PTC Taster Genomic Analysis Lab Report

Laboratory Goals: 1. Determine Taster Phenotype 2. Isolate DNA from each individual 3. Determine Taster Genotype

Hypothesis:
If I am a taster, then my genotype for PTC taster must be either TT (homozygous dominant) or Tt (heterozygous)

I – Results:

This experiment aimed to investigate the allele frequency of the PTC taster gene (TAS2R38) in a small population, represented by the students in class. The genotype obtained from genomic analysis (via PCR and gel electrophoresis) confirmed that the genotypic result is consistent with the phenotypic result observed at the beginning of the lab.
However, DNA fragments of 3 lab subjects didn’t show up on the gel. The allele frequencies can’t be calculated because the data is insufficient to apply the Hardy-Weinberg equation. There are many factors that might be contributed to the invisibility of these DNA fragments, most likely accidental errors. For example, the DNA wasn’t loaded onto the gel probably, or the DNA for some reason didn’t sink to the bottom of the well, or just simply there was not enough DNA.
To determine the genotypic profile of the students PTC gene, DNA samplers from each individual was collected from saliva. Using premade PTC primers (short oligonucleotides), a DNA template that encoded the PTC gene (approximately, 303 bp) was amplified by PCR. After amplification, the produced DNA fragments were digested with Fnu4H1 to identify if the lab subjects have a C or a T at position 785 (PTC taster gene location, Figure 3.) Fnu4H1 (5’ GCTGC 3’) is an enzyme that cuts DNA at specific restriction length polymorphism (RFLP) site present only in wild type alleles and absent in mutant alleles ((5’ GTTGC 3’.) Digested DNA will be cut into 2 fragments 239 bp and 64 bp in length. (Figure 2)
This discrepancy in length allowed us to profile the alleles