Introduction
In our genes, multiple different alleles determine whether one person will have a certain trait or not. Alleles are what make-up our genotypes and in this lab, we wanted to determine the genotypes of our class in the two loci: TAS2R38 and PV92. The TAS2R38 locus codes for a protein that involves the bitter taste of PTC; the gene determines whether or not a person will taste the PTC paper as very bitter or no taste at all. People with the “T” allele are tasters while those that are homozygous recessive (tt) are non-tasters. The taster locus can be found chromosome 7.3 The two different alleles present in the could be due to the effect of evolution and natural selection because the same can be found in chimps.4 The PV92 locus does not code for any protein but rather involves an Alu element that is 300-bp long. A person with the “+” allele would have the Alu element making that sequence longer while those with the “-“ allele don’t have the element and would have a shorter sequence. This locus can be found on chromosome 16.3 There are multiple Alu sequences found among primate genomes but there are human specific sequences such as the one found on the PV92 locus.1 In the experiment, student DNA was collected from cheek cells and PCR was used to target the loci and amplify the region of DNA. In the taster gene, after amplification, a restriction digest was performed to differentiate between the two alleles. The digest was able to show differentiation because those with the “T” allele would have two bands from gel electrophoresis and those with “t” will have one band because the restriction enzyme doesn’t cut it. For the PV92, we were able to distinguish between the alleles due to the added length of the Alu element. Those...
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...G.E., Ioannou P.A., Scheer W.D., Herrera R.J. et al. 1994. Africa origin of human-specific polymorphic Alu insertions. Evolution Vol. 91: pp 12288-12292
2Gómez-Pérez L, Alfonso-Sánchez M.A., Sánchez D, García-Obregón S, Espinosa I, Martínez-Jarreta B, De Pancorbo M.M., Peña J.A. 2011. Alu Polymorphisms in the Waorani Tribe from the Ecuadorian Amazon Reflect the Effects of Isolation and Genetic Drift. American Journal of Human Biology Vol 23(6): pp 790-795
3 Leicht B. G., McAllister B.F. 2014. Foundations of Biology 1411, 2nd edition. Southlake, TX: Fountainhead Press. Pp 137, 163-168, 177-180,
4 Wooding S. 2006. Phenylthiocarbamide: A 75-Year Adventure in Genetics and Natural Selection. In: James F. Crow, William F. Dove editors. Perspectives, Anecdotal Historical and Critical Commentaries on Genetics. Salt Lake City, Utah: Genetics Society of America. Pp 2015-2023
Rantala, M. J., and Roff, D. A. 2006. Analysis of the importance of genotypic variation,
One remarkable Alu element located at the PV92 locus on chromosome 16 was found to be specific to the Homo sapiens species. The fact that it is found exclusively in the human population provides significant support to the theory that the PV92 element established itself into the genome sometime after the human-primate split in the ancestral tree approximately 5-7 million years ago (Batzer, et al., 1994). The PV92 insert, along with all other elements belonging to the Alu family, do not code for outgoing products, instead they are considered to be a genetically silent insertions. Although different genotypes in individuals can be observed there is no effect on a person’s phenotype.
Wooding, Stephen. "Phenylthiocarbamide: A 75-Year Adventure in Genetics and Natural Selection." Genetics 174.4 (2006): 2015. Print.
Test 4: All three phenotypic frequencies saw a reduction in their number as the homozygote fishes saw a reduction in their number and were not able to pass on their alleles to create either their colored fish or a heterozygote. Both yellow and blue allele frequencies decreased by the same
My research strives to answer the presence and degree of interbreeding between Neanderthal and Modern humans. Researchers use different comparisons of the fossil record, phylogenetic, morphological, and genetic methods to explore these questions in more detail. The literature provided many positive correlations to my hypothesis that Neandertals and Modern Humans interbred on a small-scale basis after the dispersal of modern humans from Africa. The literature also predicts a time frame of likely interbreeding. To explore this question it is important to research article’s explaining the statistical, genetic, and physical evidence associated with possible interbreeding.
In 1990, the first great stride of genetics took place. This was called the Human Genome Project, a large-scale operation that was designed to understand the human genome (genetic structure). Since its commencement, there have been many leaps and bounds that have taken place. For certain genetic issues that we once knew nothing about, we no...
Lewis, Ricki, (2014), Human Genetics, 11th Edition, Chapter 12. Gene Mutation. [VitalSource Bookshelf Online]. Retrieved from
All references and resources are taken from the Public Library of Science, Biology March 2004 issue and from Science March 16, 2004
Nachman, M W., W M. Brown, M Stoneking, and C F. Aquadro. "Nonneutral Mitochondrial DNA Variation in Humans and Chimpanzees." NCBI PubMed (1996). 30 Mar. 2008 .
The majority of scientific work in genetics and genomic sequencing has been done in the last 155 years. In 1859, Charles Darwin published On the Origin of Species where he proposed evolution by natural selection. Evolution is the change of inherited characteristics of biological populations over successive generations.Yet, the principals of genetics required to explain how characters are ...
The exercise involved a series of ‘mating’ events resulting in 6 generations. Each mating event produced offspring with ‘possible’ newly inherited traits. The idea of ‘chance’ was included through simple coin tosses. Also, ideas of selection and mutations were introduced into the ‘gene pool’, which presented a deeper and more clear understanding of Mendelian inheritance and the Hardy-Weinberg equilibrium. Upon reaching the third generation, A B1 mutant allele was introduced to the blue locus-influencing fin shape and a G1 mutant allele was introduced to the green locus-influencing Mouth
This paper addresses a currently relevant topic of detection of associations of copy number polymorphism with traits and will be of interest to readers of Genetics Research.
Genetically influenced traits tend to be polygenic in character, involving many genes acting in concert to produce a certain response. Therefore, association of one gene with one behavior is usually only partially conclusive. Behavior depends on the interaction of multiple gene sequences with environmental influences. ...
Campbell, N. A. & J. B. Reece, 8th eds. (2008). Biology. San Francisco: Pearson Benjamin Cummings.
more than half the variation was found to be due to heredity. Among these traits were