A Genetic Map in theMimulus guttatusSpecies Complex Reveals Transmission Ratio Distortion due to Heterospecific Interactions

Abstract

As part of a study of the genetics of floral adaptation and speciation in the Mimulus guttatus species complex, we constructed a genetic linkage map of an interspecific cross between M. guttatus and M. nasutus. We genotyped an F2 mapping population (N = 526) at 255 AFLP, microsatellite, and gene-based markers and derived a framework map through repeated rounds of ordering and marker elimination. The final framework map consists of 174 marker loci on 14 linkage groups with a total map length of 1780 cM Kosambi. Genome length estimates (2011–2096 cM) indicate that this map provides thorough coverage of the hybrid genome, an important consideration for QTL mapping. Nearly half of the markers in the full data set (49%) and on the framework map (48%) exhibited significant transmission ratio distortion (α = 0.05). We localized a minimum of 11 transmission ratio distorting loci (TRDLs) throughout the genome, 9 of which generate an excess of M. guttatus alleles and a deficit of M. nasutus alleles. This pattern indicates that the transmission ratio distortion results from particular interactions between the heterospecific genomes and suggests that substantial genetic divergence has occurred between these Mimulus species. We discuss possible causes of the unequal representation of parental genomes in the F2 generation.

A High-Density Genetic Map and QTL Fine Mapping for Growth- and Sex-Related Traits in Red Swamp Crayfish (Procambarus clarkii)

“…The consensus linkage map was grouped and constructed by the JoinMap 4.0 program ( Ooijen and Van, 2006 ) with a threshold logarithm of odds (LOD) score of 9.5, and the Linkage Map View package in R was used to visualize the mapping results. The expected genetic map length was calculated using Ge1 ( Fishman et al, 2001 ) and Ge2 ( Chakravarti et al, 1991 ), and the average of these two indexes was used as the predicted total genetic map length ( Ge ).…”

Resolving species boundaries in a recent radiation with the Angiosperms353 probe set: the Lomatium packardiae/L. anomalum clade of the L. triternatum (Apiaceae) complex

“…Most studies at low taxonomic scales use presence/absence data, including restriction site associated DNA sequencing (RAD‐seq) derived single nucleotide polymorphisms (SNPs) or microsatellites. Examples include investigations into speciation with gene flow in lake whitefishes with RAD‐seq data (Gagnaire et al, 2013) and the creation of a genetic linkage map using microsatellites in the Mimulus guttatus species complex (Fishman et al, 2001). However, presence/absence data may not fully account for ILS due to the lack of full sequence data for intact genes.…”

Genetic architecture and temporal analysis of Caenorhabditis briggsae hybrid developmental delay

“…Developmental delay is a widely reported phenomenon in hybrids [e.g. [43][44][45][46][47][48]. In this study, we have continued to refine our understanding of the phenotype and the genetic architecture of hybrid developmental delay in C. briggsae [12,19,36,37].…”