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A Bioinformatics Pipeline for Investigating Molecular Evolution and Gene Expression using RNA-seq
Published on: May 28, 2021
Evolutionary genetics of the hydroid allodeterminant alr2
Andrea Gloria-Soria1, Maria A Moreno, Philip O Yund
1Department of Ecology and Evolutionary Biology, Yale University.
Molecular Biology and Evolution
|August 3, 2012
Summary
Genetic variation in the alr2 gene of Hydractinia symbiolongicarpus reveals extensive diversity, suggesting negative-frequency-dependent selection drives this allodeterminant
Area of Science:
- Population genetics
- Molecular evolution
- Marine invertebrate biology
Background:
- The alr2 gene in Hydractinia symbiolongicarpus is an allodeterminant involved in colony interactions.
- Understanding genetic variation in allodeterminants is crucial for comprehending immune system evolution and social behavior in colonial organisms.
Purpose of the Study:
- To survey and characterize the genetic variation of the alr2 gene in Hydractinia symbiolongicarpus.
- To investigate the evolutionary forces shaping the diversity of this allodeterminant.
Main Methods:
- cDNA sequencing of alr2 alleles from 239 Hydractinia colonies.
- Bioinformatic analysis of allele frequencies, sequence divergence, and structural types.
- Identification and analysis of alr2 pseudogene sequences.
Main Results:
- Discovered 473 alr2 alleles, with 198 unique sequences, indicating high genetic diversity.
- Observed significant amino acid divergence (18%) and identified two structural types of alr2.
- Found evidence of positive selection in immunoglobulin superfamily-like domains and identified 77 unique pseudogene sequences, suggesting pseudogene-mediated diversification.
Conclusions:
- The extensive genetic diversity, predominance of rare alleles, and signatures of positive selection support negative-frequency-dependent selection acting on alr2.
- The alr2 genetic system exhibits polymorphism levels comparable to highly variable genetic systems known in other species.
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