You have identified a recessive mutation that alters bristle p...

Question

You have identified a recessive mutation that alters bristle patterning in Drosophila and have used recombinant DNA technology to identify a genomic clone that you believe harbors the gene. How would you demonstrate that your gene is on the genomic clone?

Accepted Answer

Welcome back, everyone. Here's our next question. What would suggest the presence of the gene of interest on the genomic clone in Southern blot analysis? Choice? A hybridization pattern of the mutant sample is the same as the wild type sample. Choice B, absence of any bands in both mutant and wild type samples. Choice C unique bands present in the mutant sample but absent in the wild type sample or choice D hybridization pattern of the wild type sample is different from the mutant sample. So to pick our answer, we just want to remind ourselves of what is going on in the Southern plot and what we're looking for. So by looking for a presence of a gene of interest on the genomic cologne, we mean that we're looking for an introduced jean. So the wild type sample does not have the gene of interest because the type of genomic cloning that you are doing here is looking to introduce DNA into an organism that wasn't there before. And in the southern bloc, we look at the DNA of the organism. It's cleaved by restriction enzymes separated by size, the fragments that were generated by cleaving it and then transferred to a membrane which is then washed with a labeled DNA probe. And that probe is complimentary to the desired gene. So you have your sample, you have your original wild type organism, you have the mutant organism that you hope contains your gene of interest. And you use a labeled probe that has a sequence complementary to the gene you've introduced or a portion of the gene you've introduced. So the end result is you would expect to see a band in your mutant sample. The gene is there that is absent in the wild type because the gene wasn't originally in that organism. So that's choice C. When we look at our other answer, choices, choice A says they have the same hybridization pattern. Well, that's not going to be the case because you've introduced a gene and your probe is specific to that gene that you introduced. And then choice B absence of any bands in both is not our correct answer because we'd be looking for a band showing hybridization of our probe to the mutant where we've introduced the gene. And then choice D A hybridization pattern that is different from mutant sample is not our answer because again, the wild type sample did not have the gene at all. So you shouldn't see any bands, there shouldn't be anything for a probe to hybridize with. So again, what would suggest the presence of the gene of interest on the genomic clone? If we're doing a Southern plot choice c unique bands present in the mutant sample but absent in the wild type sample. See you in the next video.

You have identified a recessive mutation that alters bristle patterning in Drosophila and have used recombinant DNA technology to identify a genomic clone that you believe harbors the gene. How would you demonstrate that your gene is on the genomic clone?

Key Concepts

Recessive Mutation

Recombinant DNA Technology

Genomic Cloning

Watch next