ArticleProceedings of the National Academy of Sciences of the United States of America2021
Microchromosomes are building blocks of bird, reptile, and mammal chromosomes.
Article in Proceedings of the National Academy of Sciences of the United States of America, 2021. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 107 papers, 1 of them a synthesis that pooled it.
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107 citing papers in PubMed, 1 synthesis or guideline pooled it, 167 citations in OpenAlex.
- A lizard is never late: Squamate genomics as a recent catalyst for understanding sex chromosome and microchromosome evolution.The Journal of heredity · 2023Pooled it
- The rate and spectrum of germline mutations in chicken from a commercial pedigree line.Genetics, selection, evolution : GSE · 2026Article
- A genome assembly of the North American golden eagle, Aquila chrysaetos canadensis.The Journal of heredity · 2026Article
- Centromeric satellite expansion drives genome evolution in the snowy owl.Genome biology · 2026Article
- Divergent 3D genome architecture of male germ cells across vertebrates.Nature communications · 2026Article
- Chromosome-level genome assembly of the sand martin (Riparia riparia).Scientific data · 2026Article
- High-quality de novo genome assembly for the Galápagos endemic lava gull using Oxford Nanopore Technologies.G3 (Bethesda, Md.) · 2026Article
- Decoding the Avian Missing Gene Mystery: Dot Chromosomes Unmask Extensive Gene Loss and Novel Genetic Instability.Genome biology and evolution · 2026Article
- Chromosomal rearrangements and segmental deletions contribute to gene loss in squamates.BMC biology · 2026Article
- Stable genome structures in living fossil fishes.Genome research · 2026Article
- MicroFinder: conserved gene-set mapping and assembly ordering for manual curation of bird dot microchromosomes.GigaScience · 2026Article
- Host adaptation and genome evolution of the broad host range fungal rust pathogen, Austropuccinia psidii.G3 (Bethesda, Md.) · 2026Article
- The Golden Lancehead Genome Reveals Distinct Selective Processes Acting on Venom Genes of an Island Endemic Snake.Genome biology and evolution · 2026Article
- Unravelling the thread of Podarcis omics; insights into the genome and transcriptome of the Cretan wall lizard.Genes & genomics · 2026Article
- Chromosomal puzzle in snakes: adjacent interstitial telomeric sites on chromosome 5 in three species of genus Vipera.Protoplasma · 2026Article
- Sex chromosome dosage compensation in a sex reversing skink is not influenced by sexual phenotype.BMC genomics · 2025Article
- Evolution of chromosomes and nuclear architectures of amniotes.Nature communications · 2025Article
- Ancestral Chromosome-Level Assemblies Reveal Posthybridization Genome Evolution in the New Mexico Whiptail Lizard (Aspidoscelis neomexicanus).Genome biology and evolution · 2025Article
- Evolution of Large Polymorphic Inversions in a Panmictic Songbird.Molecular biology and evolution · 2025Article
- The complete genome of a songbird.bioRxiv : the preprint server for biology · 2025Article
47 more citing papers are in PubMed but not listed here.
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Authors and funding
12 authors at 8 institutions in 3 countries.
Funding
No grant is acknowledged in the PubMed record.
Abstract
Microchromosomes, once considered unimportant shreds of the chicken genome, are gene-rich elements with a high GC content and few transposable elements. Their origin has been debated for decades. We used cytological and whole-genome sequence comparisons, and chromosome conformation capture, to trace their origin and fate in genomes of reptiles, birds, and mammals. We find that microchromosomes as well as macrochromosomes are highly conserved across birds and share synteny with single small chromosomes of the chordate amphioxus, attesting to their origin as elements of an ancient animal genome. Turtles and squamates (snakes and lizards) share different subsets of ancestral microchromosomes, having independently lost microchromosomes by fusion with other microchromosomes or macrochromosomes. Patterns of fusions were quite different in different lineages. Cytological observations show that microchromosomes in all lineages are spatially separated into a central compartment at interphase and during mitosis and meiosis. This reflects higher interaction between microchromosomes than with macrochromosomes, as observed by chromosome conformation capture, and suggests some functional coherence. In highly rearranged genomes fused microchromosomes retain most ancestral characteristics, but these may erode over evolutionary time; surprisingly, de novo microchromosomes have rapidly adopted high interaction. Some chromosomes of early-branching monotreme mammals align to several bird microchromosomes, suggesting multiple microchromosome fusions in a mammalian ancestor. Subsequently, multiple rearrangements fueled the extraordinary karyotypic diversity of therian mammals. Thus, microchromosomes, far from being aberrant genetic elements, represent fundamental building blocks of amniote chromosomes, and it is mammals, rather than reptiles and birds, that are atypical.
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