Hi~ I am working on RNA-seq data to evaluate the genes changing with age in different regions. My coldata looks like:

> coldata
  tissue     age    sex
1    PFC  3month  female
2    Amy  3month  male
3    PFC 6month  female
4    Amy  6month  male
5    PFC 20month  female
6    Amy 20month  male

I would like to calculate the R-squared associated with the age-related variance for each genes in these two regions. But I am not sure how to evaluate age-related variance (the variable importance of age on genes). Can I use the deviance in linear reduced model ((exclude the age variable)?

I would highly appreciate any input on this! Thank you very much!

DESeq2 cannot do this (we calculate deviance) but try the VariancePartition package.