00:02
All right, if you have a mutation in a dna strand, how might that affect the splicing that occurs when that dna strand is transcribed into an mri strand? that's what this question is talking about.
00:18
So first of all, let's identify what splicing means.
00:22
So when a gene on a dna gets transcribed, it produces an mrna transcript of that gene, which contains let me do it this way, which contains two things.
00:37
This blue part i'm going to call exons.
00:43
I'll put one on the end right here.
00:47
And then these green parts, what we call introns.
00:51
And so what happens before an mrna transcript gets translated into an amino acid sequence is that this rna undergoes some processing.
01:02
And one of the things that happens is called splicing.
01:05
And splicing is where these.
01:07
Introns are removed.
01:10
They are the non -coding sections of dna and so they are removed because they are not actually involved in producing a sequence that's going to produce the protein that the organism or the cell is trying to make.
01:24
Okay.
01:25
So after splicing, all we would have would be the four exons from above.
01:33
Okay.
01:35
Hopefully you can see that there.
01:37
And so the question is, if errors in splicing happen, what are some different mutations that would lead to these errors? and so in order to answer that, we need to identify what determines how introns are removed.
01:58
And so in the reading, it talks about introns are marked at the five prime end, which when a dna is being read, it's always read from five prime to three prime.
02:10
And so at the five prime end of an intron, there is a g .u that's marking it.
02:19
And at the three prime end, there is an a .g.
02:25
And so when this gene is being processed and spliced, the splice zone can identify these two sections of an intron...