cDNA question - (Mar/18/2009 )
Trying to understand how cDNA works versus genomic DNA transcripts.
Say I have a genomic transcript that can encode for 2 proteins, Protein A and Protein B. Protein A can be encoded by using just the first 1/3 of the transcript. Protein B is encoded from the entire transcript.
What would the cDNA line of this transcript encode? Meaning, will both Protein A and B still be encoded by the cDNA transcript or will only Protein B be encoded?
claritylight on Mar 18 2009, 10:01 AM said:
Say I have a genomic transcript that can encode for 2 proteins, Protein A and Protein B. Protein A can be encoded by using just the first 1/3 of the transcript. Protein B is encoded from the entire transcript.
What would the cDNA line of this transcript encode? Meaning, will both Protein A and B still be encoded by the cDNA transcript or will only Protein B be encoded?
cDNA is just a copy generated from mRNA. If protein A and B are both encoded by a single mRNA and thus the control for differential expression of A or B comes from translational regulation (ie. both proteins are generated from a single transcript) and not transcriptional regulation (ie. separate transcripts are generated), then cDNA synthesis will result in only the generation of the full length transcript.
Dr Teeth on Mar 20 2009, 10:32 AM said:
claritylight on Mar 18 2009, 10:01 AM said:
Say I have a genomic transcript that can encode for 2 proteins, Protein A and Protein B. Protein A can be encoded by using just the first 1/3 of the transcript. Protein B is encoded from the entire transcript.
What would the cDNA line of this transcript encode? Meaning, will both Protein A and B still be encoded by the cDNA transcript or will only Protein B be encoded?
cDNA is just a copy generated from mRNA. If protein A and B are both encoded by a single mRNA and thus the control for differential expression of A or B comes from translational regulation (ie. both proteins are generated from a single transcript) and not transcriptional regulation (ie. separate transcripts are generated), then cDNA synthesis will result in only the generation of the full length transcript.
Hello,
In this case, I have one genomic transcript synthesizing two mRNAs and encoding two separate polypeptides, one polypeptide for Protein A and one for Protein B. If two separate polypeptides are being encoded from this, will the cDNA still synthesize only the full length transcript?
If your gene has alternative splicing you can get different proteins.
The alternative splicing occurs very quickly after the pre-mRNA is transcribed. An exon (or more) is removed along with the introns.
If the alternative splicing happens at 50% of the time you should be able to find both mRNAs.