Testing for Cilantro Aversion Using Single Nucleotide Polymorphisms
Hunter Croom and Diego Sifuentes
Biology 250, Longwood University
- Single Nucleotide Polymorphism (SNP) is the variation in the DNA sequence of single base pairs.
- They are abundant and often happen at 1 out of 1,000 bases in the human genomes (Syvänen, 2001).
- Cilantro Aversion is the dislike of cilantro due to a variation in the gene that makes it smell and taste like “soap” (Mauer and El-Sohemy, 2012).
- The importance of this study is to see if genotype matches the phenotype and see if it is homozygous or heterozygous and use this information to predict genotype
Research Question: Does the genotype for Cilantro Aversion SNP determine the phenotype for that trait.
Hypothesis: If the individual has GG alleles, then they are less likely to have Cilantro Aversion.
- Three individuals used the wooden end of a sterile swab to wipe around the cheek
- The swab was swirled in a tube of 60 μL of sterile water (CS-H2O).
- Of the 3 Samples sequenced, A and B appear to be homozygous positive for cilantro aversion. Sample C is seen as homozygous negative for cilantro aversion (see fig 1).
- C1 and C2 (A and B in fig. 1) show around 350~400bp while C3 (C in fig.1) is about 350.
- based on the results the hypothesis tested was proven, the subject sample C was taken from did not appear to show an aversion to cilantro, while subjects A and B did.
- While PCR is useful and effective in the field of forensics and genetics as it is a relatively fast and easy way to determine someone's genetic makeup, it can’t tell the whole story. PCR can only test for a specific gene or identify a single locus in someone’s genome, thus limiting how much you can do with it and how accurate it is.
- If technology advances and there are more effective and detailed ways of performing PCR on a larger section of a person's genome and contrast that one sub-section to the rest of the population then PCR would be a less limiting form of forensics and genetic testing.
- Syvänen, A. C. (2001). Accessing genetic variation: genotyping single nucleotide polymorphisms. Nature Reviews Genetics, 2(12), 930.
- Mauer, L., & El-Sohemy, A. (2012). Prevalence of cilantro (Coriandrum sativum) disliking among different ethnocultural groups. Flavour, 1(1), 8.
Polymerase Chain Reaction & Gel Electrophoresis
- Primer mix (5 μL), 17 μL of H2O, and 3 μL of CS-H20 (cheek cells) was added to the PCR tube.
- 10 μL of the sample was added to the gel wells and ran at 120v for 30min
- 100 μL of binding buffer was added to the PCR mix, spun for 1 min and dumped flow through
- 700 μL of wash buffer was added to the PCR mix, spun for 1 min and dumped flow through
- 200 μL of H2O was added to the PCR mix, spun for 1 min and dumped flow through.
Fig. 1: Sequenced results viewed in snapgene viewer through chromatogram
Fig. 2: Gel electrophoresis results
Fig. 3: predicted genotypes based on Phenotypes