RESUMO
BACKGROUND: Skin pigmentation is a broadly appearing phenomenon of most animals and humans in nature. Here we used a bird model to investigate why melanin spot deposits on the skin. RESULTS: Our result showed that growth age and the sunlight might induce melanin deposition in bird beak skin which was determined by genetic factors. GWAS helped us to identify two major loci affecting melanin deposition, located on chromosomes 13 and 25, respectively. The fine mapping works narrowed the candidate regions to 0.98 Mb and 1.0 Mb on chromosomes 13 and 25. The MITF and POU2F3 may be the causative genes and synergistically affect melanin deposition during duck beak skin. Furthermore, our data strongly demonstrated that the pathway of melanin metabolism contributes to melanin deposition on the skin. CONCLUSIONS: We demonstrated that age and sunlight induce melanin deposition in bird beak skin, while heredity is fundamental. The MITF and POU2F3 likely played a synergistic effect on the regulation of melanin synthesis, and their mutations contribute to phenotypic differences in beak melanin deposition among individuals. It is pointed out that melanin deposition in the skin is related to the pathway of melanin metabolism, which provided insights into the molecular regulatory mechanisms and the genetic improvement of the melanin deposition in duck beak.
Assuntos
Estudo de Associação Genômica Ampla , Melaninas , Animais , Bico/metabolismo , Patos/genética , Patos/metabolismo , Melaninas/metabolismo , Pigmentação da Pele/genéticaRESUMO
BACKGROUND: Beak deformity, typically expressed as the crossing of upper and lower mandibles, is found in several indigenous chicken breeds, including the Beijing-You chickens studied here. Beak deformity severely impairs the birds' growth and welfare. Although previous studies shed some light on the genetic regulation of this complex trait, the genetic basis of this malformation remains incompletely understood. RESULTS: In this study, single SNP- and pathway-based genome-wide association studies (GWASs) were performed using ROADTRIPS and SNP ratio test (SRT), respectively. A total of 48 birds with deformed beaks (case) and 48 normal birds (control) were genotyped using Affymetrix 600 K HD genotyping arrays. As a result, 95 individuals and 429,539 SNPs were obtained after quality control. The P-value was corrected by a Bonferroni adjustment based on linkage disequilibrium pruning. The single SNP-based association study identified one associated SNP with 5% genome-wide significance and seven suggestively associated SNPs. Four high-confidence genes, LOC421892, TDRD3, RET, and STMN1, were identified as the most promising candidate genes underlying this complex trait in view of their positions, functions, and overlaps with previous studies. The pathway-based association study highlighted the association of six pathways with beak deformity, including the calcium signaling pathway. CONCLUSIONS: Potentially useful candidate genes and pathways for beak deformity were identified, which should be the subject of further functional characterization.
Assuntos
Bico/metabolismo , Galinhas/genética , Estudo de Associação Genômica Ampla , Redes e Vias Metabólicas/genética , Animais , Bico/anormalidades , Genótipo , Polimorfismo de Nucleotídeo ÚnicoRESUMO
The epithelial disintegration and the mesenchymal bridging are critical steps in the fusion of facial prominences during the upper lip development. These processes of epithelial-mesenchymal transition and programmed cell death are mainly influenced by Wnt signals. Axis inhibition protein2 (Axin2), a major component of the Wnt pathway, has been reported to be involved in lip development and cleft pathogenesis. We wanted to study the involvement of Axin2 in the lip development, especially during the epithelial disintegration of facial prominences. Our results show that Axin2 was expressed mainly in the epithelium of facial prominences and decreased when the prominences were about to contact each other between Hamburger-Hamilton stages 27 and 28 of chicken embryos. The epithelial integrity was destructed or kept intact by the local gain or loss of Axin2 expression, resulting in morphological changes in the facial processes and their skeletal derivatives including the maxilla, nasal, premaxilla bone, and their junctions without cleft formation. These changes were related to expression changes in nuclear ß-catenin, pGSK3ß, Slug, Smad3, E-cadherin, and p63. All these data indicate that Axin2 participates in the regulation of epithelial integrity and fusion by promoting epithelial disassociation, basement membrane breakdown, and seam loss during the fusion of facial prominences in lip development.
Assuntos
Proteínas Aviárias/genética , Proteína Axina/genética , Bico/embriologia , Galinhas/crescimento & desenvolvimento , Galinhas/genética , Regulação da Expressão Gênica no Desenvolvimento , Morfogênese , Animais , Bico/metabolismo , Morte Celular , Embrião de Galinha/citologia , Embrião de Galinha/metabolismo , Galinhas/metabolismoRESUMO
The beak of the jumbo squid Dosidicus gigas is a fascinating example of how seamlessly nature builds with mechanically mismatched materials. A 200-fold stiffness gradient begins in the hydrated chitin of the soft beak base and gradually increases to maximum stiffness in the dehydrated distal rostrum. Here, we combined RNA-Seq and proteomics to show that the beak contains two protein families. One family consists of chitin-binding proteins (DgCBPs) that physically join chitin chains, whereas the other family comprises highly modular histidine-rich proteins (DgHBPs). We propose that DgHBPs play multiple key roles during beak bioprocessing, first by forming concentrated coacervate solutions that diffuse into the DgCBP-chitin scaffold, and second by inducing crosslinking via an abundant GHG sequence motif. These processes generate spatially controlled desolvation, resulting in the impressive biomechanical gradient. Our findings provide novel molecular-scale strategies for designing functional gradient materials.
Assuntos
Bico/química , Quitina/química , Decapodiformes/química , Proteínas/química , Água/química , Sequência de Aminoácidos , Animais , Bico/metabolismo , Fenômenos Biomecânicos , Catecóis/química , Quitina/metabolismo , Quitina/ultraestrutura , Reagentes de Ligações Cruzadas/química , Decapodiformes/metabolismo , Dureza , Dados de Sequência Molecular , Ácido Periódico/química , Ligação Proteica , Estrutura Terciária de Proteína , Proteínas/metabolismo , Proteínas/ultraestrutura , Proteômica , Análise de Sequência de RNARESUMO
Cranial neural crest cells form the majority of the facial skeleton. However exactly when the pattering information and hence jaw identity is established is not clear. We know that premigratory neural crest cells contain a limited amount of information about the lower jaw but the upper jaw and facial midline are specified later by local tissue interactions. The environmental signals leading to frontonasal identity have been explored by our group in the past. Altering the levels of two signaling pathways (Bone Morphogenetic Protein) and retinoic acid (RA) in the chicken embryo creates a duplicated midline on the side of the upper beak complete with egg tooth in place of maxillary derivatives (Lee et al., 2001). Here we analyze the transcriptome 16 h after bead placement in order to identify potential mediators of the identity change in the maxillary prominence. The gene list included RA, BMP and WNT signaling pathway genes as well as transcription factors expressed in craniofacial development. There was also cross talk between Noggin and RA such that Noggin activated the RA pathway. We also observed expression changes in several poorly characterized genes including the upregulation of Peptidase Inhibitor-15 (PI15). We tested the functional effects of PI15 overexpression with a retroviral misexpression strategy. PI15 virus induced a cleft beak analogous to human cleft lip. We next asked whether PI15 effects were mediated by changes in expression of major clefting genes and genes in the retinoid signaling pathway. Expression of TP63, TBX22, BMP4 and FOXE1, all human clefting genes, were upregulated. In addition, ALDH1A2, ALDH1A3 and RA target, RARß were increased while the degradation enzyme CYP26A1 was decreased. Together these changes were consistent with activation of the RA pathway. Furthermore, PI15 retrovirus injected into the face was able to replace RA and synergize with Noggin to induce beak transformations. We conclude that the microarrays have generated a rich dataset containing genes with important roles in facial morphogenesis. Moreover, one of these facial genes, PI15 is a putative clefting gene and is in a positive feedback loop with RA.
Assuntos
Bico/anormalidades , Bico/metabolismo , Padronização Corporal/genética , Regulação da Expressão Gênica no Desenvolvimento , Animais , Animais Geneticamente Modificados , Padronização Corporal/efeitos dos fármacos , Proteínas Morfogenéticas Ósseas/metabolismo , Proteínas de Transporte/metabolismo , Embrião de Galinha , Bases de Dados Genéticas , Face , Perfilação da Expressão Gênica , Regulação da Expressão Gênica no Desenvolvimento/efeitos dos fármacos , Hibridização In Situ , Maxila/efeitos dos fármacos , Maxila/embriologia , Análise de Sequência com Séries de Oligonucleotídeos , Proteínas Secretadas Inibidoras de Proteinases/genética , Proteínas Secretadas Inibidoras de Proteinases/metabolismo , Controle de Qualidade , Reação em Cadeia da Polimerase em Tempo Real , Transdução de Sinais/efeitos dos fármacos , Transdução de Sinais/genética , Tretinoína/metabolismo , Tretinoína/farmacologiaRESUMO
We reanalysed the role of superparamagnetic magnetite clusters observed in a pigeon's upper beak to decide if this matter can be a component of some sort of pigeon magnetometer for Earth orientation. We investigated the mutual interaction of the magnetite clusters induced by the geomagnetic field. The force sensitivity of the hypothetical magnetometer in a pigeon's upper beak was estimated considering the previously presented threshold magnetic sensitivity of pigeons, measured in electrophysiological and behavioural investigations. The typical intercluster magnetic force seems to be 10(-19)N well above the threshold magnetic sensitivity. To strengthen our results, we measured the magnetic susceptibility of superparamagnetic magnetite using a vibrating sample magnetometer. Finally we performed theoretical kinematic analysis of the motion of magnetite clusters in cell plasma. The results indicate that magnetite clusters, constituted by superparamagnetic nanoparticles and observed in a pigeon's upper beak, may not be a component of a measuring system providing the magnetic map.
Assuntos
Bico/fisiologia , Columbidae/anatomia & histologia , Fenômenos Magnéticos , Magnetometria , Modelos Biológicos , Migração Animal/fisiologia , Animais , Bico/metabolismo , Fenômenos Biomecânicos , Columbidae/metabolismo , Columbidae/fisiologia , Óxido Ferroso-Férrico/metabolismo , Orientação/fisiologiaRESUMO
Evolution by natural selection has resulted in a remarkable diversity of organism morphologies that has long fascinated scientists and served to establish the first relations among species. Despite the essential role of morphology as a phenotype of species, there is not yet a formal, mathematical scheme to quantify morphological phenotype and relate it to both the genotype and the underlying developmental genetics. Herein we demonstrate that the morphological diversity in the beaks of Darwin's Finches is quantitatively accounted for by the mathematical group of affine transformations. Specifically, we show that all beak shapes of Ground Finches (genus Geospiza) are related by scaling transformations (a subgroup of the affine group), and the same relationship holds true for all the beak shapes of Tree, Cocos, and Warbler Finches (three distinct genera). This analysis shows that the beak shapes within each of these groups differ only by their scales, such as length and depth, which are genetically controlled by Bmp4 and Calmodulin. By measuring Bmp4 expression in the beak primordia of the species in the genus Geospiza, we provide a quantitative map between beak morphology and the expression levels of Bmp4. The complete morphological variation within the beaks of Darwin's finches can be explained by extending the scaling transformations to the entire affine group, by including shear transformations. Altogether our results suggest that the mathematical theory of groups can help decode morphological variation, and points to a potentially hierarchical structure of morphological diversity and the underlying developmental processes.
Assuntos
Bico/anatomia & histologia , Bico/crescimento & desenvolvimento , Proteína Morfogenética Óssea 4/biossíntese , Calmodulina/biossíntese , Tentilhões/anatomia & histologia , Tentilhões/crescimento & desenvolvimento , Animais , Bico/metabolismo , Evolução Biológica , Tentilhões/metabolismo , Modelos Biológicos , Seleção GenéticaRESUMO
Carotenoid-based coloration has attracted much attention in evolutionary biology owing to its role in honest, condition-dependent signalling. Knowledge of the genetic pathways that regulate carotenoid coloration is crucial for an understanding of any trade-offs involved. We identified genes with potential roles in carotenoid coloration in vertebrates via (i) carotenoid uptake (SR-BI, CD36), (ii) binding and deposition (StAR1, MLN64, StAR4, StAR5, APOD, PLIN, GSTA2), and (iii) breakdown (BCO2, BCMO1). We examined the expression of these candidate loci in carotenoid-coloured tissues and several control tissues of the red-billed quelea (Quelea quelea), a species that exhibits a male breeding plumage colour polymorphism and sexually dimorphic variation in bill colour. All of the candidate genes except StAR1 were expressed in both the plumage and bill of queleas, indicating a potential role in carotenoid coloration in the quelea. However, no differences in the relative expression of any of the genes were found among the quelea carotenoid phenotypes, suggesting that other genes control the polymorphic and sexually dimorphic variation in carotenoid coloration observed in this species. Our identification of a number of potential carotenoid genes in different functional categories provides a critical starting point for future work on carotenoid colour regulation in vertebrate taxa.
Assuntos
Carotenoides/genética , Carotenoides/metabolismo , Pigmentação , Aves Canoras/genética , Animais , Bico/química , Bico/metabolismo , Carotenoides/análise , Galinhas/genética , Plumas/química , Plumas/metabolismo , Feminino , Estudos de Associação Genética/veterinária , Masculino , Especificidade de Órgãos , Polimorfismo Genético , Reação em Cadeia da Polimerase em Tempo Real/veterinária , Reação em Cadeia da Polimerase Via Transcriptase Reversa/veterinária , Alinhamento de Sequência/veterinária , Aves Canoras/metabolismo , África do Sul , ZimbábueRESUMO
A classic textbook example of adaptive radiation under natural selection is the evolution of 14 closely related species of Darwin's finches (Fringillidae, Passeriformes), whose primary diversity lies in the size and shape of their beaks. Thus, ground finches have deep and wide beaks, cactus finches have long and pointed beaks (low depth and narrower width), and warbler finches have slender and pointed beaks, reflecting differences in their respective diets. Previous work has shown that even small differences in any of the three major dimensions (depth, width and length) of the beak have major consequences for the overall fitness of the birds. Recently we used a candidate gene approach to explain one pathway involved in Darwin's finch beak morphogenesis. However, this type of analysis is limited to molecules with a known association with craniofacial and/or skeletogenic development. Here we use a less constrained, complementary DNA microarray analysis of the transcripts expressed in the beak primordia to find previously unknown genes and pathways whose expression correlates with specific beak morphologies. We show that calmodulin (CaM), a molecule involved in mediating Ca2+ signalling, is expressed at higher levels in the long and pointed beaks of cactus finches than in more robust beak types of other species. We validated this observation with in situ hybridizations. When this upregulation of the CaM-dependent pathway is artificially replicated in the chick frontonasal prominence, it causes an elongation of the upper beak, recapitulating the beak morphology of the cactus finches. Our results indicate that local upregulation of the CaM-dependent pathway is likely to have been a component of the evolution of Darwin's finch species with elongated beak morphology and provide a mechanistic explanation for the independence of beak evolution along different axes. More generally, our results implicate the CaM-dependent pathway in the developmental regulation of craniofacial skeletal structures.
Assuntos
Bico/anatomia & histologia , Evolução Biológica , Calmodulina/metabolismo , Tentilhões/anatomia & histologia , Tentilhões/metabolismo , Animais , Bico/embriologia , Bico/metabolismo , Proteínas Morfogenéticas Ósseas/metabolismo , Calmodulina/genética , Embrião de Galinha , Análise por Conglomerados , Tentilhões/classificação , Tentilhões/genética , Regulação da Expressão Gênica , Modelos Biológicos , Dados de Sequência Molecular , Análise de Sequência com Séries de Oligonucleotídeos , Transdução de SinaisRESUMO
Darwin's finches, with the primary diversity in the shape and size of their beaks, represent an excellent model system to study speciation and adaptive evolution. It is generally held that evolution depends on the natural selection of heritable phenotypic variations originating from the genetic mutations. However, it is now increasingly evident that epigenetic transgenerational inheritance of phenotypic variation can also guide evolutionary change. Several studies have shown that the bone morphogenetic protein BMP4 is a major driver of beak morphology. A recent study explored variability of the morphological, genetic, and epigenetic differences in the adjacent "urban" and "rural" populations of two species of Darwin's finches on the Galápagos Islands and revealed significant changes in methylation patterns in several genes including those involved in the BMP/TGFß pathway in the sperm DNA compared to erythrocyte DNA. These observations indicated that epigenetic changes caused by environmental fluctuations can be passed on to the offspring. Nonetheless, the mechanism by which dysregulated expression of BMP4 impacts beak morphology remains poorly understood. Here, we show that BMP4 is an intrinsically disordered protein and present a causal a link between epigenetic changes, BMP4 dysregulation and the evolution of the beak of the finch by natural selection.
Assuntos
Tentilhões , Proteínas Intrinsicamente Desordenadas , Animais , Bico/anatomia & histologia , Bico/metabolismo , Evolução Biológica , Proteínas Morfogenéticas Ósseas/genética , Tentilhões/anatomia & histologia , Tentilhões/genética , Tentilhões/metabolismo , Proteínas Intrinsicamente Desordenadas/metabolismo , Masculino , Sêmen/metabolismoRESUMO
In stark contrast to most aggressive predators, Dosidicus gigas (jumbo squids) do not use minerals in their powerful mouthparts known as beaks. Their beaks instead consist of a highly sclerotized chitinous composite with incremental hydration from the tip to the base. We previously reported l-3,4-dihydroxyphenylalanine (dopa)-histidine (dopa-His) as an important covalent cross-link providing mechanical strengthening to the beak material. Here, we present a more complete characterization of the sclerotization chemistry and describe additional cross-links from D. gigas beak. All cross-links presented in this report share common building blocks, a family of di-, tri-, and tetra-histidine-catecholic adducts, that were separated by affinity chromatography and high performance liquid chromatography (HPLC) and identified by tandem mass spectroscopy and proton nuclear magnetic resonance ((1)H NMR). The data provide additional insights into the unusually high cross-link density found in mature beaks. Furthermore, we propose both a low molecular weight catechol, and peptidyl-dopa, to be sclerotization agents of squid beak. This appears to represent a new strategy for forming hard tissue in animals. The interplay between covalent cross-linking and dehydration on the graded properties of the beaks is discussed.
Assuntos
Bico/metabolismo , Decapodiformes/metabolismo , Histidina/metabolismo , Levodopa/metabolismo , AnimaisRESUMO
Magnetic compass orientation of migratory birds is known to be light dependent, and radical-pair processes have been identified as the underlying mechanism. Here we report for the first time results of tests with European robins, Erithacus rubecula, in total darkness and, as a control, under 565 nm green light. Under green light, the robins oriented in their normal migratory direction, with southerly headings in autumn and northerly headings in spring. By contrast, in darkness they significantly preferred westerly directions in spring as well as autumn. This failure to show the normal seasonal change characterizes the orientation in total darkness as a "fixed direction" response. Tests in magnetic fields with the vertical or the horizontal component inverted showed that the preferred direction depended on the magnetic field but did not involve the avian inclination compass. A high-frequency field of 1.315 MHz did not affect the behavior, whereas local anesthesia of the upper beak resulted in disorientation. The behavior in darkness is thus fundamentally different from normal compass orientation and relies on another source of magnetic information: It does not involve the radical-pair mechanism but rather originates in the iron-containing receptors in the upper beak.
Assuntos
Migração Animal/fisiologia , Escuridão , Magnetismo , Orientação/fisiologia , Aves Canoras/fisiologia , Animais , Bico/metabolismo , Óxido Ferroso-Férrico/metabolismo , Aves Canoras/metabolismoRESUMO
Stress can have widespread effects on animal behaviors and phenotypes, including sexually selected traits. Ornamental colors have long been studied as honest signals of condition, but few studies have been conducted on how the physiological stress response (i.e., corticosterone (CORT) elevation) impacts color expression. We used a traditional capture-and-restraint technique to examine the effect of repeated handling stress on carotenoid-dependent beak coloration in male and female zebra finches (Taeniopygia guttata). Birds subjected to daily, 10-min handling treatments, which elevated circulating CORT levels, for a four-week period displayed deeper orange/red beak coloration than did control animals. Stressed males lost body mass during the experiment and marginally decreased in circulating carotenoid concentrations. Hence, handling stress may have reduced food intake or induced mobilization of body stores (i.e., fat) of carotenoids. In contrast to males, stressed females maintained orange beak color, while control females faded in color. This study highlights sex- and pigment-specific mechanisms by which stress may temporarily enhance the expression of sexual traits, but at the expense of other key fitness traits (e.g., body mass maintenance, reproduction).
Assuntos
Bico/metabolismo , Carotenoides/sangue , Tentilhões/fisiologia , Pigmentação/fisiologia , Estresse Psicológico/fisiopatologia , Animais , Feminino , MasculinoRESUMO
Scaffoldin, an S100 fused-type protein (SFTP) with high amino acid sequence similarity to the mammalian hair follicle protein trichohyalin, has been identified in reptiles and birds, but its functions are not yet fully understood. Here, we investigated the expression pattern of scaffoldin and cornulin, a related SFTP, in the developing beaks of birds. We determined the mRNA levels of both SFTPs by reverse transcription polymerase chain reaction (RT-PCR) in the beak and other ectodermal tissues of chicken (Gallus gallus) and quail (Coturnix japonica) embryos. Immunohistochemical staining was performed to localize scaffoldin in tissues. Scaffoldin and cornulin were expressed in the beak and, at lower levels, in other embryonic tissues of both chickens and quails. Immunohistochemistry revealed scaffoldin in the peridermal compartment of the egg tooth, a transitory cornified protuberance (caruncle) on the upper beak which breaks the eggshell during hatching. Furthermore, scaffoldin marked a multilayered peridermal structure on the lower beak. The results of this study suggest that scaffoldin plays an evolutionarily conserved role in the development of the avian beak with a particular function in the morphogenesis of the egg tooth.
Assuntos
Proteínas Aviárias/genética , Bico/metabolismo , Galinhas/genética , Coturnix/genética , Plumas/metabolismo , Casco e Garras/metabolismo , Animais , Proteínas Aviárias/metabolismo , Bico/citologia , Bico/embriologia , Evolução Biológica , Embrião de Galinha , Galinhas/crescimento & desenvolvimento , Galinhas/metabolismo , Sequência Conservada , Coturnix/embriologia , Coturnix/metabolismo , Embrião não Mamífero , Epiderme/embriologia , Epiderme/metabolismo , Plumas/citologia , Plumas/embriologia , Regulação da Expressão Gênica no Desenvolvimento , Casco e Garras/citologia , Casco e Garras/embriologia , Proteínas de Filamentos Intermediários/genética , Proteínas de Filamentos Intermediários/metabolismo , Queratinócitos/citologia , Queratinócitos/metabolismo , Mamíferos , Morfogênese/genética , Zigoto/crescimento & desenvolvimento , Zigoto/metabolismoRESUMO
OBJECTIVE: Hybrid zones are geographic regions where genetically distinct taxa interbreed, resulting in offspring of mixed ancestry. California Scrub-Jays (Aphelocoma californica) and Woodhouse's Scrub-Jays (A. woodhouseii) come into secondary contact and hybridize in western Nevada. Although previous work investigated divergence and gene flow between these species using a handful of microsatellite markers, the hybrid zone has not been studied using genome-scale markers, providing an opportunity to assess genome-wide introgression, test for a genetic basis for ecomorphological traits, and compare these estimates to those derived from microsatellites. RESULTS: Using variant sites flanking ultraconserved elements (UCEs), we performed population assignment and quantified hybrid ancestry for 16 individuals across the zone of secondary contact. Our study included 2468 SNPs distributed throughout the genome, allowing discrimination of genetic affinities of hybrid individuals that were similar to estimates from microsatellites. We show a relationship between bill and wing length and the genetic composition of individuals that was not found in prior work using microsatellites, suggesting a genetic basis for these traits. Our analyses demonstrate the utility of UCEs for the analysis of hybrid zones and provide a basis for future studies to identify the genomic architecture of speciation and phenotypic differences between these incipient species.
Assuntos
Sondas de DNA , Genoma , Hibridização Genética , Passeriformes/genética , Característica Quantitativa Herdável , Animais , Bico/anatomia & histologia , Bico/metabolismo , Cruzamentos Genéticos , Feminino , Fluxo Gênico , Especiação Genética , Genética Populacional , Masculino , Repetições de Microssatélites , Passeriformes/classificação , Fenótipo , Polimorfismo de Nucleotídeo Único , Análise de Sequência de DNA , Asas de Animais/anatomia & histologia , Asas de Animais/metabolismoRESUMO
The beak is the dominant avian facial feature, and beak deformity occurs in 0.5 to 2.5% of some indigenous chicken breeds, resulting in difficulties when eating, drinking, and performing natural behaviors. Previous studies on beak deformity focused largely on candidate molecules associated with skeletogenic development, providing insight into the molecular and genetic underpinnings of beak deformity. The present study was performed to identify candidate proteins related to this malformation in chickens. Three 12-day-old Beijing-You roosters with deformed beaks (D1, D2, and D3) and 3 with normal beaks (N1, N2, and N3) were used, and total beak proteins were isolated and subjected to standard iTRAQ labeling, strong cation-exchange chromatography, and liquid chromatography-tandem mass spectrometry. Mascot 2.3.02 was used to identify and quantitatively analyze proteins. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathway enrichment analyses were used to identify functions and metabolic pathways of differentially expressed proteins, and key proteins were further validated using western blot. A total of 2,370, 2,401, and 2,378 proteins were reliably quantified in 3 biological replicates, among which, 2,345 were common to all, and 92 were differentially expressed between the 2 groups. These included 37 upregulated and 55 downregulated proteins in deformed beaks. Pentraxin-related protein 3, hemopexin, lipoprotein lipase, retinoid-binding protein 7, and biliverdin reductase A were downregulated in all 3 sets, while parvalbumin, peptidyl-prolyl cis-trans isomerase, and ubiquitin-fold modifier 1 were upregulated. Pathway analysis returned no enriched pathways, and western blot validated the iTRAQ results. Parvalbumin and lipoprotein lipase could be firstly selected as key proteins in view of their known functions in regulating the buffering of intracellular free Ca2+ in both cartilage and bone cells and bone mass, respectively. Their potential roles in beak deformity, however, deserve further studies. In summary, the onset of beak deformity could be very complex, and this study will be helpful for future investigation of mechanistic explanation for beak deformity.
Assuntos
Proteínas Aviárias/genética , Galinhas/anormalidades , Galinhas/genética , Proteoma/genética , Animais , Proteínas Aviárias/metabolismo , Bico/anormalidades , Bico/metabolismo , Galinhas/metabolismo , Ontologia Genética , Proteoma/metabolismo , ProteômicaRESUMO
Liquid-liquid phase separation (LLPS) of intrinsically disordered proteins (IDPs) is involved in both intracellular membraneless organelles and extracellular tissues. Despite growing understanding of LLPS, molecular-level mechanisms behind this process are still not fully established. Here, we use histidine-rich squid beak proteins (HBPs) as model IDPs to shed light on molecular interactions governing LLPS. We show that LLPS of HBPs is mediated though specific modular repeats. The morphology of separated phases (liquid-like versus hydrogels) correlates with the repeats' hydrophobicity. Solution-state NMR indicates that LLPS is a multistep process initiated by deprotonation of histidine residues, followed by transient hydrogen bonding with tyrosine, and eventually by hydrophobic interactions. The microdroplets are stabilized by aromatic clustering of tyrosine residues exhibiting restricted molecular mobility in the nano-to-microsecond timescale according to solid-state NMR experiments. Our findings provide guidelines to rationally design pH-responsive peptides with LLPS ability for various applications, including bioinspired protocells and smart drug-delivery systems.
Assuntos
Bico/metabolismo , Decapodiformes/metabolismo , Histidina/metabolismo , Proteínas Intrinsicamente Desordenadas/metabolismo , Tirosina/metabolismo , Animais , Bico/química , Materiais Biocompatíveis , Biopolímeros/química , Biopolímeros/metabolismo , Coloides/química , Coloides/metabolismo , Ligação de Hidrogênio , Concentração de Íons de Hidrogênio , Interações Hidrofóbicas e Hidrofílicas , Proteínas Intrinsicamente Desordenadas/química , Espectroscopia de Ressonância Magnética , Microscopia , Engenharia de Proteínas/métodos , Espalhamento a Baixo ÂnguloRESUMO
Pyrenestes finches are unique among birds in showing a non-sex-determined polymorphism in bill size and are considered a textbook example of disruptive selection. Morphs breed randomly with respect to bill size, and differ in diet and feeding performance relative to seed hardness. Previous breeding experiments are consistent with the polymorphism being controlled by a single genetic factor. Here, we use genome-wide pooled sequencing to explore the underlying genetic basis of bill morphology and identify a single candidate region. Targeted resequencing reveals extensive linkage disequilibrium across a 300 Kb region containing the insulin-like growth factor 1 (IGF1) gene, with a single 5-million-year-old haplotype associating with phenotypic dominance of the large-billed morph. We find no genetic similarities controlling bill size in the well-studied Darwin's finches (Geospiza). Our results show how a single genetic factor may control bill size and provide a foundation for future studies to examine this phenomenon within and among avian species.
Assuntos
Bico/anatomia & histologia , Evolução Biológica , Tentilhões/genética , Fator de Crescimento Insulin-Like I/genética , Polimorfismo Genético , Animais , Bico/metabolismo , Ingestão de Alimentos/fisiologia , Tentilhões/anatomia & histologia , Expressão Gênica , Haplótipos , Dureza , Desequilíbrio de Ligação , Tamanho do Órgão , Fenótipo , Sementes , Seleção Genética , Sequenciamento Completo do GenomaAssuntos
Bico/anatomia & histologia , Evolução Biológica , Calmodulina/metabolismo , Tentilhões/anatomia & histologia , Tentilhões/metabolismo , Animais , Bico/embriologia , Bico/metabolismo , Proteínas Morfogenéticas Ósseas/metabolismo , Calmodulina/genética , Embrião de Galinha , Tentilhões/classificação , Tentilhões/genética , Análise de Sequência com Séries de OligonucleotídeosRESUMO
Sexually selected traits like complex vocalizations or vibrant colors communicate reliable information about mate quality when they are costly to display. Although several general condition-dependent mechanisms underlying the acquisition of mating advertisements have been identified, we rarely know the precise physiological and molecular challenges that animals must meet to develop their sexual ornaments. The flashy pigment-based colors commonly displayed by birds are ideal candidates for investigating the pathways and demands of sexual-signal expression, because we know the biochemical currency with which the trait is produced. Carotenoid colors in birds, for example, are derived from pigments that are acquired from the diet and assimilated into feathers and bare parts. In previous work, we showed that variation in the sexually attractive red carotenoid-colored beak of male zebra finches (Taeniopygia guttata) was predicted not by the amount of food or pigments ingested, but by the levels of carotenoids that birds circulated in blood. Here we elucidate a novel physiological mechanism by which birds are able to accumulate high levels of carotenoids in the body and develop a colorful bill. Carotenoids are transported through the bloodstream bound to lipoproteins. We assayed a critical component of lipoprotein particles-cholesterol-and found that males with higher cholesterol levels circulated more carotenoids and displayed redder beaks. Experimental supplementation of dietary cholesterol elevated carotenoid levels in the blood and beak hue. Experimental reductions in blood cholesterol, using the human lipid-lowering agent atorvastatin, diminished blood carotenoids and faded the beak; carotenoid and cholesterol levels were restored, however, by subsequent addition of dietary cholesterol. These results suggest that the production of circulating lipoproteins critically regulates the development of a colorful sexually selected trait in zebra finches.