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Identifying zero sequence diversity genes in maize using Temperature Gradient Capillary Electrophoresis (TGCE) Julie M. 1 Meyer , 2 Chen , Hsin Debbie Josh 2 Patrick S. Schnable 2 Shendelman , 1 Truman State University, Kirksville, MO 63501 2 Iowa State University, Ames, IA 50011 Results Summary Twenty-four inbred lines of maize were tested for zero sequence diversity genes using primers designed from Maize Assembled Genomic Islands (MAGI) sequences. After no polymorphisms were observed on an agarose gel, they were run on TGCE instrument to detect the presence of polymorphisms. Data was obtained for 67 primers and 66 were confirmed to have zero sequence diversity. Further testing of teosinte lines will show which of the zero sequence diversity genes in maize are responsible for the domestic phenotype of modern maize. •Of the 81 primer pairs retested, data was obtained from 67. 66 were confirmed to have zero sequence diversity and one failed to be confirmed. •Multiple peaks indicate that more than one sequence of DNA is present while single peaks indicate the presence of only one DNA sequence. Figure 3. Graph of TGCE peaks from one of the confirmed primers. Introduction •Genes that exhibit no diversity might be the key genes responsible for the domestic phenotype of maize compared to its wild relatives. •TGCE is a faster, cheaper and more accurate way of determining if two sequences are in fact distinct. •Heteroduplexes form when two distinct strands of DNA anneal together. These are displayed on a graph as multiple peaks. See Figure 1. •Homoduplexes form when two identical strands of DNA anneal together. These are displayed on a graph as a single peak. Figure 1. Top shows a single peak. Bottom shows multiple peaks. Conclusions •Further testing of these primers on teosinte inbred lines is needed to identify genes responsible for maize domestication traits. •Those genes with high levels of diversity in teosinte but zero diversity in maize could be genes that influenced the domestication of maize. •It is important to understand these genes because they are the traits important to humans and they might shed more light of the process of domestication. Methods •Twenty-four maize inbred lines tested. •81 primers designed from MAGI sequences. •After PCR, run on 1% agarose gel to find polymorphisms. See Figure 2. •If none, DNA was combined with B73 DNA and allowed to denature and reanneal. •Run on TGCE to find polymorphisms. •All primers tested at least twice to confirm. Figure 2. Agarose gel electrophoresis. Top shows a polymorphic gene. Bottom shows a candidate zero diversity gene. Acknowledgements This project was funded by the National Science Foundation grant (DBI-0321711).