Pv92 Lab Report

Presence of Alu element within PV92 on chromosome 18 in a mixed ethnical population and its connection with humans’ ancestral origins

By Shiyu Song

Biology 155Q
LAB-A: 14:30-17:30
Dr. Jacob
April 17th 2013

Abstract The Alu insertion (+) within PV92 on chromosome 16 usually reflects a person’s ancestral origin. This study aimed to find the correlation between the presences of Alu insertion (+) within PV92 on chromosome 16 within a population. We used PCR to detect the Alu insertions by amplifying the PV92 region on chromosome 16 in order to detect the presence or absence of Alu at this locus. The result shows that 78% of the population in this population had a genotype “+/-”, and rest of the 22% of the populations had a genotype
2.3 Gel Electrophoreses After the PCR program completed, 2.7μL of 10X loading dye was transferred into each PCR tube. An electrophoresis gel chamber was completely immersed by 1X Tae buffer. Then, 10μL of DNA ladder was loaded in to the middle of the gel, and 20μL of each PCR sample were loaded into distinguish location in the gel. After all lanes are loaded, electrophoresis was turned on at a constant rate of 110-115V for one hour.
2.4 Gel imaging and analysis After the gel electrophoresis was completed, the gel was put into Kodak Gel Logic 100 Gel Documentation, and an image of the gel was captured. The DNA ladder fragments were used to locate 1000bp, which serves as an object of reference to locate Alu insertion. After the sample band was established, the captured image was used to decide the genotype by analyzing the locations of the bands compared to 1000bp. After the genotype was obtained, PV92 genotype data for the whole population, genotype frequency and allele frequency were analyzed. Genotype frequency was calculated by count total number of individual with specific genotype, such as “+/+” or “+/-” divided by the total number of individuals in the population. Allele frequency was calculated by the number of “+” or “-” alleles in the population divided by the total number of all alleles in the population, which is total number of individuals in the population multiples by
Even though Alu element on PV92 could use to trace the ethnicity origin of one person, there might be people who do not fit in expected trends because people report their ethnic identity might not clearly distinguish their ethnical background (Tripathi, et al. 2008). Any unknown ethical background might have an impact with the presence of Alu element within PV92 (Solovieva, et al. 2010). These statements explain why 28 percent of the populations who are non East Asian and American Indian obtain Alu insertion while 25 percent of the populations who have ancestral origins of East Asian and American Indian do not have Alu insertion within PV92. In this experiment, the information of country/ethnicity/tribe of ancestral origin was solely based on self-report. The participants’ unfamiliarity of their accurate ethnical backgrounds might explain the obtained