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In Vivo Functional Study of Disease-associated Rare Human Variants Using Drosophila
Published on: August 20, 2019
"Orphan" retrogenes in the human genome
Joanna Ciomborowska1, Wojciech Rosikiewicz, Damian Szklarczyk
1Laboratory of Bionformatics, Faculty of Biology, Adam Mickiewicz University, Poznań, Poland.
Molecular Biology and Evolution
|October 16, 2012
Summary
Functional retrogenes, born from retroposition, can replace their parent genes. These "orphan" retrogenes face strong purifying selection and are linked to human diseases, impacting evolutionary and medical studies.
Area of Science:
- Evolutionary biology
- Genomics
- Molecular biology
Background:
- Gene duplication via retroposition was thought to primarily yield non-functional pseudogenes.
- The evolutionary fate and prevalence of functional retrogenes, especially those replacing parental genes, remain incompletely understood.
- Comparative genomics is crucial for identifying novel gene families and understanding evolutionary processes.
Purpose of the Study:
- To identify and characterize
- orphan
- retrogenes in the human genome that have replaced their parental genes.
- To investigate the evolutionary history and selective pressures acting on these retrogenes.
- To assess the association of these retrogenes with human diseases.
Main Methods:
- Comparative genomic analysis of human, chicken, and worm genomes.
- Identification of retrogenes that have replaced their progenitor genes.
- Analysis of evolutionary patterns, selection pressures (purifying selection), and expression profiles.
- Examination of associations between identified retrogenes and human diseases.
Main Results:
- Identified 25 candidate "orphan" retrogenes in the human genome, previously unrecognized as retrogenes.
- Demonstrated that replacement of parental genes by retrocopies occurs throughout animal evolution and can be species-specific.
- Found that these retrogenes are under significantly stronger purifying selection than other human genes, contrary to expectations.
- Observed that retrogenes do not typically exhibit testis-specific expression.
- Discovered that seven of these retrogenes are associated with human diseases.
Conclusions:
- Functional retrogenes that replace parental genes are a significant evolutionary phenomenon, contributing to species diversity.
- Despite their origin, these retrogenes are subject to strong purifying selection, indicating functional importance.
- The distinct regulatory mechanisms of "orphan" retrocopies necessitate careful consideration in disease studies and cross-species research.
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