Download Document

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).