Gene Mapping in Ascospore Sordaria Cultures by Recombination

1043 WordsFeb 16, 20145 Pages
Gene Mapping in Ascospore Sordaria Cultures by Recombination Abstract The laboratory experiment demonstrates the process of meiosis using the Sordaria Fimicola fungi. Meiosis is important because it is the process that generates diversity in genetics. A wildtype was crossed with two mutant types: tan and grey. In order to exhibit recombination, the sequence of ascospores needed to result in a 2:2:2:2 or 2:4:2 sequence. From the crossover event, the percentage of asci that had this pattern was used to calculate the distance from the gene to centromere in map units. The distance or location is a significant because it can affect the frequency of…show more content…
The distances between the centromeres and genes were determined. Refer to results section for exact distances for each gene. The distance or location is a significant because it can affect the frequency of crossing over and thus recombination. The results of this crossing further determine if recombination occurred in Sordaria. Recombination is important because it is an indication of the genes joining together to form new combinations; increasing genetic variation/diversity. The results encountered (according to percentage error) indicate that recombination did not occur in high quantities. The data collected experimentally (my own group) resulted with a 60% recombinant rate concerning the wildtype and tan crossing. The wildtype and grey crossing resulted with a 52% recombinant rate. The arrangement most encountered was a 2+: 2t: 2+: 2t, meaning a crossover between the gene and centromere did occur in the second division of meiosis II (recombinant chromatids). Another common arrangement encountered were the asci having a pattern of 6:2 and one 5:3 arrangement due to the genes undergoing gene conversion. The error in the lab is certainly due to counting of the asci. There are multiple factors that may have affected the counting. For instance, incorrect uses of the microscope, not counting the correct bi-colored asci or tallying up the same region of asci. To avoid some of these problems it would be preferable to have a better microscope. The
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