library(ggplot2)

data<-data.frame(Sample<-c(rep('3M-AG',5),rep('7M-AG',5),rep('12M-AG',5),rep('24M-AG',5)),

mRNA<-rep(c('Lep','HSL','LPL','FASN','FABP4'),4),

value<-c(1,1,1,1,1,16.255,3.481,10.813,15.411,14.291,107.69,1.9445,2.4237,40.368,30.107,17.44,16.321,0.37164,7.9188,5.1579))

colnames(data)[1:3]<-c("Sample","mRNA","Relative expression")

ggplot(data, aes(Sample,value, fill=mRNA))+geom_bar(stat='identity',position='fill') +labs(x = 'Specie',y = 'Relative expression') +theme(axis.title =element_text(size = 16),axis.text =element_text(size = 14, color = 'black'))