Variation in Nucleotide Substitution Rates in Arabidopsis
Author Information
Author(s): DeRose-Wilson Leah J, Gaut Brandon S
Primary Institution: Dept. of Ecology and Evolutionary Biology, U.C. Irvine, Irvine, CA, USA
Hypothesis
Do intergenic sequences evolve at rates similar to synonymous sites in coding data?
Conclusion
Mutation rates vary among genomic regions as a function of base composition, suggesting that previous observations of selective constraint on non-coding regions could be attributed to a GC effect instead of selection.
Supporting Evidence
- The average rate of nucleotide substitution is slower in intergenic regions than in synonymous sites.
- Rate variation in both intergenic and coding regions correlates with GC content.
- Rates of evolution in intergenic regions correlate negatively with gene density.
Takeaway
This study looked at how quickly different parts of plant DNA change over time, finding that some areas change slower than others because of their DNA makeup.
Methodology
The study generated a set of 66 intergenic sequences in Arabidopsis lyrata and compared substitution rates among these loci to a set of 64 orthologous coding sequences.
Potential Biases
PCR success rates varied, which could introduce bias in the data.
Limitations
The data are not random with respect to genomic location and may be biased toward more slowly evolving regions of the genome.
Statistical Information
P-Value
0.0074
Statistical Significance
p<0.05
Digital Object Identifier (DOI)
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