As mentioned in sample data, we have subjectId, sstart, send from blastn hits. How to find precursor sequence of this est using these. How to use upstream and downstream technique. Pls help me to do this.

Or Is there any way to find precursor sequence of est using blastn result. I need a clear description.

subject id s. start s. end gi|546669925|gb|AWWX01450616.1| 282 305 gi|546669842|gb|AWWX01450698.1| 359 375 gi|546669842|gb|AWWX01450698.1| 455 471 gi|546669842|gb|AWWX01450698.1| 80 64 gi|546669842|gb|AWWX01450698.1| 606 587 gi|546669842|gb|AWWX01450698.1| 217 238 gi|546669977|gb|AWWX01450566.1| 221 240

So, what i have to do this to find precursor sequence for each of est?