title: Insight into genomic changes accompanying divergence: genetic linkage maps and synteny of Lucania goodei and L. parva reveal a Robertsonian fusion.
abstract: Linkage maps are important tools in evolutionary genetics and in studies of speciation. We performed a karyotyping study and constructed high-density linkage maps for two closely related killifish species, Lucania parva and L. goodei, that differ in salinity tolerance and still hybridize in their contact zone in Florida. Using SNPs from orthologous EST contigs, we compared synteny between the two species to determine how genomic architecture has shifted with divergence. Karyotyping revealed that L. goodei possesses 24 acrocentric chromosomes (1N) whereas L. parva possesses 23 chromosomes (1N), one of which is a large metacentric chromosome. Likewise, high-density single-nucleotide polymorphism-based linkage maps indicated 24 linkage groups for L. goodei and 23 linkage groups for L. parva. Synteny mapping revealed two linkage groups in L. goodei that were highly syntenic with the largest linkage group in L. parva. Together, this evidence points to the largest linkage group in L. parva being the result of a chromosomal fusion. We further compared synteny between Lucania with the genome of a more distant teleost relative medaka (Oryzias latipes) and found good conservation of synteny at the chromosomal level. Each Lucania LG had a single best match with each medaka chromosome. These results provide the groundwork for future studies on the genetic architecture of reproductive isolation and salinity tolerance in Lucania and other Fundulidae.
authors.affiliation: Department of Animal Biology, University of Illinois, Champaign, Illinois 61820 emma.berdan@mfn-berlin.de.
authors.forename: Emma L
authors.initials: EL
authors.lastname: Berdan
authors.affiliation: Department of Animal Biology, University of Illinois, Champaign, Illinois 61820.
authors.forename: Genevieve M
authors.initials: GM
authors.lastname: Kozak
authors.affiliation: Department of Plant Biology, University of Illinois, Urbana, Illinois 61801.
authors.forename: Ray
authors.initials: R
authors.lastname: Ming
authors.affiliation: Department of Crop Sciences, University of Illinois, Urbana, Illinois 61801.
authors.forename: A Lane
authors.initials: AL
authors.lastname: Rayburn
authors.affiliation: Department of Biology, Ursinus College, Collegeville, Pennsylvania 19426.
authors.forename: Ryan
authors.initials: R
authors.lastname: Kiehart
authors.affiliation: Department of Animal Biology, University of Illinois, Champaign, Illinois 61820.
authors.forename: Rebecca C
authors.initials: RC
authors.lastname: Fuller
mesh_terms: D000818:Animals; D002874:Chromosome Mapping; D008040:Genetic Linkage; D049810:Genetic Speciation; D023281:Genomics; D007621:Karyotyping; D007695:Killifishes / Q000235:genetics*; D020641:Polymorphism, Single Nucleotide; D060047:Reproductive Isolation; D055049:Salt Tolerance / Q000235:genetics*; D013045:Species Specificity; D026801:Synteny
keywords: EST-based SNPs; Robertsonian fusion; chromosomal rearrangement; fundulidae; linkage map; speciation; synteny