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1.
Nat Commun ; 12(1): 1019, 2021 02 15.
Artigo em Inglês | MEDLINE | ID: mdl-33589637

RESUMO

Genome-wide variation in introgression rates across hybrid zones offers a powerful opportunity for studying population differentiation. One poorly understood pattern of introgression is the geographic displacement of a trait implicated in lineage divergence from genome-wide population boundaries. While difficult to interpret, this pattern can facilitate the dissection of trait genetic architecture because traits become uncoupled from their ancestral genomic background. We studied an example of trait displacement generated by the introgression of head plumage coloration from personata to alba subspecies of the white wagtail. A previous study of their hybrid zone in Siberia revealed that the geographic transition in this sexual signal that mediates assortative mating was offset from other traits and genetic markers. Here we show that head plumage is associated with two small genetic regions. Despite having a simple genetic architecture, head plumage inheritance is consistent with partial dominance and epistasis, which could contribute to its asymmetric introgression.


Assuntos
Introgressão Genética , Genoma , Passeriformes/genética , Pigmentação/genética , Característica Quantitativa Herdável , Animais , Quimera , Cor , Epistasia Genética , Plumas/anatomia & histologia , Plumas/metabolismo , Feminino , Masculino , Passeriformes/anatomia & histologia , Passeriformes/classificação , Sibéria , Uzbequistão
2.
Nat Commun ; 12(1): 246, 2021 01 11.
Artigo em Inglês | MEDLINE | ID: mdl-33431812

RESUMO

Previous Mendelian randomization (MR) studies on 25-hydroxyvitamin D (25(OH)D) and cancer have typically adopted a handful of variants and found no relationship between 25(OH)D and cancer; however, issues of horizontal pleiotropy cannot be reliably addressed. Using a larger set of variants associated with 25(OH)D (74 SNPs, up from 6 previously), we perform a unified MR analysis to re-evaluate the relationship between 25(OH)D and ten cancers. Our findings are broadly consistent with previous MR studies indicating no relationship, apart from ovarian cancers (OR 0.89; 95% C.I: 0.82 to 0.96 per 1 SD change in 25(OH)D concentration) and basal cell carcinoma (OR 1.16; 95% C.I.: 1.04 to 1.28). However, after adjustment for pigmentation related variables in a multivariable MR framework, the BCC findings were attenuated. Here we report that lower 25(OH)D is unlikely to be a causal risk factor for most cancers, with our study providing more precise confidence intervals than previously possible.


Assuntos
Predisposição Genética para Doença , Análise da Randomização Mendeliana , Neoplasias/genética , Vitamina D/metabolismo , Estudos de Casos e Controles , Criança , Humanos , Análise Multivariada , Pigmentação/genética , Fatores de Risco , Queimadura Solar/genética
3.
Gene ; 767: 145180, 2021 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-33002572

RESUMO

As an important plant single cell model and textile application materials, poorly known about fiber color formation in cotton, which is sensitively regulated by environmental signals. Our studies underline the importance of photo signal on sensitive fiber color formation and characterize fiber color early initiation (15 DPA) and late accumulated metabolites (45 DPA) in different lighting condition. The results revealed 236 differential metabolites between control and shading, of which phenylpropanoids metabolites accounted for 20%, including uncharacterized novel metabolites and pathways. Furthermore, the early initiation specific genes respond to the absence of light are highly correlated with phenylpropanoid metabolites related to pigmentation. The current study reveals the complex pathways involving early initiation regulation and late metabolic pathways. In addition, the collection composed of uncharacterized photoinduced metabolites and early initiation signaling/regulatory genes were identified, which are important resources for understanding fiber color formation. This report provides new insight into molecular regulatory and biochemical basis underlying photoinduced fiber color formation in cotton.


Assuntos
Gossypium/genética , Gossypium/metabolismo , Pigmentos Biológicos/metabolismo , Fibra de Algodão/análise , Perfilação da Expressão Gênica/métodos , Regulação da Expressão Gênica de Plantas/genética , Genes de Plantas/genética , Redes e Vias Metabólicas/genética , Metaboloma , Pigmentação/genética , Pigmentos Biológicos/genética , Reguladores de Crescimento de Planta/genética , Transdução de Sinais/genética , Transcriptoma
4.
PLoS One ; 15(9): e0230651, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32886662

RESUMO

The births of domestic dogs with pigment deletion and associated congenital hearing and/or vision impairments are increasing, as a result of mutations of certain genes expressing popular coat colour patterns (Merle, piebald, Irish spotting). The future of these dogs is often pessimistic (early euthanasia or placement in rescues/fosters, lack of interactions and activities for adults). These pessimistic scenarios result from popular assumptions predicting that dogs with congenital hearing/vision impairments exhibit severe Merle-related health troubles (cardiac, skeletal, neurological), impairment-related behavioural troubles (aggressiveness, anxiety), and poor capacities to communicate, to be trained, and to be engaged in leisure or work activities. However, there is no direct scientific testing, and hence no evidence or refutation, of these assumptions. We therefore addressed an online questionnaire to owners of 223 congenitally sensory impaired (23 vision impaired, 63 hearing impaired, 137 hearing and vision impaired) and 217 sensory normal dogs from various countries. The sensory normal cohort was matched in age, lifetime with owner, breed and sex with the sensory impaired cohort, and was used as a baseline. The questionnaire assessed demographics, morphology, sensory impairments, health and behavioural troubles, activities, and dog-owner communication. Most hearing and/or vision impaired dogs exhibited abnormal pigment deletion in their coat and irises. Vision impaired dogs additionally exhibited ophthalmic abnormalities typically related to Merle. The results are opposed to all above-listed assumptions, except for neurological troubles, which were more frequently reported in sensory impaired dogs. However, we suggest that this finding could be partially accounted for by a lack of diagnosis of breed-related drug sensitivity and impairment-related compulsive behaviours. Results about communication and activities are particularly optimistic. The need for future studies of numerous dogs from various breeds tested for Merle, piebald and medical-drug-resistance genes, and the beneficial effects that present and future research may have on the future of sensory impaired dogs, are discussed.


Assuntos
Comportamento Animal/fisiologia , Cegueira/veterinária , Doenças do Cão/fisiopatologia , Perda Auditiva/veterinária , Animais de Estimação/anormalidades , Animais , Cegueira/congênito , Cegueira/fisiopatologia , Cegueira/psicologia , Cruzamento , Comunicação , Doenças do Cão/congênito , Doenças do Cão/psicologia , Cães , Feminino , Perda Auditiva/congênito , Perda Auditiva/fisiopatologia , Perda Auditiva/psicologia , Humanos , Masculino , Animais de Estimação/fisiologia , Animais de Estimação/psicologia , Pigmentação/genética , Inquéritos e Questionários/estatística & dados numéricos
5.
Proc Biol Sci ; 287(1931): 20201267, 2020 07 29.
Artigo em Inglês | MEDLINE | ID: mdl-32693728

RESUMO

Müllerian mimicry strongly exemplifies the power of natural selection. However, the exact measure of such adaptive phenotypic convergence and the possible causes of its imperfection often remain unidentified. Here, we first quantify wing colour pattern differences in the forewing region of 14 co-mimetic colour pattern morphs of the butterfly species Heliconius erato and Heliconius melpomene and measure the extent to which mimicking colour pattern morphs are not perfectly identical. Next, using gene-editing CRISPR/Cas9 KO experiments of the gene WntA, which has been mapped to colour pattern diversity in these butterflies, we explore the exact areas of the wings in which WntA affects colour pattern formation differently in H. erato and H. melpomene. We find that, while the relative size of the forewing pattern is generally nearly identical between co-mimics, the CRISPR/Cas9 KO results highlight divergent boundaries in the wing that prevent the co-mimics from achieving perfect mimicry. We suggest that this mismatch may be explained by divergence in the gene regulatory network that defines wing colour patterning in both species, thus constraining morphological evolution even between closely related species.


Assuntos
Mimetismo Biológico , Borboletas/fisiologia , Animais , Borboletas/genética , Borboletas/crescimento & desenvolvimento , Genes de Insetos , Pigmentação/genética , Seleção Genética , Asas de Animais
6.
Mol Genet Genomics ; 295(6): 1393-1400, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32651630

RESUMO

Anthocyanins are a group of important secondary metabolites, functioning as colorant in plant organs as well as protective agents against several stresses. Sub-red plant (Rs) cottons, accumulating moderate level of anthocyanins in shoots, had increased photosynthesis efficiency compared to green- (GL) and red-plant (R1) cottons. The present work aimed to clarify the molecular base of anthocyanin regulation in Rs cotton. It was found that GhPAP1A was significantly up-regulated in Rs plants compared to GL cottons, but its expression level is lower than that of GhPAP1D in R1 plants. Virus induced gene silencing of GhPAP1s inhibited the red pigmentation in Rs plants. Comparative cloning revealed a 50-bp tandem repeat in the promoter of GhPAP1A in Rs cotton, which showed stronger activity to drive the expression of downstream genes in petals. Considered that the coding sequence of GhPAP1As from Rs and GL cottons had similar functions to promote anthocyanin biosynthesis in transgenic tobaccos, we attributed moderate anthocyanin accumulation in Rs cotton to increased transcription of GhPAP1A, resulted from varied promoter structure. Our works suggested GhPAP1s as useful tool to manipulate anthocyanin level and several breeding targets, including herbivore- and pathogen- resistance, high photosynthesis efficiency and colored fibers.


Assuntos
Antocianinas/biossíntese , Regulação da Expressão Gênica de Plantas , Gossypium/metabolismo , Pigmentação/genética , Folhas de Planta/metabolismo , Proteínas de Plantas/metabolismo , Gossypium/genética , Gossypium/crescimento & desenvolvimento , Folhas de Planta/genética , Folhas de Planta/crescimento & desenvolvimento , Proteínas de Plantas/genética
7.
Arch Insect Biochem Physiol ; 105(2): e21728, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32710467

RESUMO

Re-nd, which was induced from the wild-type C108 by the chemical mutagen N-methane-N-methylnitrourea, is a nondiapause red-egg mutant of silkworm Bombyx mori. The special significance of the Re-nd mutant is that it is an independent dominant mutant. The aim of this study was to establish the type of pigment responsible for the red coloration in the Re-nd mutant eggs in silkworm. We compared the eggs of Re-nd mutants with those of the other B. mori egg color strains and confirmed that the Re-nd mutant is the only strain with red color and red pigment granules in nondiapause, showing this mutant belongs to the pigmentation in the serosa. We speculated that the red substance, which contributed to the bright red pigmentation for nondiapause eggs of the Re-nd mutant, could potentially be a novel pigment according to its solubility, optimum absorption peak, and oxidation-reduction reaction. Moreover, we have successfully constituted the system for enrichment, extraction, and purification of the red substance responsible for the Re-nd mutant, providing a new method for the separation and purification of other known and unknown pigments or substances.


Assuntos
Bombyx/química , Óvulo/química , Pigmentos Biológicos/química , Animais , Bombyx/genética , Cromatografia Líquida de Alta Pressão/métodos , Extração Líquido-Líquido/métodos , Mutação , Pigmentação/genética
8.
BMC Evol Biol ; 20(1): 63, 2020 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-32487064

RESUMO

BACKGROUND: Local coexistence of distinct, genetically determined color morphs can be unstable and transitional. Stable, long-term coexistence requires some form of balancing selection to protect morphs from getting lost by directional selection or genetic drift. However, not all phenotypic polymorphism need to have a genetic basis. We here report on the genetic basis of two color polymorphisms in the club-legged grasshopper Gomphocerus sibiricus: a green-brown polymorphism that is phylogenetically and geographically widespread among orthopteran insects and a pied-brown pattern polymorphism that is shared among many gomphocerine grasshoppers. RESULTS: We found a remarkably clear outcome of matings within and between morph that suggest not only that the green-brown polymorphism is heritable in this species, but that results can be most parsimoniously explained by a single autosomal locus with two alleles in which the green allele is dominant over the brown allele. A few individuals did not match this pattern and suggest the existence of genetic modifiers and/or developmental phenocopies. We also show that the pied-brown polymorphism is highly heritable, although the evidence for the involvement of one or more loci is less clear-cut. CONCLUSIONS: Overall, our data demonstrate that the two polymorphisms are heritable in the club-legged grasshopper and appear genetically simple, at least with respect to green morphs. The results are consistent with the idea that the synthesis or transport of a pigment involved in the production of green coloration (likely biliverdin) is lost by homozygosity for loss-of-function alleles in brown individuals. The apparently simple genetic architecture of the green-brown polymorphism offer potential for studying balancing selection in the field and for genetic mapping in this species.


Assuntos
Gafanhotos/genética , Pigmentação/genética , Polimorfismo Genético , Alelos , Animais , Fenótipo
9.
Science ; 368(6496): 1270-1274, 2020 06 12.
Artigo em Inglês | MEDLINE | ID: mdl-32527835

RESUMO

Sexual dichromatism, a difference in coloration between males and females, may be due to sexual selection for ornamentation and mate choice. Here, we show that carotenoid-based dichromatism in mosaic canaries, a hybrid phenotype that arises in offspring of the sexually dichromatic red siskin and monochromatic canaries, is controlled by the gene that encodes the carotenoid-cleaving enzyme ß-carotene oxygenase 2 (BCO2). Dichromatism in mosaic canaries is explained by differential carotenoid degradation in the integument, rather than sex-specific variation in physiological functions such as pigment uptake or transport. Transcriptome analyses suggest that carotenoid degradation in the integument might be a common mechanism contributing to sexual dichromatism across finches. These results suggest that differences in ornamental coloration between sexes can evolve through simple molecular mechanisms controlled by genes of major effect.


Assuntos
Canários/fisiologia , Carotenoides/metabolismo , Dioxigenases/genética , Tentilhões/fisiologia , Pigmentação/genética , Caracteres Sexuais , Animais , Evolução Biológica , Canários/anatomia & histologia , Canários/genética , Feminino , Tentilhões/anatomia & histologia , Tentilhões/genética , Masculino , Fatores Sexuais , Transcriptoma
10.
Nat Commun ; 11(1): 2456, 2020 05 15.
Artigo em Inglês | MEDLINE | ID: mdl-32415123

RESUMO

Anthocyanin pigments furnish a powerful visual output of the stress and metabolic status of Arabidopsis thaliana plants. Essential for pigment accumulation is TRANSPARENT TESTA19 (TT19), a glutathione S-transferase proposed to bind and stabilize anthocyanins, participating in their vacuolar sequestration, a function conserved across the flowering plants. Here, we report the identification of genetic suppressors that result in anthocyanin accumulation in the absence of TT19. We show that mutations in RDR6, SGS3, or DCL4 suppress the anthocyanin defect of tt19 by pushing carbon towards flavonoid biosynthesis. This effect is not unique to tt19 and extends to at least one other anthocyanin pathway gene mutant. This synergy between mutations in components of the RDR6-SGS3-DCL4 siRNA system and the flavonoid pathway reveals genetic/epigenetic mechanisms regulating metabolic fluxes.


Assuntos
Antocianinas/metabolismo , Proteínas de Arabidopsis/metabolismo , Arabidopsis/metabolismo , Carbono/metabolismo , RNA Interferente Pequeno/metabolismo , Ribonuclease III/metabolismo , Arabidopsis/genética , Proteínas de Arabidopsis/genética , Sequência de Bases , Regulação da Expressão Gênica de Plantas , Genes Supressores , Genótipo , Glutationa Transferase/genética , Mutação/genética , Fenótipo , Pigmentação/genética , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Plântula/crescimento & desenvolvimento , Açúcares/metabolismo
11.
Proc Natl Acad Sci U S A ; 117(21): 11589-11596, 2020 05 26.
Artigo em Inglês | MEDLINE | ID: mdl-32393634

RESUMO

Organisms have evolved endless morphological, physiological, and behavioral novel traits during the course of evolution. Novel traits were proposed to evolve mainly by orchestration of preexisting genes. Over the past two decades, biologists have shown that cooption of gene regulatory networks (GRNs) indeed underlies numerous evolutionary novelties. However, very little is known about the actual GRN properties that allow such redeployment. Here we have investigated the generation and evolution of the complex wing pattern of the fly Samoaia leonensis We show that the transcription factor Engrailed is recruited independently from the other players of the anterior-posterior specification network to generate a new wing pattern. We argue that partial cooption is made possible because 1) the anterior-posterior specification GRN is flexible over time in the developing wing and 2) this flexibility results from the fact that every single gene of the GRN possesses its own functional time window. We propose that the temporal flexibility of a GRN is a general prerequisite for its possible cooption during the course of evolution.


Assuntos
Drosophilidae , Regulação da Expressão Gênica no Desenvolvimento/genética , Redes Reguladoras de Genes/genética , Pigmentação/genética , Asas de Animais , Animais , Padronização Corporal/genética , Drosophilidae/genética , Drosophilidae/crescimento & desenvolvimento , Proteínas de Insetos/genética , Fatores de Transcrição/genética , Asas de Animais/anatomia & histologia , Asas de Animais/crescimento & desenvolvimento , Asas de Animais/fisiologia
12.
PLoS Genet ; 16(5): e1008274, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-32433666

RESUMO

Rock pigeons (Columba livia) display an extraordinary array of pigment pattern variation. One such pattern, Almond, is characterized by a variegated patchwork of plumage colors that are distributed in an apparently random manner. Almond is a sex-linked, semi-dominant trait controlled by the classical Stipper (St) locus. Heterozygous males (ZStZ+ sex chromosomes) and hemizygous Almond females (ZStW) are favored by breeders for their attractive plumage. In contrast, homozygous Almond males (ZStZSt) develop severe eye defects and often lack plumage pigmentation, suggesting that higher dosage of the mutant allele is deleterious. To determine the molecular basis of Almond, we compared the genomes of Almond pigeons to non-Almond pigeons and identified a candidate St locus on the Z chromosome. We found a copy number variant (CNV) within the differentiated region that captures complete or partial coding sequences of four genes, including the melanosome maturation gene Mlana. We did not find fixed coding changes in genes within the CNV, but all genes are misexpressed in regenerating feather bud collar cells of Almond birds. Notably, six other alleles at the St locus are associated with depigmentation phenotypes, and all exhibit expansion of the same CNV. Structural variation at St is linked to diversity in plumage pigmentation and gene expression, and thus provides a potential mode of rapid phenotypic evolution in pigeons.


Assuntos
Columbidae/genética , Variações do Número de Cópias de DNA/fisiologia , Plumas/metabolismo , Pigmentação/genética , Alelos , Animais , Cor , Columbidae/metabolismo , Feminino , Estudos de Associação Genética/veterinária , Loci Gênicos , Genética Populacional , Heterozigoto , Masculino , Fenótipo , Polimorfismo de Nucleotídeo Único
13.
Gene ; 752: 144788, 2020 Aug 20.
Artigo em Inglês | MEDLINE | ID: mdl-32439375

RESUMO

Primulina genus is an ideal wild ornamental flower and emerging model for studying biosynthesis, diversity, and evolution of flower pigment. However, the molecular mechanism underlying anthocyanin biosynthesis and regulation in Primulina remains unknown. Here, changes in anthocyanin content and the expression profiles of anthocyanin biosynthetic structural genes were examined in developing Primulina swinglei flowers and three other organs. Seventy-three R2R3-MYB transcription factor genes were identified from transcriptome of P. swinglei flowers, two of which, PsMYB1 and PsMYB2, are candidate regulators of anthocyanin biosynthesis according to clustering analysis. Furthermore, transient over-expression studies using tobacco leaves showed distinct pigment accumulation following co-infection with PsMYB1 and MrbHLH1 (a previously confirmed anthocyanin regulator from Morella rubra). Additionally, dual luciferase assays showed that PsMYB1 trans-activated the PsANS promoter, with the addition of MrbHLH1 resulting in a 5-fold increase in the intensity of this interaction. PsMYB1 did not, however, have any effect on the PsF3H promoter. The expression profile and dual luciferase assays showed that PsMYB2 plays no roles in anthocyanin regulation. Therefore, PsMYB1 is proposed to be the transcription factor gene regulating anthocyanin biosynthesis in P. swinglei.


Assuntos
Antocianinas/biossíntese , Antocianinas/genética , Fatores de Transcrição/genética , Sequência de Aminoácidos/genética , Antocianinas/metabolismo , Proteínas de Arabidopsis/metabolismo , Flores/genética , Perfilação da Expressão Gênica/métodos , Regulação da Expressão Gênica de Plantas/genética , Genes de Plantas/genética , Lamiales/genética , Magnoliopsida/genética , Pigmentação/genética , Proteínas de Plantas/genética , Plantas Geneticamente Modificadas/genética , Tabaco/genética , Transativadores/genética , Fatores de Transcrição/metabolismo , Transcriptoma/genética
14.
Anim Genet ; 51(4): 631-633, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32452546

RESUMO

In dogs and cats, unusual coat colour phenotypes may result from various phenomena, including chimerism. In the domestic cat, the tortoiseshell coat colour that combines red and non-red hairs is the most obvious way to identify chimeras in males. Several cases of tortoiseshell males have been reported, some of which were diagnosed as chimeras without any molecular confirmation. Here, we report the case of a female feline chimera identified thanks to its coat colour and confirmed through DNA profiling and a coat colour test. We ruled out the hypothesis of mosaicism and aneuploidy. All the data were consistent with a natural case of female chimerism.


Assuntos
Gatos/genética , Quimerismo/veterinária , Cabelo/fisiologia , Animais , Cor , Impressões Digitais de DNA/veterinária , Feminino , Pigmentação/genética
15.
Nat Rev Genet ; 21(8): 461-475, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32382123

RESUMO

Coloration is an easily quantifiable visual trait that has proven to be a highly tractable system for genetic analysis and for studying adaptive evolution. The application of genomic approaches to evolutionary studies of coloration is providing new insight into the genetic architectures underlying colour traits, including the importance of large-effect mutations and supergenes, the role of development in shaping genetic variation and the origins of adaptive variation, which often involves adaptive introgression. Improved knowledge of the genetic basis of traits can facilitate field studies of natural selection and sexual selection, making it possible for strong selection and its influence on the genome to be demonstrated in wild populations.


Assuntos
Adaptação Biológica , Evolução Biológica , Genoma , Genômica , Pigmentação/genética , Característica Quantitativa Herdável , Animais , Variação Genética , Genômica/métodos , Herança Multifatorial , Mutação , Fenótipo , Pigmentos Biológicos/genética , Locos de Características Quantitativas , Seleção Genética
16.
Sheng Wu Gong Cheng Xue Bao ; 36(4): 678-692, 2020 Apr 25.
Artigo em Chinês | MEDLINE | ID: mdl-32347062

RESUMO

As water-soluble, natural pigments, anthocyanins are responsible for the red, purple and blue colors of many flowers, which attract pollinators to spread pollen. The colors of flowers are also essential for plants to survive in the nature and become one of the most significant characteristics of ornamental plants. In the booming floriculture industry, to produce various flower colors could increase the richness of natural colors, but it is still difficult to breed flowers with coveted blue color. The diversity of flower color is mainly determined by the types and contents of anthocyanins and their derivatives. The synthesis of delphinidin pigments is the key factor for breeding blue flowers. However, there are no structural genes in many plants to biosynthesize delphinidin pigments. Blue flowers are successfully created by genetic engineering in recent years. In this paper, using common ornamental plants as examples, we review the mechanism of plant flower coloration from the aspects of the key factors affecting the synthesis of delphinidin pigment and the production strategies of blue flowers based on the regulation of anthocyanin metabolism. Different strategies of molecular breeding could provide opportunities to improve colors of other floriculture plants and to develop anthocyanin-rich economic crops, such as colored cotton with blue fibers.


Assuntos
Antocianinas , Flores , Pigmentação , Antocianinas/metabolismo , Regulação da Expressão Gênica de Plantas , Engenharia Genética , Pigmentação/genética
17.
Nat Genet ; 52(5): 494-504, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-32341527

RESUMO

Most genetic susceptibility to cutaneous melanoma remains to be discovered. Meta-analysis genome-wide association study (GWAS) of 36,760 cases of melanoma (67% newly genotyped) and 375,188 controls identified 54 significant (P < 5 × 10-8) loci with 68 independent single nucleotide polymorphisms. Analysis of risk estimates across geographical regions and host factors suggests the acral melanoma subtype is uniquely unrelated to pigmentation. Combining this meta-analysis with GWAS of nevus count and hair color, and transcriptome association approaches, uncovered 31 potential secondary loci for a total of 85 cutaneous melanoma susceptibility loci. These findings provide insights into cutaneous melanoma genetic architecture, reinforcing the importance of nevogenesis, pigmentation and telomere maintenance, together with identifying potential new pathways for cutaneous melanoma pathogenesis.


Assuntos
Predisposição Genética para Doença/genética , Melanoma/genética , Neoplasias Cutâneas/genética , Feminino , Loci Gênicos/genética , Estudo de Associação Genômica Ampla/métodos , Genótipo , Humanos , Masculino , Fenótipo , Pigmentação/genética , Polimorfismo de Nucleotídeo Único/genética
18.
Mol Phylogenet Evol ; 149: 106844, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32325194

RESUMO

Several centers of endemism have been proposed for Melastomataceae, particularly in Amazonia and Atlantic Forest. Despite the high degree of human-caused degradation in the last 500 years, the Atlantic Forest still presents some of the largest levels of diversity and endemism across all angiosperms. With several recently described species in the last decade, the knowledge on Bertolonia's distribution and morphological characterization has changed, with most new species found in northern Atlantic Forest and with different flower color patterns than the species from southern Atlantic Forest. We first tested the monophyly of the genus sampling over 85% of its species to generate a reliable phylogenetic hypothesis. Afterwards, we used Bertolonia as a model group to study distribution patterns and morphological evolution of lineages in the Atlantic Forest. Bertolonia is particularly interesting to address such questions because it is endemic to this domain, with species distributed either in the southern, central or northern portions of the Atlantic Forest. The second step of our work aimed to respond (1) Do closely related species endemic to Atlantic Forest tend to have similar distributions and share similar morphological traits? and (2) Are floral traits more conserved within clades than vegetative characters? We hypothesize that both (1) and (2) are true due to the low dispersal ability and consequent microendemic distribution of most species in the genus. Our results confirm the veracity of the proposed hypotheses. Three major groups were recovered in our analysis: marmorata, formosa and nymphaeifolia clades. Most species that occur in northern Atlantic Forest were recovered in the marmorata clade. Most species distributed in central Atlantic Forest were recovered in the formosa clade, and the ones from the southern Atlantic Forest in the nymphaeifolia clade. A similar pattern was recovered with reproductive characters reconstructed across the phylogeny. Generally, species with pink petals and cream-colored anthers with an extrorse pore occur in northern Atlantic Forest, and species with white petals and yellow anthers with an introrse or apical pore tend to occur in southern Atlantic Forest. Some vegetative characters also have evolutionary congruence and are restricted to one or few lineages, while other characters, such as the texture of the leaf blade surface, have a strong taxonomic value and are useful to identify species, but are not homologous. Our analysis also indicates that the division between southern and northern Atlantic Forest could also be related to ancient events, not only linked with recent phylogeographic patterns. Moreover, we suggest that the orientation of the anther pore in Bertolonia could be related with diversity of species and stability of its populations. In summary, we corroborate, based on the evolutionary history of Bertolonia, that closely related species endemic to Atlantic Forest tend to have similar distributions and share similar morphological floral traits.


Assuntos
Flores/anatomia & histologia , Florestas , Melastomataceae/anatomia & histologia , Melastomataceae/classificação , Filogenia , Teorema de Bayes , Biodiversidade , Brasil , Fenótipo , Filogeografia , Pigmentação/genética
19.
PLoS One ; 15(4): e0231263, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32282839

RESUMO

A common evolutionary trend in highly selfing plants is the evolution of the "selfing syndrome", in which traits associated with pollinator attraction are lost or greatly reduced. Limited information is available on whether these trait reductions are favored by natural selection or result from reduced purifying selection coupled with genetic drift. This study attempted to distinguish between these two possibilities for the evolutionary loss of floral pigmentation in the highly selfing species Ipomoea lacunosa. This study also tested the hypothesis that loss of floral pigmentation is caused by downregulation or loss of function in a tissue-specific anthocyanin transcription factor, as has been found in other plants. F2 individuals of a cross between white and pigmented individuals revealed segregation at two epistatically acting loci: one affecting pigmentation in both corolla throat and limbs (Anl1) and one affecting limb pigmentation (Anl2). Individuals that are homozygous for the "white" allele at Anl1 have white throats and limbs regardless of genotype at Anl2. In individuals with pigmented throats, homozygosity of the "white" allele at Anl2 produces white limbs. Flower color variation at Anl1 cosegregates with an R2R3-Myb anthocyanin transcription factor, which is down-regulated in white-flowers but not in pigmented flowers. Differential expression of the two alleles of this gene indicates that down regulation is caused by a cis-regulatory change. Finally, allele-frequency differences at Anl1 were substantially and significantly greater than differences in allele frequencies at four microsatellite loci. These results are consistent with the hypotheses that the identified R2R3-Myb gene corresponds to Anl1 and that evolutionary loss of pigmentation in I. lacunosa was caused by selection. They are also consistent with previous studies demonstrating that loss of floral pigmentation is usually caused by down-regulation or functional inactivation of an R2R3-Myb gene.


Assuntos
Antocianinas/genética , Flores/genética , Genes de Plantas/genética , Ipomoea/genética , Pigmentação/genética , Seleção Genética , Evolução Biológica , Regulação da Expressão Gênica de Plantas , Proteínas de Plantas/genética , Fatores de Transcrição
20.
Res Vet Sci ; 131: 117-130, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32334156

RESUMO

First references of the endangered autochthonous Majorcan Ca Mè dog date from the 13th century and enhance its skills and adaptability to the orography. Genealogical historical records were traced back to founders. Founder number in the reference population (397), maximum generations traced, and average number of complete generations were 32, 5, and 2.75, respectively. Structure assessment revealed the existence of subpopulations regarding criteria such as owners (402), breeders (55), coat colours (liver, lemon, black and orange) and spotting patterns (piebald, roan, solid colour, tie or star presence). Average inbreeding (F) within colour groups ranged from 6.3-10.4%, for orange and black populations, respectively. F ranged from 9.43-12.22% for roan patterns and star presence, respectively. Tan point markings showed an F coefficient of 5.85%. The study of genetic diversity revealed a slightly different genetic background between subpopulations. Average coancestry between and within coat colours suggested orange and roan traits could be ascribed to the original nuclei, without omitting the high relationships among other subpopulations. Breeding strategy should select breeding pairs holding a relatedness coefficient below 15%. Hence, coat patterns in dog breeds can help preserving the genetic diversity in endangered dogs, even when these are geographically isolated.


Assuntos
Cruzamento , Cães/genética , Variação Genética , Pigmentação/genética , Animais , Cruzamento/métodos , Cães/anatomia & histologia , Patrimônio Genético , Endogamia , Linhagem , Fenótipo
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