RESUMO
How does sexual selection impact introgression dynamics across a hybrid zone? Long et al. (2024) used historical (1989-1994) and contemporary (2017-2020) samples to quantify the stability of a Panamanian hybrid zone between golden-collared manakins (Manacus vitellinus) and white-collared manakins (M. candei). Their analyses revealed a spatially stable hybrid zone, except for one trait, belly plumage coloration, which has introgressed into the distribution of the white-collared manakin. This finding suggests possible sexual selection for this trait.
Assuntos
Hibridização Genética , Passeriformes , Pigmentação , Animais , Panamá , Pigmentação/genética , Passeriformes/genética , Passeriformes/fisiologia , Plumas , Introgressão Genética , Masculino , Seleção SexualRESUMO
Indicine cattle breeds are adapted to the tropical climate, and their coat plays an important role in this process. Coat color influences thermoregulation and the adhesion of ectoparasites and may be associated with productive and reproductive traits. Furthermore, coat color is used for breed qualification, with breeders preferring certain colors. The Gir cattle is characterized by a wide variety of coat colors. Therefore, we performed genome-wide association studies to identify candidate genes for coat color in Gir cattle. Different phenotype scenarios were considered in the analyses and regions were identified on eight chromosomes. Some regions and many candidate genes are influencing coat color in the Gir cattle, which was found to be a polygenic trait. The candidate genes identified have been associated with white spotting patterns and base coat color in cattle and other species. In addition, a possible epistatic effect on coat color determination in the Gir cattle was suggested. This is the first published study that identified genomic regions and listed candidate genes associated with coat color in Gir cattle. The findings provided a better understanding of the genetic architecture of the trait in the breed and will allow to guide future fine-mapping studies for the development of genetic markers for selection.
Assuntos
Estudo de Associação Genômica Ampla , Bovinos/genética , Animais , Fenótipo , Cor de Cabelo/genética , Polimorfismo de Nucleotídeo Único , Pigmentação/genética , Genoma , Cruzamento , Locos de Características QuantitativasRESUMO
Next generation sequencing techniques currently represent a practical and efficient way to infer robust evolutionary hypotheses. Palyadini is a small Neotropical tribe of geometrid moths composed of six genera that feature strikingly colourful wings. Here, we investigated patterns of evolution and amount of phylogenetic signal contained in various colour characters featured in the wings of members of this tribe by (i) inferring a robust phylogenetic hypothesis using ultraconserved elements (UCEs), and afterwards, (ii) mapping the morphological characters onto the molecular topology under a parsimonious ancestral character optimization. Our matrix, obtained with 60% completeness, includes 754 UCE loci and 73 taxa (64 ingroup, nine outgroup). Maximum likelihood and parsimony generated largely identical topologies with strongly supported nodes, except for one node inside the genus Opisthoxia. According to our topology, most wing colour characters are reconstructed as homoplastic, particularly at the tribe level, but five of the seven provide evidence supporting common ancestry at the genus level. Our results emphasize, once again, that no character system is infallible, and that more research is necessary to take our understanding of the evolution of wing colour in moths to a level comparable with the knowledge we have for butterflies.
Assuntos
Mariposas , Filogenia , Pigmentação , Asas de Animais , Animais , Asas de Animais/anatomia & histologia , Mariposas/genética , Mariposas/anatomia & histologia , Mariposas/classificação , Pigmentação/genética , Cor , Evolução BiológicaRESUMO
Incomplete speciation can be leveraged to associate phenotypes with genotypes, thus providing insights into the traits relevant to the reproductive isolation of diverging taxa. We investigate the genetic underpinnings of the phenotypic differences between Sporophila plumbea and Sporophila beltoni. Sporophila beltoni has only recently been described based, most notably, based on differences in bill coloration (yellow vs. black in S. plumbea). Both species are indistinguishable through mtDNA or reduced-representation genomic data, and even whole-genome sequencing revealed low genetic differentiation. Demographic reconstructions attribute this genetic homogeneity to gene flow, despite divergence in the order of millions of generations. We found a narrow hybrid zone in southern Brazil where genetically, yet not phenotypically, admixed individuals appear to be prevalent. Despite the overall low genetic differentiation, we identified 3 narrow peaks along the genome with highly differentiated SNPs. These regions harbor 6 genes, one of which is involved in pigmentation (EDN3) and is a candidate for controlling bill color. Within the outlier peaks, we found signatures of resistance to gene flow, as expected for islands of speciation. Our study shows how genes related to coloration traits are likely involved in generating prezygotic isolation and establishing species boundaries early in speciation.
Assuntos
Fluxo Gênico , Especiação Genética , Pigmentação , Pigmentação/genética , Brasil , Ilhas Genômicas , Animais , Isolamento Reprodutivo , Fenótipo , Polimorfismo de Nucleotídeo ÚnicoRESUMO
In the previous century, each intrabreed type of the Karakul sheep breed was characterized by significant numbers, representing a super population with rich genetic diversity. However, over time, the genetic diversity within the breed's gene pool has undergone significant depletion. At present, the Karakul breed is predominantly composed of only two small populations, distinguished by their fur colors: black and gray. Consequently, under such circumstances, genetic advancements in breeding endeavors are likely to be relatively limited, especially given the potential risk of these populations disappearing altogether in the future. Hence, the preservation and judicious utilization of the available genetic resources within the black and gray Karakul sheep populations hold paramount importance in breeding efforts. The primary objective of our research was to investigate the heritability of breeding traits among gray lambs through various selection options. The study was conducted at the "Kumkent" base farm in the Sozak district of the Kyzylorda region. Our findings revealed that the inheritance of gray and black fur colors across the different selection options occurred in a consistent ratio. In the first selection variant (a gray ram with even silver marking â x a black jacket fur type ewe with intense pigmentation â), the proportion of gray offspring was 50.6%. Similarly, in the second selection variant (a black jacket fur type ram with intense pigmentation â x a gray ewe with even silver marking â), the proportion of gray offspring was 49.6%. The percentage of black lambs obtained in both selection options was nearly equivalent, with 49.4% and 50.4% in the first and second variants, respectively.
Assuntos
Fenótipo , Carneiro Doméstico , Animais , Feminino , Masculino , Pigmentação/genética , Ovinos/genética , Carneiro Doméstico/genéticaRESUMO
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.
Assuntos
Borboletas , Animais , Filogenia , Borboletas/genética , Borboletas/anatomia & histologia , Caracteres Sexuais , Pigmentação/genética , Asas de Animais/anatomia & histologiaRESUMO
Little is known about the extent to which species use homologous regulatory architectures to achieve phenotypic convergence. By characterizing chromatin accessibility and gene expression in developing wing tissues, we compared the regulatory architecture of convergence between a pair of mimetic butterfly species. Although a handful of color pattern genes are known to be involved in their convergence, our data suggest that different mutational paths underlie the integration of these genes into wing pattern development. This is supported by a large fraction of accessible chromatin being exclusive to each species, including the de novo lineage-specific evolution of a modular optix enhancer. These findings may be explained by a high level of developmental drift and evolutionary contingency that occurs during the independent evolution of mimicry.
Assuntos
Evolução Biológica , Mimetismo Biológico , Borboletas , Montagem e Desmontagem da Cromatina , Asas de Animais , Animais , Mimetismo Biológico/genética , Borboletas/anatomia & histologia , Borboletas/genética , Borboletas/crescimento & desenvolvimento , Pigmentação/genética , Asas de Animais/anatomia & histologia , Asas de Animais/crescimento & desenvolvimento , Regulação da Expressão Gênica no Desenvolvimento , Elementos Facilitadores GenéticosRESUMO
KEY MESSAGE: High pigment mutants in tomato (Solanum lycopersicum L.), a loss of function in the control of photomorphogenesis, with greater pigment production, show altered growth, greater photosynthesis, and a metabolic reprogramming. High pigment mutations cause plants to be extremely responsive to light and produce excessive pigmentation as well as fruits with high levels of health-beneficial nutrients. However, the association of these traits with changes in the physiology and metabolism of leaves remains poorly understood. Here, we performed a detailed morphophysiological and metabolic characterization of high pigment 1 (hp1) and high pigment 2 (hp2) mutants in tomato (Solanum lycopersicum L. 'Micro-Tom') plants under different sunlight conditions (natural light, 50% shading, and 80% shading). These mutants occur in the DDB1 (hp1) and DET1 (hp2) genes, which are related to the regulation of photomorphogenesis and chloroplast development. Our results demonstrate that these mutations delay plant growth and height, by affecting physiological and metabolic parameters at all stages of plant development. Although the mutants were characterized by higher net CO2 assimilation, lower stomatal limitation, and higher carboxylation rates, with anatomical changes that favour photosynthesis, we found that carbohydrate levels did not increase, indicating a change in the energy flow. Shading minimized the differences between mutants and the wild type or fully reversed them in the phenotype at the metabolic level. Our results indicate that the high levels of pigments in hp1 and hp2 mutants represent an additional energy cost for these plants and that extensive physiological and metabolic reprogramming occurs to support increased pigment biosynthesis.
Assuntos
Solanum lycopersicum , Carbono/metabolismo , Proteínas Cromossômicas não Histona/metabolismo , Solanum lycopersicum/metabolismo , Fotossíntese/genética , Pigmentação/genética , Folhas de Planta/metabolismo , Proteínas de Plantas/genética , Plantas/metabolismoRESUMO
Pigmentation in insects has been linked to mate selection and predator evasion, thus representing an important aspect for natural selection. Insect body color is classically associated to the activity of tyrosine pathway enzymes, and eye color to pigment synthesis through the tryptophan and guanine pathways, and their transport by ATP-binding cassette proteins. Among the hemiptera, the genetic basis for pigmentation in kissing bugs such as Rhodnius prolixus, that transmit Chagas disease to humans, has not been addressed. Here, we report the functional analysis of R. prolixus eye and cuticle pigmentation genes. Consistent with data for most insect clades, we show that knockdown for yellow results in a yellow cuticle, while scarlet and cinnabar knockdowns display red eyes as well as cuticle phenotypes. In addition, tyrosine pathway aaNATpreto knockdown resulted in a striking dark cuticle that displays no color pattern or UV reflectance. In contrast, knockdown of ebony and tan, that encode N-beta-alanyl dopamine hydroxylase branch tyrosine pathway enzymes, did not generate the expected dark and light brown phenotypes, respectively, as reported for other insects. We hypothesize that R. prolixus, which requires tyrosine pathway enzymes for detoxification from the blood diet, evolved an unusual strategy for cuticle pigmentation based on the preferential use of a color erasing function of the aaNATpreto tyrosine pathway branch. We also show that genes classically involved in the generation and transport of eye pigments regulate red body color in R. prolixus. This is the first systematic approach to identify the genes responsible for the generation of color in a blood-feeding hemiptera, providing potential visible markers for future transgenesis.
Assuntos
Rhodnius , Animais , Pigmentação/genética , Rhodnius/genética , TirosinaRESUMO
Ocular squamous cell carcinoma and infectious keratoconjunctivitis are common ocular pathologies in Hereford cattle with considerable economic impact. Both pathologies have been associated with low eyelid pigmentation, and thus, genetic selection for higher eyelid pigmentation could reduce their incidence. The objective of the present study was to reveal the genetic basis of eyelid pigmentation in Hereford cattle. The analysis included a single-step genome-wide association study (ssGWAS) and a subsequent gene-set analysis in order to identify individual genes, genetic mechanisms, and biological pathways implicated in this trait. Data consisted of eyelid pigmentation records in 1,165 Hereford bulls and steers, visually assessed in five categories between 0% and 100%. Genotypic data for 774,660 single-nucleotide polymorphism markers were available for 886 animals with pigmentation records. Pedigree information of three generations of ancestors of animals with phenotype was considered in this study, with a total of 4,929 animals. Our analyses revealed that eyelid pigmentation is a moderately heritable trait, with heritability estimates around 0.41. The ssGWAS identified at least eight regions, located on BTA1, BTA3, BTA5, BTA14, BTA16, BTA18, BTA19, and BTA24, associated with eyelid pigmentation. These regions harbor genes that are directly implicated in melanocyte biology and skin pigmentation, such as ADCY8, PLD1, KITLG, and PRKCA. The gene-set analysis revealed several functional terms closely related to melanogenesis, such as positive regulation of melanocyte differentiation and regulation of ERK1 and ERK2 cascade. Overall, our findings provide evidence that eyelid pigmentation is a heritable trait influenced by many loci. Indeed, the ssGWAS detected several candidate genes that are directly implicated in melanocyte biology, including melanogenesis. This study contributes to a better understanding of the genetic and biological basis of eyelid pigmentation and presents novel information that could aid to design breeding strategies for reducing the incidence of ocular pathologies in cattle. Additional research on the genetic link between eyelid pigmentation and ocular pathologies is needed.
Low eyelid pigmentation is considered as a predisposing factor associated with common ocular pathologies in cattle, such as ocular squamous cell carcinoma and infectious keratoconjunctivitis, with considerable economic impact. The aim of our study was to investigate the genetic basis of eyelid pigmentation in Hereford cattle. The analysis included estimation of genetic parameters, a genome-wide association study, and a subsequent gene-set analysis to identify individual genes, genetic mechanisms, and biological pathways implicated in eyelid pigmentation. Our results indicate that eyelid pigmentation is a complex trait, with a moderate heritability around 0.41, and affected by multiple loci, including genes related to melanocyte biology, melanogenesis, skin pigmentation, and development of melanoma. Evidence that biological processes such as melanocyte development and melanocyte differentiation explain part of the observed variation in eyelid pigmentation were also found. Overall, this study provides a better understanding of the genetics underlying eyelid pigmentation in Hereford. Our findings could contribute to point out breeding strategies for reducing the incidence of ocular pathologies in cattle.