History of Intron-rich Eukaryotic Ancestors from 100 Genomes
Author Information
Author(s): Csuros Miklos, Rogozin Igor B., Koonin Eugene V.
Primary Institution: Université de Montréal
Hypothesis
Did introns accumulate during the evolution of eukaryotes?
Conclusion
The study concludes that ancestral eukaryotes were intron-rich, with significant intron loss occurring in many lineages.
Supporting Evidence
- Ancestral eukaryotes were inferred to be intron-rich, with LECA having a high intron density.
- Evolution of eukaryotic genes was dominated by intron loss, with substantial gain only at the bases of several major branches.
- The last common ancestor of animals had an intron density of 120-130% of the human value.
Takeaway
This study shows that early eukaryotes had a lot of introns in their genes, and over time, many of these introns were lost in different species.
Methodology
The researchers used a Markov Chain Monte Carlo method to analyze intron gain and loss across 245 orthologous genes from 99 eukaryotic genomes.
Potential Biases
Potential biases in ancestral reconstructions due to the methods used, particularly with Dollo parsimony.
Limitations
The study's conclusions are based on available genomic data, which may not represent all eukaryotic diversity.
Statistical Information
P-Value
p<0.05
Confidence Interval
95% confidence interval of 3.7–5.1 introns/kilobase for LECA
Statistical Significance
p<0.05
Digital Object Identifier (DOI)
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