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
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The 64bp fragments are faint and not visible. According to the profile for PTC gene in 18 individual: 8 heterozygous tasters (Tt), 2 homozygous tasters (TT) and 8 homozygous recessive non-tasters (tt). (Figure 4)
| Individual (N=1) | Class (N= 21) | | Expected | Observed | Expected | Observed | Phenotype | Taster | 0.75 | 1 | 15.75 | 11 | | Non-Taster | 0.25 | 0 | 5.25 | 10 | Genotype | TT | 0.25 | 0 | 5.25 | 2 | | Tt | 0.50 | 1 | 10.5 | 8 | | tt | 0.25 | 0 | 5.25 | 8 |
* genotype was undetermined for 3 individuals due to lack of data.
Figure 1. Tally of the class’ genomic analysis for PTC taster gene.
II – Discussion:
Receptor proteins recognize bitter-tasting compounds on the surface of taste cells. There are approximately 30 genes for different bitter taste receptors. The gene for the PTC taste receptor, TAS2R38, was identified in 2003. Sequencing identified three nucleotide positions that vary within the human population (Kim et al.); each variable position is termed a single nucleotide polymorphism (SNP). One specific combination of the three SNPs, termed a haplotype, correlates most strongly with tasting ability. In this lab, non-tasters (homozygous recessive, tt) can determine their genotype without having to run the PCR and electrophoresis because non-taster gene is recessive. Thus, the only way for them to express recessive phenotype is to have the tt alleles of
This polymorphism is practical and brings about lessened chemical movement. This single amino acid substitution brings about impeded Flavin adenine dinucleotide (FAD) authoritative, prompting loss of folate coming about, in its turn, in diminished action of MTHFR. For the C677T polymorphism, homozygote variations have 30% compound action in correlation with homozygote for the wild-sort C allele, while heterozygote holds 65% of wild-sort MTHFR chemical
Moreover, common, known and synonymous variants were not included in their final analysis. In our study we will investigate all variant types because our aim is to determine what pathways variants occupy and their interactions with other variants. Eliminating variants may well result in lose of
Part1) To understand and be able to complete a pedigree chart, one must be able to identify and be able to comprehend the genotypes being presented. Any child with a double recessive with have parents with either homozygous recessive and heterozygous, or heterozygous dominant and heterozygous dominant. Any child with a heterozygous genotype will have parents with, homozygous dominant and homozygous recessive, homozygous dominant and heterozygous dominant, homozygous recessive and heterozygous dominant. Any child with a homozygous dominant genotype needs to have parents who are, homozygous dominant and homozygous dominant, or homozygous dominant and homozygous recessive. A homozygous dominant and a heterozygous dominant will have the same phenotype,
The tongue, soft palate, and epiglottis are covered with structures known as taste buds, or lingual papillae, that allow humans to sense different tastes in the foods they eat. They are chemoreceptors, meaning that they transduce, or translate, chemical signals in food into electrical signals in the body. These electrical signals, called action potentials, travel to the brain via the nervous system, allowing us to experience the sensation of taste. Taste buds are known as direct chemoreceptors, meaning that they must make direct contact with the chemicals in food in order for us to taste. Distance chemoreceptors, on the other hand, such as those that sense smells, do not need to make direct contact with chemicals.
“Taste, like smell, is a doorman for the digestive tract, a chemical scan for the possible dangerous (bitter, sour) elements and desireable (salty, sweet) nutrients.” (46)
Researchers screened over 3,000 genes and selected 19 random genomic regions for their comparisons, which was much more than previously cited studies. The regions that were chosen for comparison were attached to a core SNP in the coding region of a gene. This was further qualified using only fully known genomic sequence up to 160 kb in either direction of the core SNP and having a frequency of at least 35% in all ethnic groups sampled. The choice of high-frequency SNPs was explained by known factors that affect the rate. Mainly, that they tend to be found in all populations, when LD are around rare alleles the are expected to extend further because these alleles are younger and have had less recombination, and when around common alleles they tend to be more closely associated with diseases. The researchers examined 251,310 bp and found a total of 272 high-frequency SNP’s of which they chose the 19 that they examined and analyzed for this
Lp(a) being a known autosomal dominant genetic trait the expected familial pattern would be around 50% as it is in this family. Some family members may be avoiding disease from various interventions and lifestyle choices such as niacin therapy, weight loss, and physical activity as well as lack of concomitant disease.
We deduced possible modes of inheritances by observing the F1 generation of a pure-bred cross. F1 generation data was used to construct our null hypothesis that the white eyed mutant phenotype is autosomal recessive to the wild type brick red eyes. We then attempted to falsify this hypothesis using a chi-square analysis. We obtained a significant p-value greater than 0.1%, rejecting our null hypothesis, allowing us to accept our alternative hypothesis.
The hypothesis is that the dihybrid cross of an Acid (AC AC) and Red (r r) purebred mother with a Lightning (lt lt) and Gold (AU AU) purebred father will result in an F1 generation that expresses only the dominant
(Laidlaw and Taylor, 1-9). Queer taste in the mouth can also manifest as one of the nonspecific
Thanksgiving is a holiday that comes with a great feast of very different and unique flavors. Imagine the mouthwatering meal, the zest of the ruby-red cranberry sauce, or the sweet scent of a pumpkin pie fresh out of the oven. When imagining tastes and smells sensory cues are often combined. The senses work together, but have you ever wondered how much the sense of taste influenced by other sensory information? If you pinch your nose you will taste less flavor? If the subjects nose is plugged and cannot smell, then can the subjects detect the flavors as well as those with unplugged noses.
Colorblindness is a fascinating vison defect that impacts every day lives of those with the condition. There are multiple types of colorblindness that an individual can have, starting with partial color blindness and ending with total color blindness. However, the condition most commonly is passed genetically, effecting primarily males. In this paper I will be exploring the types of colorblindness that travel through genes, and how they impact people with the condition.
The PTC tasting trait is governed by two pairs of alleles eg. dominate T for tasting and a t for non tasting. If the mother or father has a genotype of TT and Tt they are tasters. If the mother or father has a genotype of tt they are non tasters. Studies have shown that there appears to be a hormonal intervention for the PTC tasting ability, but, women are thought to have more taste-sensitivity in regards to men. Scientists have hypothesised that PTC tasting may impart to the genetic level of dithiotyrosine in their saliva. Non tasters have a higher than average rate of gotire. This is a disease in the thyroid gland, that can be associated with lack of iodine. Predictions say that tasters could have more food aversions compared too non-tasters.
was used to find the frequencies of the dominant and recessive alleles. After noting and calculating the results of the first fifty people at the mall, I tested a second experiment, deducing that attached ear lobes seemed to be more prevalent in younger females. My new hypothesis was females under age thirty had a higher frequency of attached ear lobes, so I then observed the next fifty females that appeared under the age of thirty and recorded the results. The Hardy Weinberg formula was again used in the calculations.
We further screened PRRT2 gene for mutations in his parents and confirmed two variants p.Pro138Ala and p.Arg229Lys in his unaffected mother (BI-2), indicating deficient penetrance. Whereas, we failed to confirm c.709G>A variant in both his mother and his father. This implicate that this mutation may derive from de novo (fig 1). This finding is consistent with the genetics where putative mutation occurs de novo in the affected child of unaffected parents and corresponds well with the previous study reported de novo mutagenesis of PRRT2 mutations in Chinese PKD, PKD/IC, and BFIE (Li, Ni et al. 2013). PRRT2 p.Pro138Ala variant has been reported among 15 Chinese sporadic PKD patients previously (Yu Zhang 2017). Moreover, it was identified in 14 patients who were affected with Epileptic febrile seizures and punctuated as loss function mutation (He, Qu et al. 2014). Accordingly with the previous reports, c.412CA (p.Arg229 Lys) and p.Ser 248Thr (c.743 GA (p.Arg229 Lys) could not be proven, predicted to be benign by polyphen-2, it has more prevalence among PKD/IC patients. Only 2 out of 4 sporadic patients affected with PKD/IC (F8, F11) have shown PRRT2 c.686G>A variant (Tble1). These results eliminates doubt and additionally underpins the conceivable part of c.686G>A variant as the cause in the PKD/IC. Together with our finding we proposed that, the PRRT2