Lactase Gene Essay

764 Words 4 Pages
Certain single nucleotide polymorphisms in the human lactase phlorizin-hydrolase gene have been associated with the ability of certain individuals to constantly digest milk products. These mutations in the lactase gene lead to constitutive expression of lactase, which is then used to break disaccharide lactose into glucose and galactose constantly throughout adulthood as lactase persistence. In particular, past research has shown that some individuals of the African and European descent have been found to have single polymorphisms at the C-14010, G13915, G-13907 base pairs and T-13910, G-220,18 base pairs, respectively. Evolutionary biologists have traced the phenotype of lactase persistence in these African and European populations to the …show more content…
One of these individuals will be from Asian heritage and the other from European heritage, and following the successful sequencing of both of their DNA, the nucleotides will be compared to already known sequences of individuals from the same heritage and who have the non-mutated lactase gene to determine the exact nucleotide location of both of these single nucleotide polymorphisms. In this experiment, the independent variable will be the DNA sequence from the two individuals of differing ethnic backgrounds, while the dependent variable will be the location of the single nucleotide polymorphisms in the lactase gene of the single nucleotide. The hypothesis is that both of these test subjects whom have the known phenotype of lactase persistence, will have different locations of the single nucleotide polymorphism due to the past evidence which suggests that ethnic background impacts the genotype of certain …show more content…
This saline/cell solution was then centrifuged and added to a 10% Chelex slurry to remove any metal ions which could have degraded the DNA of the cell pellets. The cell/Chelex solution was placed in a boiling water bath to break open the cells and centrifuged once more to remove the Chelex beads and unwanted cell debris, leaving the DNA isolated in the supernatant. Since the DNA solution of both individuals has already been isolated, the first step will be for each to transfer their DNA sample to two PCR tubes to undergo a Polymerase Chain Reaction to amplify the current amount of DNA. The addition of the 1x PCR buffer, PCR nucleotide mix, 13.1 forward and reverse primers (specific to sequences upstream of the lactase gene), and 2 units of Taq polymerase will be in the form of the LCT-Amplification Mixture of which will get mixed into the extracted DNA samples. A Thermocycler will be used to run 40 cycles of the sample at 95°C, 59°C, and 72°C to denature the DNA strands, anneal the primers, and extend the DNA chain via polymerase activity, respectively. The PCR products will be mixed with Loading Dye and then added to wells of a 1.3% agarose gel with a staining agent, to undergo gel electrophoresis which will separate the DNA samples based on nucleotide length. After ensuring the presence of a 690 base

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