Describe and give an example (real or hypothetical) of each of...

Question

Describe and give an example (real or hypothetical) of each of the following:

Insulator sequence action

Accepted Answer

Welcome back, everyone. Let's look at our next question, which one of the following statements accurately describes the function of insulator sequences. When they bind to specific proteins. Choice A, they increase the transcription of downstream genes B, they decrease the transcription of downstream genes C, they enhance the expression of neighboring genes or D, they act as boundary elements to prevent the spread of heterochromatin and enhance your activity between adjacent genomic regions. So we're talking about insulator sequences and asking what describes their function when they bind to specific proteins. Well, we have a pretty big clue in the name insulator when we look at our different options because when we look at choice ad, it says they act as boundary elements to prevent the spread of heterochromatin and enhanced activity between adjacent genomic regions. Well, if we think about the word insulator, we think of just that something that's a barrier preventing a adjacent things from having uncontrolled spread, whether it's insulating a hot drink to prevent exchanging temperature with the outside air or insulating an electrical wire to prevent electricity from going where you don't want it. And indeed choice of D is our option here as you recall, heterochromatin is the highly condensed area of chromatin where you have very little gene expression and of course, enhanced your activity would mean you have increased gene expression. So if you're having gene expression being reduced by this tight packing in an area that's immediately adjacent to a part of the gene where you have enhancer activity, turning up gene expression, you would want to prevent these areas from affecting each other. You would want to maintain the proper gene activity in these adjacent areas. And so that's just what insulator sequences do. They are boundary elements between adjacent areas to prevent their different regulations from affecting each other. So when we look at our other answer choices, uh A says increase the transcription while these insulator sequences can affect increasing transcription or decreasing transcription because they're preventing from both, both from happening when you don't want it to happen. So that's why that's not the correct answer. And the same goes for B and C decrease the transcription of downstream genes, enhance the expression of neighboring genes. They don't have either any of these specific increase or decrease effects, rather just preventing increasing or decreasing transcription from spreading from one element to another. So again, the best description of the function of insulator sequences, when they bind to specific proteins, choice d, they act as boundary elements to prevent the spread of heterochromatin and enhance your activity between adjacent genomic regions. See you in the next video.

Describe and give an example (real or hypothetical) of each of the following:
Insulator sequence action

Key Concepts

Insulator Sequences

Gene Regulation

Chromatin Structure

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