Kohn Linda M.
Publication year - 2010
Publication title -
evolution
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.84
H-Index - 199
eISSN - 1558-5646
pISSN - 0014-3820
DOI - 10.1111/j.1558-5646.2009.00863.x
Subject(s) - biology , reproductive isolation , genetics , genome , locus (genetics) , genotyping , evolutionary biology , introgression , epistasis , population , gene , genotype , demography , sociology
Inherent incompatibilities between genetic components from genomes of different species may cause intrinsic reproductive isolation. In evolution experiments designed to instigate speciation in laboratory populations of the filamentous fungus Neurospora, we previously discovered a pair of incompatibility loci ( dfe and dma ) that interact negatively to cause severe defects in sexual reproduction. Here we show that the dfe ‐ dma incompatibility also is a significant cause of genetic isolation between two naturally occurring species of Neurospora ( N. crassa and N. intermedia ). The strong incompatibility interaction has a simple genetic basis (two biallelic loci) and antagonistic epistasis occurs between heterospecific alleles only, consistent with the Dobzhansky–Muller model of genic incompatibility. We developed microarray‐based, restriction‐site associated DNA (RAD) markers that identified ∼1500 polymorphisms between the genomes of the two species, and constructed the first interspecific physical map of Neurospora. With this new mapping resource, the approximate genomic locations of the incompatibility loci were determined using three different approaches: genome scanning, bulk‐segregant analyses, and introgression. These population, quantitative, and classical genetics methods concordantly identified two candidate regions, narrowing the search for each incompatibility locus to only ∼2% of the nuclear genome. This study demonstrates how advances in high‐throughput, genome‐wide genotyping can be applied to mapping reproductive isolation genes and speciation research.