The fine-scale recombination rate variation and associations with genomic features in a butterfly

Genome Research, Journal Year: 2023, Volume and Issue: 33(5), P. 810 - 823

Published: May 1, 2023

Recombination is a key molecular mechanism that has profound implications on both micro- and macroevolutionary processes. However, the determinants of recombination rate variation in holocentric organisms are poorly understood, particular Lepidoptera (moths butterflies). The wood white butterfly (

Language: Английский

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Annelid Comparative Genomics and the Evolution of Massive Lineage-specific Genome Rearrangement in Bilaterians

Molecular Biology and Evolution, Journal Year: 2024, Volume and Issue: 41(9)

Published: Aug. 13, 2024

Abstract The organization of genomes into chromosomes is critical for processes such as genetic recombination, environmental adaptation, and speciation. All animals with bilateral symmetry inherited a genome structure from their last common ancestor that has been highly conserved in some taxa but seemingly unconstrained others. However, the evolutionary forces driving these differences by which they emerge have remained largely uncharacterized. Here, we analyze across phylum Annelida using 23 chromosome-level annelid genomes. We find while many lineages maintained bilaterian structure, Clitellata, group containing leeches earthworms, possesses completely scrambled develop rearrangement index to quantify extent evolution show that, compared bilaterians, earthworms among most rearranged any currently sampled species. further can be classified two distinct categories—high low rearrangement—largely influenced presence or absence, respectively, chromosome fission events. Our findings demonstrate animal variable within reveal occur both gradual, stepwise fashion, rapid, all-encompassing changes over short timescales.

Language: Английский

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Do chromosome rearrangements fix by genetic drift or natural selection? Insights from Brenthis butterflies

Molecular Ecology, Journal Year: 2023, Volume and Issue: 33(24)

Published: Oct. 9, 2023

Large-scale chromosome rearrangements, such as fissions and fusions, are a common feature of eukaryote evolution. They can have considerable influence on the evolution populations, yet it remains unclear exactly how rearrangements become established eventually fix. Rearrangements could fix by genetic drift if they weakly deleterious or neutral, may instead be favoured positive natural selection. Here, we compare genome assemblies three closely related Brenthis butterfly species characterize complex history fission fusion rearrangements. An inferred demographic these suggests that became fixed in populations with large long-term effective size (N

Language: Английский

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GC Content Across Insect Genomes: Phylogenetic Patterns, Causes and Consequences

Journal of Molecular Evolution, Journal Year: 2024, Volume and Issue: 92(2), P. 138 - 152

Published: March 15, 2024

Abstract The proportions of A:T and G:C nucleotide pairs are often unequal can vary greatly between animal species along chromosomes. causes consequences this variation incompletely understood. recent release high-quality genome sequences from the Darwin Tree Life other large-scale projects provides an opportunity for GC heterogeneity to be compared across a large number insect species. Here we analyse content chromosomes, within protein-coding genes codons, 150 four holometabolous orders: Coleoptera, Diptera, Hymenoptera, Lepidoptera. We find that have higher than average, Lepidoptera generally three orders examined. is in small chromosomes most species, but pattern less consistent orders. also increases towards subtelomeric regions Coleoptera Two Bombylius major B. discolo r, very atypical genomes with ubiquitous increase AT content, especially at third codon positions. Despite dramatic AT-biased usage, no evidence has driven divergent protein evolution. argue landscape Lepidoptera, Diptera influenced by GC-biased gene conversion, strongest some outlier taxa affected drastically counteracting processes.

Language: Английский

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Meiotic drive against chromosome fusions in butterfly hybrids

Chromosome Research, Journal Year: 2024, Volume and Issue: 32(2)

Published: May 4, 2024

Abstract Species frequently differ in the number and structure of chromosomes they harbor, but individuals that are heterozygous for chromosomal rearrangements may suffer from reduced fitness. Chromosomal like fissions fusions can hence serve as a mechanism speciation between incipient lineages, their evolution poses paradox. How get fixed populations if heterozygotes have fitness? One solution is this process predominantly occurs small isolated populations, where genetic drift override natural selection. However, fixation also more likely novel rearrangement favored by transmission bias, such meiotic drive. Here, we investigate distortion hybrids two wood white ( Leptidea sinapis ) butterfly with extensive karyotype differences. Using data different crossing experiments, uncover there bias favoring ancestral state derived fusions, result shows chromosome actually fix despite being counteracted This means drive not only promote runaway speciation, it be conservative force acting against karyotypic change reproductive isolation. Based on our results, suggest mechanistic model why fusion mutations opposed discuss factors contributing to Lepidoptera.

Language: Английский

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Genomic Monitoring of a Reintroduced Butterfly Uncovers Contrasting Founder Lineage Survival

Evolutionary Applications, Journal Year: 2025, Volume and Issue: 18(2)

Published: Feb. 1, 2025

Genetic factors can have a major influence on both short- and long-term success of reintroductions. Genomic monitoring give range insights into the early life reintroduced population ultimately help to avoid wasting limited conservation resources. In this study, we characterise genetic diversity Carterocephalus palaemon (Chequered Skipper butterfly) in England with respect spatial structure source populations south Belgium. We aim evaluate reintroduction, including effectiveness donor sampling strategy, assess vulnerabilities that may affect population's future. also use an isolation-by-distance approach make quantitative inferences about dispersal, explore covariance between host mitochondrial Wolbachia genomes. find that, four generations following initial release, population, founded by 66 wild-caught adults, has effective size c. 33, yet retained similar levels genomic heterozygosity those subpopulations Belgium shows low inbreeding. However, restricted number founders variance reproductive among surviving families resulted higher level kinship, likely result somewhat rates inbreeding Furthermore, there is distinct split two landscapes Belgium, all evidence suggests descended from only one these (called Fagne). discuss potential causes behind results, whether strains are causing incompatibility clades. conclude conservative strategy for any further translocations would prefer Fagne sites as sources because strong their ability survive. our results warrant investigation reasons divergence found

Language: Английский

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Incomplete recombination suppression fuels extensive haplotype diversity in a butterfly colour pattern supergene

PLoS Biology, Journal Year: 2025, Volume and Issue: 23(2), P. e3003043 - e3003043

Published: Feb. 28, 2025

Supergenes can evolve when recombination-suppressing mechanisms like inversions promote co-inheritance of alleles at two or more polymorphic loci that affect a complex trait. Theory shows such genetic architectures be favoured under balancing selection local adaptation in the face gene flow, but they also bring costs associated with reduced opportunities for recombination. These may turn offset by rare ‘gene flux’ between inverted and ancestral haplotypes, range possible outcomes. We aimed to shed light on these processes investigating BC supergene, large genomic region comprising multiple rearrangements three distinct wing colour morphs Danaus chrysippus , butterfly known as African monarch, queen plain tiger. Using whole-genome resequencing data from 174 individuals, we first confirm effects pattern: background melanism is SNPs promoter yellow within an subregion while forewing tip pattern most likely copy-number variation separate supergene. then show haplotype diversity supergene surprisingly extensive: there are least six divergent groups experience suppressed recombination respect each other. Despite high divergence groups, identify unexpectedly number natural recombinant haplotypes. Several inferred crossovers occurred adjacent inversion ‘modules’, others inversions. Furthermore, new have arisen through pre-existing ones. Specifically, allele dark colouration has recombined into backgrounds occasions. Overall, our findings paint picture dynamic evolution fuelled incomplete suppression.

Language: Английский

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Genomic regions of current low hybridisation mark long-term barriers to gene flow in scarce swallowtail butterflies

PLoS Genetics, Journal Year: 2025, Volume and Issue: 21(4), P. e1011655 - e1011655

Published: April 10, 2025

Many closely related species continue to hybridise after millions of generations divergence. However, the extent which current patterning in hybrid zones connects back speciation process remains unclear: does evidence for multilocus barriers support hypothesis due divergence? We analyse whole-genome sequencing data investigate history scarce swallowtails Iphiclidespodalirius and I . feisthamelii , abut at a narrow ( ∼ 25 km) contact zone north Pyrenees. first quantify heterogeneity effective migration rate under model isolation with migration, using genomes sampled across range identify long-term gene flow. Secondly, we recent ancestry individuals from genome polarisation estimate coupling coefficient barrier. infer low flow into podalirius - direction matches admixture complete reproductive ≈ 33 % genome. Our contrast shows that regions hybridisation are indeed enriched maintain divergence between these hybridising sister species. This finding paves way future analysis evolution along continuum.

Language: Английский

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Cytogenetics of insects in the era of chromosome-level genome assemblies

Vavilov Journal of Genetics and Breeding, Journal Year: 2025, Volume and Issue: 29(2), P. 230 - 237

Published: April 10, 2025

Over the past few years, a revolution has occurred in cytogenetics, driven by emergence and spread of methods for obtaining high-quality chromosome-level genome assemblies. In fact, this led to new tool studying chromosomes chromosomal rearrangements, is thousands times more powerful than light microscopy. This revolutionized cytogenetics many groups insects which previously karyotype information, if available at all, was limited chromosome number. Even impressive are achievements genomic approach general patterns organization evolution insects. Thus, it been shown that rapid transformations numbers, often found order Lepidoptera, most carried out parsimonious way, as result simple fusions fissions chromosomes. It established these not random occur independently different phylogenetic lineages due reuse same ancestral breakpoints. tendency correlated with presence so-called interstitial telomeres, i.e. telomere-like structures located ends chromosomes, but inside them. revealed that, insects, telomeric DNA just set short repeats, very long sequence consisting (TTAGG) n (or other motifs), regularly specifically interrupted retrotransposons, motifs diverse terms their length nucleotide composition. The number assemblies GenBank database growing exponentially now exceeds thousand species. Therefore, exceptional prospects using data analysis beyond doubt.

Language: Английский

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Temporal dynamics of faster neo-Z evolution in butterflies

Evolution, Journal Year: 2024, Volume and Issue: 78(9), P. 1554 - 1567

Published: May 30, 2024

The faster-Z/X hypothesis predicts that sex-linked genes should diverge faster than autosomal genes. However, studies across different lineages have shown mixed support for this effect. So far, most analyses focused on old and well-differentiated sex chromosomes, but less is known about the divergence of more recently acquired neo-sex chromosomes. In Lepidoptera (moths butterflies), Z-autosome fusions are frequent, evolutionary dynamics neo-Z chromosomes not been explored in detail. Here, we analyzed faster-Z effect Leptidea sinapis, a butterfly with three Z We show stepwise, resulting strata differentiation masculinization. While all showed evidence effect, selection youngest chromosome (Z3) appears to hampered by largely intact, homologous neo-W chromosome. intermediately aged (Z2), which lacks W gametologs, fewer constraints, particularly fast evolution. Our results therefore can constitute temporary hot-spots adaptation divergence. underlying likely causally linked shifts selective evolution gene expression, degeneration W-linked gametologs gradually expose Z-linked selection.

Language: Английский

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