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gwaspr: an R package for plotting GWAS results from the GAPIT package

Installation

devtools::install_github("derekmichaelwright/gwaspr")

Usage

For best practice, output from GAPIT should be in its own folder. In this case, they are located in a folder called GWAS_Results/. For this example we will plot GWAS results from 3 traits in a lentil diversity panel:

  • Testa_Pattern: a qualitative trait describing the presence or absence of seed coat pigmentation.
  • DTF_Nepal_2017: a quantitative trait describing days from sowing to flowering in a 2017 Nepal field trial.
  • DTF_Sask_2017: a quantitative trait describing days from sowing to flowering in a 2017 Saskatchewan field trial.
  • DTF_Sask_2017_b: same as above but run with the b coefficient from a photothermal model (see Wright et al. 2020) used as a covariate.

Note: for more info check out this GWAS tutorial.

List Traits

myTraits <- list_Traits(folder = "GWAS_Results/")
myTraits
## [1] "DTF_Nepal_2017"     "DTF_Sask_2017"      "DTF_Sask_2017_CV_b"
## [4] "Testa_Pattern"

List Results Files

myFiles <- list_Result_Files(folder = "GWAS_Results/")
myFiles
##  [1] "GAPIT.Association.GWAS_Results.BLINK.DTF_Nepal_2017.csv"      
##  [2] "GAPIT.Association.GWAS_Results.BLINK.DTF_Sask_2017.csv"       
##  [3] "GAPIT.Association.GWAS_Results.BLINK.DTF_Sask_2017_CV_b.csv"  
##  [4] "GAPIT.Association.GWAS_Results.BLINK.Testa_Pattern.csv"       
##  [5] "GAPIT.Association.GWAS_Results.FarmCPU.DTF_Nepal_2017.csv"    
##  [6] "GAPIT.Association.GWAS_Results.FarmCPU.DTF_Sask_2017.csv"     
##  [7] "GAPIT.Association.GWAS_Results.FarmCPU.DTF_Sask_2017_CV_b.csv"
##  [8] "GAPIT.Association.GWAS_Results.FarmCPU.Testa_Pattern.csv"     
##  [9] "GAPIT.Association.GWAS_Results.GLM.DTF_Nepal_2017.csv"        
## [10] "GAPIT.Association.GWAS_Results.GLM.DTF_Sask_2017.csv"         
## [11] "GAPIT.Association.GWAS_Results.GLM.DTF_Sask_2017_CV_b.csv"    
## [12] "GAPIT.Association.GWAS_Results.GLM.Testa_Pattern.csv"         
## [13] "GAPIT.Association.GWAS_Results.MLM.DTF_Nepal_2017.csv"        
## [14] "GAPIT.Association.GWAS_Results.MLM.DTF_Sask_2017.csv"         
## [15] "GAPIT.Association.GWAS_Results.MLM.DTF_Sask_2017_CV_b.csv"    
## [16] "GAPIT.Association.GWAS_Results.MLM.Testa_Pattern.csv"         
## [17] "GAPIT.Association.GWAS_Results.MLMM.DTF_Nepal_2017.csv"       
## [18] "GAPIT.Association.GWAS_Results.MLMM.DTF_Sask_2017.csv"        
## [19] "GAPIT.Association.GWAS_Results.MLMM.DTF_Sask_2017_CV_b.csv"   
## [20] "GAPIT.Association.GWAS_Results.MLMM.Testa_Pattern.csv"

List Significant Markers

# first reorder the result files if they are not already arranged by P.value
order_GWAS_Results(folder = "GWAS_Results/", files = myFiles)
myResults <- table_GWAS_Results(folder = "GWAS_Results/", files = myFiles,
                   threshold = 6.7, sug.threshold = 6)
myResults[1:10,]
##                        SNP Chr       Pos      P.value        MAF  H.B.P.Value
## 1   Lcu.2RBY.Chr6p12212845   6  12212845 2.553940e-55 0.42056075 6.840600e-50
## 2    Lcu.2RBY.Chr5p1061938   5   1061938 4.300613e-33 0.12345679 1.151898e-27
## 3   Lcu.2RBY.Chr6p14410759   6  14410759 9.468879e-31 0.38317757 2.536192e-25
## 4    Lcu.2RBY.Chr6p2528817   6   2528817 2.687467e-30 0.27932099 7.198246e-25
## 5  Lcu.2RBY.Chr3p188873032   3 188873032 2.260523e-29 0.01168224 3.027349e-24
## 6  Lcu.2RBY.Chr4p323097758   4 323097758 3.245062e-27 0.07943925 4.345868e-22
## 7  Lcu.2RBY.Chr6p317400151   6 317400151 4.516331e-27 0.09112150 4.032255e-22
## 8   Lcu.2RBY.Chr6p12192948   6  12192948 8.560650e-27 0.43925234 2.292927e-21
## 9   Lcu.2RBY.Chr2p42543877   2  42543877 3.264679e-25 0.06790123 4.372140e-20
## 10   Lcu.2RBY.Chr5p1061938   5   1061938 8.804190e-24 0.12345679 2.358158e-18
##         Effect -log10(p)   Model              Trait   Threshold
## 1    0.4002402  54.59279    MLMM      Testa_Pattern Significant
## 2  -12.1833602  32.36647   BLINK     DTF_Nepal_2017 Significant
## 3    0.2234545  30.02370   BLINK      Testa_Pattern Significant
## 4   -2.1310601  29.57066 FarmCPU DTF_Sask_2017_CV_b Significant
## 5    0.3969966  28.64579   BLINK      Testa_Pattern Significant
## 6    0.3775797  26.48878    MLMM      Testa_Pattern Significant
## 7    0.3144896  26.34521   BLINK      Testa_Pattern Significant
## 8    0.2223050  26.06749 FarmCPU      Testa_Pattern Significant
## 9   10.7592301  24.48616   BLINK     DTF_Nepal_2017 Significant
## 10 -10.8302898  23.05531 FarmCPU     DTF_Nepal_2017 Significant
list_Top_Markers(trait = "DTF_Nepal_2017", model = "MLMM", 
                 folder = "GWAS_Results/", 
                 threshold = 6.7, chroms = c(2,5), n = 1)
##                      SNP Chr      Pos -log10(p)
## 1 Lcu.2RBY.Chr2p42543877   2 42543877     11.53
## 2  Lcu.2RBY.Chr5p1069654   5  1069654     16.66
myMarkers <- c("Lcu.2RBY.Chr2p42543877","Lcu.2RBY.Chr5p1069654",
               "Lcu.2RBY.Chr6p2528817", "Lcu.2RBY.Chr6p12212845")
list_Top_Markers(trait = "Testa_Pattern", model = "MLM", 
                 folder = "GWAS_Results/", 
                 threshold = 6.7, chroms = 6, n = 1)
##                      SNP Chr      Pos -log10(p)
## 1 Lcu.2RBY.Chr6p12212845   6 12212845     11.55
table_Results_Summary("GWAS_Results/", isOrdered = F)
##                Trait GLM MLM MLMM FarmCPU BLINK
## 1     DTF_Nepal_2017  NA   X    X       X     X
## 2      DTF_Sask_2017  NA   X    X       X     X
## 3 DTF_Sask_2017_CV_b  NA   X    X       X     X
## 4      Testa_Pattern  NA   X    X       X     X
table_Results_Summary("GWAS_Results/", isOrdered = T)
##                Trait GLM MLM MLMM FarmCPU BLINK
## 1     DTF_Nepal_2017  NA   X    X       X     X
## 2      DTF_Sask_2017  NA   X    X       X     X
## 3 DTF_Sask_2017_CV_b  NA   X    X       X     X
## 4      Testa_Pattern  NA   X    X       X     X

Summary Plot

mp <- gg_GWAS_Summary(folder = "GWAS_Results/", 
                      traits = myTraits,
                      models = c("MLM", "MLMM", "FarmCPU", "BLINK"),
                      colors = c("darkgreen", "darkred", "darkorange3", "steelblue"),
                      threshold = 6.7, sug.threshold = 6, 
                      hlines = c(1.5,3.5), lrows = 2,
                      vlines = ,
                      vline.colors = c("red", "red", "green", "blue"),
                      title = "Summary of Significant GWAS Results")
ggsave("man/figures/GWAS_Summary.png", mp, width = 12, height = 4)


Manhattan Plots

Multi Manhattan Plots

for(i in myTraits) {
  mp <- gg_Manhattan(folder = "GWAS_Results/", 
                     trait = i, 
                     title = paste("LDP -", i), 
                     threshold = 7.3, 
                     sug.threshold = 6.7, 
                     vlines = myMarkers,
                     vline.colors = c("red","red","darkgreen","blue"),
                     vline.legend = T,
                     facet = F,
                     addQQ = T,
                     pmax = 12, 
                     models = c("MLM", "MLMM", "FarmCPU", "BLINK"),
                     model.colors = c("darkgreen", "darkred", "darkorange3", "steelblue"),
                     legend.rows = 2)
  ggsave(paste0("man/figures/Multi_", i, ".png"), 
         mp, width = 12, height = 4, bg = "white")
}


Facetted Manhattan Plots

for(i in myTraits) {
  mp <- gg_Manhattan(folder = "GWAS_Results/", 
                     trait = i, 
                     title = paste("LDP -", i), 
                     threshold = 7.3, 
                     sug.threshold = 6.7, 
                     vlines = myMarkers,
                     vline.colors = c("red","red","darkgreen","blue"),
                     vline.legend = T,
                     facet = T,
                     addQQ = T,
                     pmax = 12, 
                     models = c("MLM", "MLMM", "FarmCPU", "BLINK"),
                     chrom.colors = rep(c("darkgreen", "darkgoldenrod2"), 4),
                     legend.rows = 2)
  ggsave(paste0("man/figures/Facet_", i, ".png"), 
         mp, width = 12, height = 8)
}


GAPIT

GAPIT: and R package for performing Genome Wide Association Studies (GWAS)

https://github.com/jiabowang/GAPIT3

Dependancies

tidyverse, ggpubr, ggbeeswarm, ggrepel, ggtext, plotly, htmlwidgets


© Derek Michael Wright