Now that we've worked out the kinks in the procedure of isolating, amplifying and running gel electrophoresis, we figured it was time to go bigger. Instead of working on a project that had been done at HPA many times, we decided to design an experiment that would test something new. We have decided to study ACTN3 gene prevalence in different sports at my school. There are two different types of skeletal muscles, slow-twitch and fast-twitch. Differences in their myosin fibers means that each type of muscle uses energy differently. Slow-twitch muscles fire slowly but use energy efficiently, meaning they can work for a long time. In contrast, fast-twitch muscles, as the name implies, fire rapidly. However, they use energy quite inefficiently and thus tire quickly. The ACTN3 gene controls fast-twitch muscle development. There are two different types of ACTN3 copies. One contains DNA that is a fully expressed in the body. The other copy contains a premature stop codon, R577X, which means that transcription of the DNA strand is cut short and a defective, but not harmful, copy of the gene is expressed. Genotype, the combination of different copies of genes you inherit, is unique in each person. Studies have indicated that different genotypes of the ACTN3 gene affect athletic performance at an elite level (Olympic and other international competitions). They have shown that high performance sprint athletes have a lower prevalence of homozygosity for the stop codon (R577XX genotype), a higher prevalence of homozygosity for the normal allele (RR) and a lower frequency of the heterozygous alleles (RX) as compared to control groups. Also, high performance endurance athletes have a higher prevalence of the XX genotype as compared to control groups. My project tests if that correlation holds true at the high school level. We will test three different groups of students. One group consists of sprint athletes from many sports: swimming, track and field, soccer, volleyball, basketball etc. One group consists of endurance athletes from cross-country running, long-course swimming, distance track and field etc. We will compare the results to a control group consisting of students who do minimal athletic activity. Beyond seeing if a correlation exists between the ACTN3 gene and high school sports we want to see if genotype affects the sports people choose to play. Does having a genetic predisposition to speed or endurance affect sport choice in high school or does it only affect success at an elite level?
Although we've identified the project we want to do, our eternal problem of not having enough supplies has once again struck. We need new PCR beads. These beads combine all the materials we need for PCR (except the template DNA and buffer) into one sphere. This includes the dNTPs used to make new strands, the Taq Plolymerase used to synthesize those new strands, along with various other elements such as magnesium needed to provide an optimal environment for DNA synthesis. We've ordered the PCR beads, so now all there is left to do is wait.