Evolutionary breakpoints in the gibbon suggest association between cytosine methylation and karyotype evolution

Autor: Alan R. Mootnick, Sung K. Kim, Jeffrey D. Wall, Aleksandar Milosavljevic, Jane Rogers, Pieter J. de Jong, Lucia Carbone, Sean Humphray, Jerzy Jurka, R. Alan Harris, David D. Martin, Gery M. Vessere
Přispěvatelé: Ferguson-Smith, Anne C
Rok vydání: 2009
Předmět:
Cancer Research
viruses
Molecular Biology/Bioinformatics
0302 clinical medicine
Models
Genetics (clinical)
Segmental duplication
Genetics
Gene Rearrangement
0303 health sciences
Genome
Chromosome Mapping
Nomascus
CpG site
DNA methylation
Genetics and Genomics/Comparative Genomics
Research Article
Human
lcsh:QH426-470
Evolution
Alu element
Chromosomal rearrangement
Biology
Synteny
Evolution
Molecular
03 medical and health sciences
Cytosine
Species Specificity
Genetic
Alu Elements
Genetics and Genomics/Epigenetics
Animals
Humans
Hylobates
Molecular Biology
Ecology
Evolution
Behavior and Systematics
030304 developmental biology
Evolutionary Biology/Evolutionary and Comparative Genetics
Breakpoint
Human Genome
DNA Breaks
Molecular
DNA Methylation
biology.organism_classification
Chromosomes
Mammalian
lcsh:Genetics
Evolutionary biology
Karyotyping
030217 neurology & neurosurgery
Epigenesis
Developmental Biology
Zdroj: PLoS genetics, vol 5, iss 6
PLoS Genetics, Vol 5, Iss 6, p e1000538 (2009)
PLoS Genetics
Popis: Gibbon species have accumulated an unusually high number of chromosomal changes since diverging from the common hominoid ancestor 15–18 million years ago. The cause of this increased rate of chromosomal rearrangements is not known, nor is it known if genome architecture has a role. To address this question, we analyzed sequences spanning 57 breaks of synteny between northern white-cheeked gibbons (Nomascus l. leucogenys) and humans. We find that the breakpoint regions are enriched in segmental duplications and repeats, with Alu elements being the most abundant. Alus located near the gibbon breakpoints (
Author Summary Mammalian genomes are remarkably stable (with few exceptions). In humans, wrong recombination events occur quite rarely, manifesting themselves in genomic disorders or cancer. On exceptional occasions, the rate of genome evolution has been accelerated by genome-wide reshuffling events giving rise to some highly derivative karyotypes. The genomes of gibbon species (Hylobatidae) are an example of accelerated genome structural evolution; gibbons display a rate of chromosome evolution 10–20 fold higher than the default rate found in mammals (one chromosome change every 4 million years). As we are interested in investigating the possible genetic causes of this phenomenon, we sequenced a considerable number of chromosomal breakpoints in the northern white-cheeked gibbon genome and analyzed the genomic features of these sites. We observe that the gibbon breakpoints are mostly associated with endogenous retrotransposons called Alus, which are normally abundant in the genomes of primates. Furthermore, our analysis revealed that gibbon Alus have a lower content of methylated CpG when compared to the orthologous human Alus. In mammals, CpG methylation is known to be responsible for keeping retrotransposons in a repressed state and protect genome integrity. We therefore suggest that a glitch in the methylation apparatus might have driven the higher genome recombination in gibbons.
Databáze: OpenAIRE
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