| 1. |
- Brandão, Andreia, et al.
(författare)
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The CHEK2 Variant C.349A>G Is Associated with Prostate Cancer Risk and Carriers Share a Common Ancestor
- 2020
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Ingår i: Cancers. - : MDPI AG. - 2072-6694. ; 12:11
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Tidskriftsartikel (refereegranskat)abstract
- The identification of recurrent founder variants in cancer predisposing genes may have important implications for implementing cost-effective targeted genetic screening strategies. In this study, we evaluated the prevalence and relative risk of the CHEK2 recurrent variant c.349A>G in a series of 462 Portuguese patients with early-onset and/or familial/hereditary prostate cancer (PrCa), as well as in the large multicentre PRACTICAL case-control study comprising 55,162 prostate cancer cases and 36,147 controls. Additionally, we investigated the potential shared ancestry of the carriers by performing identity-by-descent, haplotype and age estimation analyses using high-density SNP data from 70 variant carriers belonging to 11 different populations included in the PRACTICAL consortium. The CHEK2 missense variant c.349A>G was found significantly associated with an increased risk for PrCa (OR 1.9; 95% CI: 1.1-3.2). A shared haplotype flanking the variant in all carriers was identified, strongly suggesting a common founder of European origin. Additionally, using two independent statistical algorithms, implemented by DMLE+2.3 and ESTIAGE, we were able to estimate the age of the variant between 2300 and 3125 years. By extending the haplotype analysis to 14 additional carrier families, a shared core haplotype was revealed among all carriers matching the conserved region previously identified in the high-density SNP analysis. These findings are consistent with CHEK2 c.349A>G being a founder variant associated with increased PrCa risk, suggesting its potential usefulness for cost-effective targeted genetic screening in PrCa families.
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| 2. |
- Lisa De-Silva, Donna, et al.
(författare)
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North Andean origin and diversification of the largest ithomiine butterfly genus
- 2017
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Ingår i: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 7
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Tidskriftsartikel (refereegranskat)abstract
- The Neotropics harbour the most diverse flora and fauna on Earth. The Andes are a major centre of diversification and source of diversity for adjacent areas in plants and vertebrates, but studies on insects remain scarce, even though they constitute the largest fraction of terrestrial biodiversity. Here, we combine molecular and morphological characters to generate a dated phylogeny of the butterfly genus Pteronymia (Nymphalidae: Danainae), which we use to infer spatial, elevational and temporal diversification patterns. We first propose six taxonomic changes that raise the generic species total to 53, making Pteronymia the most diverse genus of the tribe Ithomiini. Our biogeographic reconstruction shows that Pteronymia originated in the Northern Andes, where it diversified extensively. Some lineages colonized lowlands and adjacent montane areas, but diversification in those areas remained scarce. The recent colonization of lowland areas was reflected by an increase in the rate of evolution of species' elevational ranges towards present. By contrast, speciation rate decelerated with time, with no extinction. The geological history of the Andes and adjacent regions have likely contributed to Pteronymia diversification by providing compartmentalized habitats and an array of biotic and abiotic conditions, and by limiting dispersal between some areas while promoting interchange across others.
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| 3. |
- Chazot, Nicolas, et al.
(författare)
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Conserved ancestral tropical niche but different continental histories explain the latitudinal diversity gradient in brush-footed butterflies
- 2021
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Ingår i: Nature Communications. - : Springer Science and Business Media LLC. - 2041-1723. ; 12:1
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Tidskriftsartikel (refereegranskat)abstract
- The global increase in species richness toward the tropics across continents and taxonomic groups, referred to as the latitudinal diversity gradient, stimulated the formulation of many hypotheses to explain the underlying mechanisms of this pattern. We evaluate several of these hypotheses to explain spatial diversity patterns in a butterfly family, the Nymphalidae, by assessing the contributions of speciation, extinction, and dispersal, and also the extent to which these processes differ among regions at the same latitude. We generate a time-calibrated phylogeny containing 2,866 nymphalid species (~45% of extant diversity). Neither speciation nor extinction rate variations consistently explain the latitudinal diversity gradient among regions because temporal diversification dynamics differ greatly across longitude. The Neotropical diversity results from low extinction rates, not high speciation rates, and biotic interchanges with other regions are rare. Southeast Asia is also characterized by a low speciation rate but, unlike the Neotropics, is the main source of dispersal events through time. Our results suggest that global climate change throughout the Cenozoic, combined with tropical niche conservatism, played a major role in generating the modern latitudinal diversity gradient of nymphalid butterflies.
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| 4. |
- Moraes, Simeão de Souza, et al.
(författare)
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A double-edged sword : Unrecognized cryptic diversity and taxonomic impediment in Eois (Lepidoptera, Geometridae)
- 2021
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Ingår i: Zoologica Scripta. - : Wiley. - 0300-3256 .- 1463-6409. ; 50:5, s. 633-646
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Tidskriftsartikel (refereegranskat)abstract
- The genus Eois Hübner (Geometridae: Larentiinae) comprises 254 valid species. Being a hyperdiverse genus, Eois potentially includes many undescribed cryptic species and embodies a problematic taxonomic scenario. The actual diversity of Eois is greatly underestimated and the Neotropical fauna needs to be well known since it figures as one of the most threatened terrestrial ecosystem. In the present study, we compare three species delimitation methods to highlight the hidden diversity within a subset of Eois species: Automatic Barcode Gap Discovery, Bayesian Poisson Tree Processes and Multi-Rate Poisson Tree Processes. Our results point to an increase up to 176% in the currently valid species number. The hypothesis of cryptic diversity is corroborated by morphological characters within some species complexes. For complexes comprising species of Brazilian fauna, we provide a preliminary taxonomic assessment. Additionally, we found no congruence among the three delimitation methods for some species complexes, which indicates the importance of species and locality sampling as well as the previous alpha taxonomic knowledge in avoiding result bias. In this sense, we tried to standardize the identification provided for the Genbank sequences used in most relevant publications for Eois, in order to minimize biases and maximize the replicability of analyses in future studies. Moreover, we stress the importance of an integrative taxonomic approach for cryptic species discovery approach by employing both morphological attributes and life history to corroborate molecular analysis.
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| 5. |
- Garzón-Orduña, Ivonne J., et al.
(författare)
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Wing pattern diversity in Eunica butterflies (Nymphalidae: Biblidinae) : phylogenetic analysis implies decoupled adaptive trends in dorsal sexual dimorphism and ventral eyespot evolution
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Ingår i: Cladistics. - 0748-3007.
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Tidskriftsartikel (refereegranskat)abstract
- Butterfly eyespots are wing patterns reminiscent of vertebrate eyes, formed by concentric rings of contrastingly coloured scales. Eyespots are usually located close to the wing margin and often regarded as the single most conspicuous pattern element of butterfly wing colour displays. Recent efforts to understand the processes involved in the formation of eyespots have been driven mainly by evo-devo approaches focused on model species. However, patterns of change implied by phylogenetic relationships can also inform hypotheses about the underlying developmental mechanisms associated with the formation or disappearance of eyespots, and the limits of phenotypic diversity occurring in nature. Here we present a combined evidence phylogenetic hypothesis for the genus Eunica, a prominent member of diverse Neotropical butterfly communities, that features notable variation among species in eyespot patterns on the ventral hind wing surface. The data matrix consists of one mitochondrial gene region (COI), four nuclear gene regions (GAPDH, RPS5, EF1a and Wingless) and 68 morphological characters. A combined cladistic analysis with all the characters concatenated produced a single most parsimonious tree that, although fully resolved, includes many nodes with modest branch support. The phylogenetic hypothesis presented corroborates a previously proposed morphological trend leading to the loss of eyespots, together with an increase in the size of the conserved eyespots, relative to outgroup taxa. Furthermore, wing colour pattern dimorphism and the presence of androconia suggest that the most remarkable instances of sexual dimorphism are present in the species of Eunica with the most derived eyespot patterns, and are in most cases accompanied by autapomorphic combinations of scent scales and “hair pencils”. We discuss natural and sexual selection as potential adaptive explanations for dorsal and ventral wing patterns.
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| 6. |
- Rosser, Neil, et al.
(författare)
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Hybrid speciation driven by multilocus introgression of ecological traits
- 2024
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Ingår i: Nature. - 0028-0836. ; 628, s. 811-817
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Tidskriftsartikel (refereegranskat)abstract
- Hybridization allows adaptations to be shared among lineages and may trigger the evolution of new species1,2. However, convincing examples of homoploid hybrid speciation remain rare because it is challenging to demonstrate that hybridization was crucial in generating reproductive isolation3. Here we combine population genomic analysis with quantitative trait locus mapping of species-specific traits to examine a case of hybrid speciation in Heliconius butterflies. We show that Heliconius elevatus is a hybrid species that is sympatric with both parents and has persisted as an independently evolving lineage for at least 180,000 years. This is despite pervasive and ongoing gene flow with one parent, Heliconius pardalinus, which homogenizes 99% of their genomes. The remaining 1% introgressed from the other parent, Heliconius melpomene, and is scattered widely across the H. elevatus genome in islands of divergence from H. pardalinus. These islands contain multiple traits that are under disruptive selection, including colour pattern, wing shape, host plant preference, sex pheromones and mate choice. Collectively, these traits place H. elevatus on its own adaptive peak and permit coexistence with both parents. Our results show that speciation was driven by introgression of ecological traits, and that speciation with gene flow is possible with a multilocus genetic architecture.
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