Fig 1.
Sampling localities and relationships among populations.
A) Heat map of mean annual temperature (MAT) in North America with the parallel eastern and western house mouse transects with populations at similar latitudes shown in the same color. Degrees of latitude are marked on the y-axis, longitude on the x-axis, and MAT in °C is indicated by color. This map was created using the R package “raster’ to plot Mean Annual Temperature data from worldclim (MAT = bioclim variable 1). B) A bootstrap consensus neighbor-joining tree constructed in PAUP using a distance matrix generated from the exome sequences of all 100 mice in both the eastern and western transects depicting the relatedness among all 10 populations. This tree is rooted using five M. m. domesticus samples from Europe.
Fig 2.
Population structure in mice from the western transect.
A) Three dimensional principal components plot of the five western populations from Fig 1: Tucson, AZ (red), St. George, UT (orange), Provo, UT (purple), Missoula, MT (cyran), and Edmonton, AB (dark blue); B) plot of genetic distance as measured by Fst versus geographic distance (km); C) admixture plot of the five western populations with M. m. castaneus ancestry plotted in green and M. m. domesticus ancestry plotted in black.
Fig 3.
Phenotypic variation in lab-reared and wild-caught mice.
A) Body mass of fifth-generation laboratory-reared female (F) and male (M) mice from Arizona (red) and Alberta (blue); B) mass of nesting material used by fifth-generation laboratory-reared female (F) and male (M) mice from Arizona (red) and Alberta (blue) in a 24-hour period; C) a typical large nest built by a mouse from Alberta; D) a typical small nest built by a mouse from Arizona; E) brightness of the dorsal fur of 50 wild-caught mice as measured by a spectrometer. Brightness is measured as the total area under the average reflectance curve from 300–700 nm in arbitrary units.
Fig 4.
Manhattan plots depicting the results of A) a population genomic scan for selection using LFMM (blue line indicates q-value = 0.05 and the red line indicates q-value = 0.001; B) a genome-wide association study of body weight using 38 mice from the western transect (blue line indicates a q-value = 0.01 and the red line indicates a q-value = 0.0001).
Fig 5.
Examples of concordant and discordant clinal patterns between the eastern and western transects.
Allele frequency changes at SNPs in Mc3r are similar in the western (A) and eastern (B) transects, while allele frequency changes at SNPs in Pkhd1 are different in the western (C) and eastern (D) transects. Mc3r is believed to be involved in body size variation, while Pkhd1 is involved in kidney function.