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 |
Externí odkaz: |