Thanks for your reply. This example works fine but it works only for 1 gene. But I want to write a script for the whole human genes. I download the coordinates of all exons from biomart: It contains 5 columns 1st three are chromosome no., start exon, end exon. 4th column is transcript id, 5th column is exon rank.
10 100009838 100009947 ENST00000324109 1
10 99875577 99877336 ENST00000324109 17
10 99879811 99880361 ENST00000324109 16
10 99884011 99884209 ENST00000324109 15
10 99885687 99885866 ENST00000324109 14
10 99886300 99886632 ENST00000324109 13
10 99888825 99888953 ENST00000324109 12
10 99894946 99895050 ENST00000324109 11
10 99896267 99896397 ENST00000324109 10
10 99898086 99898285 ENST00000324109 9
10 99898743 99898760 ENST00000324109 8
10 99899919 99900066 ENST00000324109 7
10 99907995 99908094 ENST00000324109 6
10 99908953 99909146 ENST00000324109 5
10 99955214 99957205 ENST00000324109 4
10 99969115 99969237 ENST00000324109 3
10 99971980 99972134 ENST00000324109 2
10 100042193 100042573 ENST00000370418 9
10 100048758 100048876 ENST00000370418 8
10 100054347 100054446 ENST00000370418 7
10 100057013 100057152 ENST00000370418 6
10 100063614 100063725 ENST00000370418 5
10 100065188 100065370 ENST00000370418 4
10 100069714 100069869 ENST00000370418 3
10 100075911 100076107 ENST00000370418 2
10 100081403 100081869 ENST00000370418 1
So by these coordinates file can I make all possible combinations of whole genes and get in fasta format with different names. Thanks in advance
You are probably looking for GTF files which store these information. Once you extracted the coordinates of the features you want you can use
bedtools fastato pull the sequences of the coordinates from a reference genome fasta file.No, I want to make a library of mRNA of all possible combinations of exons and introns present in one gene. Likewise, I want to prepare a library for whole human genes.
Can anyone help me to make an mRNA library? I don't know how to start it. Thanks in advance
As @ATPoint suggested above it should be possible to get the sequence of all exons but to create all possible combinatorial (pair-wise? since you seem to have only pairs in example above) sequences out of those exons will require writing some custom code. Conceptually you would create a list of exons for a particular gene and then write out combinations. Then move on to gene2 , gene3.
But I want to make a library of the whole human genes so like this I have to save different genes in different files or there is any other way to do this. I am new in this thing to write a script. So there is no software available for this to do easily. If you know how to make the custom code for this thing , then can you help me to make the library. Thanks in advance
if you don't want to elaborate that's fine.
but I was just wondering why you would want to do this? I can somewhat see to get a set of different exon/exon combinations in the same order as the original gene but not to make all possible combinations of exons in a gene. There is a biological 'order' in those exons, so randomly combining them does not make much sense to me ...
and why you want to then even throw in all the introns makes even less sense :/