Last updated: 2022-08-20

Checks: 6 1

Knit directory: RatXcan_Training/

This reproducible R Markdown analysis was created with workflowr (version 1.6.2). The Checks tab describes the reproducibility checks that were applied when the results were created. The Past versions tab lists the development history.


The R Markdown is untracked by Git. To know which version of the R Markdown file created these results, you’ll want to first commit it to the Git repo. If you’re still working on the analysis, you can ignore this warning. When you’re finished, you can run wflow_publish to commit the R Markdown file and build the HTML.

Great job! The global environment was empty. Objects defined in the global environment can affect the analysis in your R Markdown file in unknown ways. For reproduciblity it’s best to always run the code in an empty environment.

The command set.seed(20220711) was run prior to running the code in the R Markdown file. Setting a seed ensures that any results that rely on randomness, e.g. subsampling or permutations, are reproducible.

Great job! Recording the operating system, R version, and package versions is critical for reproducibility.

Nice! There were no cached chunks for this analysis, so you can be confident that you successfully produced the results during this run.

Great job! Using relative paths to the files within your workflowr project makes it easier to run your code on other machines.

Great! You are using Git for version control. Tracking code development and connecting the code version to the results is critical for reproducibility.

The results in this page were generated with repository version 4f1a0e2. See the Past versions tab to see a history of the changes made to the R Markdown and HTML files.

Note that you need to be careful to ensure that all relevant files for the analysis have been committed to Git prior to generating the results (you can use wflow_publish or wflow_git_commit). workflowr only checks the R Markdown file, but you know if there are other scripts or data files that it depends on. Below is the status of the Git repository when the results were generated:


Ignored files:
    Ignored:    .Rhistory
    Ignored:    .Rproj.user/
    Ignored:    analysis/.Rhistory

Untracked files:
    Untracked:  .DS_Store
    Untracked:  .gitignore
    Untracked:  README.html
    Untracked:  analysis/EN_Prediction_Model.Rmd
    Untracked:  analysis/PrediXcan.Rmd
    Untracked:  analysis/Process_Geno_Gex_Data.Rmd
    Untracked:  analysis/Rat_PTRS.Rmd
    Untracked:  rsconnect/
    Untracked:  scripts/

Unstaged changes:
    Modified:   code/.DS_Store
    Deleted:    output/README.md

Note that any generated files, e.g. HTML, png, CSS, etc., are not included in this status report because it is ok for generated content to have uncommitted changes.


There are no past versions. Publish this analysis with wflow_publish() to start tracking its development.


Setup

library(tidyverse)
── Attaching packages ─────────────────────────────────────── tidyverse 1.3.0 ──
✔ ggplot2 3.3.6     ✔ purrr   0.3.4
✔ tibble  3.0.4     ✔ dplyr   1.0.2
✔ tidyr   1.1.2     ✔ stringr 1.4.0
✔ readr   1.4.0     ✔ forcats 0.5.0
── Conflicts ────────────────────────────────────────── tidyverse_conflicts() ──
✖ dplyr::filter() masks stats::filter()
✖ dplyr::lag()    masks stats::lag()
library(data.table)

Attaching package: 'data.table'
The following objects are masked from 'package:dplyr':

    between, first, last
The following object is masked from 'package:purrr':

    transpose
library(RSQLite)
library(glmnet)
Loading required package: Matrix

Attaching package: 'Matrix'
The following objects are masked from 'package:tidyr':

    expand, pack, unpack
Loaded glmnet 4.1-3
"%&%" = function(a,b) paste(a,b,sep="")
devtools::source_gist("ee5f67abddd0b761ee24410ea71c41aa")
Sourcing https://gist.githubusercontent.com/natashasanthanam/ee5f67abddd0b761ee24410ea71c41aa/raw/185ab37e5a31f1d3bab1530e468950e30ff31337/fn_generate_trait.R
SHA-1 hash of file is c56941964697a118c351c3f81322a221fa13a1b3
devtools::source_gist("38431b74c6c0bf90c12f")
Sourcing https://gist.githubusercontent.com/hakyim/38431b74c6c0bf90c12f/raw/f16d9de559d20ce605e1e13eee75e82a0f6e1507/qqunif.R
SHA-1 hash of file is c5aba9ddce06b95125b727d96bffe7bd1557fcc3
devtools::source_gist("1e9053c8f35c30396429350a08f33ea7")
Sourcing https://gist.githubusercontent.com/natashasanthanam/1e9053c8f35c30396429350a08f33ea7/raw/e35c8cabb742f17f1998f9ac4198878f9c683605/qqunif.R
SHA-1 hash of file is 7388784ab8c7c2dc5c3f950dc8a47a1c76e3d7ac

Yanyu’s PTRS weights estimate the effect of genes on a given trait, in this case we pick height and BMI.

traits <- c("height", "bmi")
# folder with PrediXcan results
results.dir <- "/Users/sabrinami/Box/imlab-data/data-Github/Rat_Genomics_Paper_Pipeline/Results/PrediXcan/metabolic_traits/"
# folder with PTRS weights, predicted traits will output here
data.dir <- "/Users/sabrinami/Box/imlab-data/data-Github/Rat_Genomics_Paper_Pipeline/data/"

Data Wrangling

The orth.rats file contains gives a dictionary between human genes and the corresponding gene in rats.

orth.rats <- read_tsv(data.dir %&% "expression/ortholog_genes_rats_humans.tsv", col_names = TRUE)

We first replace rat genes in the predicted expression results with their corresponding human genes, so that it could be compatible with PTRS weights.

pred_expr <- read_tsv(results.dir %&% "rat_metabolic_Ac_best__predict.txt") %>% select(-c(FID))

#filter only for genes that have a human ortholog
pred_expr <- pred_expr %>% select(c(IID, intersect(colnames(pred_expr), orth.rats$rnorvegicus_homolog_ensembl_gene) ))

#change name to human ensembl id in humans
colnames(pred_expr)[2:ncol(pred_expr)] <- orth.rats[match(colnames(pred_expr)[2:ncol(pred_expr)], orth.rats$rnorvegicus_homolog_ensembl_gene), 1] %>% .[["ensembl_gene_id"]]

Then we reformat the PTRS weight files, removing the Ensembl version from gene names.

fn_weights = function(trait)
{
  weights <- read_tsv(data.dir %&% "PTRS_weights/weight_files/elastic_net_alpha_0.1_British.export_model/weights." %&% trait %&% ".tsv.gz")
  weights$gene_id <- sapply(strsplit(weights$gene_id, "\\."), `[`, 1)
  rownames(weights) <- weights$gene_id
  weights <- weights %>% rename(gene_name = gene_id)
  return(weights)
}

We converted the predicted expression for rat genes to corresponding human gene names, matching the PTRS gene names. This lets us combine PTRS weights, trained from human transcriptomic data, with predicted transciptome of the rats using the fn_generate_trait function below. The output is the predicted height for individual rats.

In some ways, we can interpret generate_trait as the opposite of PrediXcan. Both start from the predicted transcriptome of a group of individuals, PrediXcan works backwards from values of their observed trait to compute association between genes and the trait, whereas fn_generate_trait assumes those associations to predict the trait for each individual. PTRS is particularly insightful in this case, because of its portability across different population groups. We hope this extends across species, motivating our final goal of comparing the performance of PTRS in humans and rats.

for(trait in traits) {
  weights <- fn_weights(trait)
  pred_trait <- fn_generate_trait(pred_expr, weights)
  saveRDS(pred_trait, data.dir %&% "rat_pred_" %&% trait %&% "_w_Human_best_PTRS.RDS")
  return(pred_trait)
}

sessionInfo()
R version 4.0.3 (2020-10-10)
Platform: x86_64-apple-darwin17.0 (64-bit)
Running under: macOS Big Sur 10.16

Matrix products: default
BLAS:   /Library/Frameworks/R.framework/Versions/4.0/Resources/lib/libRblas.dylib
LAPACK: /Library/Frameworks/R.framework/Versions/4.0/Resources/lib/libRlapack.dylib

locale:
[1] en_US.UTF-8/en_US.UTF-8/en_US.UTF-8/C/en_US.UTF-8/en_US.UTF-8

attached base packages:
[1] stats     graphics  grDevices utils     datasets  methods   base     

other attached packages:
 [1] glmnet_4.1-3      Matrix_1.2-18     RSQLite_2.2.1     data.table_1.13.2
 [5] forcats_0.5.0     stringr_1.4.0     dplyr_1.0.2       purrr_0.3.4      
 [9] readr_1.4.0       tidyr_1.1.2       tibble_3.0.4      ggplot2_3.3.6    
[13] tidyverse_1.3.0  

loaded via a namespace (and not attached):
 [1] fs_1.5.0          usethis_1.6.3     lubridate_1.7.9   devtools_2.3.2   
 [5] bit64_4.0.5       httr_1.4.2        rprojroot_1.3-2   tools_4.0.3      
 [9] backports_1.1.10  bslib_0.3.1       R6_2.4.1          DBI_1.1.0        
[13] colorspace_1.4-1  withr_2.3.0       tidyselect_1.1.0  prettyunits_1.1.1
[17] processx_3.4.4    bit_4.0.4         curl_4.3          compiler_4.0.3   
[21] git2r_0.27.1      cli_3.3.0         rvest_0.3.6       xml2_1.3.2       
[25] desc_1.2.0        sass_0.4.1        scales_1.1.1      callr_3.5.1      
[29] digest_0.6.27     rmarkdown_2.14    pkgconfig_2.0.3   htmltools_0.5.2  
[33] sessioninfo_1.1.1 dbplyr_1.4.4      fastmap_1.1.0     rlang_1.0.2      
[37] readxl_1.3.1      rstudioapi_0.11   shape_1.4.6       jquerylib_0.1.4  
[41] generics_0.0.2    jsonlite_1.7.1    magrittr_1.5      Rcpp_1.0.8.3     
[45] munsell_0.5.0     lifecycle_0.2.0   stringi_1.5.3     yaml_2.2.1       
[49] pkgbuild_1.1.0    grid_4.0.3        blob_1.2.1        promises_1.1.1   
[53] crayon_1.3.4      lattice_0.20-41   haven_2.3.1       splines_4.0.3    
[57] hms_0.5.3         knitr_1.39        ps_1.4.0          pillar_1.4.6     
[61] codetools_0.2-16  pkgload_1.1.0     reprex_0.3.0      glue_1.6.2       
[65] evaluate_0.15     remotes_2.2.0     modelr_0.1.8      vctrs_0.4.1      
[69] httpuv_1.5.4      foreach_1.5.2     testthat_2.3.2    cellranger_1.1.0 
[73] gtable_0.3.0      assertthat_0.2.1  xfun_0.31         broom_0.8.0      
[77] later_1.1.0.1     survival_3.2-7    iterators_1.0.14  memoise_1.1.0    
[81] workflowr_1.6.2   ellipsis_0.3.2