Genes with Restricted Introgression in a Field Cricket (Gryllus firmus/Gryllus pennsylvanicus) Hybrid Zone Are Concentrated on the X Chromosome and a Single Autosome

摘要: Characterizing the extent of genomic differentiation between recently diverged lineages provides an important context for understanding early stages speciation. When such form discrete hybrid zones, patterns differential introgression allow direct estimates which genome regions are likely involved in speciation and local adaptation. Here we use a backcross experimental design to construct genetic linkage map field crickets Gryllus firmus pennsylvanicus, interact well-characterized zone eastern North America. We demonstrate that loci with major allele frequency differences allopatric populations not randomly distributed across genome. Instead, most either X-linked or few small autosomal regions. Furthermore, subset those highly differentiated markers exhibit restricted cricket also concentrated on X chromosome (39 50 loci) single 7-cM region one autosome. Although accumulation sex genes responsible postzygotic barriers is well-known phenomenon, less attention has been given distribution prezygotic barriers. discuss implications our results speciation, both role chromosomes respect causes heterogeneous divergence. do yet have evidence ecological, behavioral, fertilization barrier chromosome, faster-X evolution could make these more be X-linked.