You have been given the DNA sequence for a particular fragment of DNA. You then isolated the mRNA made from that DNA and
Posted: Tue Jul 12, 2022 1:27 pm
You have been given the DNA sequence for a particular fragmentof DNA. You then isolated the mRNA made from that DNA and amplifiedit by PCR. You then determined the sequence of the cDNA obtainedfrom different cells. You notice a difference. In the sequenceobtained from DNA sequencing you see that a codon is 5' CAG howeveron the cDNA sequence it is TAG. These results are confirmed byrepeated DNA sequence analysis using DNA and cDNA from differentcell cultures (same species and tissue samples). What canexplain this?
a.
The DNA must have been mutated in all the cells that were usedto isolate mRNA since the cDNA should always match the genomicsequence.
b.
Any cDNA made through RT-PCR will have T's substitued forgenomic C's that are methyulated.
c.
The mRNA must have been deaminated at the cytosine.
d.
The cDNA generated most likely had a technical mistake caused bypoor fidelity of the Taq enzyme.
a.
The DNA must have been mutated in all the cells that were usedto isolate mRNA since the cDNA should always match the genomicsequence.
b.
Any cDNA made through RT-PCR will have T's substitued forgenomic C's that are methyulated.
c.
The mRNA must have been deaminated at the cytosine.
d.
The cDNA generated most likely had a technical mistake caused bypoor fidelity of the Taq enzyme.