title: Hybrid incompatibility caused by an epiallele.
abstract: Hybrid incompatibility resulting from deleterious gene combinations is thought to be an important step toward reproductive isolation and speciation. Here, we demonstrate involvement of a silent epiallele in hybrid incompatibility. InArabidopsis thalianaaccession Cvi-0, one of the two copies of a duplicated histidine biosynthesis gene,HISN6A, is mutated, makingHISN6Bessential. In contrast, in accession Col-0,HISN6Ais essential becauseHISN6Bis not expressed. Owing to these differences, Cvi-0 × Col-0 hybrid progeny that are homozygous for both Cvi-0HISN6Aand Col-0HISN6Bdo not survive. We show thatHISN6Bof Col-0 is not a defective pseudogene, but a stably silenced epiallele. MutatingHISTONE DEACETYLASE 6(HDA6), or the cytosine methyltransferase genesMET1orCMT3,erasesHISN6B'ssilent locus identity, reanimating the gene to circumventhisn6alethality and hybrid incompatibility. These results show thatHISN6-dependent hybrid lethality is a revertible epigenetic phenomenon and provide additional evidence that epigenetic variation has the potential to limit gene flow between diverging populations of a species.
authors.affiliation: Howard Hughes Medical Institute, Indiana University, Bloomington, IN 47405; todd.blevins@ibmp-cnrs.unistra.fr cpikaard@indiana.edu.|Department of Biology, Indiana University, Bloomington, IN 47405.
authors.forename: Todd
authors.initials: T
authors.lastname: Blevins
authors.affiliation: Department of Biology, Indiana University, Bloomington, IN 47405.
authors.forename: Jing
authors.initials: J
authors.lastname: Wang
authors.affiliation: Institut de Biologie Moléculaire des Plantes, CNRS UPR2357, Université de Strasbourg, F-67084 Strasbourg, France.
authors.forename: David
authors.initials: D
authors.lastname: Pflieger
authors.affiliation: Department of Biology, Indiana University, Bloomington, IN 47405.
authors.forename: Frédéric
authors.initials: F
authors.lastname: Pontvianne
authors.affiliation: Howard Hughes Medical Institute, Indiana University, Bloomington, IN 47405; todd.blevins@ibmp-cnrs.unistra.fr cpikaard@indiana.edu.|Department of Biology, Indiana University, Bloomington, IN 47405.|Department of Molecular and Cellular Biochemistry, Indiana University, Bloomington, IN 47405.
authors.forename: Craig S
authors.identifier: 0000-0001-8204-7459
authors.initials: CS
authors.lastname: Pikaard
mesh_terms: D000483:Alleles; D017360:Arabidopsis / Q000235:genetics / Q000502:physiology*; D029681:Arabidopsis Proteins / Q000235:genetics*; D002678:Chimera; D004248:DNA (Cytosine-5-)-Methyltransferases / Q000235:genetics; D015257:DNA-Cytosine Methylases / Q000235:genetics; D044127:Epigenesis, Genetic; D018506:Gene Expression Regulation, Plant; D020868:Gene Silencing; D005804:Genes, Lethal; D000073864:Histone Deacetylase 6 / Q000235:genetics; D009154:Mutation; D000637:Transaminases / Q000235:genetics*
chemical_list: D029681:Arabidopsis Proteins; D015257:DNA-Cytosine Methylases; C499608:MET1 protein, Arabidopsis; C429766:CMT3 protein, Arabidopsis; D004248:DNA (Cytosine-5-)-Methyltransferases; D000637:Transaminases; C000626975:HISN6B protein, Arabidopsis; C514758:HPA1 protein, Arabidopsis; D000073864:Histone Deacetylase 6
keywords: DNA methylation; epigenetic inheritance; gene silencing; histone deacetylation; hybrid incompatibility