外显子和内含子是转录本上面的概念,是基于转录这个行为的定义。
而5端UTR区域和CDS区域,还有3端UTR区域,是基于翻译这种行为的定义!
UTR(Untranslated Region),即非翻译区。在分子遗传学中,是指任意一个位于mRNA链编码序列两端的片段。如果其位于5′端,则称为5′非翻译区(5‘-untranslated region,5’-UTR)(或“前导序列,leader”), 反之若位于3′端,则称为3′非翻译区(3'-untranslated region,3‘-UTR)(或“尾随序列,trailer”)。
所谓CDS就是与蛋白质序列一 一对应的DNA序列,且该序列中间不含其它非该蛋白质对应的序列,不考虑mRNA加工等过程中的序列变化,总之,就是与蛋白质的密码子完全对应。
一个基因的一个转录本的5'utr区域可以包括多个外显子区域。
rm(list=ls())
## [url=http://www.broadinstitute.org/cancer/cga/sites/default/files/data/tools/rnaseqc/gencode.v7.annotation_goodContig.gtf.gz]http://www.broadinstitute.org/ca ... n_goodContig.gtf.gz[/url]
setwd('tmp')
gtf <- read.table('gencode.v7.annotation_goodContig.gtf.gz',stringsAsFactors = F,
header = F,comment.char = "#",sep = '\t'
)
table(gtf[,2])
gtf <- gtf[gtf[,2] =='HAVANA',]
gtf <- gtf[grepl('protein_coding',gtf[,9]),]
lapply(gtf[1:10,9], function(x){
y=strsplit(x,';')
})
gtf$gene <- lapply(gtf[,9], function(x){
y <- strsplit(x,';')[[1]][5]
strsplit(y,'\\s')[[1]][3]
}
)
draw_gene = 'TP53'
structure = gtf[gtf$gene==draw_gene,]
colnames(structure) =c(
'chr','db','record','start','end','tmp1','tmp2','tmp3','tmp4','gene'
)
gene_start <- min(c(structure$start,structure$end))
gene_end <- max(c(structure$start,structure$end))
tmp_min=min(c(structure$start,structure$end))
structure$new_start=structure$start-tmp_min
structure$new_end=structure$end-tmp_min
tmp_max=max(c(structure$new_start,structure$new_end))
num_transcripts=nrow(structure[structure$record=='transcript',])
tmp_color=rainbow(num_transcripts)
x=1:tmp_max;y=rep(num_transcripts,length(x))
#x=10000:17000;y=rep(num_transcripts,length(x))
plot(x,y,type = 'n',xlab='',ylab = '',ylim = c(0,num_transcripts+1))
title(main = draw_gene,sub = paste("chr",structure$chr,":",gene_start,"-",gene_end,sep=""))
j=0;
tmp_legend=c()
for (i in 1:nrow(structure)){
tmp=structure[i,]
if(tmp$record == 'transcript'){
j=j+1
tmp_legend=c(tmp_legend,paste("chr",tmp$chr,":",tmp$start,"-",tmp$end,sep=""))
}
if(tmp$record == 'exon') lines(c(tmp$new_start,tmp$new_end),c(j,j),col=tmp_color[j],lwd=4)
}
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