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Sample records for duck feather keratin

  1. Identification of a feather β-keratin gene exclusively expressed in pennaceous barbule cells of contour feathers in chicken.

    PubMed

    Kowata, Kinue; Nakaoka, Minori; Nishio, Kaori; Fukao, Ayaka; Satoh, Akira; Ogoshi, Maho; Takahashi, Sumio; Tsudzuki, Masaoki; Takeuchi, Sakae

    2014-05-25

    Feathers are elaborate skin appendages shared by birds and theropod dinosaurs that have hierarchical branching of the rachis, barbs, and barbules. Feather filaments consist of β-keratins encoded by multiple genes, most of which are located in tandem arrays on chromosomes 2, 25, and 27 in chicken. The expansion of the genes is thought to have contributed to feather evolution; however, it is unclear how the individual genes are involved in feather formation. The aim of the present study was to identify feather keratin genes involved in the formation of barbules. Using a combination of microarray analysis, reverse-transcription polymerase chain reaction, and in situ hybridization, we found an uncharacterized keratin gene on chromosome 7 that was expressed specifically in barbule cells in regenerating chicken feathers. We have named the gene barbule specific keratin 1 (BlSK1). The BlSK1 gene structure was similar to the gene structure of previously characterized feather keratin genes, and consisted of a non-coding leader exon, an intron, and an exon with an open reading frame (ORF). The ORF was predicted to encode a 98 aa long protein, which shared 59% identity with feather keratin B. Orthologs of BlSK1 were found in the genomes of other avian species, including turkey, duck, zebra finch, and flycatcher, in regions that shared synteny with chromosome 7 of chicken. Interestingly, BlSK1 was expressed in feather follicles that generated pennaceous barbules but not in follicles that generated plumulaceous barbules. These results suggested that the composition of feather keratins probably varies depending on the structure of the feather filaments and, that individual feather keratin genes may be involved in building different portions and/or types of feathers in chicken.

  2. Carbon Fibers from Chicken Feather Keratin

    NASA Astrophysics Data System (ADS)

    Miller, Melissa E.; Wool, Richard

    2006-03-01

    As the availability of synthetic and fossil-fuel based resources is becoming limited, bio-based materials offer an environmentally friendly alternative. Chicken feathers remain a huge agricultural waste. The feathers are comprised of approximately 97% keratin, but are currently used only to enrich animal feed. However, this usage is becoming a problem with the spread of diseases such as Bovine Spongiform Encephalopathy, commonly called ``Mad Cow Disease.'' The hollow, microcrystalline, oriented keratin feather fibers offer a novel, low cost approach to producing carbon fibers through controlled pyrolysis. Carbonized feather fibers (CFF) were prepared by first heating to 225 ^oC (below the melting point)in N2 for 26 hours to crosslink and stabilize the fiber structure; then carbonization occurred by increasing the temperature to 450 ^oC for two more hours. The resulting CFF were hollow, stiff and strong and had an affine 80% weight loss, which is near the theoretical value for the C-content of keratin. Initial studies showed that a composite with the CFF and an epoxidized soybean oil (AESO) gave an improved fiber modulus ECFF of order 13.5--66.1 GPa. With continued research, the goals are to increase the stiffness of the feathers to 100 GPa, while increasing the strength in the range of 5-10 GPa.

  3. Development of feather keratin nanoparticles and investigation of their hemostatic efficacy.

    PubMed

    Wang, Ju; Hao, Shilei; Luo, Tiantian; Yang, Qian; Wang, Bochu

    2016-11-01

    Chicken feathers are considered as the major waste in poultry industry, which are mostly constituted of keratin proteins. Development of feather keratin for biomedical application is very attractive for chicken feather recycling. Human hair keratins have been demonstrated the significant hemostatic efficacy in the previous studies, but there are few reports of feather keratin for the hemostatic application. Here, the chicken feather keratin nanoparticle was developed for use as a hemostatic agent. Keratin was extracted from chicken feather in the present study, and a modified ultrasonic dispersion method was used to prepare keratin nanoparticles. The characterizations of feather keratin extracts and nanoparticles were investigated, including electrophoretic separation, amino acid composition, particle size, zeta potential, morphology, chemical structure and crystal form. Additionally, the hemostatic efficacy in vitro and in vivo of keratin nanoparticles were also studied. The results of hemostatic tests showed that the bleeding time and blood loss in tail amputation and liver scratch rat models can be significantly decreased after application of feather keratin nanoparticles, which demonstrated the potential application of feather keratin nanoparticles for hemostasis.

  4. Linking the molecular evolution of avian beta (β) keratins to the evolution of feathers.

    PubMed

    Greenwold, Matthew J; Sawyer, Roger H

    2011-12-15

    Feathers of today's birds are constructed of beta (β)-keratins, structural proteins of the epidermis that are found solely in reptiles and birds. Discoveries of "feathered dinosaurs" continue to stimulate interest in the evolutionary origin of feathers, but few studies have attempted to link the molecular evolution of their major structural proteins (β-keratins) to the appearance of feathers in the fossil record. Using molecular dating methods, we show that before the appearance of Anchiornis (∼155 Million years ago (Ma)) the basal β-keratins of birds began diverging from their archosaurian ancestor ∼216 Ma. However, the subfamily of feather β-keratins, as found in living birds, did not begin diverging until ∼143 Ma. Thus, the pennaceous feathers on Anchiornis, while being constructed of avian β-keratins, most likely did not contain the feather β-keratins found in the feathers of modern birds. Our results demonstrate that the evolutionary origin of feathers does not coincide with the molecular evolution of the feather β-keratins found in modern birds. More likely, during the Late Jurassic, the epidermal structures that appeared on organisms in the lineage leading to birds, including early forms of feathers, were constructed of avian β-keratins other than those found in the feathers of modern birds. Recent biophysical studies of the β-keratins in feathers support the view that the appearance of the subfamily of feather β-keratins altered the biophysical nature of the feather establishing its role in powered flight.

  5. Feather keratin hydrogel for wound repair: Preparation, healing effect and biocompatibility evaluation.

    PubMed

    Wang, Ju; Hao, Shilei; Luo, Tiantian; Cheng, Zhongjun; Li, Wenfeng; Gao, Feiyan; Guo, Tingwang; Gong, Yuhua; Wang, Bochu

    2017-01-01

    Keratins are highly attractive for wound healing due to their inherent bioactivity, biocompatibility and physical properties. However, nearly all wound healing studies have focused on human hair keratins, and the wound-repair effects and in vivo biocompatibilities of feather keratins are not clear. Feather keratins are derived from chicken feathers, which are considered to be the major waste in the poultry industry, and the quality of feather keratin is easier to control than that of human hair keratin due to human hair perming and colouring-dyeing. Thus, we extracted keratins from chicken feathers, and a feather keratin hydrogel was then prepared and used to test the in vivo wound-healing properties and biocompatibility. The results indicated that feather keratins displayed wound-healing and biodegradation properties similar to those of human hair keratins and were also highly compatible with those of the tissue and devoid of immunogenicity and systematic toxicity. Collectively, these results suggested that feather keratin hydrogel could be used for biomedical applications, particularly effective wound healing.

  6. Molecular evolution and expression of archosaurian β-keratins: diversification and expansion of archosaurian β-keratins and the origin of feather β-keratins.

    PubMed

    Greenwold, Matthew J; Sawyer, Roger H

    2013-09-01

    The archosauria consist of two living groups, crocodilians, and birds. Here we compare the structure, expression, and phylogeny of the beta (β)-keratins in two crocodilian genomes and two avian genomes to gain a better understanding of the evolutionary origin of the feather β-keratins. Unlike squamates such as the green anole with 40 β-keratins in its genome, the chicken and zebra finch genomes have over 100 β-keratin genes in their genomes, while the American alligator has 20 β-keratin genes, and the saltwater crocodile has 21 β-keratin genes. The crocodilian β-keratins are similar to those of birds and these structural proteins have a central filament domain and N- and C-termini, which contribute to the matrix material between the twisted β-sheets, which form the 2-3 nm filament. Overall the expression of alligator β-keratin genes in the integument increases during development. Phylogenetic analysis demonstrates that a crocodilian β-keratin clade forms a monophyletic group with the avian scale and feather β-keratins, suggesting that avian scale and feather β-keratins along with a subset of crocodilian β-keratins evolved from a common ancestral gene/s. Overall, our analyses support the view that the epidermal appendages of basal archosaurs used a diverse array of β-keratins, which evolved into crocodilian and avian specific clades. In birds, the scale and feather subfamilies appear to have evolved independently in the avian lineage from a subset of archosaurian claw β-keratins. The expansion of the avian specific feather β-keratin genes accompanied the diversification of birds and the evolution of feathers.

  7. Keratinization of sheath and calamus cells in developing and regenerating feathers.

    PubMed

    Alibardi, Lorenzo

    2007-01-01

    The present ultrastructural and immunocytochemical study on developing and regenerating feathers in the chick, zebrafinch and quail describes the formation of alpha-keratin cells in the sheath and their transition into beta-keratin cells in the calamus. In the first stages of feather formation cells are produced in the lower part of the follicle, migrate upward and form the elongating sheath of the feather filaments that grows outside the follicle. Sheath cells initially (anagen) contain bundles of alpha-keratin filaments. By the end of anagen at the base of the feather inside the follicle cells in continuation with the sheath produce homogenous bundles with the aspect of beta-keratin filaments. These bundles are immunoreactive for beta-keratin antibodies suggesting that beta-keratin is added to the initial framework of alpha-keratin. The packing of dense and hard corneous material in these cells eventually forms the calamus. The Latter corneous tissue replaces at the base of feathers the softer sheath present in more apical regions of the feather filaments. The increase of feather (beta)-keratin in cells of the calamus determines the formation of long bundles of corneous material. The modality of cornification in feathers is compared to the process of hard cornification of reptilian scales and claws and mammalian hairs and nails.

  8. Keratin subsidies promote feather decomposition via an increase in keratin-consuming arthropods and microorganisms in bird breeding colonies.

    PubMed

    Sugiura, Shinji; Masuya, Hayato

    2015-06-01

    Resource subsidies are well known to increase population densities of consumers. The decomposition process of these subsidised resources can be influenced by increasing consumer abundance. However, few studies have assessed whether resource subsidies can promote resource decomposition via a population increase in consumers. Here, we examined the effects of keratin subsidies on feather decomposition in egret and heron breeding colonies. Egrets and herons (Ardeidae) frequently breed in inland forests and provide large amounts of keratin materials to the forest floor in the form of feathers of chicks (that die). We compared the decrease in the weights of egret and heron feathers (experimentally placed on the forest floor) over a 12-month period among egret/heron breeding colonies (five sites) and areas outside of colonies (five sites) in central Japan. Of the feathers placed experimentally on forest floors, 92-97 % and 99-100 % in colonies and 47-50 % and 71-90 % in non-colony areas were decomposed after 4 and 12 months, respectively. Then, decomposition rates of feathers were faster in colonies than in areas outside of colonies, suggesting that keratin subsidies can promote feather decomposition in colonies. Field observations and laboratory experiments indicated that keratin-feeding arthropods and keratinophilic fungi played important roles in feather decomposition. Therefore, scavenging arthropods and keratinophilic fungi, which dramatically increased in egret and heron breeding colonies, could accelerate the decomposition of feathers supplied to the forest floor of colonies.

  9. Keratin subsidies promote feather decomposition via an increase in keratin-consuming arthropods and microorganisms in bird breeding colonies

    NASA Astrophysics Data System (ADS)

    Sugiura, Shinji; Masuya, Hayato

    2015-06-01

    Resource subsidies are well known to increase population densities of consumers. The decomposition process of these subsidised resources can be influenced by increasing consumer abundance. However, few studies have assessed whether resource subsidies can promote resource decomposition via a population increase in consumers. Here, we examined the effects of keratin subsidies on feather decomposition in egret and heron breeding colonies. Egrets and herons (Ardeidae) frequently breed in inland forests and provide large amounts of keratin materials to the forest floor in the form of feathers of chicks (that die). We compared the decrease in the weights of egret and heron feathers (experimentally placed on the forest floor) over a 12-month period among egret/heron breeding colonies (five sites) and areas outside of colonies (five sites) in central Japan. Of the feathers placed experimentally on forest floors, 92-97 % and 99-100 % in colonies and 47-50 % and 71-90 % in non-colony areas were decomposed after 4 and 12 months, respectively. Then, decomposition rates of feathers were faster in colonies than in areas outside of colonies, suggesting that keratin subsidies can promote feather decomposition in colonies. Field observations and laboratory experiments indicated that keratin-feeding arthropods and keratinophilic fungi played important roles in feather decomposition. Therefore, scavenging arthropods and keratinophilic fungi, which dramatically increased in egret and heron breeding colonies, could accelerate the decomposition of feathers supplied to the forest floor of colonies.

  10. Genomic organization, transcriptomic analysis, and functional characterization of avian α- and β-keratins in diverse feather forms.

    PubMed

    Ng, Chen Siang; Wu, Ping; Fan, Wen-Lang; Yan, Jie; Chen, Chih-Kuan; Lai, Yu-Ting; Wu, Siao-Man; Mao, Chi-Tang; Chen, Jun-Jie; Lu, Mei-Yeh Jade; Ho, Meng-Ru; Widelitz, Randall B; Chen, Chih-Feng; Chuong, Cheng-Ming; Li, Wen-Hsiung

    2014-08-24

    Feathers are hallmark avian integument appendages, although they were also present on theropods. They are composed of flexible corneous materials made of α- and β-keratins, but their genomic organization and their functional roles in feathers have not been well studied. First, we made an exhaustive search of α- and β-keratin genes in the new chicken genome assembly (Galgal4). Then, using transcriptomic analysis, we studied α- and β-keratin gene expression patterns in five types of feather epidermis. The expression patterns of β-keratin genes were different in different feather types, whereas those of α-keratin genes were less variable. In addition, we obtained extensive α- and β-keratin mRNA in situ hybridization data, showing that α-keratins and β-keratins are preferentially expressed in different parts of the feather components. Together, our data suggest that feather morphological and structural diversity can largely be attributed to differential combinations of α- and β-keratin genes in different intrafeather regions and/or feather types from different body parts. The expression profiles provide new insights into the evolutionary origin and diversification of feathers. Finally, functional analysis using mutant chicken keratin forms based on those found in the human α-keratin mutation database led to abnormal phenotypes. This demonstrates that the chicken can be a convenient model for studying the molecular biology of human keratin-based diseases.

  11. Genomic Organization, Transcriptomic Analysis, and Functional Characterization of Avian α- and β-Keratins in Diverse Feather Forms

    PubMed Central

    Fan, Wen-Lang; Yan, Jie; Chen, Chih-Kuan; Lai, Yu-Ting; Wu, Siao-Man; Mao, Chi-Tang; Chen, Jun-Jie; Lu, Mei-Yeh Jade; Ho, Meng-Ru; Widelitz, Randall B.; Chen, Chih-Feng; Chuong, Cheng-Ming; Li, Wen-Hsiung

    2014-01-01

    Feathers are hallmark avian integument appendages, although they were also present on theropods. They are composed of flexible corneous materials made of α- and β-keratins, but their genomic organization and their functional roles in feathers have not been well studied. First, we made an exhaustive search of α- and β-keratin genes in the new chicken genome assembly (Galgal4). Then, using transcriptomic analysis, we studied α- and β-keratin gene expression patterns in five types of feather epidermis. The expression patterns of β-keratin genes were different in different feather types, whereas those of α-keratin genes were less variable. In addition, we obtained extensive α- and β-keratin mRNA in situ hybridization data, showing that α-keratins and β-keratins are preferentially expressed in different parts of the feather components. Together, our data suggest that feather morphological and structural diversity can largely be attributed to differential combinations of α- and β-keratin genes in different intrafeather regions and/or feather types from different body parts. The expression profiles provide new insights into the evolutionary origin and diversification of feathers. Finally, functional analysis using mutant chicken keratin forms based on those found in the human α-keratin mutation database led to abnormal phenotypes. This demonstrates that the chicken can be a convenient model for studying the molecular biology of human keratin-based diseases. PMID:25152353

  12. Development of a keratinase activity assay using recombinant chicken feather keratin substrates

    PubMed Central

    Jin, Hyeon-Su; Park, Seon Yeong; Kim, Kyungmin; Lee, Yong-Jik; Nam, Gae-Won; Kang, Nam Joo; Lee, Dong-Woo

    2017-01-01

    Poultry feathers consist mainly of the protein keratin, which is rich in β-pleated sheets and consequently resistant to proteolysis. Although many keratinases have been identified, the reasons for their substrate specificity towards β-keratin remain unclear due to difficulties in preparing a soluble feather keratin substrate for use in activity assays. In the present study, we overexpressed Gallus gallus chromosomes 2 and 27 β-keratin-encoding genes in Escherichia coli, purified denatured recombinant proteins by Ni2+ affinity chromatography, and refolded by stepwise dialysis to yield soluble keratins. To assess the keratinolytic activity, we compared the proteolytic activity of crude extracts from the feather- degrading bacterium Fervidobacterium islandicum AW-1 with proteinase K, trypsin, and papain using purified recombinant keratin and casein as substrates. All tested proteases showed strong proteolytic activities for casein, whereas only F. islandicum AW-1 crude extracts and proteinase K exhibited pronounced keratinolytic activity for the recombinant keratin. Moreover, LC-MS/MS analysis of keratin hydrolysates allowed us to predict the P1 sites of keratinolytic enzymes in the F. islandicum AW-1 extracts, thereby qualifying and quantifying the extent of keratinolysis. The soluble keratin-based assay has clear therapeutic and industrial potential for the development of a high-throughput screening system for proteases hydrolyzing disease-related protein aggregates, as well as mechanically resilient keratin-based polymers. PMID:28231319

  13. Immunolocalization of alpha-keratins and feather beta-proteins in feather cells and comparison with the general process of cornification in the skin of mammals.

    PubMed

    Alibardi, L

    2013-03-01

    The maturation of the corneous material of feathers is a special case of cornification in vertebrate epidermis and is believed to occur mainly by the accumulation of small proteins of about 100 amino acids and a central beta-pleated sheet region known as feather keratins. The present immunocytochemical study carried out using double-labeling immunogold shows that a small amount of alpha-keratins of intermediate filament type form the early keratin clumps in barb and barbule cells. These initial nuclei of formation of corneous material are rapidly coated by the deposition of large amounts of small feather keratin-associated beta-proteins (feather keratins). The latter proteins turn the keratin bundles of barb and barbule cells into a compact and apparently amorphous mass of corneous material where no sign of intermediate filaments are seen. Feather beta-proteins however form an irregular filamentous network of 2-3nm thick electron-pale filaments and produce the characteristic feather X-ray pattern due to their prevalent amount over any other protein present in feather cells. The modality of cornification in feathers is discussed in relation to the process of formation of corneous material in the skin of vertebrates in general that occurs by the association of intermediate filament proteins and keratin-associated proteins.

  14. Hydrophobic duck feathers and their simulation on textile substrates for water repellent treatment.

    PubMed

    Liu, Yuyang; Chen, Xianqiong; Xin, J H

    2008-12-01

    Inspired by the non-wetting phenomena of duck feathers, the water repellent property of duck feathers was studied at the nanoscale. The microstructures of the duck feather were investigated by a scanning electron microscope (SEM) imaging method through a step-by-step magnifying procedure. The SEM results show that duck feathers have a multi-scale structure and that this multi-scale structure as well as the preening oil are responsible for their super hydrophobic behavior. The microstructures of the duck feather were simulated on textile substrates using the biopolymer chitosan as building blocks through a novel surface solution precipitation (SSP) method, and then the textile substrates were further modified with a silicone compound to achieve low surface energy. The resultant textiles exhibit super water repellent properties, thus providing a simple bionic way to create super hydrophobic surfaces on soft substrates using flexible material as building blocks.

  15. Keratin Durability Has Implications for the Fossil Record: Results from a 10 Year Feather Degradation Experiment.

    PubMed

    Moyer, Alison E; Zheng, Wenxia; Schweitzer, Mary H

    2016-01-01

    Keratinous 'soft tissue' structures (i.e. epidermally derived and originally non-biomineralized), include feathers, skin, claws, beaks, and hair. Despite their relatively common occurrence in the fossil record (second only to bone and teeth), few studies have addressed natural degradation processes that must occur in all organic material, including those keratinous structures that are incorporated into the rock record as fossils. Because feathers have high preservation potential and strong phylogenetic signal, in the current study we examine feathers subjected to different burial environments for a duration of ~10 years, using transmission electron microscopy (TEM) and in situ immunofluorescence (IF). We use morphology and persistence of specific immunoreactivity as indicators of preservation at the molecular and microstructural levels. We show that feather keratin is durable, demonstrates structural and microstructural integrity, and retains epitopes suitable for specific antibody recognition in even the harshest conditions. These data support the hypothesis that keratin antibody reactivity can be used to identify the nature and composition of epidermal structures in the rock record, and to address evolutionary questions by distinguishing between alpha- (widely distributed) and beta- (limited to sauropsids) keratin.

  16. Keratin Durability Has Implications for the Fossil Record: Results from a 10 Year Feather Degradation Experiment

    PubMed Central

    Moyer, Alison E.; Zheng, Wenxia; Schweitzer, Mary H.

    2016-01-01

    Keratinous ‘soft tissue’ structures (i.e. epidermally derived and originally non-biomineralized), include feathers, skin, claws, beaks, and hair. Despite their relatively common occurrence in the fossil record (second only to bone and teeth), few studies have addressed natural degradation processes that must occur in all organic material, including those keratinous structures that are incorporated into the rock record as fossils. Because feathers have high preservation potential and strong phylogenetic signal, in the current study we examine feathers subjected to different burial environments for a duration of ~10 years, using transmission electron microscopy (TEM) and in situ immunofluorescence (IF). We use morphology and persistence of specific immunoreactivity as indicators of preservation at the molecular and microstructural levels. We show that feather keratin is durable, demonstrates structural and microstructural integrity, and retains epitopes suitable for specific antibody recognition in even the harshest conditions. These data support the hypothesis that keratin antibody reactivity can be used to identify the nature and composition of epidermal structures in the rock record, and to address evolutionary questions by distinguishing between alpha- (widely distributed) and beta- (limited to sauropsids) keratin. PMID:27384819

  17. Two-dimensional Fourier analysis of the spongy medullary keratin of structurally coloured feather barbs

    PubMed Central

    Prum, R. O.; Torres, R.; Williamson, S.; Dyck, J.

    1999-01-01

    We conducted two-dimensional (2D) discrete Fourier analyses of the spatial variation in refractive index of the spongy medullary keratin from four different colours of structurally coloured feather barbs from three species of bird: the rose-faced lovebird, Agapornis roseicollis (Psittacidae), the budgerigar, Melopsittacus undulatus (Psittacidae), and the Gouldian finch, Poephila guttata (Estrildidae). These results indicate that the spongy medullary keratin is a nanostructured tissue that functions as an array of coherent scatterers. The nanostructure of the medullary keratin is nearly uniform in all directions. The largest Fourier components of spatial variation in refractive index in the tissue are of the appropriate size to produce the observed colours by constructive interference alone. The peaks of the predicted reflectance spectra calculated from the 2D Fourier power spectra are congruent with the reflectance spectra measured by using microspectrophotometry. The alternative physical models for the production of these colours, the Rayleigh and Mie theories, hypothesize that medullary keratin is an incoherent array and that scattered waves are independent in phase. This assumption is falsified by the ring-like Fourier power spectra of these feathers, and the spacing of the scattering air vacuoles in the medullary keratin. Structural colours of avian feather barbs are produced by constructive interference of coherently scattered light waves from the optically heterogeneous matrix of keratin and air in the spongy medullary layer.

  18. Development of colour-producing β-keratin nanostructures in avian feather barbs

    PubMed Central

    Prum, Richard O.; Dufresne, Eric R.; Quinn, Tim; Waters, Karla

    2009-01-01

    The non-iridescent structural colours of avian feather barbs are produced by coherent light scattering from amorphous (i.e. quasi-ordered) nanostructures of β-keratin and air in the medullary cells of feather barb rami. Known barb nanostructures belong to two distinct morphological classes. ‘Channel’ nanostructures consist of β-keratin bars and air channels of elongate, tortuous and twisting forms. ‘Spherical’ nanostructures consist of highly spherical air cavities that are surrounded by thin β-keratin bars and sometimes interconnected by tiny passages. Using transmission electron microscopy, we observe that the colour-producing channel-type nanostructures of medullary β-keratin in feathers of the blue-and-yellow macaw (Ara ararauna, Psittacidae) develop by intracellular self-assembly; the process proceeds in the absence of any biological prepattern created by the cell membrane, endoplasmic reticulum or cellular intermediate filaments. We examine the hypothesis that the shape and size of these self-assembled, intracellular nanostructures are determined by phase separation of β-keratin protein from the cytoplasm of the cell. The shapes of a broad sample of colour-producing channel-type nanostructures from nine avian species are very similar to those self-assembled during the phase separation of an unstable mixture, a process called spinodal decomposition (SD). In contrast, the shapes of a sample of spherical-type nanostructures from feather barbs of six species show a poor match to SD. However, spherical nanostructures show a strong morphological similarity to morphologies produced by phase separation of a metastable mixture, called nucleation and growth. We propose that colour-producing, intracellular, spongy medullary β-keratin nanostructures develop their characteristic sizes and shapes by phase separation during protein polymerization. We discuss the possible role of capillary flow through drying of medullary cells in the development of the hollow

  19. Hydrogen isotope measurement of bird feather keratin, one laboratory's response to evolving methodologies.

    PubMed

    Fan, Majie; Dettman, David L

    2015-01-01

    Hydrogen in organic tissue resides in a complex mixture of molecular contexts. Some hydrogen, called non-exchangeable (H(non)), is strongly bound, and its isotopic ratio is fixed when the tissue is synthesized. Other pools of hydrogen, called exchangeable hydrogen (H(ex)), constantly exchange with ambient water vapor. The measurement of the δ(2)H(non) in organic tissues such as hair or feather therefore requires an analytical process that accounts for exchangeable hydrogen. In this study, swan feather and sheep wool keratin were used to test the effects of sample drying and capsule closure on the measurement of δ(2)H(non) values, and the rate of back-reaction with ambient water vapor. Homogenous feather or wool keratins were also calibrated at room temperature for use as control standards to correct for the effects of exchangeable hydrogen on feathers. Total δ(2)H values of both feather and wool samples showed large changes throughout the first ∼6 h of drying. Desiccant plus low vacuum seems to be more effective than room temperature vacuum pumping for drying samples. The degree of capsule closure affects exchangeable hydrogen equilibration and drying, with closed capsules responding more slowly. Using one control keratin standard to correct for the δ(2)H(ex) value for a batch of samples leads to internally consistent δ(2)H(non) values for other calibrated keratins run as unknowns. When placed in the context of other recent improvements in the measurement of keratin δ(2)H(non) values, we make recommendations for sample handing, data calibration and the reporting of results.

  20. The effects of environmental enrichment devices on feather picking in commercially housed Pekin ducks.

    PubMed

    Colton, S; Fraley, G S

    2014-09-01

    Like other poultry species, Pekin ducks occasionally show an auto-mutilation behavior referred to as feather picking. Self-picking can lead to further pecking by conspecifics and ultimately to reduced feather quality and poor overall health of the bird. Although the reasons underlying feather picking are not clear, it appears to occur when the ducks are transitioning between downy feathers and adult plumage, between 17 and 22 d of age. We hypothesized that giving Pekin ducks a substitute outlet for this behavior in the form of environmental enrichment devices (EED) would decrease feather picking and improve feather quality and duck health and welfare. The EED were plastic Wiffle-style balls, each threaded with 4 zip-ties. In the first experiment, we set out to determine that placement of EED would not induce fear or harmful behaviors. Five barns were each divided into 2 pens, holding an average combined total of approximately 4,500 ducks with one pen per barn used as control. Upon placement of the EED in one pen per barn, both pens were videotaped for a total of 2 h per day. The physical characteristics of 100 ducks per pen were scored at age 7, 21, 28, and 35. Results showed a decrease (P = 0.034) in both self-picking and conspecific-pecking in pens with EED compared with pens without EED. Although no differences in body condition scores were observed at 7 d of age, by d 21 ducks with EED showed better (P = 0.021) feather quality and cleanliness scores compared with ducks without EED. In a second experiment, we set out to determine if ducks had a color preference for blue/green, red, or white EED. Again, ducks with EED showed reduced (P = 0.038) feather picking compared with ducks without EED. Ducks interacted considerably more (P = 0.00089) frequently with blue/green EED then either red or white EED. These results suggest that providing environmental enrichment may minimize feather picking and improve feather quality and duck welfare.

  1. Molecular evidence of keratin and melanosomes in feathers of the Early Cretaceous bird Eoconfuciusornis.

    PubMed

    Pan, Yanhong; Zheng, Wenxia; Moyer, Alison E; O'Connor, Jingmai K; Wang, Min; Zheng, Xiaoting; Wang, Xiaoli; Schroeter, Elena R; Zhou, Zhonghe; Schweitzer, Mary H

    2016-12-06

    Microbodies associated with feathers of both nonavian dinosaurs and early birds were first identified as bacteria but have been reinterpreted as melanosomes. Whereas melanosomes in modern feathers are always surrounded by and embedded in keratin, melanosomes embedded in keratin in fossils has not been demonstrated. Here we provide multiple independent molecular analyses of both microbodies and the associated matrix recovered from feathers of a new specimen of the basal bird Eoconfuciusornis from the Early Cretaceous Jehol Biota of China. Our work represents the oldest ultrastructural and immunological recognition of avian beta-keratin from an Early Cretaceous (∼130-Ma) bird. We apply immunogold to identify protein epitopes at high resolution, by localizing antibody-antigen complexes to specific fossil ultrastructures. Retention of original keratinous proteins in the matrix surrounding electron-opaque microbodies supports their assignment as melanosomes and adds to the criteria employable to distinguish melanosomes from microbial bodies. Our work sheds new light on molecular preservation within normally labile tissues preserved in fossils.

  2. Feather keratin hydrolysates obtained from microbial keratinases: effect on hair fiber

    PubMed Central

    2013-01-01

    Background Hair is composed mainly of keratin protein and a small amount of lipid. Protein hydrolysates, in particular those with low molecular weight distribution have been known to protect hair against chemical and environmental damage. Many types of protein hydrolysates from plants and animals have been used in hair and personal care such as keratin hydrolysates obtained from nails, horns and wool. Most of these hydrolysates are obtained by chemical hydrolysis and hydrothermal methods, but recently hydrolyzed hair keratin, feather keratin peptides, and feather meal peptides have been obtained by enzymatic hydrolysis using Bacillus spp in submerged fermentation. Results Keratin peptides were obtained by enzymatic hydrolysis of keratinases using Bacillus subtilis AMR. The microorganism was grown on a feather medium, pH 8.0 (1% feathers) and supplemented with 0.01% of yeast extract, for 5 days, at 28°C with agitation. The supernatant containing the hydrolysates was colleted by centrifugation and ultra filtered in an AMICON system using nano–membranes (Millipore – YC05). The Proteins and peptides were analyzed using HPTLC and MALDI-TOF-MS. Commercial preparations of keratin hydrolysates were used as a comparative standard. After five days the feather had been degraded (90-95%) by the peptidases and keratinases of the microorganism. MALDI-TOF mass spectrometry showed multiple peaks that correspond to peptides in the range of 800 to 1079 Daltons and the commercial hydrolysate was in the range of 900 to 1400 Da. HPTLC showed lower molecular mass peptides and amino acids in the enzymatic hydrolysate when compared with the commercial hydrolysate . A mild shampoo and a rinse off conditioner were formulated with the enzymatic hydrolysate and applied to hair fibers to evaluate the hydration, with and without heat, using a Corneometer® CM 825. The hydration was more efficient with heat, suggesting a more complete incorporation of hydrolysates into the fibers

  3. The chicken frizzle feather is due to an α-keratin (KRT75) mutation that causes a defective rachis.

    PubMed

    Ng, Chen Siang; Wu, Ping; Foley, John; Foley, Anne; McDonald, Merry-Lynn; Juan, Wen-Tau; Huang, Chih-Jen; Lai, Yu-Ting; Lo, Wen-Sui; Chen, Chih-Feng; Leal, Suzanne M; Zhang, Huanmin; Widelitz, Randall B; Patel, Pragna I; Li, Wen-Hsiung; Chuong, Cheng-Ming

    2012-01-01

    Feathers have complex forms and are an excellent model to study the development and evolution of morphologies. Existing chicken feather mutants are especially useful for identifying genetic determinants of feather formation. This study focused on the gene F, underlying the frizzle feather trait that has a characteristic curled feather rachis and barbs in domestic chickens. Our developmental biology studies identified defects in feather medulla formation, and physical studies revealed that the frizzle feather curls in a stepwise manner. The frizzle gene is transmitted in an autosomal incomplete dominant mode. A whole-genome linkage scan of five pedigrees with 2678 SNPs revealed association of the frizzle locus with a keratin gene-enriched region within the linkage group E22C19W28_E50C23. Sequence analyses of the keratin gene cluster identified a 69 bp in-frame deletion in a conserved region of KRT75, an α-keratin gene. Retroviral-mediated expression of the mutated F cDNA in the wild-type rectrix qualitatively changed the bending of the rachis with some features of frizzle feathers including irregular kinks, severe bending near their distal ends, and substantially higher variations among samples in comparison to normal feathers. These results confirmed KRT75 as the F gene. This study demonstrates the potential of our approach for identifying genetic determinants of feather forms.

  4. Colour-producing β-keratin nanofibres in blue penguin (Eudyptula minor) feathers.

    PubMed

    D'Alba, Liliana; Saranathan, Vinodkumar; Clarke, Julia A; Vinther, Jakob A; Prum, Richard O; Shawkey, Matthew D

    2011-08-23

    The colours of living organisms are produced by the differential absorption of light by pigments (e.g. carotenoids, melanins) and/or by the physical interactions of light with biological nanostructures, referred to as structural colours. Only two fundamental morphologies of non-iridescent nanostructures are known in feathers, and recent work has proposed that they self-assemble by intracellular phase separation processes. Here, we report a new biophotonic nanostructure in the non-iridescent blue feather barbs of blue penguins (Eudyptula minor) composed of parallel β-keratin nanofibres organized into densely packed bundles. Synchrotron small angle X-ray scattering and two-dimensional Fourier analysis of electron micrographs of the barb nanostructure revealed short-range order in the organization of fibres at the appropriate size scale needed to produce the observed colour by coherent scattering. These two-dimensional quasi-ordered penguin nanostructures are convergent with similar arrays of parallel collagen fibres in avian and mammalian skin, but constitute a novel morphology for feathers. The identification of a new class of β-keratin nanostructures adds significantly to the known mechanisms of colour production in birds and suggests additional complexity in their self-assembly.

  5. Colour-producing [beta]-keratin nanofibres in blue penguin (Eudyptula minor) feathers

    SciTech Connect

    D; Alba, Liliana; Saranathan, Vinodkumar; Clarke, Julia A.; Vinther, Jakob A.; Prum, Richard O.; Shawkey, Matthew D.

    2012-03-26

    The colours of living organisms are produced by the differential absorption of light by pigments (e.g. carotenoids, melanins) and/or by the physical interactions of light with biological nanostructures, referred to as structural colours. Only two fundamental morphologies of non-iridescent nanostructures are known in feathers, and recent work has proposed that they self-assemble by intracellular phase separation processes. Here, we report a new biophotonic nanostructure in the non-iridescent blue feather barbs of blue penguins (Eudyptula minor) composed of parallel {beta}-keratin nanofibres organized into densely packed bundles. Synchrotron small angle X-ray scattering and two-dimensional Fourier analysis of electron micrographs of the barb nanostructure revealed short-range order in the organization of fibres at the appropriate size scale needed to produce the observed colour by coherent scattering. These two-dimensional quasi-ordered penguin nanostructures are convergent with similar arrays of parallel collagen fibres in avian and mammalian skin, but constitute a novel morphology for feathers. The identification of a new class of {beta}-keratin nanostructures adds significantly to the known mechanisms of colour production in birds and suggests additional complexity in their self-assembly.

  6. Origin of archosaurian integumentary appendages: the bristles of the wild turkey beard express feather-type beta keratins.

    PubMed

    Sawyer, Roger H; Washington, Lynette D; Salvatore, Brian A; Glenn, Travis C; Knapp, Loren W

    2003-06-15

    The discovery that structurally unique "filamentous integumentary appendages" are associated with several different non-avian dinosaurs continues to stimulate the development of models to explain the evolutionary origin of feathers. Taking the phylogenetic relationships of the non-avian dinosaurs into consideration, some models propose that the "filamentous integumentary appendages" represent intermediate stages in the sequential evolution of feathers. Here we present observations on a unique integumentary structure, the bristle of the wild turkey beard, and suggest that this non-feather appendage provides another explanation for some of the "filamentous integumentary appendages." Unlike feathers, beard bristles grow continuously from finger-like outgrows of the integument lacking follicles. We find that these beard bristles, which show simple branching, are hollow, distally, and express the feather-type beta keratins. The significance of these observations to explanations for the evolution of archosaurian integumentary appendages is discussed.

  7. Feather and faecal corticosterone concentrations predict future reproductive decisions in harlequin ducks (Histrionicus histrionicus)

    PubMed Central

    Hansen, Warren K.; Bate, Lisa J.; Landry, Devin W.; Chastel, Olivier; Parenteau, Charline; Breuner, Creagh W.

    2016-01-01

    Understanding sources of reproductive variation can inform management and conservation decisions, population ecology and life-history theory. Annual reproductive variation can drive population growth rate and can be influenced by factors from across the annual cycle (known as carry-over effects). The majority of studies, however, focus solely on the role of current environmental events. Past events often influence future reproductive decisions and success but can be logistically difficult to collect and quantify, especially in migratory species. Recent work indicates that glucocorticoids may prove good indicators to evaluate carry-over effects across life-history transitions. Here, we evaluated three different measures of glucocorticoid physiology (feathers, faeces and plasma) to evaluate the predictability of future breeding decision in the harlequin duck (Histrionicus histrionicus). We collected tail and back feathers, plasma and faeces for glucocorticoid analysis, and fitted female harlequin ducks with very high-frequency transmitters to track their breeding decisions. Both back feathers (moulted immediately before the current season) and faecal glucocorticoid metabolites were identified as important predictive factors of reproductive decisions; high concentrations of glucocorticoid metabolites in back feathers and faeces predicted a higher likelihood of reproductive deferral for the year. Although back and tail feather corticosterone concentrations were correlated, tail feathers (moulted at the end of the previous breeding season) did not predict breeding decisions. Plasma corticosterone concentrations were collected over too broad a time range after capture to be useful in this study. This study demonstrates the utility of non-invasive corticosterone metrics in predicting breeding decisions and supports the use of feathers to measure carry-over effects in migratory birds. With this technique, we identified the prenuptial moult as an important life

  8. Biodegradation of feather waste keratin by a keratinolytic soil fungus of the genus Chrysosporium and statistical optimization of feather mass loss.

    PubMed

    Bohacz, Justyna

    2017-01-01

    This paper assesses the ability of strains of Aphanoascus fulvescens and Chrysosporium articulatum isolated from soil (phaesol) to degrade native feather keratin. Strains were identified based on phenotypic traits and nucleotide sequencing. Response Surface Methodology was used to optimize cultivation conditions exhibiting the highest keratinolytic activity. The experiments were based on Box-Behnken designs for the loss of substrate mass (chicken feathers). While substrate mass loss is an "economic coefficient" that reliably indicates feather keratin degradation, it has not been studied before. Stationary liquid cultures of five selected strains were conducted in laboratory conditions at 28 °C using poultry feathers (1 g) as the sole source of carbon, nitrogen and energy. Enzymatic activities, keratin mineralization products and substrate mass loss were determined periodically. The mineralization of keratin proteins by strains yielded a high number of ammonium ions alkalinizing the medium. Increased ammonium ions inhibited the activity of caseinian protease and keratinase. A decrease in the concentration of these ions induced proteolytic enzymes, chiefly the activity of keratinase, at the end of fungal cultivation. Keratinase activity was related to protein- and peptide release and that of caseinian protease to sulfate ions. The highest loss of substrate mass in comparison to the reference strain CBS104.62 (35.4%) was recorded for Aphanoascus fulvescens B21/4-5 (65.9%). Based on a Box-Behnken design, the maximum loss of substrate mass for the Aphanoascus fulvescens strain (71.08%) can be achieved at pH 7.58 and temperature 28.7 °C.

  9. A New Helical Crossed-Fibre Structure of β-Keratin in Flight Feathers and Its Biomechanical Implications

    PubMed Central

    Lingham-Soliar, Theagarten; Murugan, Nelisha

    2013-01-01

    The feather aerofoil is unequalled in nature. It is comprised of a central rachis, serial paired branches or barbs, from which arise further branches, the barbules. Barbs and barbules arise from the significantly thinner lateral walls (the epicortex) of the rachis and barbs respectively, as opposed to the thicker dorsal and ventral walls (the cortex). We hypothesized a microstructural design of the epicortex that would resist the vertical or shearing stresses. The microstructures of the cortex and epicortex of the rachis and barbs were investigated in several bird species by microbe-assisted selective disassembly and conventional methods via scanning electron microscopy. We report, preeminent of the finds, a novel system of crossed fibres (ranging from ∼100–800 nm in diameter), oppositely oriented in alternate layers of the epicortex in the rachis and barbs. It represents the first cross-fibre microstructure, not only for the feather but in keratin per se. The cortex of the barbs is comprised of syncitial barbule cells, definitive structural units shown in the rachidial cortex in a related study. The structural connection between the cortex of the rachis and barbs appears uninterrupted. A new model on feather microstructure incorporating the findings here and in the related study is presented. The helical fibre system found in the integument of a diverse range of invertebrates and vertebrates has been implicated in profound functional strategies, perhaps none more so potentially than in the aerofoil microstructure of the feather here, which is central to one of the marvels of nature, bird flight. PMID:23762440

  10. The chicken frizzle feather is due to an a-keratin (KRT75) mutation that causes a defective rachis

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Feathers have complex forms and are an excellent model to study the development and evolution of morphologies. Existing chicken feather mutants are especially useful for identifying genetic determinants of feather formation. The present study focused on the gene, F, underlying the frizzle feather tr...

  11. Carbonate deposition on tail feathers of ruddy ducks using evaporation ponds

    USGS Publications Warehouse

    Euliss, N.H.; Jarvis, R.L.; Gilmer, D.S.

    1989-01-01

    Substantial carbonate deposits were observed on rectrices of Ruddy Ducks (Oxyura jamaicensis) collected during 1982-1984 on evaporation ponds in the San Joaquin Valley, California. Carbonate deposits were composed of about 75% aragonite and 25% calcite, both polymorphous forms of CaCO3. Significantly more carbonate deposits were observed on Ruddy Ducks as length of exposure to agricultural drain water increased, during the 1983-1984 field season when salt concentrations in the ponds were higher, and in certain evaporation-pond systems.

  12. A comparative evaluation of feathers, oropharyngeal swabs, and cloacal swabs for the detection of H5N1 highly pathogenic avian influenza virus infection in experimentally infected chickens and ducks.

    PubMed

    Nuradji, Harimurti; Bingham, John; Lowther, Sue; Wibawa, Hendra; Colling, Axel; Long, Ngo Thanh; Meers, Joanne

    2015-11-01

    Oropharyngeal and cloacal swabs have been widely used for the detection of H5N1 highly pathogenic avian Influenza A virus (HPAI virus) in birds. Previous studies have shown that the feather calamus is a site of H5N1 virus replication and therefore has potential for diagnosis of avian influenza. However, studies characterizing the value of feathers for this purpose are not available, to our knowledge; herein we present a study investigating feathers for detection of H5N1 virus. Ducks and chickens were experimentally infected with H5N1 HPAI virus belonging to 1 of 3 clades (Indonesian clades 2.1.1 and 2.1.3, Vietnamese clade 1). Different types of feathers and oropharyngeal and cloacal swab samples were compared by virus isolation. In chickens, virus was detected from all sample types: oral and cloacal swabs, and immature pectorosternal, flight, and tail feathers. During clinical disease, the viral titers were higher in feathers than swabs. In ducks, the proportion of virus-positive samples was variable depending on viral strain and time from challenge; cloacal swabs and mature pectorosternal feathers were clearly inferior to oral swabs and immature pectorosternal, tail, and flight feathers. In ducks infected with Indonesian strains, in which most birds did not develop clinical signs, all sampling methods gave intermittent positive results; 3-23% of immature pectorosternal feathers were positive during the acute infection period; oropharyngeal swabs had slightly higher positivity during early infection, while feathers performed better during late infection. Our results indicate that immature feathers are an alternative sample for the diagnosis of HPAI in chickens and ducks.

  13. Use of Stable Isotopes to Investigate Keratin Deposition in the Claw Tips of Ducks

    PubMed Central

    Hopkins, John B.; Cutting, Kyle A.; Warren, Jeffrey M.

    2013-01-01

    Stable isotopes derived from the claws of birds could be used to determine the migratory origins of birds if the time periods represented in excised sections of claws were known. We investigated new keratin growth in the claws of adult female Lesser Scaup (Aythya affinis) by estimating the equilibration rates of stable isotopes (δ13C, δ15N, and δ2H) from the breeding grounds into 1 mm claw tips. We sampled birds on their breeding ground through time and found that it took approximately 3–3.5 months for isotope values in most claw tips to equilibrate to isotope values that reflected those present in the environment on their breeding grounds. Results from this study suggest that isotopes equilibrate slowly into claw tips of Lesser Scaup, suggesting isotopes could potentially be used to determine the wintering grounds of birds. We suggest using controlled feeding experiments or longitudinal field investigations to understand claw growth and isotopic equilibration in claw tips. Such information would be valuable in ascertaining whether claw tips can be used in future studies to identify the migratory origins of birds. PMID:24282563

  14. Keratinase production and biodegradation of whole chicken feather keratin by a newly isolated bacterium under submerged fermentation.

    PubMed

    Sahoo, Dipak K; Das, Arpan; Thatoi, Hrudayanath; Mondal, Keshab C; Mohapatra, Pradeep K Das

    2012-07-01

    A new feather-degrading bacterium PKD 5 was isolated from feather dumping soil and identified as Bacillus weihenstephanensis based on morphological and physiochemical characteristics as well as 16S rRNA gene analysis. Extracellular keratinase was produced during submerged aerobic cultivation in a medium containing chicken feather as sole carbon and energy source and supplemented with salt solutions (NaCl 5.0, MgSO₄ 1.0, K₂HPO₄ 1.0, (NH₄)₂SO₄, 2.0 g/l). The optimal conditions for keratinase production include initial pH of 7.0, inoculum size of 2% (v/v), and cultivation at 40 °C. The maximum keratinase production and keratinolytic activity of PKD 5 was achieved after 7 days of fermentation under shaking condition (120 rpm). The enzyme has found application in developing cost-effective feather by-products for feeds and fertilizers. The manuscript first time describes B. weihenstephanensis PKD 5-mediated keratinase production under submerged fermentation and whole chicken feather biodegradation.

  15. Thermally processed keratin films

    NASA Astrophysics Data System (ADS)

    Barone, Justin; Schmidt, Walter

    2004-03-01

    Keratin obtained from poultry feathers is blended with -OH containing second phases. Films are prepared by pressing the blended keratin at temperatures concurrent with typical polymer processing temperatures. The films are completely cohesive as opposed to partially cohesive if pressed under the same conditions without blending. The films are "tough" and the mechanical properties show similarities to the properties of commercially available commodity thermoplastics. The keratin films are produced in a few minutes without reducing or oxidizing agents. The mobility of the keratin chains during blending is shown to relate to the serine (S), threonine (T), and tyrosine (Y) contents in the amino acid sequence relative to cystine (C).

  16. 50 CFR 20.91 - Commercial use of feathers.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 50 Wildlife and Fisheries 8 2011-10-01 2011-10-01 false Commercial use of feathers. 20.91 Section... WILDLIFE AND PLANTS (CONTINUED) MIGRATORY BIRD HUNTING Feathers or Skins § 20.91 Commercial use of feathers... pillows, and mattresses, and for similar commercial uses the feathers of migratory waterfowl (ducks,...

  17. 50 CFR 20.91 - Commercial use of feathers.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 50 Wildlife and Fisheries 6 2010-10-01 2010-10-01 false Commercial use of feathers. 20.91 Section... WILDLIFE AND PLANTS (CONTINUED) MIGRATORY BIRD HUNTING Feathers or Skins § 20.91 Commercial use of feathers... pillows, and mattresses, and for similar commercial uses the feathers of migratory waterfowl (ducks,...

  18. Bioprospecting keratinous materials.

    PubMed

    Jones, L N; Sinclair, R D; Carver, J; Ecroyd, H; Lui, Y; Bennett, L E

    2010-01-01

    The concept of bioprospecting for bioactive peptides from keratin-containing materials such as wool, hair, skin and feathers presents an exciting opportunity for discovery of novel functional food ingredients and nutraceuticals, while value-adding to cheap and plentiful natural sources. The published literature reports multiple examples of proline-rich peptides with productive bio-activity in models of human disease including tumour formation, hypertension control and Alzheimer's disease. Bioactive peptides have been identified from food and other protein sources however the bioactivity of keratin-related proteins and peptides is largely unknown. Considering the high representation of proline-rich peptides among proven bioactive peptides, the proline-rich character of keratinous proteins supports current research. A selection of mammalian (cow epidermis, sheep wool) and avian (chicken feather) keratinous materials were subjected to enzymatic hydrolysis using established processing methods. A bio-assay of determining inhibition of early stage amyloid aggregation involved using a model fibril-forming protein - reduced and carboxymethylated bovine K-casein (RCMk-CN) and quantitation of fibril development with the amyloid-specific fluorophore, Thioflavin T (ThT). The assay was fully validated for analytical repeatability and used together with appropriate positive controls. Peptide library products derived from chicken feather (n=9), sheep wool (n=9) and bovine epidermis (n=9) were screened in the fibril inhibition assay based on K-casein. 3 of 27 products exhibited interesting levels of bio-activity with regard to fibril inhibition. HPLC profiles provide an indication of the complexity of the assemblage of peptides in the three active products. We conclude the bioprospecting research using keratinous materials shows promise for discovery of useful bioactive peptides.

  19. The evolutionary origin and diversification of feathers.

    PubMed

    Prum, Richard O; Brush, Alan H

    2002-09-01

    Progress on the evolutionary origin and diversification of feathers has been hampered by conceptual problems and by the lack of plesiomorphic feather fossils. Recently, both of these limitations have been overcome by the proposal of the developmental theory of the origin of feathers, and the discovery of primitive feather fossils on nonavian theropod dinosaurs. The conceptual problems of previous theories of the origin of feathers are reviewed, and the alternative developmental theory is presented and discussed. The developmental theory proposes that feathers evolved through a series of evolutionary novelties in developmental mechanisms of the follicle and feather germ. The discovery of primitive and derived fossil feathers on a diversity of coelurosaurian theropod dinosaurs documents that feathers evolved and diversified in nonavian theropods before the origin of birds and before the origin of flight. The morphologies of these primitive feathers are congruent with the predictions of the developmental theory. Alternatives to the theropod origin of feathers are critique and rejected. Hypotheses for the initial function of feathers are reviewed. The aerodynamic theory of feather origins is falsified, but many other functions remain developmentally and phylogenetically plausible. Whatever their function, feathers evolved by selection for a follicle that would grow an emergent tubular appendage. Feathers are inherently tubular structures. The homology of feathers and scales is weakly supported. Feathers are composed of a suite of evolutionary novelties that evolved by the duplication, hierarchical organization, interaction, dissociation, and differentiation of morphological modules. The unique capacity for modular subdivision of the tubular feather follicle and germ has fostered the evolution of numerous innovations that characterize feathers. The evolution of feather keratin and the molecular basis of feather development are also discussed.

  20. Keratin Transamidation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Low molecular weight keratin was self-crosslinked by microbial transglutaminase (mTGase) for application to wool fabric. From amino acid determination, keratin produced by the alkaline hydrolysis of wool showed requisite glutamine and lysine required for mTGase-mediated transamidation. Keratin sho...

  1. Colourful parrot feathers resist bacterial degradation.

    PubMed

    Burtt, Edward H; Schroeder, Max R; Smith, Lauren A; Sroka, Jenna E; McGraw, Kevin J

    2011-04-23

    The brilliant red, orange and yellow colours of parrot feathers are the product of psittacofulvins, which are synthetic pigments known only from parrots. Recent evidence suggests that some pigments in bird feathers function not just as colour generators, but also preserve plumage integrity by increasing the resistance of feather keratin to bacterial degradation. We exposed a variety of colourful parrot feathers to feather-degrading Bacillus licheniformis and found that feathers with red psittacofulvins degraded at about the same rate as those with melanin and more slowly than white feathers, which lack pigments. Blue feathers, in which colour is based on the microstructural arrangement of keratin, air and melanin granules, and green feathers, which combine structural blue with yellow psittacofulvins, degraded at a rate similar to that of red and black feathers. These differences in resistance to bacterial degradation of differently coloured feathers suggest that colour patterns within the Psittaciformes may have evolved to resist bacterial degradation, in addition to their role in communication and camouflage.

  2. Colourful parrot feathers resist bacterial degradation

    PubMed Central

    Burtt, Edward H.; Schroeder, Max R.; Smith, Lauren A.; Sroka, Jenna E.; McGraw, Kevin J.

    2011-01-01

    The brilliant red, orange and yellow colours of parrot feathers are the product of psittacofulvins, which are synthetic pigments known only from parrots. Recent evidence suggests that some pigments in bird feathers function not just as colour generators, but also preserve plumage integrity by increasing the resistance of feather keratin to bacterial degradation. We exposed a variety of colourful parrot feathers to feather-degrading Bacillus licheniformis and found that feathers with red psittacofulvins degraded at about the same rate as those with melanin and more slowly than white feathers, which lack pigments. Blue feathers, in which colour is based on the microstructural arrangement of keratin, air and melanin granules, and green feathers, which combine structural blue with yellow psittacofulvins, degraded at a rate similar to that of red and black feathers. These differences in resistance to bacterial degradation of differently coloured feathers suggest that colour patterns within the Psittaciformes may have evolved to resist bacterial degradation, in addition to their role in communication and camouflage. PMID:20926430

  3. Non-food industrial applications of poultry feathers.

    PubMed

    Reddy, Narendra

    2015-11-01

    Poultry feathers are one of the unique coproducts that have versatile applications ranging from composites, fibers, tissue engineering scaffolds, nano and micro particles, electronic devices and many others. Despite their low cost, abundant availability, wide applicability and unique properties, non-food industrial applications of feather keratin are very limited. Poor-thermoplasticity, difficulty in dissolving keratin and limited knowledge on the processability and properties of products developed are some of the limitations for the large scale use of feather/keratin. Nevertheless, increasing interests in using renewable and sustainable raw materials and need to decrease dependence on non-renewable petroleum resources make feathers an attractive raw material for bioproducts. This review provides an overview of the products developed from poultry feathers and their limitations and advantages.

  4. Skin Keratins

    PubMed Central

    Wang, Fengrong; Zieman, Abigail; Coulombe, Pierre A.

    2016-01-01

    Keratins comprise the type I and type II intermediate filament-forming proteins and occur primarily in epithelial cells. They are encoded by 54 evolutionarily conserved genes (28 type I, 26 type II) and regulated in a pairwise and tissue type-, differentiation-, and context-dependent manner. Keratins serve multiple homeostatic and stress-enhanced mechanical and nonmechanical functions in epithelia, including the maintenance of cellular integrity, regulation of cell growth and migration, and protection from apoptosis. These functions are tightly regulated by posttranslational modifications as well as keratin-associated proteins. Genetically determined alterations in keratin-coding sequences underlie highly penetrant and rare disorders whose pathophysiology reflects cell fragility and/or altered tissue homeostasis. Moreover, keratin mutation or misregulation represents risk factors or genetic modifiers for several acute and chronic diseases. This chapter focuses on keratins that are expressed in skin epithelia, and details a number of basic protocols and assays that have proven useful for analyses being carried out in skin. PMID:26795476

  5. beta-Keratins in crocodiles reveal amino acid homology with avian keratins.

    PubMed

    Ye, Changjiang; Wu, Xiaobing; Yan, Peng; Amato, George

    2010-03-01

    The DNA sequences encoding beta-keratin have been obtained from Marsh Mugger (Crocodylus palustris) and Orinoco Crocodiles (Crocodylus intermedius). Through the deduced amino acid sequence, these proteins are rich in glycine, proline and serine. The central region of the proteins are composed of two beta-folded regions and show a high degree of identity with beta-keratins of aves and squamates. This central part is thought to be the site of polymerization to build the framework of beta-keratin filaments. It is believed that the beta-keratins in reptiles and birds share a common ancestry. Near the C-terminal, these beta-keratins contain a peptide rich in glycine-X and glycine-X-X, and the distinctive feature of the region is some 12-amino acid repeats, which are similar to the 13-amino acid repeats in chick scale keratin but absent from avian feather keratin. From our phylogenetic analysis, the beta-keratins in crocodile have a closer relationship with avian keratins than the other keratins in reptiles.

  6. What makes a feather shine? A nanostructural basis for glossy black colours in feathers

    PubMed Central

    Maia, Rafael; D'Alba, Liliana; Shawkey, Matthew D.

    2011-01-01

    Colours in feathers are produced by pigments or by nanostructurally organized tissues that interact with light. One of the simplest nanostructures is a single layer of keratin overlying a linearly organized layer of melanosomes that create iridescent colours of feather barbules through thin-film interference. Recently, it has been hypothesized that glossy (i.e. high specular reflectance) black feathers may be evolutionarily intermediate between matte black and iridescent feathers, and thus have a smooth keratin layer that produces gloss, but not the layered organization of melanosomes needed for iridescence. However, the morphological bases of glossiness remain unknown. Here, we use a theoretical approach to generate predictions about morphological differences between matte and glossy feathers that we then empirically test. Thin-film models predicted that glossy spectra would result from a keratin layer 110–180 nm thick and a melanin layer greater than 115 nm thick. Transmission electron microscopy data show that nanostructure of glossy barbules falls well within that range, but that of matte barbules does not. Further, glossy barbules had a thinner and more regular keratin cortex, as well as a more continuous underlying melanin layer, than matte barbules. Thus, their quasi-ordered nanostructures are morphologically intermediate between matte black and iridescent feathers, and perceived gloss may be a form of weakly chromatic iridescence. PMID:21123257

  7. What makes a feather shine? A nanostructural basis for glossy black colours in feathers.

    PubMed

    Maia, Rafael; D'Alba, Liliana; Shawkey, Matthew D

    2011-07-07

    Colours in feathers are produced by pigments or by nanostructurally organized tissues that interact with light. One of the simplest nanostructures is a single layer of keratin overlying a linearly organized layer of melanosomes that create iridescent colours of feather barbules through thin-film interference. Recently, it has been hypothesized that glossy (i.e. high specular reflectance) black feathers may be evolutionarily intermediate between matte black and iridescent feathers, and thus have a smooth keratin layer that produces gloss, but not the layered organization of melanosomes needed for iridescence. However, the morphological bases of glossiness remain unknown. Here, we use a theoretical approach to generate predictions about morphological differences between matte and glossy feathers that we then empirically test. Thin-film models predicted that glossy spectra would result from a keratin layer 110-180 nm thick and a melanin layer greater than 115 nm thick. Transmission electron microscopy data show that nanostructure of glossy barbules falls well within that range, but that of matte barbules does not. Further, glossy barbules had a thinner and more regular keratin cortex, as well as a more continuous underlying melanin layer, than matte barbules. Thus, their quasi-ordered nanostructures are morphologically intermediate between matte black and iridescent feathers, and perceived gloss may be a form of weakly chromatic iridescence.

  8. Topographical mapping of α- and β-keratins on developing chicken skin integuments: Functional interaction and evolutionary perspectives

    PubMed Central

    Wu, Ping; Ng, Chen Siang; Yan, Jie; Lai, Yung-Chih; Chen, Chih-Kuan; Lai, Yu-Ting; Wu, Siao-Man; Chen, Jiun-Jie; Luo, Weiqi; Widelitz, Randall B.; Li, Wen-Hsiung; Chuong, Cheng-Ming

    2015-01-01

    Avian integumentary organs include feathers, scales, claws, and beaks. They cover the body surface and play various functions to help adapt birds to diverse environments. These keratinized structures are mainly composed of corneous materials made of α-keratins, which exist in all vertebrates, and β-keratins, which only exist in birds and reptiles. Here, members of the keratin gene families were used to study how gene family evolution contributes to novelty and adaptation, focusing on tissue morphogenesis. Using chicken as a model, we applied RNA-seq and in situ hybridization to map α- and β-keratin genes in various skin appendages at embryonic developmental stages. The data demonstrate that temporal and spatial α- and β-keratin expression is involved in establishing the diversity of skin appendage phenotypes. Embryonic feathers express a higher proportion of β-keratin genes than other skin regions. In feather filament morphogenesis, β-keratins show intricate complexity in diverse substructures of feather branches. To explore functional interactions, we used a retrovirus transgenic system to ectopically express mutant α- or antisense β-keratin forms. α- and β-keratins show mutual dependence and mutations in either keratin type results in disrupted keratin networks and failure to form proper feather branches. Our data suggest that combinations of α- and β-keratin genes contribute to the morphological and structural diversity of different avian skin appendages, with feather-β-keratins conferring more possible composites in building intrafeather architecture complexity, setting up a platform of morphological evolution of functional forms in feathers. PMID:26598683

  9. Do feather-degrading bacteria actually degrade feather colour? No significant effects of plumage microbiome modifications on feather colouration in wild great tits.

    PubMed

    Jacob, Staffan; Colmas, Léa; Parthuisot, Nathalie; Heeb, Philipp

    2014-11-01

    Parasites are known to exert selective pressures on host life history traits since the energy and nutrients needed to mount an immune response are no longer available to invest in other functions. Bird feathers harbour numerous microorganisms, some of which are able to degrade feather keratin (keratinolytic microorganisms) and affect feather integrity and colouration in vitro. Although named "feather-degrading" microorganisms, experimental evidence for their effects on feathers of free-living birds is still lacking. Here, we tested whether (i) keratinolytic microorganisms can degrade feathers in vivo and thus modify the colour of feathers during the nesting period and (ii) whether feather microorganisms have a long-term effect on the investment in colouration of newly moulted feathers. We designed treatments to either favour or inhibit bacterial growth, thus experimentally modifying plumage bacterial communities, in a wild breeding population of great tits (Parus major). Our analyses revealed no significant effects of the treatments on feather colours. Moreover, we found that differences in bacterial exposure during nesting did not significantly affect the colouration of newly moulted feathers. Our results suggest that significant feather degradation obtained during in vitro studies could have led to an overestimation of the potential of keratinolytic microorganisms to shape feather colouration in free-living birds.

  10. Structural coloration in a fossil feather

    PubMed Central

    Vinther, Jakob; Briggs, Derek E. G.; Clarke, Julia; Mayr, Gerald; Prum, Richard O.

    2010-01-01

    Investigation of feathers from the famous Middle Eocene Messel Oil Shale near Darmstadt, Germany shows that they are preserved as arrays of fossilized melanosomes, the surrounding beta-keratin having degraded. The majority of feathers are preserved as aligned rod-shaped eumelanosomes. In some, however, the barbules of the open pennaceous, distal portion of the feather vane are preserved as a continuous external layer of closely packed melanosomes enclosing loosely aligned melanosomes. This arrangement is similar to the single thin-film nanostructure that generates an iridescent, structurally coloured sheen on the surface of black feathers in many lineages of living birds. This is, to our knowledge, the first evidence of preservation of a colour-producing nanostructure in a fossil feather and confirms the potential for determining colour differences in ancient birds and other dinosaurs. PMID:19710052

  11. Keratin decomposition by trogid beetles: evidence from a feeding experiment and stable isotope analysis

    NASA Astrophysics Data System (ADS)

    Sugiura, Shinji; Ikeda, Hiroshi

    2014-03-01

    The decomposition of vertebrate carcasses is an important ecosystem function. Soft tissues of dead vertebrates are rapidly decomposed by diverse animals. However, decomposition of hard tissues such as hairs and feathers is much slower because only a few animals can digest keratin, a protein that is concentrated in hairs and feathers. Although beetles of the family Trogidae are considered keratin feeders, their ecological function has rarely been explored. Here, we investigated the keratin-decomposition function of trogid beetles in heron-breeding colonies where keratin was frequently supplied as feathers. Three trogid species were collected from the colonies and observed feeding on heron feathers under laboratory conditions. We also measured the nitrogen (δ15N) and carbon (δ13C) stable isotope ratios of two trogid species that were maintained on a constant diet (feathers from one heron individual) during 70 days under laboratory conditions. We compared the isotopic signatures of the trogids with the feathers to investigate isotopic shifts from the feathers to the consumers for δ15N and δ13C. We used mixing models (MixSIR and SIAR) to estimate the main diets of individual field-collected trogid beetles. The analysis indicated that heron feathers were more important as food for trogid beetles than were soft tissues under field conditions. Together, the feeding experiment and stable isotope analysis provided strong evidence of keratin decomposition by trogid beetles.

  12. Review: cornification, morphogenesis and evolution of feathers.

    PubMed

    Alibardi, Lorenzo

    2017-05-01

    Feathers are corneous microramifications of variable complexity derived from the morphogenesis of barb ridges. Histological and ultrastructural analyses on developing and regenerating feathers clarify the three-dimensional organization of cells in barb ridges. Feather cells derive from folds of the embryonic epithelium of feather germs from which barb/barbule cells and supportive cells organize in a branching structure. The following degeneration of supportive cells allows the separation of barbule cells which are made of corneous beta-proteins and of lower amounts of intermediate filament (IF)(alpha) keratins, histidine-rich proteins, and corneous proteins of the epidermal differentiation complex. The specific protein association gives rise to a corneous material with specific biomechanic properties in barbules, rami, rachis, or calamus. During the evolution of different feather types, a large expansion of the genome coding for corneous feather beta-proteins occurred and formed 3-4-nm-thick filaments through a different mechanism from that of 8-10 nm IF keratins. In the chick, over 130 genes mainly localized in chromosomes 27 and 25 encode feather corneous beta-proteins of 10-12 kDa containing 97-105 amino acids. About 35 genes localized in chromosome 25 code for scale proteins (14-16 kDa made of 122-146 amino acids), claws and beak proteins (14-17 kDa proteins of 134-164 amino acids). Feather morphogenesis is periodically re-activated to produce replacement feathers, and multiple feather types can result from the interactions of epidermal and dermal tissues. The review shows schematic models explaining the translation of the morphogenesis of barb ridges present in the follicle into the three-dimensional shape of the main types of branched or un-branched feathers such as plumulaceous, pennaceous, filoplumes, and bristles. The temporal pattern of formation of barb ridges in different feather types and the molecular control from the dermal papilla through

  13. Influence of raised plastic floors compared with pine shaving litter on environment and Pekin duck condition.

    PubMed

    Karcher, D M; Makagon, M M; Fraley, G S; Fraley, S M; Lilburn, M S

    2013-03-01

    Commercial poultry production management practices have been under increased public scrutiny driven by concerns for food safety and animal welfare. Within the United States, wood shavings and raised plastic floors are common flooring systems used in duck production. It is intuitive that each flooring type would present different management challenges influencing physical characteristics of growing ducks. This study evaluated the relationship between flooring type and duck condition during the winter. Random samples of 20 ducks from 5 predetermined areas (n = 100) were examined in commercial duck houses (n = 9, litter; n = 11, raised plastic slats). Ducks were assessed at 7, 21, and 32 d of age for eye, nostril, and feather cleanliness, feather and foot pad quality, and gait. The data were analyzed to determine the proportion of ducks with a given score. In both housing types, the proportion of 0 scores for foot pad quality improved during the production cycle (P < 0.0001). Feather hygiene declined with age in ducks reared on litter flooring, whereas ducks reared on slatted flooring had cleaner feathers at d 32 (P < 0.011). With the exception of foot pad scores, the majority of ducks had no detectable problems for any single trait. The only main effect due to flooring pertained to feather quality with the proportion of ducks having a 0 or 1 score greater in litter flooring systems than slats (P < 0.05). Overall, the condition of ducks reared, regardless of flooring system, was considered to be good.

  14. Value-added products from chicken feather fiber and protein

    NASA Astrophysics Data System (ADS)

    Fan, Xiuling

    Worldwide poultry consumption has generated a huge amount of feather "waste" annually. Currently, the feather has a low value-being used for animal feed in the world. The quality of fibrous air filters depend on their main component, fibers. The main physical structure of chicken feathers is barbs which can be used directly as fibers. They have small diameter, which makes them a good choice for air filtration. The main chemical structure of chicken feathers is structural fibrous protein, keratin. Therefore, chicken feathers could potentially be used for protein fiber production. To obtain chicken feather fibers, barbs were stripped from the quills by a stripping device and separated with a blender. Some feather fibers were entangled with polyester staple fibers, and needlepunched to form a nonwoven fabric. Some feather fibers were blended with CelBond(TM) bi-component polyester as binder fibers, and pressed between two hot plates to produce thermobonded nonwovens. Whole chicken feathers were ground into powder and their keratin was reduced in water. The reduced keratin was salt precipitated, dried and dissolved in ionic liquid with/without bleach cotton. The reduced chicken feather keratin ionic liquid solutions were spun into regenerated fibers through dry-jet wet spinning. The needlepunched and thermobonded nonwovens were tested for filtration and other properties. With an increase of areal density and feather fiber composition, the air permeability of the needlepunched nonwovens decreased, and their filtration efficiency and pressure drop both increased. The case can be made that feather fibers gave fabrics better filtration at the same fabric weight, but at the expense of air permeability and pressure drop. The scrim and needlepunching process improved the filtration efficiency. Their strength depended on scrim. The hot-press process was very simple. The thermobonded nonwovens had very high air permeability. In them, there was also an inverse relation between

  15. [Improved IgG Antibody Diagnostics of Feather Duvet Lung by an Antibody Screening Test].

    PubMed

    Sennekamp, J; Lehmann, E

    2015-11-01

    The underdiagnosed feather duvet lung, an extrinsic allergic alveolitis (hypersensitivity pneumonitis) caused by duck and goose feathers, can be more frequently diagnosed, if duck and goose feather antibodies are included in the panel of the routinely applied IgG antibody screening test. This does not necessarily require extending the screening test to include duck and goose feather antigens. By analysing 100 sera with duck and goose antibodies we found that the commonly used pigeon and budgerigar antibodies can also screen for feather duvet antibodies. All examined sera lacking pigeon and budgerigar antibodies also lacked clear-cut duck and goose feather antibodies. The examined sera with strong pigeon or budgerigar antibodies always also contained feather duvet antibodies. However, sera with medium or low concentrated pigeon or budgerigar antibodies are not always associated with feather duvet antibodies. In the light of these observations, we find that 71% of the duck and goose antibody analyses would be dispensable without essential loss of quality, if the results of screening for pigeon and budgerigar antibodies were incorporated into the procedure of a step-by- step diagnostics.

  16. Nocardiopsis sp. SD5: a potent feather degrading rare actinobacterium isolated from feather waste in Tamil Nadu, India.

    PubMed

    Saha, Subhasish; Dhanasekaran, D; Shanmugapriya, S; Latha, S

    2013-07-01

    Feather waste, generated in large quantities as a byproduct of commercial poultry processing, is nearly pure keratin protein, and keratin in its native state is not degradable by common proteolytic enzymes. The aim of the study was to find a potent feather degrading actinobacteria from feather waste soil. Out of 91 actinobacterial isolates recorded from feather waste soil in Tiruchirappalli and Nammakkal District, Tamil Nadu, India, isolate SD5 was selected for characterization because it exhibited significant keratinolytic activity. On the basis of the phenotypic, biochemical characterization and 16S rRNA gene-sequencing studies, the isolate was identified as Nocardiopsis sp. SD5. Protease and keratinase activity of Nocardiopsis sp. SD5 were analyzed. The enzyme was more stable over the neutral pH and the temperature of 40 °C. The optimum temperature and pH for both proteolytic and keratinolytic activity was determined at 50 °C and pH 9, respectively. Enzyme inhibitors, detergents and chelator declined the enzyme activity with increasing concentration. Nondenaturing polyacrylamide gel electrophoresis and zymogram elucidated the presence of 30 and 60 kDa protease enzymes. These findings indicated that thermo alkaliphilic feather degrading strain Nocardiopsis sp. SD5 could be used to control the feather waste pollution and to convert keratin rich feather waste into useful feedstock for poultry industry.

  17. [Water provisions for Muscovy ducks--behaviour at duck showers and modified plasson drinkers].

    PubMed

    Briese, Andreas; Hänsch, Friederike; Hartung, Jörg

    2009-01-01

    Feather pecking and cannibalism are serious problems in keeping Moscovy ducks. Prevention of feather pecking by regularly applied beak and claw trimming are increasingly criticised by the public. The recommendation of the Council of Europe (COE) for the keeping of Muscovy ducks in farming systems calls for environmental enrichment including water for preening and bathing after December 31,2010. A total of 126 female Muscovy ducks (not beak nor claw trimmed) from commercial breeding lines were kept for 63 resp. 70 days in four compartments with 15-16 ducks each during two production cycles. Two pens where equipped either with duck showers or open water facility (modified Plasson drinker). Water provisions were made available for the ducks four hours daily at working days from their fifth week of life until slaughter. Behaviour at the water provision was registered and analysed for the number of ducks being engaged with water (944 hours recordings over 59 days from four pens analysed in five-minute-intervals (11,540 observations). Additionally 858 feather preening bouts (five a day for each compartment) were analysed for the duration of feather preening behaviour at the water provision. From the fifth to the tenth week of life the mean percentage of animals of a pen was significantly higher at the open trough (trough: 8,3% (+/-5,37); shower: 4.9% (+/-6.1), Mann-Whitney p <0,01) and feather preening took significantly longer (trough: 134.4 sec (+/-154.8); shower: 111.2 sec (+/-152.0), Mann-Whitney p <0.01) than at the showers. Bout duration and percentage of animals observed at both water provisions increased with age. Nonetheless only ten percent of the feather preening behaviour exceeded five minutes. Most animals made use of water in the first hour of the time period when water was provided. In the first weeks of water provision open water troughs were used more often and preening behaviour was longer. When given the choice, younger ducks preferred open drinkers to

  18. Improving digestibility of feather meal by steam flash explosion.

    PubMed

    Zhang, Yiqi; Yang, Ruijin; Zhao, Wei

    2014-04-02

    Poultry feathers are available in large quantities. However, natural feathers have poor digestibility and are often considered as solid wastes. To improve the digestibility of poultry feathers, steam flash explosion (SFE) was applied to duck feathers at different pressures ranging from 0.5 to 2.5 MPa for 1 min. The pepsin digestibility, disulfide bond content, and major secondary structure component (β-sheets) of duck feathers before and after the process were examined. The results showed that SFE could effectively increase pepsin digestibility of feather meal. Under the optimal conditions (1.8 MPa for 1 min), the pepsin digestibility of exploded feather meal achieved approximately 91%, which was about 9 times higher than that of the original feathers. The pepsin digestibility was highly correlated with the degree of reduction of disulfide bonds (R(2) = 0.98) and slightly negatively correlated with β-sheet structure. SFE is an effective method to improve the bio-utilization of feather meal.

  19. Feather regeneration as a model for organogenesis.

    PubMed

    Lin, Sung-Jan; Wideliz, Randall B; Yue, Zhicao; Li, Ang; Wu, Xiaoshan; Jiang, Ting-Xin; Wu, Ping; Chuong, Cheng-Ming

    2013-01-01

    In the process of organogenesis, different cell types form organized tissues and tissues are integrated into an organ. Most organs form in the developmental stage, but new organs can also form in physiological states or following injuries during adulthood. Feathers are a good model to study post-natal organogenesis because they regenerate episodically under physiological conditions and in response to injuries such as plucking. Epidermal stem cells in the collar can respond to activation signals. Dermal papilla located at the follicle base controls the regenerative process. Adhesion molecules (e.g., neural cell adhesion molecule (NCAM), tenascin), morphogens (e.g., Wnt3a, sprouty, fibroblast growth factor [FGF]10), and differentiation markers (e.g., keratins) are expressed dynamically in initiation, growth and resting phases of the feather cycle. Epidermal cells are shaped into different feather morphologies based on the molecular micro-environment at the moment of morphogenesis. Chicken feather variants provide a rich resource for us to identify genetic determinants involved in feather regeneration and morphogenesis. An example of using genome-wide single nucleotide polymorphism (SNP) analysis to identify alpha keratin 75 as the mutation in frizzled chickens is demonstrated. Due to its accessibility to experimental manipulation and observation, results of regeneration can be analyzed in a comprehensive way. The layout of time dimension along the distal (formed earlier) to proximal (formed later) feather axis makes the morphological analyses easier. Therefore feather regeneration can be a unique model for understanding organogenesis: from activation of stem cells under various physiological conditions to serving as the Rosetta stone for deciphering the language of morphogenesis.

  20. Towards a comprehensive model of feather regeneration.

    PubMed

    Maderson, Paul F A; Hillenius, Willem J; Hiller, Uwe; Dove, Carla C

    2009-10-01

    Understanding of the regeneration of feathers, despite a 140 year tradition of study, has remained substantially incomplete. Moreover, accumulated errors and mis-statements in the literature have confounded the intrinsic difficulties in describing feather regeneration. Lack of allusion to Rudall's (Rudall [1947] Biochem Biophys Acta 1:549-562) seminal X-ray diffraction study that revealed two distinct keratins, beta- and alpha-, in a mature feather, is one of the several examples where lack of citation long inhibited progress in understanding. This article reviews and reevaluates the available literature and provides a synthetic, comprehensive, morphological model for the regeneration of a generalized, adult contour feather. Particular attention is paid to several features that have previously been largely ignored. Some of these, such as the beta-keratogenic sheath and the alpha-keratogenic, supra-umbilical, pulp caps, are missing from mature, functional feathers sensu stricto because they are lost through preening, but these structures nevertheless play a critical role in development. A new developmental role for a tissue unique to feathers, the medullary pith of the rachis and barb rami, and especially its importance in the genesis of the superior umbilical region (SUR) that forms the transition from the spathe (rachis and vanes) to the calamus, is described. It is postulated that feathers form through an intricate interplay between cyto- and histodifferentiative processes, determined by patterning signals that emanate from the dermal core, and a suite of interacting biomechanical forces. Precisely regulated patterns of loss of intercellular adhesivity appear to be the most fundamental aspect of feather morphogenesis and regeneration: rather than a hierarchically branched structure, it appears more appropriate to conceive of feathers as a sheet of mature keratinocytes that is "full of holes.

  1. Ultrastructure of the feather follicle in relation to the formation of the rachis in pennaceous feathers.

    PubMed

    Alibardi, Lorenzo

    2010-06-01

    The present ultrastructural study on follicle of regenerating feathers of four different avian species focuses on the formation and cytology of the rachis. Epithelial cells within the bottom part of the follicle (the collar) are contacted from mesenchymal cells of the dermal papilla. The most basal part of the collar is formed by a circular epithelium containing germinal cells, while in the upper ramogenic part of the collar barb ridges are generated. Epithelial cells rest upon a basement membrane that is stretched in actively forming barb ridges among which anchored mesenchymal cells send thin elongation. This observation suggests that an intense exchange of molecules with the epithelium occurs. The process of formation of the rachis occurs by fusion of barb ridges with the nonsegmented, dorsal or anterior part of the collar. The latter becomes the rachidial ridge, the upper part of the collar where barbs form the branches of the pennaceous feather. The rachis grows and matures into an external cortical part, containing compact corneous material (feather keratin, as confirmed by immunocytochemistry), and a vacuolated medulla with a process similar to that occurring in rami of single barbs. The extension of the medulla and cortex varies along the rachis in different species. In general a thin cortex is formed in those sections of the rachis where barbs are absent, and the feather keratin positive layer increases in the basal part of the feather, the calamus.

  2. Eggshell bacterial load is related to antimicrobial properties of feathers lining barn swallow nests.

    PubMed

    Peralta-Sánchez, Juan Manuel; Soler, Juan José; Martín-Platero, Antonio Manuel; Knight, Rob; Martínez-Bueno, Manuel; Møller, Anders Pape

    2014-02-01

    The use of feathers to line bird's nests has traditionally been interpreted as having a thermoregulatory function. Feather-degrading bacteria growing on feathers lining nests may have antimicrobial properties, which may provide an additional benefit to lining nests with feathers. We test the hypothesis that the production of antimicrobial substances by feather bacteria affects the microbiological environment of the nest, and therefore the bacterial density on eggshells and, indirectly, hatching success. These effects would be expected to differ between nests lined with pigmented and white feathers, because bacteria grow differently on feathers of different colors. We experimentally manipulated the composition of pigmented and unpigmented feathers in nests of the barn swallow (Hirundo rustica) and studied the antimicrobial properties against the keratin-degrading bacterium Bacillus licheniformis of bacteria isolated from feathers of each color. Analyzed feathers were collected at the end of the incubation period, and antimicrobial activity was defined as the proportion of bacteria from the feathers that produce antibacterial substances effective against B. licheniformis. Our experimental manipulation affected antimicrobial activity, which was higher in nests with only white feathers at the beginning of incubation. Moreover, white feathers showed higher antimicrobial activity than black ones. Interestingly, antimicrobial activity in feathers of one of the colors correlated negatively with bacterial density on feather of the opposite color. Finally, antimicrobial activity of white feathers was negatively related to eggshell bacterial load. These results suggest that antimicrobial properties of feathers in general and of white feathers in particular affect the bacterial environment in nests. This environment in turn affects the bacterial load on eggshells, which may affect hatching success.

  3. Melanin-based color of plumage: role of condition and of feathers' microstructure.

    PubMed

    D'Alba, Liliana; Van Hemert, Caroline; Spencer, Karen A; Heidinger, Britt J; Gill, Lisa; Evans, Neil P; Monaghan, Pat; Handel, Colleen M; Shawkey, Matthew D

    2014-10-01

    Whether melanin-based colors honestly signal a bird's condition during the growth of feathers is controversial, and it is unclear if, or how, the physiological processes underlying melanogenesis or the role of the microstructure of feathers in imparting structural color to feathers may be adversely affected by condition. Here, we report results from two experiments designed to measure the effect of condition on expression of eumelanic and pheomelanic coloration in black-capped chickadees (Poecile atricapillus) and zebra finches (Taeniopygia guttata), respectively. In chickadees, we compared feathers of birds affected and unaffected by avian keratin disorder, whereas in zebra finches we compared feathers of controls with feathers of those subjected to an unpredictable food supply during development. In both cases, we found that control birds had brighter feathers (higher total reflectance) and more barbules, but similar densities of melanosomes. In addition, the microstructure of the feathers explained variation in color more strongly than did melanosome density. Together, these results suggest that melanin-based coloration may in part be condition-dependent, but that this may be driven by changes in keratin and feather development, rather than melanogenesis itself. Researchers should be cautious when assigning variation in melanin-based color to melanin alone and microstructure of the feather should be taken into account.

  4. Melanosomes or Microbes: Testing an Alternative Hypothesis for the Origin of Microbodies in Fossil Feathers

    NASA Astrophysics Data System (ADS)

    Moyer, Alison E.; Zheng, Wenxia; Johnson, Elizabeth A.; Lamanna, Matthew C.; Li, Da-Qing; Lacovara, Kenneth J.; Schweitzer, Mary H.

    2014-03-01

    Microbodies associated with fossil feathers, originally attributed to microbial biofilm, have been reinterpreted as melanosomes: pigment-containing, eukaryotic organelles. This interpretation generated hypotheses regarding coloration in non-avian and avian dinosaurs. Because melanosomes and microbes overlap in size, distribution and morphology, we re-evaluate both hypotheses. We compare melanosomes within feathers of extant chickens with patterns induced by microbial overgrowth on the same feathers, using scanning (SEM), field emission (FESEM) and transmission (TEM) electron microscopy. Melanosomes are always internal, embedded in a morphologically distinct keratinous matrix. Conversely, microbes grow across the surface of feathers in continuous layers, more consistent with published images from fossil feathers. We compare our results to both published literature and new data from a fossil feather ascribed to Gansus yumenensis (ANSP 23403). `Mouldic impressions' were observed in association with both the feather and sediment grains, supporting a microbial origin. We propose criteria for distinguishing between these two microbodies.

  5. Melanosomes or microbes: testing an alternative hypothesis for the origin of microbodies in fossil feathers.

    PubMed

    Moyer, Alison E; Zheng, Wenxia; Johnson, Elizabeth A; Lamanna, Matthew C; Li, Da-qing; Lacovara, Kenneth J; Schweitzer, Mary H

    2014-03-05

    Microbodies associated with fossil feathers, originally attributed to microbial biofilm, have been reinterpreted as melanosomes: pigment-containing, eukaryotic organelles. This interpretation generated hypotheses regarding coloration in non-avian and avian dinosaurs. Because melanosomes and microbes overlap in size, distribution and morphology, we re-evaluate both hypotheses. We compare melanosomes within feathers of extant chickens with patterns induced by microbial overgrowth on the same feathers, using scanning (SEM), field emission (FESEM) and transmission (TEM) electron microscopy. Melanosomes are always internal, embedded in a morphologically distinct keratinous matrix. Conversely, microbes grow across the surface of feathers in continuous layers, more consistent with published images from fossil feathers. We compare our results to both published literature and new data from a fossil feather ascribed to Gansus yumenensis (ANSP 23403). 'Mouldic impressions' were observed in association with both the feather and sediment grains, supporting a microbial origin. We propose criteria for distinguishing between these two microbodies.

  6. Melanosomes or Microbes: Testing an Alternative Hypothesis for the Origin of Microbodies in Fossil Feathers

    PubMed Central

    Moyer, Alison E.; Zheng, Wenxia; Johnson, Elizabeth A.; Lamanna, Matthew C.; Li, Da-qing; Lacovara, Kenneth J.; Schweitzer, Mary H.

    2014-01-01

    Microbodies associated with fossil feathers, originally attributed to microbial biofilm, have been reinterpreted as melanosomes: pigment-containing, eukaryotic organelles. This interpretation generated hypotheses regarding coloration in non-avian and avian dinosaurs. Because melanosomes and microbes overlap in size, distribution and morphology, we re-evaluate both hypotheses. We compare melanosomes within feathers of extant chickens with patterns induced by microbial overgrowth on the same feathers, using scanning (SEM), field emission (FESEM) and transmission (TEM) electron microscopy. Melanosomes are always internal, embedded in a morphologically distinct keratinous matrix. Conversely, microbes grow across the surface of feathers in continuous layers, more consistent with published images from fossil feathers. We compare our results to both published literature and new data from a fossil feather ascribed to Gansus yumenensis (ANSP 23403). ‘Mouldic impressions’ were observed in association with both the feather and sediment grains, supporting a microbial origin. We propose criteria for distinguishing between these two microbodies. PMID:24595214

  7. Effects of radio packages on wild ducks

    USGS Publications Warehouse

    Gilmer, D.S.; Ball, I.J.; Cowardin, L.M.; Riechmann, J.H.

    1974-01-01

    A total of 211 wild, free-flying mallards (Anas platyrhynchos) and wood ducks (Aix sponsa) were equipped with breast-mounted radio packages during the breeding seasons of 1968-72. Known predation loss was 7.6 and 12.0 percent for mallards and wood ducks respectively, 60 percent occurred within 3 weeks of instrumentation. The highest predation rate for mallards was 0.0048 kills per tracking day and 0.0136 for wood ducks. A higher direct recovery rate for instrumented birds (19.5 percent) than noninstrumented birds (8.1 percent) was probably due to the novelty of the transmitter to hunters. Departure patterns and locations of direct recoveries were similar between radio-equipped and normal-banded birds. Among female wood ducks with radios, recovery rates were lower than expected. Hunters indicated that 84 percent of the instrumented ducks recovered were in good or excellent condition. Recaptures of ducks as long as 1 year after being equipped with radio packages indicated that feather wear and skin abrasion were not serious. A high rate for feeding on land by instrumented mallards was probably due to our ability to more easily locate and observe these birds in cover. Preening rates were higher for instrumented ducks. As the birds became adjusted to the package, preening decreased and feeding on water increased. Social and breeding behavior of instrumented ducks did not appear to be adversely affected by the radio package.

  8. Keratin degradation by bacteria and fungi isolated from a poultry farm and plumage.

    PubMed

    Sivakumar, N; Raveendran, S

    2015-04-01

    1. Poultry processing generates a large quantity of feather waste. Feathers are a rich source of keratin and could be used as a feather meal in the feed industry if the keratin is degraded using suitable micro-organisms. 2. In this study, keratin-degrading micro-organisms were isolated from a poultry farm. The predominant organisms were identified as Bacillus subtilis, Aspergillus flavus, A. fumigatus and Trychophyton sp. 3. The isolates were inoculated into feather medium and observed for keratin degradation by measuring the protein content, free amino acids and change in pH. 4. During feather degradation by B. subtilis, the concentration of soluble protein released to the medium increased gradually and reached the maximum (433 µg/ml) during d 7 of incubation and the pH increased from the initial 6.9 to 8.4 on d 9 of incubation. Similarly, the maximum protein content of 414 µg/ml and pH of 8.5 was observed for A. fumigatus on d 21 of incubation. 5. B. subtilis and A. fumigatus showed almost the same level of keratinase activity.

  9. Avian skin development and the evolutionary origin of feathers.

    PubMed

    Sawyer, Roger H; Knapp, Loren W

    2003-08-15

    The discovery of several dinosaurs with filamentous integumentary appendages of different morphologies has stimulated models for the evolutionary origin of feathers. In order to understand these models, knowledge of the development of the avian integument must be put into an evolutionary context. Thus, we present a review of avian scale and feather development, which summarizes the morphogenetic events involved, as well as the expression of the beta (beta) keratin multigene family that characterizes the epidermal appendages of reptiles and birds. First we review information on the evolution of the ectodermal epidermis and its beta (beta) keratins. Then we examine the morphogenesis of scutate scales and feathers including studies in which the extraembryonic ectoderm of the chorion is used to examine dermal induction. We also present studies on the scaleless (sc) mutant, and, because of the recent discovery of "four-winged" dinosaurs, we review earlier studies of a chicken strain, Silkie, that expresses ptilopody (pti), "feathered feet." We conclude that the ability of the ectodermal epidermis to generate discrete cell populations capable of forming functional structural elements consisting of specific members of the beta keratin multigene family was a plesiomorphic feature of the archosaurian ancestor of crocodilians and birds. Evidence suggests that the discrete epidermal lineages that make up the embryonic feather filament of extant birds are homologous with similar embryonic lineages of the developing scutate scales of birds and the scales of alligators. We believe that the early expression of conserved signaling modules in the embryonic skin of the avian ancestor led to the early morphogenesis of the embryonic feather filament, with its periderm, sheath, and barb ridge lineages forming the first protofeather. Invagination of the epidermis of the protofeather led to formation of the follicle providing for feather renewal and diversification. The observations that

  10. Melanin-based color of plumage: role of condition and of feathers' microstructure

    USGS Publications Warehouse

    D'Alba, Liliana; Van Hemert, Caroline R.; Spencer, Karen A.; Heidinger, Britt J.; Gill, Lisa; Evans, Neil P.; Monaghan, Pat; Handel, Colleen M.; Shawkey, Matthew D.

    2014-01-01

    Whether melanin-based colors honestly signal a bird's condition during the growth of feathers is controversial, and it is unclear if or how the physiological processes underlying melanogenesis or color-imparting structural feather microstructure may be adversely affected by condition. Here we report results from two experiments designed to measure the effect of condition on expression of eumelanic and pheomelanic coloration in black-capped chickadees (Poecile atricapillus) and zebra finches (Taeniopygia guttata), respectively. In chickadees, we compared feathers of birds affected and unaffected by avian keratin disorder, while in zebra finches we compared feathers of controls with feathers of those subjected to an unpredictable food supply during development. In both cases we found that control birds had brighter feathers (higher total reflectance) and more barbules, but similar densities of melanosomes. In addition, the microstructure of the feathers explained variation in color more strongly than did melanosome density. Together, these results suggest that melanin-based coloration may in part be condition-dependent, but that this may be driven by changes in keratin and feather development, rather than melanogenesis itself. Researchers should be cautious when assigning variation in melanin-based color to melanin alone and microstructure of the feather should be taken into account.

  11. Characterizing wool keratin

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Keratin from wool is a reactive, biocompatible, and biodegradable material. Efficient alkaline extractions gave yields of 68% to 82% protein within 2 to 5 hours of exposure at 65 ºC. The water soluble keratin preparations contained intermediate filament and microfibrillar component-proteins of fra...

  12. Despotic Ducks

    ERIC Educational Resources Information Center

    Darling, Randi A.

    2008-01-01

    This field experiment is designed to test for despotic behavior in Mallards ("Anas platyrhynchos"), and to examine how ducks distribute themselves relative to their resources. Students present Mallards with food patches differing in profitability in order to examine whether ducks distribute themselves ideal freely or ideal despotically. Students…

  13. The epidermis of scales in gecko lizards contains multiple forms of beta-keratins including basic glycine-proline-serine-rich proteins.

    PubMed

    Toni, M; Dalla Valle, L; Alibardi, L

    2007-05-01

    The epidermis of scales of gecko lizards comprises alpha- and beta-keratins. Using bidimensional electrophoresis and immunoblotting, we have characterized keratins of corneous layers of scales in geckos, especially beta-keratins in digit pad lamellae. In the latter, the formation of thin bristles (setae) allow for the adhesion and climbing vertical or inverted surfaces. alpha-Keratins of 55-66 kDa remain in the acidic and neutral range of pI, while beta-keratins of 13-18 kDa show a broader variation of pI (4-10). Some protein spots for beta-keratins correspond to previously sequenced, basic glycine-proline-serine-rich beta-keratins of 169-191 amino acids. The predicted secondary structure shows that a large part of the molecule has a random-coiled conformation, small alpha helix regions, and a central region with 2-3 strands (beta-folding). The latter, termed core-box, shows homology with feather-scale-claw keratins of birds and is involved in the formation of beta-keratin filaments. Immunolocalization of beta-keratins indicates that these proteins are mainly present in the beta-layer and oberhautchen layer, including setae. The sequenced proteins of setae form bundles of keratins that determine their elongation. This process resembles that of feather-keratin on the elongation of barbule cells in feathers. It is suggested that small proteins rich in glycine, serine, and proline evolved in reptiles and birds to reinforce the mechanical resistance of the cytokeratin cytoskeleton initially present in the epidermis of scales and feathers.

  14. Characterization of a novel feather-degrading Bacillus sp. strain.

    PubMed

    Werlang, Patricia Orosco; Brandelli, Adriano

    2005-01-01

    Feather waste is generated in large amounts as a byproduct of commercial poultry processing. This residue is almost pure keratin, which is not easily degradable by common proteolytic enzymes. A feather-degrading bacterium was isolated from poultry feathers in decomposition. The strain identified as kr16 showed important feather-degrading activity when grown on basal medium containing 10 g/L of native feather as the source of energy, carbon, and nitrogen. The isolate was characterized according to the phenotypical characteristics and biochemical profiling that belong to the Bacillus genus. Keratinolytic activity of this isolate was monitored during cultivation of the bacterium on raw feathers at different temperatures. Maximum growth and feather-degrading activity were observed at 30-37 degrees C. The keratinolytic enzyme had a pH optimum ranging from 8.0 to 11.0 and a temperature optimum of 45-65 degrees C. The keratinase was strongly inhibited by EDTA and the metal ions Hg2+ and Sn2+.

  15. Symbiotic bacteria living in the hoopoe's uropygial gland prevent feather degradation.

    PubMed

    Ruiz-Rodríguez, M; Valdivia, E; Soler, Juan J; Martín-Vivaldi, M; Martín-Platero, A M; Martínez-Bueno, M

    2009-11-01

    Among potential agents that might damage bird feathers are certain microorganisms which secrete enzymes that digest keratin, as is the case of the ubiquitous bacterium Bacillus licheniformis, present in both the feathers and skin of wild birds. It is therefore a good candidate for testing the effects of bird defences against feather-degrading microorganisms. One of these defences is the oil secreted by the uropygial gland, which birds use to protect their feathers against parasites. In previous studies we have shown how Enterococcus faecalis strains isolated from nestling hoopoes exert antagonistic effects against B. licheniformis, mediated by the production of bacteriocins. Consequently we hypothesized that this enterococcus and the bacteriocins it engenders might act as a defence against feather-degrading microorganisms in hoopoes. We investigated this hypothesis in a series of laboratory experiments and evaluated the extent to which the keratinolytic effects caused by B. licheniformis were reduced by the E. faecalis MRR10-3 strain, isolated from hoopoes, and its bacteriocins. In different treatments, feathers or pure keratin was incubated with B. licheniformis, B. licheniformis together with E. faecalis MRR10-3, and B. licheniformis together with the bacteriocins produced by E. faecalis MRR10-3. Our results were in accordance with the predicted effects on hoopoe feathers. There was a significant decrease both in pure keratin loss and in feather degradation in the presence of the symbiotic bacterium or its bacteriocin. These results suggest that by preening their feathers hoopoes benefit from their symbiotic relationship with bacteriocin-producing enterococci, which constitute a chemical defence against feather degradation.

  16. Rapid evolution of Beta-keratin genes contribute to phenotypic differences that distinguish turtles and birds from other reptiles.

    PubMed

    Li, Yang I; Kong, Lesheng; Ponting, Chris P; Haerty, Wilfried

    2013-01-01

    Sequencing of vertebrate genomes permits changes in distinct protein families, including gene gains and losses, to be ascribed to lineage-specific phenotypes. A prominent example of this is the large-scale duplication of beta-keratin genes in the ancestors of birds, which was crucial to the subsequent evolution of their beaks, claws, and feathers. Evidence suggests that the shell of Pseudomys nelsoni contains at least 16 beta-keratins proteins, but it is unknown whether this is a complete set and whether their corresponding genes are orthologous to avian beak, claw, or feather beta-keratin genes. To address these issues and to better understand the evolution of the turtle shell at a molecular level, we surveyed the diversity of beta-keratin genes from the genome assemblies of three turtles, Chrysemys picta, Pelodiscus sinensis, and Chelonia mydas, which together represent over 160 Myr of chelonian evolution. For these three turtles, we found 200 beta-keratins, which indicate that, as for birds, a large expansion of beta-keratin genes in turtles occurred concomitantly with the evolution of a unique phenotype, namely, their plastron and carapace. Phylogenetic reconstruction of beta-keratin gene evolution suggests that separate waves of gene duplication within a single genomic location gave rise to scales, claws, and feathers in birds, and independently the scutes of the shell in turtles.

  17. Keratinases and sulfide from Bacillus subtilis SLC to recycle feather waste.

    PubMed

    Cedrola, Sabrina Martins Lage; de Melo, Ana Cristina Nogueira; Mazotto, Ana Maria; Lins, Ulysses; Zingali, Russolina Benedeta; Rosado, Alexandre Soares; Peixoto, Raquel S; Vermelho, Alane Beatriz

    2012-03-01

    The aim of this study is to investigate the culture conditions of chicken feather degradation and keratinolytic enzyme production by the recently isolated Bacillus subtilis SLC and to evaluate the potential of the SLC strain to recycle feather waste discarded by the poultry industry. The SLC strain was isolated from the agroindustrial waste of a poultry farm in Brazil and was confirmed to belong to Bacillus subtilis by rDNA gene analysis. There was high keratinase production when the medium was at pH 8 (280 U ml(-1)). Activity was higher using the inoculum propagated for 72 h on 1% whole feathers supplemented with 0.1% yeast extract. In the enzymatic extract, the keratinases were active in the pH range from 2.0 to 12.0 with a maximum activity at pH 10.0 and temperature 60°C. For gelatinase the best pH was 5.0 and the best temperature was 37°C. All keratinases are serine peptidases. The crude enzymatic extract degraded keratin, gelatin, casein, and hemoglobin. Scanning electron microscopy showed Bacillus cells adhered onto feather surfaces after 98 h of culture and degraded feather filaments were observed. MALDI-TOF mass spectrometric analysis showed multiple peaks from 522 to 892 m/z indicating feather degradation. The presence of sulfide was detected on extracellular medium probably participating in the breakdown of sulfide bridges of the feather keratin. External addition of sulfide increased feather degradation.

  18. A closer look at the feather coloration in the male purple sunbird, Nectarinia asiatica.

    PubMed

    Mahapatra, Biswa Bhusana; Marathe, Sandhya Amol; Meyer-Rochow, Victor Benno; Mishra, Monalisa

    2016-06-01

    During the breeding season male, but not female, individuals of the purple sunbird possess colourful plumage of chiefly blue and black coloration with a splatter of orange and yellow on the chest. Representative feathers of these colours were collected from male birds during the breeding season and analyzed by reflectance and scanning electron microscopy. The rachis, which is the central support of a feather on which various barbs and barbules are arranged, is spongy and made up of keratin layers with rod-shaped melanosomes sparsely distributed within these layers. Barbs and barbules are the structural units of the feather and depending on how they are arranged provide a characteristic shape to the feather. X-Ray diffraction (XRD) analyses of the feathers revealed the presence of various metal elements that might contribute to the feathers' colorations. Blue feathers are iridescent and contain mainly iron, copper, zinc and cobalt (in that order of abundance); black feathers were also found to contain mainly iron and copper, but chromium instead of zinc and cobalt, while yellow feathers were found to contain predominantly cobalt and nickel. The metal content of the feathers in an as yet unknown way may be involved in the production of the distinct absorbance and reflectance patterns that the brilliant plumage of the purple sunbird is renowned for.

  19. Biological Pretreatment of Chicken Feather and Biogas Production from Total Broth.

    PubMed

    Patinvoh, Regina J; Feuk-Lagerstedt, Elisabeth; Lundin, Magnus; Sárvári Horváth, Ilona; Taherzadeh, Mohammad J

    2016-12-01

    Chicken feathers are available in large quantities around the world causing environmental challenges. The feathers are composed of keratin that is a recalcitrant protein and is hard to degrade. In this work, chicken feathers were aerobically pretreated for 2-8 days at total solid concentrations of 5, 10, and 20 % by Bacillus sp. C4, a bacterium that produces both α- and β-keratinases. Then, the liquid fraction (feather hydrolysate) as well as the total broth (liquid and solid fraction of pretreated feathers) was used as substrates for biogas production using anaerobic sludge or bacteria granules as inoculum. The biological pretreatment of feather waste was productive; about 75 % of feather was converted to soluble crude protein after 8 days of degradation at initial feather concentration of 5 %. Bacteria granules performed better during anaerobic digestion of untreated feathers, resulting in approximately two times more methane yield (i.e., 199 mlCH4/gVS compared to 105 mlCH4/gVS when sludge was used). Pretreatment improved methane yield by 292 and 105 % when sludge and granules were used on the hydrolysate. Bacteria granules worked effectively on the total broth, yielded 445 mlCH4/gVS methane, which is 124 % more than that obtained with the same type of inoculum from untreated feather.

  20. Dietary inclusion of feathers affects intestinal microbiota and microbial metabolites in growing Leghorn-type chickens.

    PubMed

    Meyer, B; Bessei, W; Bessei, A W; Vahjen, W; Zentek, J; Harlander-Matauschek, A

    2012-07-01

    Feather pecking in laying hens is a serious behavioral problem that is often associated with feather eating. The intake of feathers may influence the gut microbiota and its metabolism. The aim of this study was to determine the effect of 2 different diets, with or without 5% ground feathers, on the gut microbiota and the resulting microbial fermentation products and to identify keratin-degrading bacteria in chicken digesta. One-day-old Lohmann-Selected Leghorn chicks were divided into 3 feeding groups: group A (control), B (5% ground feathers in the diet), and C, in which the control diet was fed until wk 12 and then switched to the 5% feather diet to study the effect of time of first feather ingestion. The gut microbiota was analyzed by cultivation and denaturing gradient gel electrophoresis of ileum and cecum digesta. Short-chain fatty acids, ammonia, and lactate concentrations were measured as microbial metabolites. The concentration of keratinolytic bacteria increased after feather ingestion in the ileum (P < 0.001) and cecum (P = 0.033). Bacterial species that hydrolyzed keratin were identified as Enterococcus faecium, Lactobacillus crispatus, Lactobacillus reuteri-like species (97% sequence homology), and Lactobacillus salivarius-like species (97% sequence homology). Molecular analysis of cecal DNA extracts showed that the feather diet lowered the bacterial diversity indicated by a reduced richness (P < 0.001) and shannon (P = 0.012) index. The pattern of microbial metabolites indicated some changes, especially in the cecum. This study showed that feather intake induced an adaptation of the intestinal microbiota in chickens. It remains unclear to what extent the changed metabolism of the microbiota reflects the feather intake and could have an effect on the behavior of the hens.

  1. Magnetic cleansing of weathered/tarry oiled feathers--the role of pre-conditioners.

    PubMed

    Dao, Hien V; Ngeh, Lawrence N; Bigger, Stephen W; Orbell, John D; Healy, Margaret; Jessop, Rosalind; Dann, Peter

    2006-12-01

    Iron powder has previously been demonstrated to be effective in the removal, via magnetic harvesting, of a wide variety of oil contaminants from feathers and plumage. This study investigates the efficacy of magnetic cleansing for the removal from feathers of tarry contamination that has been allowed to weather. Clusters of feathers from Mallard duck (Anas platyrhnchos) and Little Penguin (Eudyptula minor) were completely immersed in a tarry contaminant and allowed to weather from one to fourteen days. The contaminant was removed using a magnetic cleansing protocol and the removal efficacy assessed gravimetrically. For one, seven and fourteen days of weathering, a final removal (after fourteen treatments) of more than 99% and 97% was achieved for duck feathers and penguin feathers, respectively. Repeating the experiments (for a seven-day weathering period) for both duck and penguin feathers, with the judicious application of a pre-conditioner (olive oil), further improved removal efficacy. A convenient method to screen for improved pre-conditioning agents is suggested.

  2. Unzipping bird feathers.

    PubMed

    Kovalev, Alexander; Filippov, Alexander E; Gorb, Stanislav N

    2014-03-06

    The bird feather vane can be separated into two parts by pulling the barbs apart. The original state can be re-established easily by lightly stroking through the feather. Hooklets responsible for holding vane barbs together are not damaged by multiple zipping and unzipping cycles. Because numerous microhooks keep the integrity of the feather, their properties are of great interest for understanding mechanics of the entire feather structure. This study was undertaken to estimate the separation force of single hooklets and their arrays using force measurement of an unzipping feather vane. The hooklets usually separate in some number synchronously (20 on average) with the highest observed separation force of 1.74 mN (average force 0.27 mN), whereas the single hooklet separation force was 14 μN. A simple numerical model was suggested for a better understanding of zipping and unzipping behaviour in feathers. The model demonstrates features similar to those observed in experiments.

  3. Regulation of keratin network organization.

    PubMed

    Loschke, Fanny; Seltmann, Kristin; Bouameur, Jamal-Eddine; Magin, Thomas M

    2015-02-01

    Keratins form the major intermediate filament cytoskeleton of epithelia and are assembled from heterodimers of 28 type I and 26 type II keratins in cell- and differentiation-dependent patterns. By virtue of their primary sequence composition, interactions with cell adhesion complexes and components of major signaling cascades, keratins act as targets and effectors of mechanical force and chemical signals to determine cell mechanics, epithelial cohesion and modulate signaling in keratin isotype-specific manners. Therefore, cell-specific keratin expression and organization impact on cell growth, migration and invasion. Here, we review the recent literature, focusing on the question how keratin networks are regulated and how the interplay of keratins with adhesion complexes affects these processes and provides a framework to understand keratins contribution to blistering and inflammatory disorders and to tumor metastasis.

  4. Experimental maturation of feathers: implications for reconstructions of fossil feather colour.

    PubMed

    McNamara, Maria E; Briggs, Derek E G; Orr, Patrick J; Field, Daniel J; Wang, Zhengrong

    2013-06-23

    Fossil feathers often preserve evidence of melanosomes-micrometre-scale melanin-bearing organelles that have been used to infer original colours and patterns of the plumage of dinosaurs. Such reconstructions acknowledge that evidence from other colour-producing mechanisms is presently elusive and assume that melanosome geometry is not altered during fossilization. Here, we provide the first test of this assumption, using high pressure-high temperature autoclave experiments on modern feathers to simulate the effects of burial on feather colour. Our experiments show that melanosomes are retained despite loss of visual evidence of colour and complete degradation of other colour-producing structures (e.g. quasi-ordered arrays in barbs and the keratin cortex in barbules). Significantly, however, melanosome geometry and spatial distribution are altered by the effects of pressure and temperature. These results demonstrate that reconstructions of original plumage coloration in fossils where preserved features of melanosomes are affected by diagenesis should be treated with caution. Reconstructions of fossil feather colour require assessment of the extent of preservation of various colour-producing mechanisms, and, critically, the extent of alteration of melanosome geometry.

  5. Determination of keratin degradation by fungi using keratin azure.

    PubMed

    Scott, J A; Untereiner, W A

    2004-06-01

    Azure dye-impregnated sheep's wool keratin (keratin azure) was incorporated in a high pH medium and overlaid on a keratin-free basal medium. The release and diffusion of the azure dye into the lower layer indicated production of keratinase. Fifty-eight fungal taxa, including 49 members of the Arthrodermataceae, Gymnoascaceae and Onygenaceae (Order Onygenales), were assessed for keratin degradation using this method. The results were comparable to measures of keratin utilization reported in studies using tests based on the perforation or erosion of human hair in vitro.

  6. Spatially modulated structural colour in bird feathers.

    PubMed

    Parnell, Andrew J; Washington, Adam L; Mykhaylyk, Oleksandr O; Hill, Christopher J; Bianco, Antonino; Burg, Stephanie L; Dennison, Andrew J C; Snape, Mary; Cadby, Ashley J; Smith, Andrew; Prevost, Sylvain; Whittaker, David M; Jones, Richard A L; Fairclough, J Patrick A; Parker, Andrew R

    2015-12-21

    Eurasian Jay (Garrulus glandarius) feathers display periodic variations in the reflected colour from white through light blue, dark blue and black. We find the structures responsible for the colour are continuous in their size and spatially controlled by the degree of spinodal phase separation in the corresponding region of the feather barb. Blue structures have a well-defined broadband ultra-violet (UV) to blue wavelength distribution; the corresponding nanostructure has characteristic spinodal morphology with a lengthscale of order 150 nm. White regions have a larger 200 nm nanostructure, consistent with a spinodal process that has coarsened further, yielding broader wavelength white reflectance. Our analysis shows that nanostructure in single bird feather barbs can be varied continuously by controlling the time the keratin network is allowed to phase separate before mobility in the system is arrested. Dynamic scaling analysis of the single barb scattering data implies that the phase separation arrest mechanism is rapid and also distinct from the spinodal phase separation mechanism i.e. it is not gelation or intermolecular re-association. Any growing lengthscale using this spinodal phase separation approach must first traverse the UV and blue wavelength regions, growing the structure by coarsening, resulting in a broad distribution of domain sizes.

  7. Spatially modulated structural colour in bird feathers

    PubMed Central

    Parnell, Andrew J.; Washington, Adam L.; Mykhaylyk, Oleksandr O.; Hill, Christopher J.; Bianco, Antonino; Burg, Stephanie L.; Dennison, Andrew J. C.; Snape, Mary; Cadby, Ashley J.; Smith, Andrew; Prevost, Sylvain; Whittaker, David M.; Jones, Richard A. L.; Fairclough, J. Patrick. A.; Parker, Andrew R.

    2015-01-01

    Eurasian Jay (Garrulus glandarius) feathers display periodic variations in the reflected colour from white through light blue, dark blue and black. We find the structures responsible for the colour are continuous in their size and spatially controlled by the degree of spinodal phase separation in the corresponding region of the feather barb. Blue structures have a well-defined broadband ultra-violet (UV) to blue wavelength distribution; the corresponding nanostructure has characteristic spinodal morphology with a lengthscale of order 150 nm. White regions have a larger 200 nm nanostructure, consistent with a spinodal process that has coarsened further, yielding broader wavelength white reflectance. Our analysis shows that nanostructure in single bird feather barbs can be varied continuously by controlling the time the keratin network is allowed to phase separate before mobility in the system is arrested. Dynamic scaling analysis of the single barb scattering data implies that the phase separation arrest mechanism is rapid and also distinct from the spinodal phase separation mechanism i.e. it is not gelation or intermolecular re-association. Any growing lengthscale using this spinodal phase separation approach must first traverse the UV and blue wavelength regions, growing the structure by coarsening, resulting in a broad distribution of domain sizes. PMID:26686280

  8. Spatially modulated structural colour in bird feathers

    NASA Astrophysics Data System (ADS)

    Parnell, Andrew J.; Washington, Adam L.; Mykhaylyk, Oleksandr O.; Hill, Christopher J.; Bianco, Antonino; Burg, Stephanie L.; Dennison, Andrew J. C.; Snape, Mary; Cadby, Ashley J.; Smith, Andrew; Prevost, Sylvain; Whittaker, David M.; Jones, Richard A. L.; Fairclough, J. Patrick. A.; Parker, Andrew R.

    2015-12-01

    Eurasian Jay (Garrulus glandarius) feathers display periodic variations in the reflected colour from white through light blue, dark blue and black. We find the structures responsible for the colour are continuous in their size and spatially controlled by the degree of spinodal phase separation in the corresponding region of the feather barb. Blue structures have a well-defined broadband ultra-violet (UV) to blue wavelength distribution; the corresponding nanostructure has characteristic spinodal morphology with a lengthscale of order 150 nm. White regions have a larger 200 nm nanostructure, consistent with a spinodal process that has coarsened further, yielding broader wavelength white reflectance. Our analysis shows that nanostructure in single bird feather barbs can be varied continuously by controlling the time the keratin network is allowed to phase separate before mobility in the system is arrested. Dynamic scaling analysis of the single barb scattering data implies that the phase separation arrest mechanism is rapid and also distinct from the spinodal phase separation mechanism i.e. it is not gelation or intermolecular re-association. Any growing lengthscale using this spinodal phase separation approach must first traverse the UV and blue wavelength regions, growing the structure by coarsening, resulting in a broad distribution of domain sizes.

  9. Influence of dietary feathers on the fecal microbiota in captive Arctic fox: do dietary hair or feathers play a role in the evolution of carnivorous mammals?

    PubMed

    Zhang, Liang; Yang, Shuhui; Xu, Yanchun; Dahmer, Thomas D

    2014-11-01

    Hair and feathers are composed of keratin and are indigestible, inalimental and unpalatable for carnivores. However, carnivores often ingest hair and feathers during feeding or when grooming. We hypothesized that ingestion of hair and feathers changes species diversity and relative abundance of bacteria in the gut of carnivores. To test this hypothesis, we added disinfected poultry down feathers to the normal diet of captive Arctic foxes (Alopex lagopus). We then used fluorescently labeled terminal restriction fragments (T-RFs) to examine changes in fecal bacterial diversity and abundance. The results showed that the number of bacterial species increased significantly after feather ingestion, but that total abundance was unchanged. This demonstrated that addition of disinfected feathers to the diet stimulated increased production among less abundant bacteria, resulting in a balancing of relative abundance of different bacterial species, or that some newly-ingested microbial species would colonize the gut because a suitable microhabitat had become available. This implies that the overall production of bacterial metabolites would be made up of a greater range of substances after feather ingestion. On one hand, the host's immune response would be more diverse, increasing the capacity of the immune system to regulate gut microflora. On the other hand, the animal's physiological performance would also be affected. For wild animals, such altered physiological traits would be subjected to natural selection, and, hence, persistent geographic differences in the character of ingested feathers or fur would drive speciation.

  10. Biodegradation of keratinous waste by Chryseobacterium sp. RBT isolated from soil contaminated with poultry waste.

    PubMed

    Gurav, Ranjit G; Jadhav, Jyoti P

    2013-02-01

    In the present study, a feather degrading bacterial strain was isolated from poultry waste disposal site, Kolhapur, India. The bacterium was identified as Chryseobacterium sp. RBT using 16S rRNA gene sequence analysis. Chryseobacterium sp. RBT showed rapid hydrolysis of native feathers within 30 h and produced the highest level of keratinase activity (98.3 U/ml). Keratin containing wastes viz. silk, human hair, wool and chicken feathers were tested for keratin degrading ability of the bacterium. Amongst the tested substrates, the Chryseobacterium sp. RBT showed more specificity towards chicken feathers (98.6% degradation) with maximum keratinase activity (98.3 U/ml) and solubilized protein concentration (3.84 mg/ml). Effect of various physico-chemical parameters (temperature, pH, carbon and nitrogen sources) on keratinase production was monitored. The maximum keratinase activity was observed at pH (8.6) and temperature (50 °C). Molasses (1.0% w/v) acted as an inducer and enhanced the keratinolytic activity by two fold, while starch worked as an inhibitor. The goat skin when treated with crude keratinase enzyme (2% v/v), showed complete dehairing within 12 h. Hence, Chryseobacterium sp. RBT shows potential as a candidate for treating the keratinous waste in an ecofriendly manner.

  11. Cells of embryonic and regenerating germinal layers within barb ridges: implication for the development, evolution and diversification of feathers.

    PubMed

    Alibardi, L

    2006-04-01

    The formation of feathers occurs by the transformation of the embryonic epidermis of feather filaments into keratinized barbules and barbs. The present ultrastructural study directly documents this transformation in chick and zebrafinch downfeathers and juvenile feathers. The transformation of the epidermis in the feather filament (downfeathers) or in the follicle (juvenile feathers) is similar. The change in cell shape of subperiderm or subsheath cells and surrounding barb vane ridge cells derives from the re-organization of the linear embryonic epithelium into barb ridges. In the latter the stratification of the outer and inner periderm, of the subperiderm/subsheath, and of the germinal layer of the embryonic epidermis is altered. While the external layers produce the sheath and barb vane ridge cells, subperiderm/subsheath cells are displaced into barbule plates that converge medially in the ramus area of the barb ridge. Cells in the barbule plates elongate into barbule and barb cortical cells by the synthesis of longitudinally oriented feather keratin bundles. In the mid-central area of the barb ridge (the ramus area) cells become polygonal and pile up. The external cells accumulate numerous keratin filaments forming cortical cells and are in contact with barbule cells. The above process also occurs in barb ridges of juvenile feathers and of adult feathers before molting. However, barb ridges produced within follicles of juveniles and adult feathers are longer than in downfeathers, and possess long rami. The incorporation of tritiated histidine in barbule and barb cortical cells has been studied by ultrastructural autoradiography. Most of the labeling is cytoplasmic or is associated with bundles of keratin but is not concentrated over keratin. This indicates that together with keratin possible histidine-rich keratin-associated proteins are produced during the elongation from subperiderm/subsheath to barbule/barb cells. Barb cortical cells merge with medullary

  12. Ducks Overboard!

    ERIC Educational Resources Information Center

    Weiland, Ingrid; Sheffield, Caroline

    2013-01-01

    The authors open this article with a description of an incident that happened in 1992, when 28,800 rubber bath toys (i.e., ducks, frogs, turtles, and beavers) fell off a cargo ship in the middle of the Pacific Ocean. In 2009, these rubber bath toys were still washing ashore on beaches all around the world. This science instruction can be used with…

  13. Production of feather hydrolysates with antioxidant, angiotensin-I converting enzyme- and dipeptidyl peptidase-IV-inhibitory activities.

    PubMed

    Fontoura, Roberta; Daroit, Daniel J; Correa, Ana P F; Meira, Stela M M; Mosquera, Mauricio; Brandelli, Adriano

    2014-09-25

    The antioxidant and antihypertensive activities of feather hydrolysates obtained with the bacterium Chryseobacterium sp. kr6 were investigated. Keratin hydrolysates were produced with different concentrations of thermally denatured feathers (10-75 g l(-1)) and initial pH values (6.0-9.0). Soluble proteins accumulated in high amounts in media with 50 and 75 g l(-1) of feathers, reaching values of 18.5 and 22 mg ml(-1), respectively, after 48 hours of cultivation. In media with 50 g l(-1) of feathers, initial pH had minimal effect after 48 hours. Maximal protease production was observed after 24 hours of cultivation, and feather concentration and initial pH values showed no significant effect on enzyme yields at this time. Feather hydrolysates displayed in vitro antioxidant properties, and optimal antioxidant activities were observed in cultures with 50 g l(-1) feathers, at initial pH 8.0, after 48 hours growth at 30°C. Also, feather hydrolysates were demonstrated to inhibit the angiotesin I-converting enzyme by 65% and dipeptidyl peptidase-IV by 44%. The bioconversion of an abundant agroindustrial waste such as chicken feathers can be utilized as a strategy to obtain hydrolysates with antioxidant and antihypertensive activities. Feather hydrolysates might be employed as supplements in animal feed, and also as a potential source of bioactive molecules for feed, food and drug development.

  14. Dynamics of keratin assembly: exogenous type I keratin rapidly associates with type II keratin in vivo

    PubMed Central

    1993-01-01

    Keratin intermediate filaments (IF) are obligate heteropolymers containing equal amounts of type I and type II keratin. We have previously shown that microinjected biotinylated type I keratin is rapidly incorporated into endogenous bundles of keratin IF (tonofilaments) of PtK2 cells. In this study we show that the earliest steps in the assembly of keratin subunits into tonofilaments involve the extremely rapid formation of discrete aggregates of microinjected keratin. These are seen as fluorescent spots containing both type I and type II keratins within 1 min post-injection as determined by double label immunofluorescence. These observations suggest that endogenous type II keratin subunits can be rapidly mobilized from their endogenous state to form complexes with the injected type I protein. Furthermore, confocal microscopy and immunogold electron microscopy suggest that the type I-type II keratin spots from in close association with the endogenous keratin IF network. When the biotinylated protein is injected at concentrations of 0.3-0.5 mg/ml, the organization of the endogenous network of tonofilaments remains undisturbed during incorporation into tonofilaments. However, microinjection of 1.5-2.0 mg/ml of biotinylated type I results in significant alterations in the organization and assembly state of the endogenous keratin IF network soon after microinjection. The results of this study are consistent with the existence of a state of equilibrium between keratin subunits and polymerized keratin IF in epithelial cells, and provide further proof that IF are dynamic elements of the cytoskeleton of mammalian cells. PMID:7686161

  15. Determination of trace elements in pigeon and raven feathers by ICPMS

    NASA Astrophysics Data System (ADS)

    Adout, Atar; Hawlena, Dror; Maman, Rachel; Paz-Tal, Ofra; Karpas, Zeev

    2007-11-01

    The concentration of 11 trace elements (Mg, Al, Mn, Cu, Zn, Rb, Mo, Cd, Ba, Hg and Pb) and sulfur in feathers of pigeons and ravens was determined by ICPMS after wet digestion of the sample. Pigeon feathers were collected 6rom five habitats: rural, industrial, urban, natural area and from a controlled environment, and raven feathers from the former two habitats. The distribution along the feather shaft was studied and for most elements it was found that the concentration increased from the quill towards the distal end of the feather. There were statistically significant differences in the concentration of trace elements between pigeons from different environments and between ravens and pigeons from similar habitats. It was found that for most elements the lowest concentration was in feathers from the control population and the highest in the industrial habitat. In general, higher concentrations were found in the omnivore raven feathers than in the granivore pigeons. Sulfur, that is abundant in keratin, was found to be a potential internal standard as its concentration presented the lowest variation among different samples. Thus, feathers from common birds, collected from the ground, can serve as bio-indicators of environmental levels of trace elements.

  16. Unzipping bird feathers

    PubMed Central

    Kovalev, Alexander; Filippov, Alexander E.; Gorb, Stanislav N.

    2014-01-01

    The bird feather vane can be separated into two parts by pulling the barbs apart. The original state can be re-established easily by lightly stroking through the feather. Hooklets responsible for holding vane barbs together are not damaged by multiple zipping and unzipping cycles. Because numerous microhooks keep the integrity of the feather, their properties are of great interest for understanding mechanics of the entire feather structure. This study was undertaken to estimate the separation force of single hooklets and their arrays using force measurement of an unzipping feather vane. The hooklets usually separate in some number synchronously (20 on average) with the highest observed separation force of 1.74 mN (average force 0.27 mN), whereas the single hooklet separation force was 14 μN. A simple numerical model was suggested for a better understanding of zipping and unzipping behaviour in feathers. The model demonstrates features similar to those observed in experiments. PMID:24352674

  17. Cell structure of developing barbs and barbules in downfeathers of the chick: Central role of barb ridge morphogenesis for the evolution of feathers.

    PubMed

    Alibardi, L

    2005-04-01

    The present ultrastructural study shows how cells organize to form the complex structure of downfeathers in chick embryos. The embryonic epidermis of the apical part of feather filaments folds inward forming barb ridges which extend toward the base of the feather. The stratification of epidermal cells in barb ridges is maintained but the basal layer loses most of the germinal activity. New cells for the growth of feather filaments are mainly produced in its basal part. In barb ridges only the original four epidermal layers of the embryonic epidermis remain to form feathers: 1) the external periderm, 2) three-five layers of the feather sheath and barb vane ridge cells, 3) subperiderm cells, and 4) basal or cylindrical cells. Periderm, sheath, barb vane ridge and cylindrical cells synthesize only alpha-keratin. Instead, cells of the subperiderm layer synthesize a small type of beta-keratin: feather beta-keratin. At hatching, the subperiderm layer is lost in most areas of the skin of the chick (apteric and scaled), and is replaced by cells containing alpha-keratin (interfollicular-apteric epidermis), scale beta-keratin (scales), beak beta-keratin (beak), and claw beta-keratin (claws). Only in feathers, cells of the original subperiderm layer remain and give origin to barb and barbule cells. The formation of separated chains of barb and barbule cells is allowed by the presence of barb vane ridge cells that function as spacers between merging cells of barb and barbule cells. Subperiderm cells elongate and merge into a syncitium to form barbules and barbs. While barbule and barb cells accumulate feather-keratin, barb vane and cylindrical cells accumulate lipids, vesicles and little alpha-keratin. These cells eventually degenerate by necrosis leaving empty spaces and lipids between barbules and barbs. No apoptosis is necessary to explain the process of carving out of barb and barbules in feathers after dissolution of the external sheath. In fact, the retraction of blood

  18. Complex optical structure in the ribbon-like feathers of the African open-bill stork

    NASA Astrophysics Data System (ADS)

    Vigneron, Jean Pol; Lousse, Virginie; Colomer, Jean-François; Rassart, Marie; Louette, Michel

    2006-08-01

    The structural origin of the weak iridescence from the very peculiar ribbon-shaped feathers of the African open-bill stork, Anastomus lamelligerus (Ciconiidae) is investigated, using a combination of spectrophotometry, electron microscopy, and theoretical modelling. The cortex of these feathers can be described as a slab of keratin, transformed into a multilayer by the insertion of thin parallel planes containing harder nodules, disposed sideby- side and oriented along the feather axis. These nodules each show a sperically capped cylindrical shape. An empty cylindrical channel - the vacuole - occupies the long axis of the nodule. These nodules act in a collective and individual way to produce the frequency selection giving rise to the observed dark-green coloration of these special feathers.

  19. Functional keratin as structural platforms

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Wool with up to 95% keratin by weight is a rich and pure source of proteinous biomaterial. As polymeric polyamide it exhibits high functionality through amide, carboxyl, sulfoxide, sulfide, and thiosulfide functions. Solubilized wool was transformed into keratin morphologies with the unique characte...

  20. Synthesis, structure and antimicrobial property of green composites from cellulose, wool, hair and chicken feather.

    PubMed

    Tran, Chieu D; Prosencyes, Franja; Franko, Mladen; Benzi, Gerald

    2016-10-20

    Novel composites between cellulose (CEL) and keratin (KER) from three different sources (wool, hair and chicken feather) were successfully synthesized in a simple one-step process in which butylmethylimidazolium chloride (BMIm(+)Cl(-)), an ionic liquid, was used as the sole solvent. The method is green and recyclable because [BMIm(+)Cl(-)] used was recovered for reuse. Spectroscopy (FTIR, XRD) and imaging (SEM) results confirm that CEL and KER remain chemically intact and homogeneously distributed in the composites. KER retains some of its secondary structure in the composites. Interestingly, the minor differences in the structure of KER in wool, hair and feather produced pronounced differences in the conformation of their corresponding composites with wool has the highest α-helix content and feather has the lowest content. These results correlate well with mechanical and antimicrobial properties of the composites. Specifically, adding CEL into KER substantially improves mechanical strength of [CEL+KER] composites made from all three different sources, wool, hair and chicken feathers i.e., [CEL+wool], [CEL+hair] and [CEL+feather]. Since mechanical strength is due to CEL, and CEL has only random structure, [CEL+feather] has, expectedly, the strongest mechanical property because feather has the lowest content of α-helix. Conversely, [CEL+wool] composite has the weakest mechanical strength because wool has the highest α-helix content. All three composites exhibit antibacterial activity against methicillin resistant Staphylococcus aureus (MRSA). The antibacterial property is due not to CEL but to the protein and strongly depends on the type of the keratin, namely, the bactericidal effect is strongest for feather and weakest for wool. These results together with our previous finding that [CEL+KER] composites can control release of drug such as ciprofloxacin clearly indicate that these composites can potentially be used as wound dressing.

  1. Endocrine controls of keratin expression.

    PubMed

    Ramot, Yuval; Paus, Ralf; Tiede, Stephan; Zlotogorski, Abraham

    2009-04-01

    Keratins are a family of intermediate filaments that serve various crucial roles in skin physiology. For mammalian skin to function properly, and to produce epidermal and hair keratins that are optimally adapted for their environment, it is critical that keratin gene and protein expression are stringently controlled. Given that the skin is not only targeted by multiple hormones, but also constitutes a veritable peripheral endocrine organ, it is not surprizing that intracutaneous keratin expression is underlined by tight endocrine controls. These controls encompass thyroid hormones, steroid hormones such as glucocorticoids (GCs), retinoic acid (RA) and vitamin D, and several neuroendocrine mediators. Here, we review why a better understanding of the endocrine controls of keratin expression is not only required for an improved insight into normal human skin and hair function, but may also open new therapeutic avenues in a wide range of skin and hair diseases.

  2. Keratin proteins in human lung carcinomas. Combined use of morphology, keratin immunocytochemistry, and keratin immunoprecipitation.

    PubMed Central

    Banks-Schlegel, S. P.; McDowell, E. M.; Wilson, T. S.; Trump, B. F.; Harris, C. C.

    1984-01-01

    Light-microscopic immunocytochemistry and electron microscopy demonstrated that adenocarcinomas (AC) and squamous cell (epidermoid) carcinomas (SCCs) of human lung contained keratin proteins in the form of tonofilament bundles. However, moderately differentiated (md) SCCs contained abundant keratin, whereas poorly differentiated (pd) SCCs and all ACs contained lesser amounts. Lung tumors with the diagnosis of AC or SCC, as defined by WHO criteria, were also analyzed by immunoprecipitation techniques for the presence of keratin proteins. Regardless of the degree of tumor differentiation, SCCs contained a 44 kd keratin which was lacking in ACs. Interestingly, normal bronchial epithelium also contained the same 44 kd keratin. In addition, as SCCs became more differentiated, they exhibited even greater differences in the profile of synthesized keratins. Specifically, the relative abundance of the intermediate-sized keratins (57 and 59 kd) was increased in the md SCCs. Although keratin protein patterns appear to be a valuable adjunct in distinguishing AC from SCC, their usefulness as a diagnostic tool will require survey of a larger number of poorly differentiated tumors. Images Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 PMID:6198920

  3. Production of keratinolytic enzyme by an indigenous feather-degrading strain Bacillus cereus Wu2.

    PubMed

    Lo, Wei-Hsun; Too, Jui-Rze; Wu, Jane-Yii

    2012-12-01

    A novel feather-degrading microorganism was isolated from a poultry farm in Taiwan, and was identified Bacillus cereus Wu2 according to 16S rRNA sequencing. The isolated strain produces keratinolytic enzyme using chicken feather as the sole carbon and nitrogen source. The experimental results indicated that the extra carbon sources (glucose, fructose, starch, sucrose, or lactose) could act as a catabolite repressor to the enzyme secretion or keratinolytic activity when keratinous substrates were employed as protein sources. However, addition of 2 g/L of NH(4)Cl to the feather medium increased the enzyme production. The optimum temperature and initial pH for enzyme production were 30°C and 7.0, respectively. The maximum yield of the enzyme was 1.75 kU/mL in the optimal chicken feather medium; this value was about 17-fold higher than the yield in the basal hair medium. The B. cereus Wu2 possessed disulfide reductase activity along with keratinolytic activity. The amino acid contents of feathers degradated by B. cereus Wu2 were higher, especially for lysine, methionine and threonine which were nutritionally essential amino acids and usually deficient in the feather meal. Thus, B. cereus Wu2 could be not only used to enhance the nutritional value of feather meal but is also a potential bioinoculant in agricultural environments.

  4. Increased water contamination and grow-out Pekin duck mortality when raised with water troughs compared to pin-metered water lines using a United States management system.

    PubMed

    Schenk, A; Porter, A L; Alenciks, E; Frazier, K; Best, A A; Fraley, S M; Fraley, G S

    2016-04-01

    Controversy has developed as to whether or not pin-metered water lines or water troughs are more appropriate for Pekin ducks. We hypothesized that water troughs would show improved duck body conditions and environmental quality compared to pin-metered water lines. To test this hypothesis, we housed ducks in 2 barns, one with water lines and one with water troughs. Water troughs were constructed to meet RSPCA guidelines for number and density of ducks and with recently described verandas. Ducks were divided into 4 pens per barn (n=1,000 ducks/pen). The study was then repeated (n=8 pens per water source) in a cross-over design so the barns each contained the opposite water source to the first experiment. We scored the ducks' body condition using an established scoring rubric and analyzed using SAS Proc GLM-Mix as binomial data. Ducks housed with water troughs showed higher (thus worse condition; P<0.001) scores for eyes, nostrils, feather quality, feather cleanliness, and foot pads. We also compared water condition, water quality, and duck mortality using a Student t test for both water sources each week. We found that the water troughs showed higher iron (P<0.001), nitrites (P<0.001), pH (P<0.01), and bacterial growth (P<0.001). The bacterial growth was shown to have higher (P<0.001)E. coli, coliforms, and Staphylococcusin the water troughs. Water lines typically showed no bacterial growth in culture-based assays. Ducks housed with water troughs used greater (P=0.001) volumes of water compared to ducks housed with water lines. Ducks with water troughs also showed a greater percent (P=0.008) mortality at all ages compared to ducks with water lines. These data suggest that water troughs may not be beneficial for duck welfare and could adversely impact both environment and duck or human health.

  5. Grumman JF-1 Duck

    NASA Technical Reports Server (NTRS)

    1934-01-01

    Grumman JF-1 Duck: The Grumman JF-1 Duck was in service with the NACA at Langley during the summer of 1934. The JF-1 was notably different from the later J2F Duck in that the JF-1 had a shorter central float. The NACA used the JF-1 in part as a propeller testbed aircraft.

  6. LM and TEM study of the orthokeratinized and parakeratinized epithelium of the tongue in the domestic duck (Anas platyrhynchos f. domestica).

    PubMed

    Skieresz-Szewczyk, Kinga; Jackowiak, Hanna; Ratajczak, Marlena

    2014-12-01

    The previous histological studies of the lingual mucosa in birds characterized two types of keratinized epithelium, i.e. orthokeratinized and parakeratinized. These epithelia are composed of three layers: basal, intermediate and keratinized. The present study showed detailed ultrastructural features of cells in particular layers of two types of keratinized epithelia on the tongue in the domestic duck and defined structural differences. TEM observations showed a gradual reduction in cell organelles in the following layers, at increasing amounts of keratin fibers. The characteristic feature of the ortho- and parakeratinized epithelium is the presence of sub-layers in the intermediate layer, i.e. the upper and lower part, which results from the different shape of cell nuclei and dye affinity of the cytoplasm. The keratinized layer of ortho- and parakeratinized epithelium is built of two types of cells such as electron dark and light cells, which undergo exfoliation. The basic difference between the keratinized epithelia is the presence of flattened cell nuclei in the keratinized layer of the parakeratinized epithelium. The differentiating feature is also an arrangement of keratin fibers in the cell cytoplasm of the keratinized layer. The analysis of the thickness of the epithelium and the keratinized layer, indicated differences between keratinized epithelia, which result from two variants of performing protective functions, either through a thick keratinized layer or by a higher epithelium. Differences in the ultrastructure of the ortho- and parakeratinized epithelium are associated with mechanical functions of the epithelium resulting from different forces acting on the tongue during feeding activities.

  7. Family Feathers. [Videotape Series].

    ERIC Educational Resources Information Center

    1999

    Family Feathers is a set of 18 videotapes for parents of preschool children, created by the Alaska Native Home Base Video Project of the Tlingit and Haida Head Start Program. This series offers culturally relevant solutions to the challenges of parenting, drawing on practical advice from Tlingit and Haida parents, wisdom from elders, and some of…

  8. Keratins in health and disease.

    PubMed

    Toivola, Diana M; Boor, Peter; Alam, Catharina; Strnad, Pavel

    2015-02-01

    The cytoprotective keratins (K) compose the intermediate filaments of epithelial cells and their inherited and spontaneous mutations give rise to keratinopathies. For example, mutations in K1/K5/K10/K14 cause epidermal skin diseases whereas simple epithelial K8/K18/K19 variants predispose to development of several liver disorders. Due to their abundance, tissue- and context-specific expression, keratins constitute excellent diagnostic markers of both neoplastic and non-neoplastic diseases. During injury and in disease, keratin expression levels, cellular localization or posttranslational modifications are altered. Accumulating evidence suggests that these changes modulate multiple processes including cell migration, tumor growth/metastasis and development of infections. Therefore, our understanding of keratins is shifting from diagnostic markers to active disease modifiers.

  9. The impact of uropygial gland secretions on mechanically induced wearing of barn owl and pigeon body feathers

    NASA Astrophysics Data System (ADS)

    Ott, Benjamin; Müsse, Annika; Wagner, Hermann

    2016-04-01

    Bird feathers are remarkable structures light but yet durable providing insulation and the ability of flight. Owls are highly specialized birds of prey, widely known for their ability to y silently which is enabled by (micro-) structural specializations of the feathers. The barn owl replaces feathers less frequently in comparison to other same sized birds like pigeons, indicating a much better resistance against material fatigue of these delicate microstructures. We used axisymmetric drop shape analysis (ADSA) of water drop contact angles as a non-destructive method of characterizing wearing processes in feathers. We hypothesized that feathers become more wettable when worn. We also investigated the impact of ethanol treatment in order to remove fatty residues of the uropygial gland secretions, barn owls and pigeons use for preening, on ageing processes. Ethanol treatment resulted in a slight, but significant increase of water repellency in barn owl but not in pigeon flight feathers. Our preliminary data also suggest that the uropygial gland secretions decelerate the wearing process of the feather keratin. We observed this effect in both species, however, it was more distinct for barn owl uropygial gland secretions. The results of this study, obtained by contact angle measurements used as a non-destructive evaluation method of material fatigue, yield insights into the material fatigue of feathers and the decelerating effect of uropygial gland secretions on wear on the other hand.

  10. On the Morphogenesis of Feathers

    PubMed Central

    Yu, Mingke; Wu, Ping; Widelitz, Randall B.; Chuong, Cheng-Ming

    2015-01-01

    The most unique character of the feather is its highly ordered hierarchical branched structure1, 2. This evolutionary novelty confers flight function to birds3–5. Recent discoveries of fossils in China have prompted keen interest in the origin and evolution of feathers6–14. However, controversy arises whether the irregularly branched integumentary fibers on dinosaurs such as Sinornithosaurus are truly feathers6, 11, and whether an integumentary appendage with a major central shaft and notched edges is a non-avian feather or a proto-feather8–10. Here we take a developmental approach to analyze molecular mechanisms in feather branching morphogenesis. We have used the replication competent avian sarcoma (RCAS) retrovirus15 to efficiently deliver exogenous genes to regenerating chicken flight feather follicles. We show that the antagonistic balance between noggin and bone morphogenetic protein 4 (BMP4) plays a critical role in feather branching, with BMP4 promoting rachis formation and barb fusion, and noggin enhancing rachis and barb branching. Furthermore we show that sonic hedgehog (SHH) is essential for apoptosis of the marginal plate epithelia to become spaces between barbs. Our analyses show the molecular pathways underlying the topological transformation of feathers from cylindrical epithelia to the hierarchical branched structures, and provide first clues on the possible developmental mechanisms in the evolution of feather forms. PMID:12442169

  11. The molecular basis of human keratin disorders.

    PubMed

    Arin, Meral Julia

    2009-05-01

    Keratins are cytoskeletal proteins that provide structural support to epithelial cells and tissues. Perturbation causes cell and tissue fragility and accounts for a large number of genetic disorders in humans. In humans, 54 functional keratin genes exist and 21 different keratin genes including hair keratins and hair follicle-specific epithelial keratins have been associated with hereditary disorders. Moreover, keratins have been implicated in more complex traits such as liver disease and inflammatory bowel disease. Understanding the molecular basis of keratin disorders has been the basis for improved diagnosis with prognostic implications, genetic counseling and prenatal testing for severe disorders. Besides their mechanical role, keratins have newly identified functions in apoptosis, cell growth, tissue polarity, wound healing and tissue remodeling. Improved understanding of the regulatory functions of keratins may offer novel approaches to overcome current treatment limitations.

  12. Proximate bases of silver color in anhinga (Anhinga anhinga) feathers.

    PubMed

    Shawkey, Matthew D; Maia, Rafael; D'Alba, Liliana

    2011-11-01

    Colors of living organisms are produced by selective light absorption from pigments and/or by light scattering from highly ordered nanostructures (i.e., structural color). While the physical bases of metallic colors of arthropods and fish are fairly well-known, those of birds are not. Here we examine structurally based silver color and its production in feathers of the waterbird species Anhinga. This achromatic color is distinguished from grey by high specular reflectance, from white by low diffuse reflectance, and from both by high gloss. Light and electron microscopy revealed three modifications of feathers likely leading to silver color. First, proximal barbules were highly elongated and contained glossy black color at their base and white color at their pennulum. Second, this glossy black portion contained a single outer layer of keratin weakly bounded by melanosomes. Finally, the white portion contained a disordered amorphous matrix of keratin and air. Optical analyzes suggest that these structures produce, respectively, glossy black color through thin-film interference and white color through incoherent light scattering. Silver color likely results from the combined reflectance of these adjacent structures. This represents a distinct mechanism for attaining silver colors that may have been partially derived through selection for display, thermoregulation or decreased hydrophobicity.

  13. Effect of clay content on morphology and processability of electrospun keratin/poly(lactic acid) nanofiber.

    PubMed

    Isarankura Na Ayutthaya, Siriorn; Tanpichai, Supachok; Sangkhun, Weradesh; Wootthikanokkhan, Jatuphorn

    2016-04-01

    This research work has concerned the development of volatile organic compounds (VOCs) removal filters from biomaterials, based on keratin extracted from chicken feather waste and poly(lactic acid) (PLA) (50/50%w/w) blend. Clay (Na-montmorillonite) was also added to the blend solution prior to carrying out an electro-spinning process. The aim of this study was to investigate the effect of clay content on viscosity, conductivity, and morphology of the electrospun fibers. Scanning electron micrographs showed that smooth and bead-free fibers were obtained when clay content used was below 2 pph. XRD patterns of the electrospun fibers indicated that the clay was intercalated and exfoliated within the polymers matrix. Percentage crystallinity of keratin in the blend increased after adding the clay, as evidenced from FTIR spectra and DSC thermograms. Transmission electron micrographs revealed a kind of core-shell structure with clay being predominately resided within the keratin rich shell and at the interfacial region. Filtration performance of the electrospun keratin/PLA fibers, described in terms of pressure drop and its capability of removing methylene blue, were also explored. Overall, our results demonstrated that it was possible to improve process-ability, morphology and filtration efficiency of the electrospun keratin fibers by adding a suitable amount of clay.

  14. Sprouty/FGF signaling regulates the proximal-distal feather morphology and the size of dermal papillae.

    PubMed

    Yue, Zhicao; Jiang, Ting Xin; Wu, Ping; Widelitz, Randall B; Chuong, Cheng Ming

    2012-12-01

    In a feather, there are distinct morphologies along the proximal-distal axis. The proximal part is a cylindrical stalk (calamus), whereas the distal part has barb and barbule branches. Here we focus on what molecular signaling activity can modulate feather stem cells to generate these distinct morphologies. We demonstrate the drastic tissue remodeling during feather cycling which includes initiation, growth and resting phases. In the growth phase, epithelial components undergo progressive changes from the collar growth zone to the ramogenic zone, to maturing barb branches along the proximal-distal axis. Mesenchymal components also undergo progressive changes from the dermal papilla, to the collar mesenchyme, to the pulp along the proximal-distal axis. Over-expression of Spry4, a negative regulator of receptor tyrosine kinases, promotes barb branch formation at the expense of the epidermal collar. It even induces barb branches from the follicle sheath (equivalent to the outer root sheath in hair follicles). The results are feathers with expanded feather vane regions and small or missing proximal feather shafts (the calamus). Spry4 also expands the pulp region while reducing the size of dermal papillae, leading to a failure to regenerate. In contrast, over-expressing Fgf10 increases the size of the dermal papillae, expands collar epithelia and mesenchyme, but also prevents feather branch formation and feather keratin differentiation. These results suggest that coordinated Sprouty/FGF pathway activity at different stages is important to modulate feather epidermal stem cells to form distinct feather morphologies along the proximal-distal feather axis.

  15. Structural color change following hydration and dehydration of iridescent mourning dove (Zenaida macroura) feathers.

    PubMed

    Shawkey, Matthew D; D'Alba, Liliana; Wozny, Joel; Eliason, Chad; Koop, Jennifer A H; Jia, Li

    2011-04-01

    Dynamic changes in integumentary color occur in cases as diverse as the neurologically controlled iridiphores of cephalopod skin and the humidity-responsive cuticles of longhorn beetles. By contrast, feather colors are generally assumed to be relatively static, changing by small amounts only over periods of months. However, this assumption has rarely been tested even though structural colors of feathers are produced by ordered nanostructures that are analogous to those in the aforementioned dynamic systems. Feathers are neither innervated nor vascularized and therefore any color change must be caused by external stimuli. Thus, we here explore how feathers of iridescent mourning doves Zenaida macroura respond to a simple stimulus: addition and evaporation of water. After three rounds of experimental wetting and subsequent evaporation, iridescent feather color changed hue, became more chromatic and increased in overall reflectance by almost 50%. To understand the mechanistic basis of this change, we used electron microscopy to examine macro- and nanostructures before and after treatment. Transmission electron microscopy and transfer matrix thin-film models revealed that color is produced by thin-film interference from a single (∼ 35 nm layer of keratin around the edge of feather barbules, beneath which lies a layer of air and melanosomes. After treatment, the most striking morphological difference was a twisting of colored barbules that exposed more of their surface area for reflection, explaining the observed increase in brightness. These results suggest that some plumage colors may be more malleable than previously thought, leading to new avenues for research on dynamic plumage color.

  16. Environmental-induced acquisition of nuptial plumage expression: a role of denaturation of feather carotenoproteins?

    PubMed Central

    Blanco, Guillermo; Frías, Oscar; Garrido-Fernández, Juan; Hornero-Méndez, Dámaso

    2005-01-01

    Several avian species show a bright carotenoid-based coloration during spring and following a period of duller coloration during the previous winter, despite carotenoids presumably being fully deposited in feathers during the autumn moult. Carotenoid-based breast feathers of male linnets (Carduelis cannabina) increased in hue (redness), saturation and brightness after exposing them to outdoor conditions from winter to spring. This represents the first experimental evidence showing that carotenoid-based plumage coloration may increase towards a colourful expression due to biotic or abiotic environmental factors acting directly on full-grown feathers when carotenoids may be fully functional. Sunlight ultraviolet (UV) irradiation was hypothesized to denature keratin and other proteins that might protect pigments from degradation by this and other environmental factors, suggesting that sunlight UV irradiation is a major factor in the colour increase from winter to spring. Feather proteins and other binding molecules, if existing in the follicles, may be linked to carotenoids since their deposition into feathers to protect colourful features of associated carotenoids during the non-breeding season when its main signalling function may be relaxed. Progress towards uncovering the significance of concealment and subsequent display of colour expression should consider the potential binding and protecting nature of feather proteins associated with carotenoids. PMID:16191594

  17. Microstructural tissue-engineering in the rachis and barbs of bird feathers

    PubMed Central

    Lingham-Soliar, Theagarten

    2017-01-01

    Feathers do not have to be especially strong but they do need to be stiff and at the same time resilient and to have a high work of fracture. Syncitial barbule fibres are the highest size-class of continuous filaments in the cortex of the rachis of the feather. However, the rachis can be treated as a generalized cone of rapidly diminishing volume. This means that hundreds of syncitial barbule fibres of the rachis may have to be terminated before reaching the tip – creating potentially thousands of inherently fatal crack-like defects. Here I report a new microstructural architecture of the feather cortex in which most syncitial barbule fibres deviate to the right and left edges of the feather rachis from far within its borders and extend into the barbs, side branches of the rachis, as continuous filaments. This novel morphology adds significantly to knowledge of β-keratin self-assembly in the feather and helps solve the potential problem of fatal crack-like defects in the rachidial cortex. Furthermore, this new complexity, consistent with biology’s robust multi-functionality, solves two biomechanical problems at a stroke. Feather barbs deeply ‘rooted’ within the rachis are also able to better withstand the aerodynamic forces to which they are subjected. PMID:28345593

  18. Keratinase production and keratin degradation by a mutant strain of Bacillus subtilis *

    PubMed Central

    Cai, Cheng-gang; Lou, Bing-gan; Zheng, Xiao-dong

    2008-01-01

    A new feather-degrading bacterium was isolated from a local feather waste site and identified as Bacillus subtilis based on morphological, physiochemical, and phylogenetic characteristics. Screening for mutants with elevated keratinolytic activity using N-methyl-N′-nitro-N-nitrosoguanidine mutagenesis resulted in a mutant strain KD-N2 producing keratinolytic activity about 2.5 times that of the wild-type strain. The mutant strain produced inducible keratinase in different substrates of feathers, hair, wool and silk under submerged cultivation. Scanning electron microscopy studies showed the degradation of feathers, hair and silk by the keratinase. The optimal conditions for keratinase production include initial pH of 7.5, inoculum size of 2% (v/v), age of inoculum of 16 h, and cultivation at 23 °C. The maximum keratinolytic activity of KD-N2 was achieved after 30 h. Essential amino acids like threonine, valine, methionine as well as ammonia were produced when feathers were used as substrates. Strain KD-N2, therefore, shows great promise of finding potential applications in keratin hydrolysis and keratinase production. PMID:18196614

  19. Effects of keratin phosphorylation on the mechanical properties of keratin filaments in living cells.

    PubMed

    Fois, Giorgio; Weimer, Michael; Busch, Tobias; Felder, Erika T; Oswald, Franz; von Wichert, Götz; Seufferlein, Thomas; Dietl, Paul; Felder, Edward

    2013-04-01

    Keratin filaments impart resilience against mechanical extension of the cell. Despite the pathophysiological relevance of this function, very little is known about the mechanical properties of intermediate filaments in living cells and how these properties are modulated. We used keratin mutants that mimic or abrogate phosphorylation of keratin 8-serine(431) and keratin 18-serine(52) and investigated their effect on keratin tortuousness after cell stretch release in squamous cell carcinoma cells. Cells transfected with the wild-type keratins were used as controls. We can show that keratin dephosphorylation alters the stretch response of keratin in living cells since keratin tortuousness was abolished when phosphorylation of keratin18-serine(52) was abrogated. Additional experiments demonstrate that keratin tortuousness is not simply caused by a plastic overextension of keratin filaments because tortuousness is reversible and requires an intact actin-myosin system. The role of actin in this process remains unclear, but we suggest anchorage of keratin filaments to actin during stretch that leads to buckling on stretch release. Dephosphorylated keratin18-serine(52) might strengthen the recoil force of keratin filaments and hence explain the abolished buckling. The almost exclusive immunolabeling for phosphorylated keratin18-serine (52) in the cell periphery points at a particular role of the peripheral keratin network in this regard.

  20. Amorphous diamond-structured photonic crystal in the feather barbs of the scarlet macaw

    PubMed Central

    Yin, Haiwei; Dong, Biqin; Liu, Xiaohan; Zhan, Tianrong; Shi, Lei; Zi, Jian; Yablonovitch, Eli

    2012-01-01

    Noniridescent coloration by the spongy keratin in parrot feather barbs has fascinated scientists. Nonetheless, its ultimate origin remains as yet unanswered, and a quantitative structural and optical description is still lacking. Here we report on structural and optical characterizations and numerical simulations of the blue feather barbs of the scarlet macaw. We found that the sponge in the feather barbs is an amorphous diamond-structured photonic crystal with only short-range order. It possesses an isotropic photonic pseudogap that is ultimately responsible for the brilliant noniridescent coloration. We further unravel an ingenious structural optimization for attaining maximum coloration apparently resulting from natural evolution. Upon increasing the material refractive index above the level provided by nature, there is an interesting transition from a photonic pseudogap to a complete bandgap. PMID:22615350

  1. Moulting tail feathers in a juvenile oviraptorisaur.

    PubMed

    Prum, Richard O

    2010-11-04

    Xu et al. describe the extraordinarily preserved feathers from two subadults of the oviraptorisaur Similicaudipteryx from the Yixian Formation of Liaoning, China. The preserved tail feathers of the juvenile specimen (STM4.1) show a morphology not previously observed in any fossil feathers. The tail feathers of an older, immature specimen (STM22-6) show a typical closed pennaceous structure with a prominent, planar vane. I propose that the feathers of the tail of the juvenile specimen are not a specialized feather generation, but fossilized 'pin feathers' or developing feather germs.

  2. Laying hens learn to avoid feathers.

    PubMed

    Harlander-Matauschek, A; Wassermann, F; Zentek, J; Bessei, W

    2008-09-01

    Previous work demonstrated an association between feather pecking and feather eating in laying hens. This raised the question if digestive feedback affects feather eating or feather pecking in laying hens. We hypothesized that feathers enriched with sugar form a positive feedback and feathers enriched with quinine sulfate form a negative feedback. Forty-eight laying hens were kept in individual cages and fed a pelleted diet ad libitum. Twenty-four birds were offered feathers on a daily basis; 12 of these birds were offered feathers soaked in 4% quinine sulfate solution (Q), and the other 12 were offered feathers soaked in 4% sucrose solution (S). The other 24 birds were kept as a control (C) without access to feathers. After a 10-d feather feeding period, 3 groups of 4 S and 4 C birds each and 3 groups of 4 Q and 4 C birds each were assembled. Feather-pecking behavior was recorded over a period of 8 d. The number of Q feathers eaten was significantly lower than the number of S feathers. Birds that were offered Q feathers in the feather feeding phase showed significantly less severe feather pecking than S and C birds. The results clearly show that Q as an unpalatable substance was the signal the animal used to avoid damaging the feather cover in laying hens.

  3. Kinetic study of sulphuric acid hydrolysis of protein feathers.

    PubMed

    Ben Hamad Bouhamed, Sana; Kechaou, Nabil

    2017-02-28

    Poultry feather keratin is the most important by-product from the poultry industry due to its abundance. Different methods have been still applied to process this by-product such as enzymatic hydrolysis which is expensive and inapplicable at the industrial level. This paper presents a study of acid hydrolysis of poultry feathers using different types of acids, sulphuric acid concentration, different temperatures and solid to liquid ratio to obtain a liquid product rich in peptides. The feathers analysis revealed a crude protein content of 88.83%. A maximum peptides production of 676 mg/g was reached using sulphuric acid, 1 molar acid concentration and 50 g/l solid to liquid ratio at a temperature of 90 °C after 300 min. A reaction scheme for protein aggregation and decomposition to polypeptides and amino acids was proposed and a kinetic model for peptides production was developed. The proposed kinetic model proved to be well adapted to the experimental data with R (2) = 0.99.

  4. Resonating feathers produce courtship song.

    PubMed

    Bostwick, Kimberly S; Elias, Damian O; Mason, Andrew; Montealegre-Z, Fernando

    2010-03-22

    Male Club-winged Manakins, Machaeropterus deliciosus (Aves: Pipridae), produce a sustained tonal sound with specialized wing feathers. The fundamental frequency of the sound produced in nature is approximately 1500 Hz and is hypothesized to result from excitation of resonance in the feathers' hypertrophied shafts. We used laser Doppler vibrometry to determine the resonant properties of male Club-winged Manakin's wing feathers, as well as those of two unspecialized manakin species. The modified wing feathers exhibit a response peak near 1500 Hz, and unusually high Q-values (a measure of resonant tuning) for biological objects (Q up to 27). The unmodified wing feathers of the Club-winged Manakin do not exhibit strong resonant properties when measured in isolation. However, when measured still attached to the modified feathers (nine feathers held adjacent by an intact ligament), they resonate together as a unit near 1500 Hz, and the wing produces a second harmonic of similar or greater amplitude than the fundamental. The feathers of the control species also exhibit resonant peaks around 1500 Hz, but these are significantly weaker, the wing does not resonate as a unit and no harmonics are produced. These results lend critical support to the resonant stridulation hypothesis of sound production in M. deliciosus.

  5. The colour of fossil feathers.

    PubMed

    Vinther, Jakob; Briggs, Derek E G; Prum, Richard O; Saranathan, Vinodkumar

    2008-10-23

    Feathers are complex integumentary appendages of birds and some other theropod dinosaurs. They are frequently coloured and function in camouflage and display. Previous investigations have concluded that fossil feathers are preserved as carbonized traces composed of feather-degrading bacteria. Here, an investigation of a colour-banded feather from the Lower Cretaceous Crato Formation of Brazil revealed that the dark bands are preserved as elongate, oblate carbonaceous bodies 1-2 microm long, whereas the light bands retain only relief traces on the rock matrix. Energy dispersive X-ray analysis showed that the dark bands preserve a substantial amount of carbon, whereas the light bands show no carbon residue. Comparison of these oblate fossil bodies with the structure of black feathers from a living bird indicates that they are the eumelanin-containing melanosomes. We conclude that most fossil feathers are preserved as melanosomes, and that the distribution of these structures in fossil feathers can preserve the colour pattern in the original feather. The discovery of preserved melanosomes opens up the possibility of interpreting the colour of extinct birds and other dinosaurs.

  6. Every Feather Tells a Story

    ERIC Educational Resources Information Center

    Chessin, Debby; Chessin, Laura

    2006-01-01

    For Mr. Kim's fifth-grade students, recess is not just for playing and getting exercise! One spring, he observed a small group of his students near their class bluebird box, examining various bird feathers found on the ground. Building on students' natural curiosity, Mr. Kim purchased some feathers for further exploration in the classroom. He was…

  7. Blade feathering system for wind turbines

    SciTech Connect

    Harner, K.I.; Patrick, J.P.; Vosseller, K.F.

    1984-07-31

    A blade feathering system for wind turbines includes a feather actuator, control means operatively connected thereto and an adjustment means operatively connected to the control means for selectively varying the rate of operation of the feather actuator for feathering the wind turbine blades at a variable rate.

  8. Manakins can produce iridescent and bright feather colours without melanosomes.

    PubMed

    Igic, Branislav; D'Alba, Liliana; Shawkey, Matthew D

    2016-06-15

    Males of many species often use colourful and conspicuous ornaments to attract females. Among these, male manakins (family: Pipridae) provide classic examples of sexual selection favouring the evolution of bright and colourful plumage coloration. The highly iridescent feather colours of birds are most commonly produced by the periodic arrangement of melanin-containing organelles (melanosomes) within barbules. Melanin increases the saturation of iridescent colours seen from optimal viewing angles by absorbing back-scattered light; however, this may reduce the wide-angle brightness of these signals, contributing to a dark background appearance. We examined the nanostructure of four manakin species (Lepidothrix isidorei, L. iris, L. nattereri and L. coeruleocapilla) to identify how they produce their bright plumage colours. Feather barbs of all four species were characterized by dense and fibrous internal spongy matrices that likely increase scattering of light within the barb. The iridescent, yet pale or whitish colours of L. iris and L. nattereri feathers were produced not by periodically arranged melanosomes within barbules, but by periodic matrices of air and β-keratin within barbs. Lepidothrix iris crown feathers were able to produce a dazzling display of colours with small shifts in viewing geometry, likely because of a periodic nanostructure, a flattened barb morphology and disorder at a microstructural level. We hypothesize that iridescent plumage ornaments of male L. iris and L. nattereri are under selection to increase brightness or luminance across wide viewing angles, which may potentially increase their detectability by females during dynamic and fast-paced courtship displays in dim light environments.

  9. Development, regeneration, and evolution of feathers.

    PubMed

    Chen, Chih-Feng; Foley, John; Tang, Pin-Chi; Li, Ang; Jiang, Ting Xin; Wu, Ping; Widelitz, Randall B; Chuong, Cheng Ming

    2015-01-01

    The feather is a complex ectodermal organ with hierarchical branching patterns. It provides functions in endothermy, communication, and flight. Studies of feather growth, cycling, and health are of fundamental importance to avian biology and poultry science. In addition, feathers are an excellent model for morphogenesis studies because of their accessibility, and their distinct patterns can be used to assay the roles of specific molecular pathways. Here we review the progress in aspects of development, regeneration, and evolution during the past three decades. We cover the development of feather buds in chicken embryos, regenerative cycling of feather follicle stem cells, formation of barb branching patterns, emergence of intrafeather pigmentation patterns, interplay of hormones and feather growth, and the genetic identification of several feather variants. The discovery of feathered dinosaurs redefines the relationship between feathers and birds. Inspiration from biomaterials and flight research further fuels biomimetic potential of feathers as a multidisciplinary research focal point.

  10. Structure and functions of keratin proteins in simple, stratified, keratinized and cornified epithelia

    PubMed Central

    Bragulla, Hermann H; Homberger, Dominique G

    2009-01-01

    Historically, the term ‘keratin’ stood for all of the proteins extracted from skin modifications, such as horns, claws and hooves. Subsequently, it was realized that this keratin is actually a mixture of keratins, keratin filament-associated proteins and other proteins, such as enzymes. Keratins were then defined as certain filament-forming proteins with specific physicochemical properties and extracted from the cornified layer of the epidermis, whereas those filament-forming proteins that were extracted from the living layers of the epidermis were grouped as ‘prekeratins’ or ‘cytokeratins’. Currently, the term ‘keratin’ covers all intermediate filament-forming proteins with specific physicochemical properties and produced in any vertebrate epithelia. Similarly, the nomenclature of epithelia as cornified, keratinized or non-keratinized is based historically on the notion that only the epidermis of skin modifications such as horns, claws and hooves is cornified, that the non-modified epidermis is a keratinized stratified epithelium, and that all other stratified and non-stratified epithelia are non-keratinized epithelia. At this point in time, the concepts of keratins and of keratinized or cornified epithelia need clarification and revision concerning the structure and function of keratin and keratin filaments in various epithelia of different species, as well as of keratin genes and their modifications, in view of recent research, such as the sequencing of keratin proteins and their genes, cell culture, transfection of epithelial cells, immunohistochemistry and immunoblotting. Recently, new functions of keratins and keratin filaments in cell signaling and intracellular vesicle transport have been discovered. It is currently understood that all stratified epithelia are keratinized and that some of these keratinized stratified epithelia cornify by forming a Stratum corneum. The processes of keratinization and cornification in skin modifications are

  11. Dramatic colour changes in a bird of paradise caused by uniquely structured breast feather barbules.

    PubMed

    Stavenga, Doekele G; Leertouwer, Hein L; Marshall, N Justin; Osorio, Daniel

    2011-07-22

    The breast-plate plumage of male Lawes' parotia (Parotia lawesii) produces dramatic colour changes when this bird of paradise displays on its forest-floor lek. We show that this effect is achieved not solely by the iridescence--that is an angular-dependent spectral shift of the reflected light--which is inherent in structural coloration, but is based on a unique anatomical modification of the breast-feather barbule. The barbules have a segmental structure, and in common with many other iridescent feathers, they contain stacked melanin rodlets surrounded by a keratin film. The unique property of the parotia barbules is their boomerang-like cross section. This allows each barbule to work as three coloured mirrors: a yellow-orange reflector in the plane of the feather, and two symmetrically positioned bluish reflectors at respective angles of about 30°. Movement during the parotia's courtship displays thereby achieves much larger and more abrupt colour changes than is possible with ordinary iridescent plumage. To our knowledge, this is the first example of multiple thin film or multi-layer reflectors incorporated in a single structure (engineered or biological). It nicely illustrates how subtle modification of the basic feather structure can achieve novel visual effects. The fact that the parotia's breast feathers seem to be specifically adapted to give much stronger colour changes than normal structural coloration implies that colour change is important in their courtship display.

  12. Dramatic colour changes in a bird of paradise caused by uniquely structured breast feather barbules

    PubMed Central

    Stavenga, Doekele G.; Leertouwer, Hein L.; Marshall, N. Justin; Osorio, Daniel

    2011-01-01

    The breast-plate plumage of male Lawes' parotia (Parotia lawesii) produces dramatic colour changes when this bird of paradise displays on its forest-floor lek. We show that this effect is achieved not solely by the iridescence—that is an angular-dependent spectral shift of the reflected light—which is inherent in structural coloration, but is based on a unique anatomical modification of the breast-feather barbule. The barbules have a segmental structure, and in common with many other iridescent feathers, they contain stacked melanin rodlets surrounded by a keratin film. The unique property of the parotia barbules is their boomerang-like cross section. This allows each barbule to work as three coloured mirrors: a yellow-orange reflector in the plane of the feather, and two symmetrically positioned bluish reflectors at respective angles of about 30°. Movement during the parotia's courtship displays thereby achieves much larger and more abrupt colour changes than is possible with ordinary iridescent plumage. To our knowledge, this is the first example of multiple thin film or multi-layer reflectors incorporated in a single structure (engineered or biological). It nicely illustrates how subtle modification of the basic feather structure can achieve novel visual effects. The fact that the parotia's breast feathers seem to be specifically adapted to give much stronger colour changes than normal structural coloration implies that colour change is important in their courtship display. PMID:21159676

  13. Construction of a Rapid Feather-Degrading Bacterium by Overexpression of a Highly Efficient Alkaline Keratinase in Its Parent Strain Bacillus amyloliquefaciens K11.

    PubMed

    Yang, Lian; Wang, Hui; Lv, Yi; Bai, Yingguo; Luo, Huiying; Shi, Pengjun; Huang, Huoqing; Yao, Bin

    2016-01-13

    Keratinase is essential to degrade the main feather component, keratin, and is of importance for wide industrial applications. In this study, Bacillus amyloliquefaciens strain K11 was found to have significant feather-degrading capacity (completely degraded whole feathers within 24 h). The keratinase encoding gene, kerK, was expressed in Bacillus subtilis SCK6. The purified recombinant KerK showed optimal activity at 50 °C and pH 11.0 and degraded whole feathers within 0.5 h in the presence of DTT. The recombinant plasmids harboring kerK were extracted from B. subtilis SCK6 and transformed into B. amyloliquefaciens K11. As a result, the recombinant B. amyloliquefaciens K11 exhibited enhanced feather-degrading capacity with shortened reaction time within 12 h and increased keratinolytic activity (1500 U/mL) by 6-fold. This efficient and rapid feather-degrading character makes the recombinant strain of B. amyloliquefaciens K11 have potential for applications in feather meal preparation and waste feather disposal.

  14. Feather seal slot for vanes

    SciTech Connect

    Del Mastro, B. P.; Eckart, F.

    1985-10-22

    The slots for accommodating feather seals in the turbine vanes of a gas turbine engine has the end thereof sealed off by use of weld wire inserted into the slot and simultaneously welded and cut to the required length.

  15. Branching of keratin intermediate filaments.

    PubMed

    Nafeey, Soufi; Martin, Ines; Felder, Tatiana; Walther, Paul; Felder, Edward

    2016-06-01

    Keratin intermediate filaments (IFs) are crucial to maintain mechanical stability in epithelial cells. Since little is known about the network architecture that provides this stiffness and especially about branching properties of filaments, we addressed this question with different electron microscopic (EM) methods. Using EM tomography of high pressure frozen keratinocytes, we investigated the course of several filaments in a branching of a filament bundle. Moreover we found several putative bifurcations in individual filaments. To verify our observation we also visualized the keratin network in detergent extracted keratinocytes with scanning EM. Here bifurcations of individual filaments could unambiguously be identified additionally to bundle branchings. Interestingly, identical filament bifurcations were also found in purified keratin 8/18 filaments expressed in Escherichia coli which were reassembled in vitro. This excludes that an accessory protein contributes to the branch formation. Measurements of the filament cross sectional areas showed various ratios between the three bifurcation arms. This demonstrates that intermediate filament furcation is very different from actin furcation where an entire new filament is attached to an existing filament. Instead, the architecture of intermediate filament bifurcations is less predetermined and hence consistent with the general concept of IF formation.

  16. Keratin subsets in spindle cell sarcomas. Keratins are widespread but synovial sarcoma contains a distinctive keratin polypeptide pattern and desmoplakins.

    PubMed Central

    Miettinen, M.

    1991-01-01

    The presence of individual keratin polypeptides and desmoplakins was immunohistochemically studied in 25 spindle cell sarcomas of different types using acetone-fixed frozen sections. Results revealed that keratins 8 and 18 were present in a high number of tumors: 9 of 9 synovial sarcomas, 5 of 7 leiomyosarcomas, 5 of 5 malignant schwannomas, and 1 of 4 undifferentiated spindle cell sarcomas. In addition to keratins 8 and 18, the glandular component of synovial sarcoma showed prominent reactivity with antibodies to keratins 7 and 19. Also the glandular epithelial cells in synovial sarcoma showed desmoplakin immunoreactivity preferentially in a luminal distribution, but desmoplakin was absent in other spindle cell sarcomas. Furthermore keratin 13 was seen focally in 4 of 9 synovial sarcomas. In contrast, keratins 7, 13, and 19 were practically absent in leiomyosarcomas, malignant schwannomas, and undifferentiated spindle cell sarcomas. The widespread presence of keratins 8 and 18 in various spindle cell sarcomas may reflect aberrant keratin expression in mesenchymal cells, previously described in cultured transformed fibroblasts. The presence of keratins 7 and 19 and desmoplakin is highly associated with morphologically observable epithelial differentiation restricted to synovial sarcoma among spindle cell sarcomas. Images Figure 1 Figure 2 Figure 3 PMID:1704194

  17. Influence of plastic slatted floors compared with pine shaving litter on Pekin Duck condition during the summer months.

    PubMed

    Fraley, S M; Fraley, G S; Karcher, D M; Makagon, M M; Lilburn, M S

    2013-07-01

    The management and well-being of commercial Pekin ducks has been studied in the European Union where straw is the predominant litter source. In the United States, however, the most prevalent litter is wood shavings, with a recent trend toward using plastic slatted flooring. A previous study in the United States evaluated the relationship between flooring type (litter, slats) and duck condition during winter months and found very few differences between the 2 in terms of overall duck condition. The purpose of the current study was to reevaluate the 2 flooring systems during the summer months to determine if seasonal differences would interact with flooring type to have an impact on duck condition. Eighteen commercial barns that produce Pekin ducks for Maple Leaf Farms Inc. (Leesburg, IN), located in northern Indiana and southern Wisconsin (n = 9 litter; n = 9 raised slatted floor), were used for this study. Twenty ducks were randomly selected from 5 predetermined areas within each house (n = 100 total) and scored for eye condition, nostril and feather cleanliness, and feather and foot pad quality at 7, 21, and 32 d of age. Environmental data, including carbon monoxide, ammonia, RH, and temperature, were also obtained at each collection day. The only statistical differences in body condition occurred at 7 d; there were more ducks with clear eyes and eye rings on the litter flooring, whereas average nostril scores were better on the plastic slatted floors. Live weight, weight gain per day, flock mortality, and condemnations at the plant were collected, and the only statistical difference was a higher gain per day for ducks reared on slatted floors compared with litter (P < 0.05). There were no differences between flooring systems in the environmental parameters measured within the barns. In summary, there were very few differences between the litter and slatted flooring systems, indicating that there may not be clear advantages for one particular flooring system over

  18. The role of keratin subfamilies and keratin pairs in the formation of human epidermal intermediate filaments

    PubMed Central

    1986-01-01

    The four major keratins of normal human epidermis (molecular mass 50, 56.5, 58, and 65-67 kD) can be subdivided on the basis of charge into two subfamilies (acidic 50-kD and 56.5-kD keratins vs. relatively basic 58-kD and 65-67-kD keratins) or subdivided on the basis of co- expression into two "pairs" (50-kD/58-kD keratin pair synthesized by basal cells vs. 56.5-kD/65-67-kD keratin pair expressed in suprabasal cells). Acidic and basic subfamilies were separated by ion exchange chromatography in 8.5 M urea and tested for their ability to reassemble into 10-nm filaments in vitro. The two keratins in either subfamily did not reassemble into 10-nm filaments unless combined with members of the other subfamily. While electron microscopy of acidic and basic keratins equilibrated in 4.5 M urea showed that keratins within each subfamily formed distinct oligomeric structures, possibly representing precursors in filament assembly, chemical cross-linking followed by gel analysis revealed dimers and larger oligomers only when subfamilies were combined. In addition, among the four major keratins, the acidic 50-kD and basic 58-kD keratins showed preferential association even in 8.5 M urea, enabling us to isolate a 50-kD/58-kD keratin complex by gel filtration. This isolated 50-kD/58-kD keratin pair readily formed 10-nm filaments in vitro. These results demonstrate that in tissues containing multiple keratins, two keratins are sufficient for filament assembly, but one keratin from each subfamily is required. More importantly, these data provide the first evidence for the structural significance of specific co-expressed acidic/basic keratin pairs in the formation of epithelial 10-nm filaments. PMID:2422179

  19. Seagull feather shaft: Correlation between structure and mechanical response.

    PubMed

    Wang, Bin; Meyers, Marc André

    2017-01-15

    Flight feathers are unique among a variety of keratinous appendages in that they are lightweight, stiff and strong. They are designed to withstand aerodynamic forces, but their morphology and structure have been oversimplified and thus understudied historically. Here we present an investigation of the shaft from seagull primary feathers, elucidate the hierarchical fibrous and porous structure along the shaft length, and correlate the tensile and nanomechanical properties to the fiber orientation. An analysis of the compressive behavior of the rachis based on a square-section model shows a good fit with experimental results, and demonstrates the synergy between the cortex and medulla. Flexural properties of the shaft along the shaft length, analyzed as a sandwich composite, reveal that although all flexural parameters decrease towards the distal shaft, the specific equivalent flexural modulus and strength increase by factors of 2 and 3, respectively. The failure mode in flexure for all specimens is buckling on the compressive surface, whereas the foamy medulla prevents destructive axial cracking and introduces important toughening mechanisms: crack deflection, fiber bridging, and microcracking.

  20. 14 CFR 35.22 - Feathering propellers.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... intended to feather from all flight conditions, taking into account expected wear and leakage. Any... control systems that use engine oil to feather must incorporate a method to allow the propeller to...

  1. 14 CFR 35.22 - Feathering propellers.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... intended to feather from all flight conditions, taking into account expected wear and leakage. Any... control systems that use engine oil to feather must incorporate a method to allow the propeller to...

  2. 14 CFR 35.22 - Feathering propellers.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... intended to feather from all flight conditions, taking into account expected wear and leakage. Any... control systems that use engine oil to feather must incorporate a method to allow the propeller to...

  3. 14 CFR 35.22 - Feathering propellers.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... intended to feather from all flight conditions, taking into account expected wear and leakage. Any... control systems that use engine oil to feather must incorporate a method to allow the propeller to...

  4. 14 CFR 35.22 - Feathering propellers.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... intended to feather from all flight conditions, taking into account expected wear and leakage. Any... control systems that use engine oil to feather must incorporate a method to allow the propeller to...

  5. Do black ducks and wood ducks habituate to aircraft disturbance?

    USGS Publications Warehouse

    Conomy, J.T.; Dubovsky, J.A.; Collazo, J.A.; Fleming, W.J.

    1998-01-01

    Requests to increase military aircraft activity in some training facilities in the United States have raised the need to determine if waterfowl and other wildlife are adversely affected by aircraft disturbance. We hypothesized that habituation was a possible proximate factor influencing the low proportion of free-ranging ducks reacting to military aircraft activities in a training range in coastal North Carolina during winters 1991 and 1992. To test this hypothesis, we subjected captive, wild-strain American black ducks (Anas rubripes) and wood ducks (Aix sponsa) to actual and simulated activities of jet aircraft. In the first experiment, we placed black ducks in an enclosure near the center of aircraft activities on Piney Island, a military aircraft target range in coastal North Carolina. The proportion of times black ducks reacted (e.g., alert posture, fleeing response) to visual and auditory aircraft activity decreased from 38 to 6% during the first 17 days of confinement. Response rates remained stable at 5.8% thereafter. In the second experiment, black ducks and wood ducks were exposed to 6 different recordings of jet noise. The proportion of times black ducks reacted to noise decreased (P 0.05) in time-activity budgets of black ducks between pre-exposure to noise and 24 hr after first exposure. Unlike black ducks, wood duck responses to jet noise did not decrease uniformly among experimental groups following initial exposure to noise (P = 0.01). We conclude that initial exposure to aircraft noise elicits behavioral responses from black ducks and wood ducks. With continued exposure of aircraft noise, black ducks may become habituated. However, wood ducks did not exhibit the same pattern of response, suggesting that the ability of waterfowl to habituate to aircraft noise may be species specific.

  6. Keratin materials for new product development

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Keratin from wool is a reactive, biocompatible, and biodegradable material found as pure protein in over 90% by weight of fiber. As a polymeric amide, keratin is a rich source of intermediate filament proteins (IFPs) which are being investigated for a wide range of biomaterial applications. The po...

  7. Feather on the Cap of Medicine

    PubMed Central

    Chiu, Cathleen; Chuong, Cheng Ming

    2015-01-01

    SUMMARY Through cyclic regeneration, feather stem cells are molded into different shapes under different physiological states. With its distinct morphology, context-dependent growth and experimental manipulability, the feather provides a rich model to study growth control, regeneration and morphogenesis in vivo. Recent examples include novel insights revealed by transient perturbation with chemotherapeutic reagents and irradiation during feather growth. PMID:26066892

  8. Two Feathers Endowment Scholarship Program: Program Evaluation

    ERIC Educational Resources Information Center

    Pierce, Alexandra

    2004-01-01

    The Saint Paul Foundation contracted with the Wilder Research Center to conduct an evaluation of their Two Feathers Scholarship Program. The Two Feathers Scholarship Program is funded through the Two Feathers Endowment, which is one part of the Foundation's SpectrumTrust. SpectrumTrust is a unique partnership between communities of color and The…

  9. Feeding ecology and development of juvenile black ducks in Maine

    USGS Publications Warehouse

    Reinecke, K.J.

    1979-01-01

    Data from 41 juvenile Black Ducks (Anas rubripes) collected in the Penobscot River valley of Maine from June through August 1974-76 were used to estimate the proportion of aquatic invertebrates in the prefledging diet and the allometric growth rates of the tarsi, flight muscles, and alimentary system. The proportion of aquatic invertebrates in the diet of downy and partially feathered juveniles averaged 88 and 91% of dry weight, but decreased to 43% for fully feathered young. The most important invertebrate food organisms for juvenile Black Ducks were asellid isopods, molluscs, nymphs of Ephemeroptera and Odonata, and larvae of Coleoptera, Trichoptera, and Diptera. A high proportion of invertebrates was consumed during the period of fastest absolute and relative growth. Estimation of allometric growth rates with the power formula (Y = a 'X b) showed that (1) the legs were relatively large at hatching and developed slowly; (2) the flight muscles, which were relatively small at hatching, grew slowly until the 4-week period preceding fledging, when they increased as the 4.75 power of body weight; and (3) growth of the liver and gizzard was approximately proportional to body weight. The data support Ricklefs' thesis that delayed functional maturity of the wings permits an increase in the overall growth rate of waterfowl.

  10. Physical characteristics of feathers play a role in feather eating behavior.

    PubMed

    Harlander-Matauschek, A; Feise, U

    2009-09-01

    Feather pecking is positively associated with feather eating in laying hens; however the criteria of the birds for pecking, plucking, and eating feathers has not yet been systematically examined. In the present study, we investigated if laying hens show preferences for feathers of different lengths and regions. Twenty Lohmann Selected Leghorn hens with a high feather pecking activity were used in the present experiment. Ten birds were individually given access to 4 plastic elements, each perforated with 4 feathers 2, 4, 6, or 8 cm in length (i.e., 1 flat piece of plastic for each feather length). Another 10 hens were given access to 3 identical plastic elements, each perforated with 4 pieces of feather 2 cm in length from the calamus (part of the shaft closest to the bird body), middle (shaft with outer and inner vane), or tip (part of the shaft with vane furthest from bird body) of the feathers, respectively. The number of feathers of different lengths and regions plucked and eaten from each plastic element was recorded. Birds were tested over a period of 10 d on a daily basis. Laying hens preferred shorter feathers over longer ones. A rank ordering of preferred feather regions from the most to the least important using the number of pieces eaten gives a sequence of the tip, middle, and calamus of the feathers. The results clearly show that physical texture or appearance, or both, of feathers plays a role in feather pecking-eating behavior in laying hens.

  11. Fabrication of dual-sensitive keratin-based polymer hydrogels and their controllable release behaviors.

    PubMed

    Sun, Kangqi; Guo, Juhua; He, Yufeng; Song, Pengfei; Xiong, Yubing; Wang, Rong-Min

    2016-10-03

    Using feather keratin (FK) as a biocompatible and inexpensive biopolymer, a kind of dual-sensitive keratin-based polymer hydrogel (FK/PNiPA/PIAc-Gel) with interpenetrating network structure was prepared by two-step polymerization of N-isopropyl acrylamide (NiPA) and itaconic acid (IAc) in presence of crosslinker. After being characterized by Fourier transform infrared spectroscopy, thermogravimetric analysis and scanning electron microscopy, its swelling behaviors and environmental sensitivity were investigated. The obtained biopolymer based hydrogel has good swelling and deswelling performance, and it is sensitive to pH value, temperature and salts of environment. Using anticancer drug, doxorubicin hydrochloride (Dox·HCl),  and Bovine serum albumin (BSA) as different drug molecules, its release behaviors in different environment were investigated. It was found that the release behaviors of FK/PNiPA/PIAc-Gel were controllable via adjusting pH value or temperature of environment. The cumulative release of the anticancer drug (Dox·HCl) reached 93.3% within 16 h, and the cumulative release rate of macromolecular drug (BSA) got to 75.9% in 24 h. In summary, the keratin-based biopolymer hydrogel with interpenetrating network structure, pH-sensitivity and temperature sensitivity are potentially applied to sustain drug carrier and humid medicinal material in the biomedical field or clinical nursing field.

  12. The DUCK Manual.

    DTIC Science & Technology

    1985-06-01

    the form (AND goal, goal, ... goal) For instance, if you type (AND (BIG ?X) (GREEN ?X) ( RUTABAGA ?X)) then Duck will try to find an assertion (BIG thing...GREEN THING9) ( RUTABAGA THINGg) then the program would set ?X to THIN~g, and this value would be printed. Duck has found a single object that...qualifies as a big green rutabaga . One obstacle to this tidy scenario is that the database might also contain these assertions: (BIG THING80) (GREEN THINGSO

  13. Production of Proteolytic Enzymes by a Keratin-Degrading Aspergillus niger

    PubMed Central

    Lopes, Fernanda Cortez; Silva, Lucas André Dedavid e; Tichota, Deise Michele; Daroit, Daniel Joner; Velho, Renata Voltolini; Pereira, Jamile Queiroz; Corrêa, Ana Paula Folmer; Brandelli, Adriano

    2011-01-01

    A fungal isolate with capability to grow in keratinous substrate as only source of carbon and nitrogen was identified as Aspergillus niger using the sequencing of the ITS region of the rDNA. This strain produced a slightly acid keratinase and an acid protease during cultivation in feather meal. The peak of keratinolytic activity occurred in 48 h and the maximum proteolytic activity in 96 h. These enzymes were partly characterized as serine protease and aspartic protease, respectively. The effects of feather meal concentration and initial pH on enzyme production were evaluated using a central composite design combined with response surface methodology. The optimal conditions were determined as pH 5.0 for protease and 7.8 for keratinase and 20 g/L of feather meal, showing that both models were predictive. Production of keratinases by A. niger is a less-exploited field that might represent a novel and promising biotechnological application for this microorganism. PMID:22007293

  14. Feather corticosterone reveals developmental stress in seabirds.

    PubMed

    Will, Alexis P; Suzuki, Yuya; Elliott, Kyle H; Hatch, Scott A; Watanuki, Yutaka; Kitaysky, Alexander S

    2014-07-01

    In nest-bound avian offspring, food shortages typically trigger a release of the stress hormone corticosterone (CORT). Recent studies indicate that CORT is passively deposited in the tissue of growing feathers and thus may provide an integrated measure of stress incurred during development in the nest. The current hypothesis predicts that, assuming a constant rate of feather growth, elevated CORT circulating in the blood corresponds to higher levels of CORT in feather tissue, but experimental evidence for nutritionally stressed chicks is lacking. Here, we examined how food limitation affects feather CORT content in the rhinoceros auklet (Cerorhinca moncerata). We (i) used captive chicks reared on control versus restricted diets, and (ii) applied this technique to free-living chicks with unknown nutritional histories that fledged at three separate colonies. We found that (i) feather growth was not affected by experimentally induced nutritional stress; (ii) captive chicks raised on a restricted diet had higher levels of CORT in their primary feathers; (iii) feather CORT deposition is a sensitive method of detecting nutritional stress; and (iv) free-living fledglings from the colony with poor reproductive performance had higher CORT in their primary feathers. We conclude that feather CORT is a sensitive integrated measure revealing the temporal dynamics of food limitations experienced by rhinoceros auklet nestlings. The use of feather CORT may be a powerful endocrine tool in ecological and evolutionary studies of bird species with similar preferential allocation of limited resources to feather development.

  15. Why Does the Motorbike Feather?

    ERIC Educational Resources Information Center

    Ruocco, A.; De Luca, R.

    2007-01-01

    The problem of motorbike feathering has been analysed by writing the angular momentum theorem for non-inertial reference systems. The acceleration, for which the ideal line joining the median points of the axles of the two wheels makes an angle [theta] with the horizontal, has been calculated neglecting air friction and considering that the…

  16. Eagle Feathers, the Highest Honor.

    ERIC Educational Resources Information Center

    Beaverhead, Pete

    Following his own advice that elders of the tribe share their knowledge so that "the way of the Indians would come back to the children of today," Pete Beaverhead (1899-1975) tells of the traditions of respect and honor surrounding the eagle feather in a booklet illustrated with black and white drawings. The eagle is an Indian symbol of…

  17. Investigations of trace metals in long-tailed duck (Clangula hyemalis L.) from the Gdańsk Bay.

    PubMed

    Szefer, P; Falandysz, J

    1983-08-01

    The determination of iron, zinc, manganese, copper, lead, cadmium, cobalt and nickel was carried out on liver, breast muscle, heart, stomach and feathers of 50 male and 40 female long-tailed ducks (Clangula hyemalis L.) staying in their winter quarters in Gdańsk Bay during 1980-81. There were no significant differences in the concentration of metals between male and female long-tailed ducks. The correlation coefficients between the concentration of metals in the liver and breast muscle were determined.

  18. Degradation of raw feather by a novel high molecular weight extracellular protease from newly isolated Bacillus cereus DCUW.

    PubMed

    Ghosh, Abhrajyoti; Chakrabarti, Krishanu; Chattopadhyay, Dhrubajyoti

    2008-08-01

    Biotreatment of feather wastes and utilization of the degraded products in feed and foodstuffs has been a challenge. In the present study, we have demonstrated the degradation of feather waste by Bacillus cereus DCUW strain isolated during a functional screening based microbial diversity study on East Calcutta Wetland Area. A high molecular weight keratinolytic protease from feather degrading DCUW strain was purified and characterized. Moreover, utilization of degraded products during feather hydrolysis was developed and demonstrated. The purified keratinolytic protease was found to show pH and temperature optima of 8.5 and 50 degrees C, respectively. PMSF was found to inhibit the enzyme completely. The purified enzyme showed molecular weight of 80 kDa (from SDS-PAGE). The protease was found to have broad range substrate specificities that include keratin, casein, collagen, fibrin, BAPNA and gelatin. The protease was identified as minor extracellular protease (Vpr) by RT-PCR and northern blotting techniques. This is the first report describing the characterization of minor extracellular protease (Vpr) and its involvement in feather degradation in B. cereus group of organisms.

  19. Compatibility study of alginate/keratin blend for biopolymer development.

    PubMed

    Gupta, Pratima; Nayak, Kush Kumar

    2015-12-18

    The ultimate characteristics of blend film depend on the properties of its polymeric components, composition, and on the compatibility of the polymers. Binary polymer blend films of alginate (ALG) and keratin (KER) fibers (obtained from chicken feathers) were prepared by simple solution casting techniques and their compatibility properties were studied by X-ray diffraction and scanning electron microscopy. The tensile strength and percent of elongation were measured by a tensile strength tester. The results of the present studies elucidate that ALG and KER are compatible and suitable for the development of a blend film. It was found that the ALG/KER blend ratios of 90:10 and 80:20 possess characteristics to make a blend film with a high tensile strength value. The blend with composition 90:10 of ALG/KER is the one of the strongest candidates in the preparation of blending films, because it has the highest tensile strength (0.38 MPa) and percentage of elongation (59.5%) among all tested blend compositions. The blend ratio of 80:20 of ALG/KER achieves maximum compatibility, since its intensity pattern changes drastically as recorded in an X-ray diffraction study. The fabricated blend film can be a suitable candidate for a range of biomaterials such as for a drug delivery vesicle, hydrogel, and scaffolding, etc.

  20. Mechanistic investigation of a hemostatic keratin biomaterial

    NASA Astrophysics Data System (ADS)

    Rahmany, Maria Bahawdory

    Traumatic injury leads to more productive years lost than heart disease, cancer and stroke combined. Trauma is often accompanied and complicated by uncontrolled bleeding. Human hair keratin biomaterials have demonstrated efficacy in controlling hemorrhage in both small and large animal models; however little is known about the mechanism by which these proteins aid in blood clotting. Inspection of the amino acid sequence of known keratins shows the presence of several cellular binding motifs, suggesting a possible mechanism and potentially eliminating the need to functionalize the material's surface for cellular interaction. In addition to small animal studies, the hemostatic activity of keratin hydrogels was explored through porcine hemorrhage models representing both a high flow and low flow bleed. In both studies, keratin hydrogels appeared to lead to a significant reduction in blood loss. The promising results from these in vivo studies provided the motivation for this project. The objective of this dissertation work was to assess the mechanism of action of a hemostatic keratin biomaterial, and more broadly assess the biomaterial-cellular interaction(s). It is our hypothesis that keratin biomaterials have the capacity to specifically interact with cells and lead to propagation of intracellular signaling pathway, specifically contributing to hemostasis. Through application of biochemical and molecular tools, we demonstrate here that keratin biomaterials contribute to hemostasis through two probable mechanisms; integrin mediated platelet adhesion and increased fibrin polymerization. Platelets are the major cell type involved in coagulation both by acting as a catalytic surface for the clotting cascade and adhering to extracellular matrix (ECM) proteins providing a soft platelet plug. Because keratin biomaterials have structural and biochemical characteristics similar to ECM proteins, we utilized several adhesion assays to investigate platelet adhesion to keratin

  1. No Duck Left behind

    ERIC Educational Resources Information Center

    Cooper, Sandi; Thomas, Julie; Motley, Tammy

    2011-01-01

    Recently, a group of fourth graders joined "Pintail Partners"--a year-long collaborative research effort of scientists, students, classroom teachers, preservice teachers, museum educators, and university professors. Students and teachers followed satellite tracking data (marking the pintail duck's spring migration) and interacted with scientists…

  2. The Lame Duck Superintendent.

    ERIC Educational Resources Information Center

    Keane, William G.; Follo, Eric

    1995-01-01

    According to a survey of 46 recently departed Michigan school superintendents, departing superintendents can announce their intention to leave and still maintain a viable leadership role. Lame-duck superintendents should help the board think through the superintendent-selection process and review possible promotions, recognize staff achievements,…

  3. Increased water contamination and grow-out Pekin duck mortality when raised with water troughs compared to pin-metered water lines using a United States management system

    PubMed Central

    Schenk, A.; Porter, A. L.; Alenciks, E.; Frazier, K.; Best, A. A.; Fraley, S. M.; Fraley, G. S.

    2016-01-01

    Controversy has developed as to whether or not pin-metered water lines or water troughs are more appropriate for Pekin ducks. We hypothesized that water troughs would show improved duck body conditions and environmental quality compared to pin-metered water lines. To test this hypothesis, we housed ducks in 2 barns, one with water lines and one with water troughs. Water troughs were constructed to meet RSPCA guidelines for number and density of ducks and with recently described verandas. Ducks were divided into 4 pens per barn (n = 1,000 ducks/pen). The study was then repeated (n = 8 pens per water source) in a cross-over design so the barns each contained the opposite water source to the first experiment. We scored the ducks’ body condition using an established scoring rubric and analyzed using SAS Proc GLM-Mix as binomial data. Ducks housed with water troughs showed higher (thus worse condition; P < 0.001) scores for eyes, nostrils, feather quality, feather cleanliness, and foot pads. We also compared water condition, water quality, and duck mortality using a Student t test for both water sources each week. We found that the water troughs showed higher iron (P < 0.001), nitrites (P < 0.001), pH (P < 0.01), and bacterial growth (P < 0.001). The bacterial growth was shown to have higher (P < 0.001) E. coli, coliforms, and Staphylococcus in the water troughs. Water lines typically showed no bacterial growth in culture-based assays. Ducks housed with water troughs used greater (P = 0.001) volumes of water compared to ducks housed with water lines. Ducks with water troughs also showed a greater percent (P = 0.008) mortality at all ages compared to ducks with water lines. These data suggest that water troughs may not be beneficial for duck welfare and could adversely impact both environment and duck or human health. PMID:26769272

  4. Synchronous intracortical adamantinomas with keratin cyst formation.

    PubMed

    Park, Yong-Koo; Ryu, Kyung Nam; Han, Chung Soo

    2006-03-01

    Adamantinoma of the long bones is a rare primary bone tumor of uncertain embryogenesis. It tends to involve the tibia almost exclusively. We report on adamantinomas occurring in a 16-year-old male patient, with synchronous tibial and fibular lesions. Histologically, there were characteristic clusters of epithelial cells in a fibrous background, forming a keratin cyst. Immunohistochemically, these cells were strongly positive for cytokeratin. This keratin cyst formation is quite an unusual finding in classic adamantinoma.

  5. A Mesozoic bird from Gondwana preserving feathers

    PubMed Central

    de Souza Carvalho, Ismar; Novas, Fernando E.; Agnolín, Federico L.; Isasi, Marcelo P.; Freitas, Francisco I.; Andrade, José A.

    2015-01-01

    The fossil record of birds in the Mesozoic of Gondwana is mostly based on isolated and often poorly preserved specimens, none of which has preserved details on feather anatomy. We provide the description of a fossil bird represented by a skeleton with feathers from the Early Cretaceous of Gondwana (NE Brazil). The specimen sheds light on the homology and 3D structure of the rachis-dominated feathers, previously known from two-dimensional slabs. The rectrices exhibit a row of rounded spots, probably corresponding to some original colour pattern. The specimen supports the identification of the feather scapus as the rachis, which is notably robust and elliptical in cross-section. In spite of its juvenile nature, the tail plumage resembles the feathering of adult individuals of modern birds. Documentation of rachis-dominated tail in South American enantiornithines broadens the paleobiogeographic distribution of basal birds with this tail feather morphotype, up to now only reported from China. PMID:26035285

  6. A Mesozoic bird from Gondwana preserving feathers.

    PubMed

    Carvalho, Ismar de Souza; Novas, Fernando E; Agnolín, Federico L; Isasi, Marcelo P; Freitas, Francisco I; Andrade, José A

    2015-06-02

    The fossil record of birds in the Mesozoic of Gondwana is mostly based on isolated and often poorly preserved specimens, none of which has preserved details on feather anatomy. We provide the description of a fossil bird represented by a skeleton with feathers from the Early Cretaceous of Gondwana (NE Brazil). The specimen sheds light on the homology and 3D structure of the rachis-dominated feathers, previously known from two-dimensional slabs. The rectrices exhibit a row of rounded spots, probably corresponding to some original colour pattern. The specimen supports the identification of the feather scapus as the rachis, which is notably robust and elliptical in cross-section. In spite of its juvenile nature, the tail plumage resembles the feathering of adult individuals of modern birds. Documentation of rachis-dominated tail in South American enantiornithines broadens the paleobiogeographic distribution of basal birds with this tail feather morphotype, up to now only reported from China.

  7. The association between plumage damage and feather-eating in free-range laying hens.

    PubMed

    Hartcher, K M; Hemsworth, P H; Wilkinson, S J; Thomson, P C; Cronin, G M

    2016-05-01

    Severe feather-pecking (SFP) persists as a highly prevalent and detrimental behavioural problem in laying hens (Gallus gallus domesticus) worldwide. The present experiment investigated the association between feather-eating and plumage damage, a consequence of SFP, in groups of free-range, ISA Brown laying hens. Single feathers were placed on the floor of the home pens. Feathers were sourced from seven different birds. A total of 50 birds in six pens with extensive plumage damage were compared with birds in six control pens with little plumage damage at 41 to 43 weeks of age (n=12 pens, 600 hens). Birds in pens with extensive plumage damage ingested more feathers (F=8.1, DF=1, 8, P=0.02), and also showed shorter latencies to peck at (χ 2=54.5, DF=1, P<0.001), and ingest feathers (χ 2=55.6, DF=1, P<0.001). Birds ingested feathers from a bird in the free-range facility, in which the testing took place, more quickly than from a bird housed in a separate cage facility (χ 2 = 39.0, DF=6, P<0.001). A second experiment investigated the predictive relationship between feather-eating and plumage damage. Feathers were presented to 16 pens of 50 pullets prior to the development of plumage damage, at 15 weeks of age, and then to the same hens after plumage damage had become prominent, at 40 weeks of age. Birds had a higher probability of ingesting feathers (F=142.0, DF=1, 231, P<0.001), pecked feathers more times (F=11.24, DF=1, 239, P<0.001), and also pecked (χ 2 = 127.3, DF=1, P<0.001) and ingested (χ 2=189.3, DF=1, P<0.001) the feathers more quickly at 40 than 15 weeks of age. There was a trend for an interaction, where birds pecked feathers from the rump more times than feathers from the back at 40 weeks of age (F=3.46, DF=1, 237, P=0.06). However, a lack of variability in plumage damage between pens in this experiment precluded investigation of the predictive relationship. The results from the present study confirm the association between feather-eating and plumage

  8. Wild Duck Cluster

    NASA Technical Reports Server (NTRS)

    2005-01-01

    On April 7, 2005, the Deep Impact spacecraft's Impactor Target Sensor camera recorded this image of M11, the Wild Duck cluster, a galactic open cluster located 6 thousand light years away. The camera is located on the impactor spacecraft, which will image comet Tempel 1 beginning 22 hours before impact until about 2 seconds before impact. Impact with comet Tempel 1 is planned for July 4, 2005.

  9. Body condition, food habits, and molt status of late-wintering ruddy ducks in California

    USGS Publications Warehouse

    Hohman, W.L.; Ankney, C.D.; Roster, D.L.

    1992-01-01

    We studied body condition, food habits, and molt status of late-wintering ruddy ducks (Oxyura jamaicensis) using drainwater evaporation ponds in the southern San Joaquin Valley, California. Levels of body fat and protein were similar by sex but varied by age (adults greater than immatures). Masses of breast and leg muscle protein were greatest in adult males and lowest in immature males, but similar in adult and immature females. Fat and protein levels in late-wintering ruddy ducks were independent of their body size. We detected no differences among sex-age classes in the proportion of animal foods consumed. Aquatic invertebrates composed 85% of the diet; midge larvae (Diptera: Chironomidae) and brine flies (Diptera: Ephydridae) were the principal taxa consumed. Molt score by feather region and overall molt score did not vary by sex or age. Light to moderate molt (25 to 50% molting feathers) was recorded in all feather regions. High levels of body fat and protein were attributed to premigratory hyperphagia and consumption of foods with a high protein:energy ratio.

  10. Structure and optical function of amorphous photonic nanostructures from avian feather barbs: a comparative small angle X-ray scattering (SAXS) analysis of 230 bird species

    PubMed Central

    Saranathan, Vinodkumar; Forster, Jason D.; Noh, Heeso; Liew, Seng-Fatt; Mochrie, Simon G. J.; Cao, Hui; Dufresne, Eric R.; Prum, Richard O.

    2012-01-01

    Non-iridescent structural colours of feathers are a diverse and an important part of the phenotype of many birds. These colours are generally produced by three-dimensional, amorphous (or quasi-ordered) spongy β-keratin and air nanostructures found in the medullary cells of feather barbs. Two main classes of three-dimensional barb nanostructures are known, characterized by a tortuous network of air channels or a close packing of spheroidal air cavities. Using synchrotron small angle X-ray scattering (SAXS) and optical spectrophotometry, we characterized the nanostructure and optical function of 297 distinctly coloured feathers from 230 species belonging to 163 genera in 51 avian families. The SAXS data provided quantitative diagnoses of the channel- and sphere-type nanostructures, and confirmed the presence of a predominant, isotropic length scale of variation in refractive index that produces strong reinforcement of a narrow band of scattered wavelengths. The SAXS structural data identified a new class of rudimentary or weakly nanostructured feathers responsible for slate-grey, and blue-grey structural colours. SAXS structural data provided good predictions of the single-scattering peak of the optical reflectance of the feathers. The SAXS structural measurements of channel- and sphere-type nanostructures are also similar to experimental scattering data from synthetic soft matter systems that self-assemble by phase separation. These results further support the hypothesis that colour-producing protein and air nanostructures in feather barbs are probably self-assembled by arrested phase separation of polymerizing β-keratin from the cytoplasm of medullary cells. Such avian amorphous photonic nanostructures with isotropic optical properties may provide biomimetic inspiration for photonic technology. PMID:22572026

  11. [Overview on duck virus hepatitis A].

    PubMed

    Ren, Liqian; Li, Jing; Bi, Yuhai; Chen, Can; Zhang, Dabing; Liu, Wenjun

    2012-07-01

    This article describes the nomenclature, history and genetic evolution of duck hepatitis A virus, and updates the epidemiology, clinical symptom and surveillances of duck virus hepatitis A. It also summarizes the present status and progress of duck virus hepatitis A and illustrated the necessity and urgency of its research, which provides rationale for the control of duck hepatitis A virus disease in China.

  12. Keratin Dynamics: Modeling the Interplay between Turnover and Transport

    PubMed Central

    Portet, Stéphanie; Madzvamuse, Anotida; Chung, Andy; Leube, Rudolf E.; Windoffer, Reinhard

    2015-01-01

    Keratin are among the most abundant proteins in epithelial cells. Functions of the keratin network in cells are shaped by their dynamical organization. Using a collection of experimentally-driven mathematical models, different hypotheses for the turnover and transport of the keratin material in epithelial cells are tested. The interplay between turnover and transport and their effects on the keratin organization in cells are hence investigated by combining mathematical modeling and experimental data. Amongst the collection of mathematical models considered, a best model strongly supported by experimental data is identified. Fundamental to this approach is the fact that optimal parameter values associated with the best fit for each model are established. The best candidate among the best fits is characterized by the disassembly of the assembled keratin material in the perinuclear region and an active transport of the assembled keratin. Our study shows that an active transport of the assembled keratin is required to explain the experimentally observed keratin organization. PMID:25822661

  13. Some properties of keratin biomaterials: kerateines.

    PubMed

    Hill, Paulina; Brantley, Helen; Van Dyke, Mark

    2010-02-01

    Keratins are a family of structural proteins that can be isolated from a variety of tissues. "Soft" keratins are cytoskeletal elements found in epithelial tissues while protective tissues such as nails, hooves, and hair are composed of "hard" keratins. Hard keratins have been the subject of biomaterials investigations for more than three decades. Numerous methods exist for denaturing these proteins which are characterized by a high sulfur content and extensive disulfide bonding, under either oxidative or reductive conditions, extracting them from tissue and processing them into various physical states such as gels, films, coatings, and fibers. Kerateines or keratoses (oxidatively or reductively derived, respectively), alone or in combination with other biomaterials, have been tested in a small number of systems to demonstrate feasibility for medical applications such as wound healing, bone regeneration, hemostasis, and peripheral nerve repair. These investigations have shown generally good compatibility with cells and tissues, but the focus of prior investigations has been fairly narrow, and as a result there is relatively little published data on the general behavior of keratin biomaterials in biological systems beyond cell culture assays. The goal of this study was to produce a reduced form of keratin biomaterial, kerateine, using a typical and well-published technique, and characterize several aspects of its behavior that may have implications to its general use as a biomaterial. Kerateines were extracted from human hair, fabricated into gels and porous scaffolds, characterized, and placed into biological systems to determine their interactions with cells and tissue. Initially, the proteins were analyzed for molecular weight and amino acid content, as well as their ability to facilitate cell adhesion and proliferation. Crosslinked hydrogels were investigated for their hydrolytic stability in vitro; the micro-architecture and in vivo tissue response of

  14. Aeroelastic flutter produces hummingbird feather songs.

    PubMed

    Clark, Christopher J; Elias, Damian O; Prum, Richard O

    2011-09-09

    During courtship flights, males of some hummingbird species produce diverse sounds with tail feathers of varying shapes. We show that these sounds are produced by air flowing past a feather, causing it to aeroelastically flutter and generate flutter-induced sound. Scanning laser doppler vibrometery and high-speed video of individual feathers of different sizes and shapes in a wind tunnel revealed multiple vibratory modes that produce a range of acoustic frequencies and harmonic structures. Neighboring feathers can be aerodynamically coupled and flutter either at the same frequency, resulting in sympathetic vibrations that increase loudness, or at different frequencies, resulting in audible interaction frequencies. Aeroelastic flutter is intrinsic to stiff airfoils such as feathers and thus explains tonal sounds that are common in bird flight.

  15. Brazilian keratin hair treatment: a review.

    PubMed

    Weathersby, Courtney; McMichael, Amy

    2013-06-01

    Brazilian keratin treatments are widely available products that are used by women all over the world to straighten hair. Marketers of these products claim that the keratin treatments render naturally curly hair more manageable and frizz-free while enhancing color and shine, giving the hair a healthier appearance. Although widely used, there have been virtually no reports of adverse side effects. Unfortunately, many of the products that are applied by salon professionals contain formaldehyde or its derivatives and are being marketed as safe.

  16. Alpha- and beta-keratins of the snake epidermis.

    PubMed

    Toni, Mattia; Alibardi, Lorenzo

    2007-01-01

    Snake scales contain specialized hard keratins (beta-keratins) and alpha- or cyto-keratins in their epidermis. The number, isoelectric point, and the evolution of these proteins in snakes and their similarity with those of other vertebrates are not known. In the present study, alpha- and beta-keratins of snake molts and of the whole epidermis have been studied by using two-dimensional electrophoresis and immunocytochemistry. Specific keratins in snake epidermis have been identified by using antibodies that recognize acidic and basic cytokeratins and avian or lizard scale beta-keratin. Alpha keratins of 40-70 kDa and isoelectric point (pI) at 4.5-7.0 are present in molts. The study suggests that cytokeratins in snakes are acidic or neutral, in contrast to mammals and birds where basic keratins are also present. Beta keratins of 10-15 kDa and a pI of 6.5-8.5 are found in molts. Some beta-keratins appear as basic proteins (pI 8.2) comparable to those present in the epidermis of other reptiles. Some basic "beta-keratins" associate with cytokeratins as matrix proteins and replace cytokeratins forming the corneous material of the mature beta-layer of snake scales, as in other reptiles. The study also suggests that more forms of beta-keratins (more than three different types) are present in the epidermis of snakes.

  17. Comparison of game-farm and wild-strain mallard ducks in accumulation of methylmercury

    USGS Publications Warehouse

    Heinz, G.H.

    1979-01-01

    The accumulation of mercury was compared in game-farm and wild-strain mallard ducks fed a diet containing 0.5 ppm mercury in the form of methylmercury dicyandiamide. There were no significant differences between the two strains in levels of mercury that accumulated in blood, kidney, liver, breast muscle, brain, eggs, or ducklings. Mercury levels in blood were significantly correlated with levels in other tissues and eggs, as were levels in down feathers of ducklings with levels in carcasses of ducklings. The results indicate that game-farm mallards are probably suitable substitutes for wild mallards in toxicological work, that blood samples can be used to estimate levels of mercury in other tissues of adults, and that down feathers are predictive of mercury levels in duckling carcasses.

  18. Immunolocalization of alpha-keratins and associated beta-proteins in lizard epidermis shows that acidic keratins mix with basic keratin-associated beta-proteins.

    PubMed

    Alibardi, Lorenzo

    2014-07-01

    The differentiation of the corneous layers of lizard epidermis has been analyzed by ultrastructural immunocytochemistry using specific antibodies against alpha-keratins and keratin associated beta-proteins (KAbetaPs, formerly indicated as beta-keratins). Both beta-cells and alpha-cells of the corneous layer derive from the same germinal layer. An acidic type I alpha-keratin is present in basal and suprabasal layers, early differentiating clear, oberhautchen, and beta-cells. Type I keratin apparently disappears in differentiated beta- and alpha-layers of the mature corneous layers. Conversely, a basic type II alpha-keratin rich in glycine is absent or very scarce in basal and suprabasal layers and this keratin likely does not pair with type I keratin to form intermediate filaments but is weakly detected in the pre-corneous and corneous alpha-layer. Single and double labeling experiments show that in differentiating beta-cells, basic KAbetaPs are added and replace type-I keratin to form the hard beta-layer. Epidermal alpha-keratins contain scarce cysteine (0.2-1.4 %) that instead represents 4-19 % of amino acids present in KAbetaPs. Possible chemical bonds formed between alpha-keratins and KAbetaPs may derive from electrostatic interactions in addition to cross-linking through disulphide bonds. Both the high content in glycine of keratins and KAbetaPs may also contribute to increase the hydrophobicy of the beta- and alpha-layers and the resistance of the corneous layer. The increase of gly-rich KAbetaPs amount and the bonds to the framework of alpha-keratins give rise to the inflexible beta-layer while the cys-rich KAbetaPs produce a pliable alpha-layer.

  19. Capture methods for Musk Ducks

    USGS Publications Warehouse

    McCracken, K.G.; Hemmings, J.; Paton, D.C.; Afton, A.D.

    2003-01-01

    Musk Ducks Biziura lobata are endemic to wetlands, river systems and coastal oceanic waters of temperate Australia. Individuals of this species are difficult to capture because of their excellent swimming and diving abilities and frequent use of deep-water habitats. Night-lighting, baited clover-leaf traps and walk-in-nest-traps were used to capture Musk Ducks at Murray Lagoon, Cape Gantheaume Conservation Park, Kangaroo Island, South Australia. These techniques should be useful for capturing Musk Ducks at other locations in Australia.

  20. Sorption studies of human keratinized tissues

    NASA Astrophysics Data System (ADS)

    Johnsen, G. K.; Martinsen, Ø. G.; Grimnes, Sverre

    2010-04-01

    Water content is known to be the most important single parameter for keratinized tissue to remain its vital functions. In that sense, a general knowledge of the water binding properties is of great interest, and a reliable measurement setup must be found. Also, revealing the sorption properties of human keratinized tissues is vital towards a calibration of susceptance based skin hydration measurements that already is an important diagnostic tool in clinical dermatology, and we will see that any hysteresis will complicate such a calibration further. In this study we investigated the sorption properties of keratinized tissues such as human epidermal stratum corneum (SC), hair and nail. The study was performed under controlled environmental conditions with a dynamic vapor sorption (DVS) instrument, and the water uptake of the keratinized test samples was measured as the relative humidity in the ambient air was altered step-wisely. In this study, vital and characteristic water sorption properties such as the isotherm, relative water uptake, and hysteresis were investigated and will be discussed.

  1. Cysteic Acid in Dietary Keratin is Metabolized to Glutathione and Liver Taurine in a Rat Model of Human Digestion

    PubMed Central

    Wolber, Frances M.; McGrath, Michelle; Jackson, Felicity; Wylie, Kim; Broomfield, Anne

    2016-01-01

    Poultry feathers, consisting largely of keratin, are a low-value product of the poultry industry. The safety and digestibility of a dietary protein produced from keratin (KER) was compared to a cysteine-supplemented casein-based diet in a growing rat model for four weeks. KER proved to be an effective substitute for casein at 50% of the total dietary protein, with no changes in the rats’ food intake, weight gain, organ weight, bone mineral density, white blood cell counts, liver glutathione, or blood glutathione. Inclusion of KER in the diet reduced total protein digestibility from 94% to 86% but significantly increased total dietary cysteine uptake and subsequent liver taurine levels. The KER diet also significantly increased caecum weight and significantly decreased fat digestibility, resulting in a lower proportion of body fat, and induced a significant increase in blood haemoglobin. KER is therefore a safe and suitable protein substitute for casein, and the cysteic acid in keratin is metabolised to maintain normal liver and blood glutathione levels. PMID:26907334

  2. Heat stress impairs the nutritional metabolism and reduces the productivity of egg-laying ducks.

    PubMed

    Ma, Xianyong; Lin, Yingcai; Zhang, Hanxing; Chen, Wei; Wang, Shang; Ruan, Dong; Jiang, Zongyong

    2014-03-01

    This research was conducted to determine the effect of heat stress on the nutritional metabolism and productivity of egg-laying shelducks. Healthy shelducks (n=120) in the early laying stage (uniform body weights and normal feed intakes) were randomly assigned to two identical climate chambers and exposed to constant high temperature (34°C) or control temperature (23°C) for 28d. The heat-exposed ducks had reduced feed intakes and laying rates (P<0.05), increased frequency of panting and spreading wings and dull featheration; egg weight, eggshell thickness and strength, and Haugh unit also decreased and malondialdehyde (MDA) content of egg yolk increased (P<0.05). Compared with the control ducks, the plasma concentrations of HCO3(-), phosphorus, glucose, thyroxine and activities of glutamic-pyruvic transaminase and glutamic oxaloacetic transaminase were decreased, while there were increased concentrations of corticosterone (P<0.05). The content of MDA and lactate in plasma and liver was greater in heat-exposed than in control ducks, but superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), total antioxidant enzymes (T-AOC) activities and glutathione (GSH) contents were less. The expression of HSP70 gene expression in the liver was increased in heat-stressed ducks. The relative weight of oviduct, number of large ovarian follicles, length of the oviduct all decreased (P<0.05) in heat-treated ducks, as did expression of carbonic anhydrase and calcium binding protein genes in the shell gland as a result of heat stress. In summary, heat stress decreased the productivity of ducks, which related to reduced feed intake, protein synthesis, endocrine dysfunction, less antioxidant capacity, and derangement of calcium and phosphorous balance.

  3. Duck viral enteritis in domestic muscovy ducks in Pennsylvania

    USGS Publications Warehouse

    Davison, S.; Converse, K.A.; Hamir, A.N.; Eckroade, R.J.

    1993-01-01

    Duck viral enteritis (DVE) outbreaks occurred at two different locations in Pennsylvania in 1991 and 1992. In the first outbreak, four ducks died out of a group of 30 domestic ducks; in the second outbreak, 65 ducks died out of a group of 114 domestic ducks, and 15 domestic geese died as well. A variety of species of ducks were present on both premises, but only muscovy ducks (Cairina moschata) died from the disease. On necropsy, gross lesions included hepatomegaly with petechial hemorrhages, petechial hemorrhages in the abdominal fat, petechial hemorrhages on the epicardial surface of the heart, and multifocal to coalescing areas of fibrinonecrotic material over the mucosal surface of the trachea, esophagus, intestine, and cloaca. Histologically, the liver had random multifocal areas of necrosis and eosinophilic intranuclear inclusion bodies in hepatocytes. DVE virus was isolated and identified using muscovy duck embryo fibroblast inoculation and virus neutralization. /// En dos sitios diferentes se presentaron brotes de enteritis viral de los patos en el estados de Pensilvania en los a??os 1991 y 1992. En el primer brote, cuatro de un lote de 30 patos murieron mientras que en el segundo brote murieron 65 patos de un lote de 114 patos y 15 gansos. En ambas localidades exist?-a una variedad de especies de patos, sin embargo, s??lamente los patos almizcleros (Cairina moschata) murieron. A la necropsia, las lesiones macrosc??picas incluyeron hepatomegalia con hemorragias petequiales, hemorragias petequiales en la grasa abdominal y en la superficie del epicardio, y ?!reas multifocales o coalescentes de material fibrinonecr??tico sobre la superficie de la mucosa de la tr?!quea, es??fago, intestino y cloaca. Histol??gicamente, el h?-gado mostraba ?!reas multifocales de necrosis y cuerpos de inclusi??n intranucleares eosinof?-licos en los hepatocitos. El virus de la enteritis viral de los patos fue aislado e identificado usando fibroblasto de embriones de pato almizclero

  4. Mercury in feathers from Chilean birds: Influence of location, feeding strategy, and taxonomic affiliation

    USGS Publications Warehouse

    Ochoa-Acua, H.; Sepulveda, M.S.; Gross, T.S.

    2002-01-01

    This study reports baseline concentrations of mercury (Hg) in feathers from different species of birds sampled at various locations off the Chilean coast (Southeastern Pacific). Hg concentrations were evaluated in relation to geographic location, taxonomic affiliation, and feeding strategies. Between January and March of 1995, we collected mature contour feathers from 116 birds belonging to 22 species, mostly seabirds. Birds were collected from 10 different locations (26??09???S, 70??40???W to 54??56???S, 67??37???W). Feather Hg concentrations ranged from 0.11 to 13 ??gg-1 dry weight. We found differences in feather Hg concentrations across taxonomic groups, with highest concentrations in petrels, shearwaters, and albatrosses (Procellaridae), followed by boobies (Sulidae), gulls, terns, skuas (Laridae) and cormorants (Phalacrocoracidae). Ibises and oystercatchers (Threskiornithidae and Charadriidae) had intermediate values, whereas ducks and geese (Anatidae) contained the least amount of Hg. Oceanic species preying on mesopelagic fish (the Procellariformes albatrosses, petrels, and fulmars) had over twice as much Hg (overall average of 3.9 ??gg-1) when compared to the rest of the species sampled (overall average of 1.5 ??gg-1). We did not find higher Hg concentrations in birds inhabiting the more heavily industrialized and urbanized areas of the country (central and northern regions), but in birds inhabiting the remote Juan Ferna??ndez Archipelago. This is not surprising, since all the Procellariformes (the group with highest Hg values in this study) were collected from these islands. Except for Hg in Kermadec petrels (mean of 12 ??gg-1), the range of Hg values reported here (0.11-7.3 ??gg-1) fell below those known to cause adverse health and reproductive effects in birds. ?? 2002 Elsevier Science Ltd. All rights reserved.

  5. Mercury in feathers from Chilean birds: Influence of location, feeding strategy and taxonomic affiliation

    USGS Publications Warehouse

    Ochoa-Acuna, H.G.; Sepulveda, M.S.; Gross, T.S.

    2002-01-01

    This study reports baseline concentrations of mercury (Hg) in feathers from different species of birds sampled at various locations off the Chilean coast (Southeastern Pacific). Hg concentrations were evaluated in relation to geographic location, taxonomic affiliation, and feeding strategies. Between January and March of 1995, we collected mature contour feathers from 116 birds belonging to 22 species, mostly seabirds. Birds were collected from 10 different locations (26?09'S, 70?40'W to 54?56'S, 67?37'W). Feather Hg concentrations ranged from 0.11 to 13 ?g g-1 dry weight. We found differences in feather Hg concentrations across taxonomic groups, with highest concentrations in petrels, shearwaters, and albatrosses (Procellaridae), followed by boobies (Sulidae), gulls, terns, skuas (Laridae) and cormorants (Phalacrocoracidae). Ibises and oystercatchers (Threskiornithidae and Charadriidae) had intermediate values, whereas ducks and geese (Anatidae) contained the least amount of Hg. Oceanic species preying on mesopelagic fish (the Procellariformes albatrosses, petrels, and fulmars) had over twice as much Hg (overall average of 3.9 ?g g-1) when compared to the rest of the species sampled (overall average of 1.5 ?g g-1). We did not find higher Hg concentrations in birds inhabiting the more heavily industrialized and urbanized areas of the country (central and northern regions), but in birds inhabiting the remote Juan Fernandez Archipelago. This is not surprising, since all the Procellariformes (the group with highest Hg values in this study) were collected from these islands. Except for Hg in Kermadec petrels (mean of 12 ?g g-1), the range of Hg values reported here (0.11-7.3 ?g g-1) fell below those known to cause adverse health and reproductive effects in birds.

  6. Brazil The Duck Lagoon

    NASA Technical Reports Server (NTRS)

    2002-01-01

    This Multi-angle Imaging SpectroRadiometer (MISR) image of Brazil covers an area of about 298 kilometers x 358 kilometers, and was captured by the instrument's vertical-viewing (nadir) camera on December 27, 2001. The 'Lagoa dos Patos', in the Brazilian state of Rio Grande do Sul, translates to 'the Duck Lagoon'. It was named by 16th century Jesuit settlers, who asked the King of Spain to grant them title to the lagoon so that they could breed ducks. The King consented, but revoked his edict when he discovered that the 'duck-pond' (measuring about 14,000 square kilometers) was one of the largest lagoonal systems in the world. Note the sediment plume emanating from the southern end of the lagoon. Sailors in the 16th century imagined this outlet to be the mouth of a large river. Early Portuguese explorers mistook the entrance to the lagoon for the mouth of a great river and called it the Rio Grande. A series of wave-like points and curls form 'cusps' on the inner shores of the lagoon. The lagoon's characteristics change with short-term tide-induced cyclic perturbations, and with longer term large scale meteorological conditions. The distinctive wavelike 'cusps' along the inner shores result from the circulation, erosion and accumulation of sediments driven by wind and tidal action. The El Nino Southern Oscillation (ENSO) circulation affects precipitation amount and continental runoff, thereby changing the contents of the lagoon waters. High rainfall and increased freshwater discharge during El Nino events correspond with elevated dissolved nutrient concentrations and increased phytoplankton growth. La Nina years are dry and the associated low rainfall reduces the freshwater recharge to the lagoon, causing an increase in salinity. Occasional blooms of toxic cyanobacteria (Microcystis aeruginosa), have been registered in the lagoon when nutrient concentrations are elevated. A number of reeds and grasses are important to the lagoon estuary, including widgeon grass

  7. Immunolocalization of a Histidine-Rich Epidermal Differentiation Protein in the Chicken Supports the Hypothesis of an Evolutionary Developmental Link between the Embryonic Subperiderm and Feather Barbs and Barbules

    PubMed Central

    Alibardi, Lorenzo; Holthaus, Karin Brigit; Sukseree, Supawadee; Hermann, Marcela; Tschachler, Erwin

    2016-01-01

    The morphogenesis of feathers is a complex process that depends on a tight spatiotemporal regulation of gene expression and assembly of the protein components of mature feathers. Recent comparative genomics and gene transcription studies have indicated that genes within the epidermal differentiation complex (EDC) encode numerous structural proteins of cornifying skin cells in amniotes including birds. Here, we determined the localization of one of these proteins, termed EDMTFH (Epidermal Differentiation Protein starting with a MTF motif and rich in Histidine), which belongs to a group of EDC-encoded proteins rich in aromatic amino acid residues. We raised an antibody against an EDMTFH-specific epitope and performed immunohistochemical investigations by light microscopy and immunogold labeling by electron microscopy of chicken embryos at days 14–18 of development. EDMTFH was specifically present in the subperiderm, a transient layer of the embryonic epidermis, and in barbs and barbules of feathers. In the latter, it partially localized to bundles of so-called feather beta-keratins (corneous beta-proteins, CBPs). Cells of the embryonic periderm, the epidermis proper, and the feather sheath were immunonegative for EDMTFH. The results of this study indicate that EDMTFH may contribute to the unique mechanical properties of feathers and define EDMTFH as a common marker of the subperiderm and the feather barbules. This expression pattern of EDMTFH resembles that of epidermal differentiation cysteine-rich protein (EDCRP) and feather CBPs and is in accordance with the hypothesis that a major part of the cyclically regenerating feather follicle is topologically, developmentally and evolutionarily related to the embryonic subperiderm. PMID:27936131

  8. Immunolocalization of a Histidine-Rich Epidermal Differentiation Protein in the Chicken Supports the Hypothesis of an Evolutionary Developmental Link between the Embryonic Subperiderm and Feather Barbs and Barbules.

    PubMed

    Alibardi, Lorenzo; Holthaus, Karin Brigit; Sukseree, Supawadee; Hermann, Marcela; Tschachler, Erwin; Eckhart, Leopold

    2016-01-01

    The morphogenesis of feathers is a complex process that depends on a tight spatiotemporal regulation of gene expression and assembly of the protein components of mature feathers. Recent comparative genomics and gene transcription studies have indicated that genes within the epidermal differentiation complex (EDC) encode numerous structural proteins of cornifying skin cells in amniotes including birds. Here, we determined the localization of one of these proteins, termed EDMTFH (Epidermal Differentiation Protein starting with a MTF motif and rich in Histidine), which belongs to a group of EDC-encoded proteins rich in aromatic amino acid residues. We raised an antibody against an EDMTFH-specific epitope and performed immunohistochemical investigations by light microscopy and immunogold labeling by electron microscopy of chicken embryos at days 14-18 of development. EDMTFH was specifically present in the subperiderm, a transient layer of the embryonic epidermis, and in barbs and barbules of feathers. In the latter, it partially localized to bundles of so-called feather beta-keratins (corneous beta-proteins, CBPs). Cells of the embryonic periderm, the epidermis proper, and the feather sheath were immunonegative for EDMTFH. The results of this study indicate that EDMTFH may contribute to the unique mechanical properties of feathers and define EDMTFH as a common marker of the subperiderm and the feather barbules. This expression pattern of EDMTFH resembles that of epidermal differentiation cysteine-rich protein (EDCRP) and feather CBPs and is in accordance with the hypothesis that a major part of the cyclically regenerating feather follicle is topologically, developmentally and evolutionarily related to the embryonic subperiderm.

  9. Evolution: taking wing with weak feathers.

    PubMed

    Xu, Xing

    2012-12-04

    Scientists long thought they knew what the wings of early birds looked like. But new reconstructions of Archaeopteryx and its kin suggest quite different feather arrangements on their wings with profound implications for the evolution of flight.

  10. An investigation of arsenic compounds in fur and feathers using X-ray absorption spectroscopy speciation and imaging.

    PubMed

    Smith, Paula G; Koch, Iris; Reimer, Kenneth J

    2008-02-01

    The accumulation of arsenic in fur and feathers has been used as an indicator of environmental quality and animal health. However, difficulties remain in distinguishing between arsenic present from external sources versus ingestion. In addition, low extraction efficiencies limit the complete characterization of arsenic compounds in such tissues by conventional analytical techniques (e.g. high performance liquid chromatography inductively coupled plasma mass spectrometry, HPLC-ICP-MS). X-ray absorption spectroscopy (XAS) provides an alternative method for determining the speciation of arsenic compounds directly. Inorganic arsenic is hypothesized to bind to thiol groups present in keratin-rich fur and feathers; however, arsenic-sulphur compounds are rarely reported in extracts of these tissues. Here we report that 5-58% of the total detected arsenic in rodent fur (vole, deer mouse, red squirrel) and bird feathers (gray jay, American tree sparrow, dark-eyed junco) from animals living in areas of elevated arsenic best resembled an arsenic(III)-sulphur compound as determined using XAS. In addition, fur and feathers with non-detectable levels of arsenic by XAS, were able to reduce pentavalent arsenic applied as either contaminated soil or an arsenate solution. XAS-imaging was used to localize dominant trivalent (AsIII) and pentavalent (AsV) arsenic compounds, and results were used to produce a "map" of arsenic in the sample. It is believed that the some of the reduced arsenic was absorbed, while external AsV compounds associated with soil/dust particles were easily distinguished on goose feathers. However, distinguishing whether internal arsenic arose from exogenous (from the environment) or endogenous (from the body) sources proved difficult with this technique.

  11. Role of loose feathers on the development of feather pecking in laying hens.

    PubMed

    Ramadan, S G A; von Borell, E

    2008-05-01

    1. The effect of the presence of loose feathers (on the floor) on the behaviour and plumage condition of laying hens (Lohmann Silver, LS) was studied during the rearing and laying periods. 2. From one day old, 60 birds in each of 4 straw-bedded pens (n = 240 in total) with 6.5 birds/m(2) were either kept under conventional rearing and management conditions (CT: control group with feathers on the floor; n = 120) or in pens from which the feathers were collected from the floor 4 times/week (FR: feathers removed; n = 120). Fifty birds from each of these 4 groups (n = 200 in total) were randomly selected at the age of 16 weeks and allocated to 4 identical pens in a poultry layer house (PH; with perches and 1/3 slatted floor) with access to an outside area (winter garden, WG) at a stocking density of 6 birds/m(2) in both PH and WG. 3. Observations on feather pecking and other behaviours (feeding, drinking, preening, standing, sitting, foraging, moving and dust bathing) were carried out at 8 ages: 6, 10, 15 (rearing period), 20, 25, 30, 35 and 40 weeks (laying period). Feather scoring was carried out at 15, 32 and 39 weeks of age. 4. There were no differences in feather pecking rates, forms (gentle, severe and aggressive pecks) as well as in the plumage condition between groups at the end of the rearing period. 5. Birds in the FR group exhibited lower rates and less severe feather pecking during the laying period. Accordingly, birds in the control group had worse feather condition at 32 and 39 weeks of age. Feather pecking rates within groups were, in general, greater in the afternoon compared to the morning periods. Birds in the control group were more active in walking. 6. Wings, rump, tail and back were the main targets for feather pecking. The majority of feather pecking occurred on the floor (66%) followed by feeding area (26%), perches (4%) and slats (4%). 7. Our results suggest that loose feathers on the floor may play an important role in the development and

  12. On the uniqueness of color patterns in raptor feathers

    USGS Publications Warehouse

    Ellis, D.H.

    2009-01-01

    For this study, I compared sequentially molted feathers for a few captive raptors from year to year and symmetrically matched feathers (left/right pairs) for many raptors to see if color patterns of sequential feather pairs were identical or if symmetrical pairs were mirror-image identical. Feather pairs were found to be identical only when without color pattern (e.g., the all-white rectrices of Bald Eagles [Haliaeetus leucocephalus]). Complex patterns were not closely matched, but some simple patterns were sometimes closely matched, although not identical. Previous claims that complex color patterns in feather pairs are fingerprint-identical (and therefore that molted feathers from wild raptors can be used to identify breeding adults from year to year with certainty) were found to be untrue: each feather is unique. Although it is unwise to be certain of bird of origin using normal feathers, abnormal feathers can often be so used. ?? 2009 The Raptor Research Foundation, Inc.

  13. Ice Formation Delay on Penguin Feathers

    NASA Astrophysics Data System (ADS)

    Alizadehbirjandi, Elaheh; Tavakoli-Dastjerdi, Faryar; St. Leger, Judy; Davis, Stephen H.; Rothstein, Jonathan P.; Kavehpour, H. Pirouz

    2015-11-01

    Antarctic penguins reside in a harsh environment where air temperature may reach -40 °C with wind speed of 40 m/s and water temperature remains around -2.2 °C. Penguins are constantly in and out of the water and splashed by waves, yet even in sub-freezing conditions, the formation of macroscopic ice is not observed on their feathers. Bird feathers are naturally hydrophobic; however, penguins have an additional hydrophobic coating on their feathers to reinforce their non-wetting properties. This coating consists of preen oil which is applied to the feathers from the gland near the base of the tail. The combination of the feather's hydrophobicity and surface texture is known to increase the contact angle of water drops on penguin feathers to over 140 ° and classify them as superhydrophobic. We here develop an in-depth analysis of ice formation mechanism on superhydrophobic surfaces through careful experimentations and development of a theory to address how ice formation is delayed on these surfaces. Furthermore, we investigate the anti-icing properties of warm and cold weather penguins with and without preen oil to further design a surface minimizing the frost formation which is of practical interest especially in aircraft industry.

  14. Maturation experiments reveal bias in the fossil record of feathers

    NASA Astrophysics Data System (ADS)

    McNamara, Maria; Field, Daniel

    2016-04-01

    The evolutionary history of birds and feathers is a major focus in palaeobiology and evolutionary biology. Diverse exceptionally preserved birds and feathered dinosaurs from Jurassic and Cretaceous biotas in China have provided pivotal evidence of early feathers and feather-like integumentary features, but the true nature of many of these fossil soft tissues is still debated. Interpretations of feathers at intermediate developmental stages (i.e. Stages II, III and IV) and of simple quill-like (Stage I) feathers are particularly controversial. This reflects key uncertainties relating to the preservation potential of feathers at different evolutionary-developmental stages, and to the relative preservation potential of diagnostic features of Stage I feathers and hair. To resolve these issues, we used high pressure-high temperature autoclave experiments to simulate the effects of burial on modern feathers from the Black Coucal (Centropus grilii) and Common Starling (Sturnus vulgaris), and on human hair. Our results reveal profound differences in the recalcitrance of feathers of different types during maturation: Stage I and Stage V feathers retain diagnostic morphological and ultrastructural details following maturation, whereas other feather types do not. Further, the morphology and arrangement of certain ultrastructural features diagnostic of Stages III and IV, e.g. barbules, are preferentially lost during maturation. These results indicate a pervasive bias in the fossil record of feathers, whereby preservation of feathers at Stages I and V is favored. Critical stages in the evolution of feathers, i.e. Stages II, III and IV, are less likely to be preserved and more likely to be misinterpreted as feathers at earlier developmental stages. Our discovery has major implications for our understanding of the fidelity of the fossil record of feathers and provides a framework for testing the significance of putative examples of fossil feathers at different developmental

  15. Postfledging survival of Laysan ducks

    USGS Publications Warehouse

    Reynolds, Michelle H.; Citta, John J.

    2007-01-01

    Precise and unbiased estimates of demographic parameters are necessary for effective population monitoring and to parameterize population models (e.g., population viability analyses). This is especially important for endangered species, where recovery planning and managers' decisions can influence species persistence. In this study, we used mark–recapture methods to estimate survival of fledged juveniles (hatch-yr [HY]) and adult (after-hatch-yr [AHY]) Laysan ducks (Anas laysanensis), an endangered anatid restricted to Laysan Island in the northwestern Hawaiian Islands. To better understand population dynamics, we examined how survival varied as a function of Laysan duck density during 1998–2004. Using random effects models, we also quantified process variation in survival, thereby quantifying the appropriate source of variation for future population models. The dataset supported variation in survival that was time (yr), age (AHY vs. HY), and sex specific. Due to small sample sizes, we did not examine time specificity in the survival of HY ducks. Survival of HY ducks was 0.832 (SE = 0.087) for females (n = 21) and 0.999 (SE < 0.001) for males (n = 15) during 1998–2001. Trends in time and density lacked support as sources of variation in the survival of AHY ducks during 1998–2004. After-hatch-year survival ranged from 0.792 (SE = 0.033) to 0.999 (SE < 0.001). Where we modeled survival as a random effect, annual survival for AHY females was 0.881 (SE = 0.017) and process variation (σS) was 0.034. For AHY males, annual survival (μS) was 0.906 (SE = 0.019) and process variation (σS) was 0.040. This information will improve existing population viability analysis models for Laysan ducks. We believe that monitoring the source and translocation populations will be paramount for increasing our understanding of Laysan duck dynamics, recovery planning, and population management.

  16. Free radical facilitated damage of ungual keratin.

    PubMed

    Khengar, Rajeshree H; Brown, Marc B; Turner, Rob B; Traynor, Matthew J; Holt, Katherine B; Jones, Stuart A

    2010-09-01

    Thioglycolic acid (TA) and urea hydrogen peroxide (urea H(2)O(2)) are thought to disrupt alpha-keratin disulfide links in the nail. However, optimal clinical use of these agents to improve the treatment of nail disorders is currently hindered by a lack of fundamental data to support their mechanism of action. The aim of this study was to investigate how the redox environment of ungual keratin, when manipulated by TA and urea H(2)O(2), influenced the properties of the nail barrier. Potentiometric and voltammetric measurements demonstrated that urea H(2)O(2) obeyed the Nernst equation for a proton coupled one-electron transfer redox process while TA underwent a series of redox reactions that was complicated by electrode adsorption and dimer formation. The functional studies demonstrated that nail permeability, measured through TBF penetration (38.51+/-10.94 microg/cm(2)/h) and nail swelling (244.10+/-14.99% weight increase), was greatest when relatively low concentrations of the thiolate ion were present in the applied solution. Limiting the thiolate ion to low levels in the solution retards thiolate dimerisation and generates thiyl free radicals. It appeared that this free radical generation was fundamental in facilitating the redox-mediated keratin disruption of the ungual membrane.

  17. Pathobiology of avian influenza in domestic ducks

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Domestic ducks are an important source of food and income in many parts of the world. The susceptibility of domestic ducks to avian influenza (AI) viruses varies depending on many factors, including the species and the age of the ducks, the virus strain, and management practices. Although wild wat...

  18. A new feather type in a nonavian theropod and the early evolution of feathers.

    PubMed

    Xu, Xing; Zheng, Xiaoting; You, Hailu

    2009-01-20

    All described feathers in nonavian theropods are composite structures formed by multiple filaments. They closely resemble relatively advanced stages predicted by developmental models of the origin of feathers, but not the earliest stage. Here, we report a feather type in two specimens of the basal therizinosaur Beipiaosaurus, in which each individual feather is represented by a single broad filament. This morphotype is congruent with the stage I morphology predicted by developmental models, and all major predicted morphotypes have now been documented in the fossil record. This congruence between the full range of paleontological and developmental data strongly supports the hypothesis that feathers evolved and initially diversified in nonavian theropods before the origin of birds and the evolution of flight.

  19. Beyond expectations: novel insights into epidermal keratin function and regulation.

    PubMed

    Homberg, Melanie; Magin, Thomas M

    2014-01-01

    The epidermis is a stratified epithelium that relies on its cytoskeleton and cell junctions to protect the body against mechanical injury, dehydration, and infections. Keratin intermediate filament proteins are involved in many of these functions by forming cell-specific cytoskeletal scaffolds crucial for the maintenance of cell and tissue integrity. In response to various stresses, the expression and organization of keratins are altered at transcriptional and posttranslational levels to restore tissue homeostasis. Failure to restore tissue homeostasis in the presence of keratin gene mutations results in acute and chronic skin disorders for which currently no rational therapies are available. Here, we review the recent progress on the role of keratins in cytoarchitecture, adhesion, signaling, and inflammation. By focusing on epidermal keratins, we illustrate the contribution of keratin isotypes to differentiated epithelial functions.

  20. Multicenter Clinical Trial of Keratin Biomaterial for Peripheral Nerve Regeneration

    DTIC Science & Technology

    2015-12-01

    Award Number: W81XWH-10-1-0894 TITLE: Multicenter Clinical Trial of Keratin Biomaterial for Peripheral Nerve Regeneration PRINCIPAL...DATES COVERED 15Sep2010 - 14Sep2015 4. TITLE AND SUBTITLE Multicenter Clinical Trial of Keratin Biomaterial for 5a. CONTRACT NUMBER W81XWH-10-1-0894... clinical trial was to be initiated as soon as the FDA provided an IND for the keratin biomaterial hydrogel. However, due to delays in the FDA approval

  1. Multicenter Clinical Trial of Keratin Biomaterial for Peripheral Nerve Regeneration

    DTIC Science & Technology

    2014-10-01

    AD_________________ Award Number: W81XWH-10-1-0894 TITLE: Multicenter Clinical Trial of Keratin Biomaterial for Peripheral Nerve Regeneration...DATES COVERED 15 Sep 2013 - 14 Sep 2014 4. TITLE AND SUBTITLE Multicenter Clinical Trial of Keratin Biomaterial for 5a. CONTRACT NUMBER Peripheral...has developed a keratin biomaterial hydrogel that can be used as luminal filler in nerve guidance conduits to facilitate nerve regeneration

  2. The Study on Biological Function of Keratin 26, a Novel Member of Liaoning Cashmere Goat Keratin Gene Family

    PubMed Central

    Jin, Mei; Wang, Jing; Chu, Ming-Xing; Piao, Jun; Piao, Jing-Ai; Zhao, Feng-Qin

    2016-01-01

    In our research, we explored the relationship between Keratin 26 and the regulation of fine hair, BMP signaling pathway, MT, FGF5, and IGF-I. The result of hybridization in situ revealed that Keratin 26 was specially expressed in cortex of skin hair follicles; the result of immunohistochemistry indicated that Keratin 26 was expressed in internal root sheath, external root sheath. Then, Real-time quantitative PCR results showed that relative expressive quantity of Keratin 26 was 1.08 or 3.3 × greater in secondary follicle than primary follicle during anagen or catagen; the difference during anagen was not remarkable (p>0.05), however, that of catagen was extremely significant (p<0.01). Relative expressive quantity of Keratin 26 increased during telogen; the difference was extremely significant (p<0.01). Moreover, after Noggin expression interference using RNAi technology, we found that relative expressive quantity of Keratin 26 extremely remarkably declined (p<0.01); after K26 overexpression, we found that relative expressive quantity of Noggin extremely remarkably increased (p<0.01). We detected expressive quantity change of Keratin 26 and Keratin 26 using Real-time quantitative PCR and immunofluorescence technologies after fibroblasts were treated with MT, FGF5 or IGF-I; the results indicated that MT and FGF5 played a positive role in Keratin 26 and Keratin 26 expression, IGF-I played a negative role in Keratin 26 expression, positive role in Keratin 26 expression. The results above showed that Keratin 26 could inhibit cashmere growth, and was related to entering to catagen and telogen of hair follicles; Keratin 26 and BMP signaling pathway were two antagonistic pathways each other which could inhibit growth and development of cashmere; MT, FGF5 and IGF-I could affect expression of Keratin 26 and Keratin 26, and Keratin 26 was one of the important pathways that MT induced cashmere production in advance, FGF5 regulated cashmere growth and IGF-I promoted cashmere

  3. Age-class separation of blue-winged ducks

    USGS Publications Warehouse

    Hohman, W.L.; Moore, J.L.; Twedt, D.J.; Mensik, John G.; Logerwell, E.

    1995-01-01

    Accurate determination of age is of fundamental importance to population and life history studies of waterfowl and their management. Therefore, we developed quantitative methods that separate adult and immature blue-winged teal (Anas discors), cinnamon teal (A. cyanoptera), and northern shovelers (A. clypeata) during spring and summer. To assess suitability of discriminant models using 9 remigial measurements, we compared model performance (% agreement between predicted age and age assigned to birds on the basis of definitive cloacal or rectral feather characteristics) in different flyways (Mississippi and Pacific) and between years (1990-91 and 1991-92). We also applied age-classification models to wings obtained from U.S. Fish and Wildlife Service harvest surveys in the Mississippi and Central-Pacific flyways (wing-bees) for which age had been determined using qualitative characteristics (i.e., remigial markings, shape, or wear). Except for male northern shovelers, models correctly aged lt 90% (range 70-86%) of blue-winged ducks. Model performance varied among species and differed between sexes and years. Proportions of individuals that were correctly aged were greater for males (range 63-86%) than females (range 39-69%). Models for northern shovelers performed better in flyway comparisons within year (1991-92, La. model applied to Calif. birds, and Calif. model applied to La. birds: 90 and 94% for M, and 89 and 76% for F, respectively) than in annual comparisons within the Mississippi Flyway (1991-92 model applied to 1990-91 data: 79% for M, 50% for F). Exclusion of measurements that varied by flyway or year did not improve model performance. Quantitative methods appear to be of limited value for age separation of female blue-winged ducks. Close agreement between predicted age and age assigned to wings from the wing-bees suggests that qualitative and quantitative methods may be equally accurate for age separation of male blue-winged ducks. We interpret annual

  4. Novel wound dressing based on nanofibrous PHBV-keratin mats.

    PubMed

    Yuan, Jiang; Geng, Jia; Xing, Zhicai; Shim, Kyoung-Jin; Han, Insook; Kim, Jung-Chul; Kang, Inn-Kyu; Shen, Jian

    2015-09-01

    Keratin is an important protein used for wound healing and tissue recovery. In this study, keratin was first extracted from raw materials and chemically modified to obtain stable keratin (m-keratin). The raw and m-keratin were examined by Raman spectroscopy. The molecular weight of the m-keratin was analysed by SDS-PAGE. The m-keratin was then blended with poly(hydroxybutylate-co-hydroxyvalerate) (PHBV) and electrospun to afford nanofibrous mats. These mats were characterized by field emission scanning electron microscopy (FE-SEM), electron spectroscopy for chemical analysis (ESCA) and atomic force microscopy (AFM). From the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) data, it was found that introduction of keratin enhanced cell proliferation. From wound-healing test and histological examination results, it was shown that the composite mats accelerated wound recovery remarkably as compared to the PHBV control. It was concluded that PHBV-keratin may be a good candidate as a wound dressing.

  5. Keratins significantly contribute to cell stiffness and impact invasive behavior

    PubMed Central

    Seltmann, Kristin; Fritsch, Anatol W.; Käs, Josef A.; Magin, Thomas M.

    2013-01-01

    Cell motility and cell shape adaptations are crucial during wound healing, inflammation, and malignant progression. These processes require the remodeling of the keratin cytoskeleton to facilitate cell–cell and cell–matrix adhesion. However, the role of keratins for biomechanical properties and invasion of epithelial cells is only partially understood. In this study, we address this issue in murine keratinocytes lacking all keratins on genome engineering. In contrast to predictions, keratin-free cells show about 60% higher cell deformability even for small deformations. This response is compared with the less pronounced softening effects for actin depolymerization induced via latrunculin A. To relate these findings with functional consequences, we use invasion and 3D growth assays. These experiments reveal higher invasiveness of keratin-free cells. Reexpression of a small amount of the keratin pair K5/K14 in keratin-free cells reverses the above phenotype for the invasion but does not with respect to cell deformability. Our data show a unique role of keratins as major players of cell stiffness, influencing invasion with implications for epidermal homeostasis and pathogenesis. This study supports the view that down-regulation of keratins observed during epithelial–mesenchymal transition directly contributes to the migratory and invasive behavior of tumor cells. PMID:24167274

  6. Keratins significantly contribute to cell stiffness and impact invasive behavior.

    PubMed

    Seltmann, Kristin; Fritsch, Anatol W; Käs, Josef A; Magin, Thomas M

    2013-11-12

    Cell motility and cell shape adaptations are crucial during wound healing, inflammation, and malignant progression. These processes require the remodeling of the keratin cytoskeleton to facilitate cell-cell and cell-matrix adhesion. However, the role of keratins for biomechanical properties and invasion of epithelial cells is only partially understood. In this study, we address this issue in murine keratinocytes lacking all keratins on genome engineering. In contrast to predictions, keratin-free cells show about 60% higher cell deformability even for small deformations. This response is compared with the less pronounced softening effects for actin depolymerization induced via latrunculin A. To relate these findings with functional consequences, we use invasion and 3D growth assays. These experiments reveal higher invasiveness of keratin-free cells. Reexpression of a small amount of the keratin pair K5/K14 in keratin-free cells reverses the above phenotype for the invasion but does not with respect to cell deformability. Our data show a unique role of keratins as major players of cell stiffness, influencing invasion with implications for epidermal homeostasis and pathogenesis. This study supports the view that down-regulation of keratins observed during epithelial-mesenchymal transition directly contributes to the migratory and invasive behavior of tumor cells.

  7. 14 CFR 25.1153 - Propeller feathering controls.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... feathering is accomplished by movement of the propeller pitch or speed control lever, there must be means to prevent the inadvertent movement of this lever to the feathering position during normal operation....

  8. 14 CFR 25.1153 - Propeller feathering controls.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... feathering is accomplished by movement of the propeller pitch or speed control lever, there must be means to prevent the inadvertent movement of this lever to the feathering position during normal operation....

  9. 14 CFR 25.1153 - Propeller feathering controls.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... feathering is accomplished by movement of the propeller pitch or speed control lever, there must be means to prevent the inadvertent movement of this lever to the feathering position during normal operation....

  10. 14 CFR 25.1153 - Propeller feathering controls.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... feathering is accomplished by movement of the propeller pitch or speed control lever, there must be means to prevent the inadvertent movement of this lever to the feathering position during normal operation....

  11. Dexamethasone inhibits corticosterone deposition in feathers of greenfinches.

    PubMed

    Hõrak, Peeter; Männiste, Marju; Meitern, Richard; Sild, Elin; Saks, Lauri; Sepp, Tuul

    2013-09-15

    Corticosterone (CORT) content of feathers is a potent source of information about activation of hypothalamus-pituitary-adrenal (HPA) axis during feather growth, which is used for assessment of well-being and stress history of individuals and populations in avian studies. However, little is known about factors affecting deposition of CORT into feathers and how feather CORT covaries with other markers of stress imposed upon individuals during feather growth. We addressed these questions by measuring CORT levels in feathers of wild-caught greenfinches (Carduelis chloris) brought into captivity. One tail feather was removed from all the birds upon arrival to the laboratory and the CORT levels of replacement feathers, grown in captivity were recorded. The birds were subjected to treatments of immune activation (by injection of phytohaemagglutinin) and synthetic glucocorticoid (dexamethasone, DEX) administration. Only DEX injection affected feather CORT levels. DEX-injected birds deposited on average 37% less of CORT in their feathers than saline-injected birds. Despite significant effects of DEX and immune activation treatments on differential leukocyte counts, we did not find any correlations between CORT and leukocyte hemoconcentrations or heterophil/lymphocyte ratios (a haematological index of stress), measured at three stages of feather growth. Our findings provide novel evidence that feather CORT levels are sensitive to manipulation of hormonal balance of birds, thereby supporting the diagnostic value of feather CORT measurements. However, we did not find any evidence about covariation between feather CORT and other markers of stress perceived during the period of feather growth. This calls for further research on information content of feather CORT, preferably in experiments manipulating more diverse array of psychological, immunological and abiotic stressors.

  12. Evaluation of a novel feather scoring system for monitoring feather damaging behaviour in parrots.

    PubMed

    van Zeeland, Yvonne R A; Bergers, Madeleine J; van der Valk, Lisette; Schoemaker, Nico J; Lumeij, Johannes T

    2013-05-01

    Feather damaging behaviour is common in captive psittacine birds and there is a need for reliable methods to evaluate the efficacy of therapeutic and preventive interventions. This study compared the inter- and intra-observer reliabilities of a novel feather scoring system with an existing system to assess the plumage of grey parrots (Psittacus erithacus). Regions of the body were photographed separately at 1 week intervals and shown at random to 35 examiners (avian veterinarians and veterinary students), who used the two scoring systems to assess plumage. Since the quality of the photographs was insufficient to allow accurate assessment of the individual flight and tail feathers, the novel scoring system was only evaluated for its reliability regarding covert and down feathers. Inter- and intra-observer reliabilities were determined using the intra-class correlation coefficient. Bland-Altman analysis was performed to determine absolute reliabilities for both systems. Correlation coefficients were 0.90 and 0.95 for intra-observer reliability and 0.83 and 0.89 for inter-observer reliability for the existing and novel feather scoring systems, respectively. When using the novel system, a change in plumage condition of ≥10% was needed to ensure that the change reflected a real difference in 95% of cases, while a change of ≥15% was needed for the existing system. Since it may take from 4 weeks (covert or down feathers) to over 1 year (flight or tail feathers) for feathers to regrow, sufficient time should be allowed to elapse between two scoring sessions to reliably evaluate the efficacy of preventive or therapeutic interventions for feather damaging behaviour.

  13. 14 CFR 23.1027 - Propeller feathering system.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Propeller feathering system. 23.1027... AIRCRAFT AIRWORTHINESS STANDARDS: NORMAL, UTILITY, ACROBATIC, AND COMMUTER CATEGORY AIRPLANES Powerplant Oil System § 23.1027 Propeller feathering system. (a) If the propeller feathering system uses...

  14. 14 CFR 25.1153 - Propeller feathering controls.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Propeller feathering controls. 25.1153... AIRCRAFT AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY AIRPLANES Powerplant Powerplant Controls and Accessories § 25.1153 Propeller feathering controls. (a) There must be a separate propeller feathering...

  15. Dkk2/Frzb in the dermal papillae regulates feather regeneration.

    PubMed

    Chu, Qiqi; Cai, Linyan; Fu, Yu; Chen, Xi; Yan, Zhipeng; Lin, Xiang; Zhou, Guixuan; Han, Hao; Widelitz, Randall B; Chuong, Cheng-ming; Wu, Wei; Yue, Zhicao

    2014-03-15

    Avian feathers have robust growth and regeneration capability. To evaluate the contribution of signaling molecules and pathways in these processes, we profiled gene expression in the feather follicle using an absolute quantification approach. We identified hundreds of genes that mark specific components of the feather follicle: the dermal papillae (DP) which controls feather regeneration and axis formation, the pulp mesenchyme (Pp) which is derived from DP cells and nourishes the feather follicle, and the ramogenic zone epithelium (Erz) where a feather starts to branch. The feather DP is enriched in BMP/TGF-β signaling molecules and inhibitors for Wnt signaling including Dkk2/Frzb. Wnt ligands are mainly expressed in the feather epithelium and pulp. We find that while Wnt signaling is required for the maintenance of DP marker gene expression and feather regeneration, excessive Wnt signaling delays regeneration and reduces pulp formation. Manipulating Dkk2/Frzb expression by lentiviral-mediated overexpression, shRNA-knockdown, or by antibody neutralization resulted in dual feather axes formation. Our results suggest that the Wnt signaling in the proximal feather follicle is fine-tuned to accommodate feather regeneration and axis formation.

  16. Mortality from duck plague virus in immunosuppressed adult mallard ducks

    SciTech Connect

    Goldberg, D.R.; Yuill, T.M.; Burgess, E.C. )

    1990-07-01

    Environmental contaminants contain chemicals that, if ingested, could affect the immunological status of wild birds, and in particular, their resistance to infectious disease. Immunosuppression caused by environmental contaminants, could have a major impact on waterfowl populations, resulting in increased susceptibility to contagious disease agents. Duck plague virus has caused repeated outbreaks in waterfowl resulting in mortality. In this study, several doses of cyclophosphamide (CY), a known immunosuppressant, were administered to adult mallards (Anas platyrhynchos) to determine if a resultant decrease in resistance to a normally sub-lethal strain of duck plague virus would occur, and induce mortality in these birds. Death occurred in birds given CY only, and in birds given virus and CY, but not in those given virus only. There was significantly greater mortality and more rapid deaths in the duck plague virus-infected groups than in groups receiving only the immunosuppressant. A positively correlated dose-response effect was observed with CY mortalities, irrespective of virus exposure. A fuel oil and a crude oil, common environmental contaminants with immunosuppressive capabilities, were tested to determine if they could produce an effect similar to that of CY. Following 28 days of oral oil administration, the birds were challenged with a sub-lethal dose of duck plague virus. No alteration in resistance to the virus (as measured by mortality) was observed, except in the positive CY control group.

  17. The pathogenicity of novel duck reovirus in Cherry Valley ducks.

    PubMed

    Li, Ning; Hong, Tianqi; Wang, Yao; Wang, Youling; Yu, Kexiang; Cai, Yumei; Liu, Sidang; Wei, Liangmeng; Chai, Tongjie

    2016-08-30

    The novel duck reovirus (NDRV) is an emerging, contagious infection. To better realize the pathogenic mechanism of NDRV in ducks, an infection experiment was conducted. The resulting data demonstrated that typical gross lesions were observed in the infected ducks. NDRV was able to replicate in various tissues, leading to these pathological lesions, especially on the liver and spleen. Real-time quantitative PCR showed that the expression of most innate immune-related genes was up-regulated and the antiviral innate immune response could be established in both the liver and spleen. This study indicates that NDRV is a pantropic virus. To resist viral infection, several pathogen recognition receptors can cooperatively recognize NDRV and initiate innate immunity, but the responses are different between different tissues. As far as we know, this is the first systematic investigation of the pathogenicity of NDRV in Cherry Valley ducks based on the host's innate immunity, and these data will provide new insights into the further study of the disease.

  18. Mortality from duck plague virus in immunosuppressed adult mallard ducks

    USGS Publications Warehouse

    Goldberg, D.R.; Yuill, Thomas M.; Burgess, E.C.

    1990-01-01

    Environmental contaminants contain chemicals that, if ingested, could affect the immunological status of wild birds, and in particular, their resistance to infectious disease. Immunosuppression caused by environmental contaminants, could have a major impact on waterfowl populations, resulting in increased susceptibility to contagious disease agents. Duck plague virus has caused repeated outbreaks in waterfowl resulting in mortality. In this study, several doses of cyclophosphamide (CY), a known immunosuppressant, were administered to adult mallards (Anas platyrhynchos) to determine if a resultant decrease in resistance to a normally sub-lethal strain of duck plague virus would occur, and induce mortality in these birds. Death occurred in birds given CY only, and in birds given virus and CY, but not in those given virus only. There was significantly greater mortality and more rapid deaths in the duck plague virus-infected groups than in groups receiving only the immunosuppressant. A positively correlated dose-response effect was observed with CY mortalities, irrespective of virus exposure. A fuel oil and a crude oil, common environmental contaminants with immunosuppressive capabilities, were tested to determine if they could produce an effect similar to that of CY. Following 28 days of oral oil administration, the birds were challenged with a sub-lethal dose of duck plague virus. No alteration in resistance to the virus (as measured by mortality) was observed, except in the positive CY control group.

  19. Feather eating and its associations with plumage damage and feathers on the floor in commercial farms of laying hens.

    PubMed

    Riber, A B; Hinrichsen, L K

    2016-07-01

    Feather eating has been associated with feather pecking, which continues to pose economic and welfare problems in egg production. Knowledge on feather eating is limited and studies of feather eating in commercial flocks of laying hens have not been performed previously. Therefore, the main objective was to investigate feather eating and its association with plumage damage and floor feather characteristics in commercial flocks of layers in barn and organic production systems. The study was performed in 13 flocks of barn layers and 17 flocks of organic layers. Each flock was visited at around 32 and 62 weeks of age. During both visits, the plumage condition was assessed and the density of floor feathers recorded. In week 62, droppings and floor feathers were collected. Droppings were examined for presence of feather content, whereas length, downiness and pecking damage were recorded for each floor feather. In week 62, a higher prevalence of hens with poor plumage condition was found in barn (22.2%) compared with organic production systems (7.4%; P<0.001), but the prevalence of droppings with feather content did not differ between the two production systems (8.5% in barn v. 4.3% in organic; P=0.99). Our hypothesis about a positive correlation between feather eating and plumage damage was not supported as no correlation was found between the prevalence of poor plumage condition and the prevalence of droppings with feather content. However, the prevalence of pecking damaged floor feathers was positively correlated both with prevalence of droppings with feather content (P<0.05) and poor plumage condition (P<0.01), indicating a possible association between feather eating and feather pecking. In conclusion, it was confirmed that feather eating occurs on-farm, but feather eating was only found to be positively correlated to the number of floor feathers with pecking damage and not as expected to the prevalence of plumage damage. More research is needed into the sources from

  20. Isolation of a mRNA encoding a glycine-proline-rich beta-keratin expressed in the regenerating epidermis of lizard.

    PubMed

    Dalla Valle, Luisa; Toffolo, Vania; Belvedere, Paola; Alibardi, Lorenzo

    2005-12-01

    During scale regeneration in lizard tail, an active differentiation of beta-keratin synthesizing cells occurs. The cDNA and amino acid sequence of a lizard beta-keratin has been obtained from mRNA isolated from regenerating epidermis. Degenerate oligonucleotides, selected from the translated amino acid sequence of a lizard claw protein, were used to amplify a specific lizard keratin cDNA fragment from the mRNA after reverse transcription with poly dT primer and subsequent polymerase chain reaction (3'-rapid amplification of cDNA ends analysis, 3'-RACE). The new sequence was used to design specific primers to obtain the complete cDNA sequence by 5'-RACE. The 835-nucleotide cDNA sequence encodes a glycine-proline-rich protein containing 163 amino acids with a molecular mass of 15.5 kDa; 4.3% of its amino acids is represented by cysteine, 4.9% by tyrosine, 8.0% by proline, and 29.4% by glycine. Tyrosine is linked to glycine, and proline is present mainly in the central region of the protein. Repeated glycine-glycine-X and glycine-X amino acid sequences are localized near the N-amino and C-terminal regions. The protein has the central amino acid region similar to that of claw-feather, whereas the head and tail regions are similar to glycine-tyrosine-rich proteins of mammalian hairs. In situ hybridization analysis at light and electron microscope reveals that the corresponding mRNA is expressed in cells of the differentiating beta-layers of the regenerating scales. The synthesis of beta-keratin from its mRNA occurs among ribosomes or is associated with the surface of beta-keratin filaments.

  1. Binding Interactions of Keratin-Based Hair Fiber Extract to Gold, Keratin, and BMP-2

    PubMed Central

    de Guzman, Roche C.; Tsuda, Shanel M.; Ton, Minh-Thi N.; Zhang, Xiao; Esker, Alan R.; Van Dyke, Mark E.

    2015-01-01

    Hair-derived keratin biomaterials composed mostly of reduced keratin proteins (kerateines) have demonstrated their utility as carriers of biologics and drugs for tissue engineering. Electrostatic forces between negatively-charged keratins and biologic macromolecules allow for effective drug retention; attraction to positively-charged growth factors like bone morphogenetic protein 2 (BMP-2) has been used as a strategy for osteoinduction. In this study, the intermolecular surface and bulk interaction properties of kerateines were investigated. Thiol-rich kerateines were chemisorbed onto gold substrates to form an irreversible 2-nm rigid layer for surface plasmon resonance analysis. Kerateine-to-kerateine cohesion was observed in pH-neutral water with an equilibrium dissociation constant (KD) of 1.8 × 10−4 M, indicating that non-coulombic attractive forces (i.e. hydrophobic and van der Waals) were at work. The association of BMP-2 to kerateine was found to be greater (KD = 1.1 × 10−7 M), within the range of specific binding. Addition of salts (phosphate-buffered saline; PBS) shortened the Debye length or the electrostatic field influence which weakened the kerateine-BMP-2 binding (KD = 3.2 × 10−5 M). BMP-2 in bulk kerateine gels provided a limited release in PBS (~ 10% dissociation in 4 weeks), suggesting that electrostatic intermolecular attraction was significant to retain BMP-2 within the keratin matrix. Complete dissociation between kerateine and BMP-2 occurred when the PBS pH was lowered (to 4.5), below the keratin isoelectric point of 5.3. This phenomenon can be attributed to the protonation of keratin at a lower pH, leading to positive-positive repulsion. Therefore, the dynamics of kerateine-BMP-2 binding is highly dependent on pH and salt concentration, as well as on BMP-2 solubility at different pH and molarity. The study findings may contribute to our understanding of the release kinetics of drugs from keratin biomaterials and allow for the

  2. Microrheology of keratin networks in cancer cells

    NASA Astrophysics Data System (ADS)

    Paust, T.; Paschke, S.; Beil, M.; Marti, O.

    2013-12-01

    Microrheology is a valuable tool to determine viscoelastic properties of polymer networks. For this purpose measurements with embedded tracer beads inside the extracted network of pancreatic cancer cells were performed. Observing the beads motion with a CCD-high-speed-camera leads to the dynamic shear modulus. The complex shear modulus is divided into real and imaginary parts which give insight into the mechanical properties of the cell. The dependency on the distance of the embedded beads to the rim of the nucleus shows a tendency for a deceasing storage modulus. We draw conclusions on the network topology of the keratin network types based on the mechanical behavior.

  3. Engineering stem cells into organs: Topobiological transformations demonstrated by beak, feather and other ectodermal organ morphogenesis

    PubMed Central

    Chuong, Cheng-Ming; Wu, Ping; Plikus, Maksim; Jiang, Ting-Xin; Widelitz, Randall Bruce

    2015-01-01

    To accomplish regenerative medicine, several critical issues in stem cell biology have to be solved, including the identification of sources, expanding populations, building them into organs, and assimilating them to the host. While many stem cells can now differentiate along certain lineages, knowledge on how to use them to build organs lags behind. Here we focus on topobiological events that bridge this gap, i.e., the regulation of number, size, axis, shape, arrangement, and architecture during organogenesis. Rather than reviewing detailed molecular pathways known to disrupt organogenesis when perturbed, we highlight conceptual questions at the topobiological level, and ask how cellular and molecular mechanisms can work to explain these phenomena. The avian integument is used as the Rosetta stone because the molecular activities are linked to organ forms which are visually apparent and have functional consequences during evolution as shown by the fossil record and extant diversity. For example, we show that feather pattern formation is the equilibrium of stochastic interactions among multiple activators and inhibitors. While morphogens and receptors are coded by the genome, the result is based on the summed physical-chemical properties on the whole cell surface and is self-organizing. For another example, we show developing chicken and duck beaks contain differently configured localized growth zones (LoGZ) and can modulate chicken beaks to phenocopy diverse avian beaks in Nature by altering the position, number, size, and duration of LoGZs. Different organs have their unique topology and we also discuss shaping mechanisms of the liver and different ways of branching morphogenesis. Multi-primordia organs (e.g., feathers, hairs, teeth) have additional topographic specificities across the body surface, an appendage field, or within an appendage. Promises and problems in reconstituted feather / hair follicles and other organs are discussed. Finally, simple

  4. A Numerical Study of Feathering Instability

    NASA Astrophysics Data System (ADS)

    Lee, Wing-Kit; Wang, Hsiang-Hsu

    2016-06-01

    The stability of a spiral shock of self-gravitating, magnetized interstellar medium is studied by performing two-dimensional numerical simulations of a local patch of tight-winding spiral arm. As previously suggested by the linear studies, two types of instabilities are identified, namely, wiggle instability and feathering instability. The former instability occurs in the hydrodynamics limit and results in short wavelength perturbations. On the other hand, the feathering instability requires both self-gravitating and magnetic fields and results in wider structures.

  5. Keratins mediate localization of hemidesmosomes and repress cell motility.

    PubMed

    Seltmann, Kristin; Roth, Wera; Kröger, Cornelia; Loschke, Fanny; Lederer, Marcell; Hüttelmaier, Stefan; Magin, Thomas M

    2013-01-01

    The keratin (K)-hemidesmosome (HD) interaction is crucial for cell-matrix adhesion and migration in several epithelia, including the epidermis. Mutations in constituent proteins cause severe blistering skin disorders by disrupting the adhesion complex. Despite extensive studies, the role of keratins in HD assembly and maintenance is only partially understood. Here we address this issue in keratinocytes in which all keratins are depleted by genome engineering. Unexpectedly, such keratinocytes maintain many characteristics of their normal counterparts. However, the absence of the entire keratin cytoskeleton leads to loss of plectin from the hemidesmosomal plaque and scattering of the HD transmembrane core along the basement membrane zone. To investigate the functional consequences, we performed migration and adhesion assays. These revealed that, in the absence of keratins, keratinocytes adhere much faster to extracellular matrix substrates and migrate approximately two times faster compared with wild-type cells. Reexpression of the single keratin pair K5 and K14 fully reversed the above phenotype. Our data uncover a role of keratins, which to our knowledge is previously unreported, in the maintenance of HDs upstream of plectin, with implications for epidermal homeostasis and pathogenesis. They support the view that the downregulation of keratins observed during epithelial-mesenchymal transition supports the migratory and invasive behavior of tumor cells.

  6. Keratins mediate localization of hemidesmosomes and repress cell motility

    PubMed Central

    Seltmann, Kristin; Roth, Wera; Loschke, Fanny; Lederer, Marcell; Hüttelmaier, Stefan; Magin, Thomas M.

    2013-01-01

    The keratin-hemidesmosome interaction is crucial for cell-matrix adhesion and migration in several epithelia including the epidermis. Mutations in constituent proteins cause severe blistering skin disorders by disrupting the adhesion complex. Despite extensive studies, the role of keratins in hemidesmosome assembly and maintenance is only partially understood. Here, we address this issue in keratinocytes in which all keratins are depleted by genome engineering. Unexpectedly, such keratinocytes maintain many characteristics of normal counterparts. The absence of the entire keratin cytoskeleton, however, leads to loss of plectin from the hemidesmosomal plaque and scattering of the hemidesmosome transmembrane core along the basement membrane zone. To investigate the functional consequences, we performed migration and adhesion assays. These revealed that in the absence of keratins, keratinocytes adhere much faster to ECM substrates and migrate ~2 times faster compared to wildtype cells. Re-expression of the single keratin pair K5 and K14 fully reversed the above phenotype. Our data uncover a novel role of keratins in the maintenance of hemidesmosomes upstream of plectin with implications for epidermal homeostasis and pathogenesis. They support the view that the downregulation of keratins observed during epithelial-mesenchymal transition supports the migratory and invasive behavior of tumor cells. PMID:22895363

  7. Synthesis and characterization of wool keratin/hydroxyapatite nanocomposite.

    PubMed

    Li, Jiashen; Liu, Xuan; Zhang, Jing; Zhang, Yu; Han, Yanxia; Hu, Junyan; Li, Yi

    2012-05-01

    Taking the inspiration from the biomineral, the wool keratin was selected to modulate the assembly of nanosized hydroxyapatite (HA) crystals via a coprecipitation method. A series of keratin/HA nanocomposite with different ratios were synthesized by adjusting the concentrations of keratin solutions and calcium phosphate and their final components were detected by thermogravimetric analysis (TGA). The transmission electron microscopy (TEM) and X-ray diffraction (XRD) confirmed that keratin in the composite decreased the crystallinity of HA. Fourier transform infrared (FTIR) and X-ray photoelectron spectroscopy (XPS) were used to examine the chemical and surface structure of the composites. In vitro biocompatibility results revealed that cells showed better viability on keratin/HA composites which have a ratio of organics and inorganics similar to that of natural bones.

  8. Fracture toughness design in horse hoof keratin.

    PubMed

    Bertram, J E; Gosline, J M

    1986-09-01

    An engineering fracture mechanics approach was applied to the analysis of the fracture resistance of equine hoof-wall. The relationship between fracture toughness and the morphological organization of the keratin hoof tissue was investigated. Fracture toughness was evaluated using the J-integral analysis method which employs the compact tension test geometry. Tensile tests were also conducted to evaluate the effect of the morphological organization on the stress-strain behaviour. Hoof-wall has greatest fracture resistance for cracks running proximally, parallel to the tubular component of the wall keratin. For fully hydrated material tested in this direction the mean critical J-integral value at failure was 1.19 X 10(4)J m-2. This was nearly three times greater than the value determined for the weakest orientation, in which the crack ran parallel to the material between the tubules. The lower fracture toughness of the intertubular material dominates the fracture behaviour of this tissue. The tubular components of the wall appear to reinforce against fracture along the weak plane and the entire wall organization provides the mechanical capability for limiting and controlling fracture in this tissue.

  9. Identification of shed or plucked origin of Indian peafowl (Pavo cristatus) tail feathers: preliminary findings.

    PubMed

    Sahajpal, Vivek; Goyal, S P

    2008-06-01

    Indian Peafowl (Pavo cristatus) tail covert feathers were studied to investigate the difference between shed and plucked feathers in the context of wildlife offence cases involving the killing of the Indian national bird for the purpose of plucking feathers. Plucked feathers were distinguished from shed feathers by examining their roots under low magnification of a stereoscopic microscope. A chemical test to show the presence of blood on the roots of plucked feathers was used to corroborate the plucked origin of feathers.

  10. Surface active complexes formed between keratin polypeptides and ionic surfactants.

    PubMed

    Pan, Fang; Lu, Zhiming; Tucker, Ian; Hosking, Sarah; Petkov, Jordan; Lu, Jian R

    2016-12-15

    Keratins are a group of important proteins in skin and hair and as biomaterials they can provide desirable properties such as strength, biocompatibility, and moisture regaining and retaining. The aim of this work is to develop water-soluble keratin polypeptides from sheep wool and then explore how their surface adsorption behaves with and without surfactants. Successful preparation of keratin samples was demonstrated by identification of the key components from gel electrophoresis and the reproducible production of gram scale samples with and without SDS (sodium dodecylsulphate) during wool fibre dissolution. SDS micelles could reduce the formation of disulphide bonds between keratins during extraction, reducing inter-molecular crosslinking and improving keratin polypeptide solubility. However, Zeta potential measurements of the two polypeptide batches demonstrated almost identical pH dependent surface charge distributions with isoelectric points around pH 3.5, showing complete removal of SDS during purification by dialysis. In spite of different solubility from the two batches of keratin samples prepared, very similar adsorption and aggregation behavior was revealed from surface tension measurements and dynamic light scattering. Mixing of keratin polypeptides with SDS and C12TAB (dodecyltrimethylammonium bromide) led to the formation of keratin-surfactant complexes that were substantially more effective at reducing surface tension than the polypeptides alone, showing great promise in the delivery of keratin polypeptides via the surface active complexes. Neutron reflection measurements revealed the coexistence of surfactant and keratin polypeptides at the interface, thus providing the structural support to the observed surface tension changes associated with the formation of the surface active complexes.

  11. Effects of Plectin Depletion on Keratin Network Dynamics and Organization

    PubMed Central

    Moch, Marcin; Windoffer, Reinhard; Schwarz, Nicole; Pohl, Raphaela; Omenzetter, Andreas; Schnakenberg, Uwe; Herb, Fabian; Chaisaowong, Kraisorn; Merhof, Dorit; Ramms, Lena; Fabris, Gloria; Hoffmann, Bernd; Merkel, Rudolf; Leube, Rudolf E.

    2016-01-01

    The keratin intermediate filament cytoskeleton protects epithelial cells against various types of stress and is involved in fundamental cellular processes such as signaling, differentiation and organelle trafficking. These functions rely on the cell type-specific arrangement and plasticity of the keratin system. It has been suggested that these properties are regulated by a complex cycle of assembly and disassembly. The exact mechanisms responsible for the underlying molecular processes, however, have not been clarified. Accumulating evidence implicates the cytolinker plectin in various aspects of the keratin cycle, i.e., by acting as a stabilizing anchor at hemidesmosomal adhesion sites and the nucleus, by affecting keratin bundling and branching and by linkage of keratins to actin filament and microtubule dynamics. In the present study we tested these hypotheses. To this end, plectin was downregulated by shRNA in vulvar carcinoma-derived A431 cells. As expected, integrin β4- and BPAG-1-positive hemidesmosomal structures were strongly reduced and cytosolic actin stress fibers were increased. In addition, integrins α3 and β1 were reduced. The experiments furthermore showed that loss of plectin led to a reduction in keratin filament branch length but did not alter overall mechanical properties as assessed by indentation analyses using atomic force microscopy and by displacement analyses of cytoplasmic superparamagnetic beads using magnetic tweezers. An increase in keratin movement was observed in plectin-depleted cells as was the case in control cells lacking hemidesmosome-like structures. Yet, keratin turnover was not significantly affected. We conclude that plectin alone is not needed for keratin assembly and disassembly and that other mechanisms exist to guarantee proper keratin cycling under steady state conditions in cultured single cells. PMID:27007410

  12. Selection and crossbreeding in relation to plumage color inheritance in three chinese egg type duck breeds (anas platyrhynchos).

    PubMed

    Lin, R L; Chen, H P; Rouvier, R; Poivey, J P

    2014-08-01

    could provide a solution for producing 3-way crossbred ducks Putian White×(Putian-Ma ×Shan Ma) and Putian White×(Shan Ma×Putian-Ma), with the desired Shan Ma feather color.

  13. High feather corticosterone indicates better coccidian infection resistance in greenfinches.

    PubMed

    Sild, Elin; Meitern, Richard; Männiste, Marju; Karu, Ulvi; Hõrak, Peeter

    2014-08-01

    Differential exposure or sensitivity to stressors can have substantial effects on the variation in immune responsiveness of animals. However, the questions about the causes and consequences of these processes have remained largely unclear, particularly as regards wild animals and their natural pathogens. Here we ask how a potential marker of stress responses, the feather corticosterone (CORT) content, reflects the resistance to an experimental infection with natural coccidian parasites in wild-caught captive greenfinches (Carduelis chloris). CORT content of tail feathers grown in captivity correlated positively with a behavioural measure of captivity-intolerance, i.e., the amount of damage accrued to tail feathers in captivity that results from flapping against cage bars. This finding is consistent with an idea that feather CORT reflects the amount of stress experienced during feather growth. Experimental infection with heterologous coccidian strains increased feather CORT levels. Birds with highest feather CORT levels appeared most resistant to new infection, assessed on the basis of parasite oocyst shedding at the peak phase of infection. Birds with highest feather CORT levels also cleared the infection faster than the birds with lower feather CORT levels. These findings provide the first evidence about positive covariation between feather CORT and resistance to a natural pathogen in a wild bird species. Assuming that feather CORT levels reflect circulating hormone titres, these findings suggest that parasite-mediated selection may contribute to maintenance of phenotypes with high corticosterone responsiveness to stress, despite potential negative behavioural consequences.

  14. Ultrastructural localization of hair keratins, high sulfur keratin-associated proteins and sulfhydryl oxidase in the human hair.

    PubMed

    Alibardi, Lorenzo

    2017-03-01

    Hardening of the human hair shaft during cornification results from the bonding of keratins and keratin-associated proteins. In situ hybridization and light immunocytochemical studies have shown the general distribution of different keratins and some associated proteins but not determined their ultrastructural localization. I report here the localization of hair keratins, two high-sulfur keratin-associated proteins and sulfhydryl oxidase has been studied under the transmission electron microscope in the cornification zone of the human hair. The ultrastructural study on keratin distribution in general confirms previous light microscopic studies. Sulfur-rich KAP1 is mainly cortical but the labeling disappears in fully cornified cortical cells while a diffuse labeling is also present in differentiating cuticle cells. Sulfur-rich K26 immunolocalization is only detected in the exocuticle and endocuticle. Sparse labeling for sulfhydryl oxidase occurs in differentiating cortical cells but is weak and uneven in cuticle cells and absent in medulla and inner root sheath. Labeling disappears in the upper fully cornified cortex and cuticle. The observations indicate that sulfhydryl oxidase and keratin associated proteins are initially produced in the cytoplasm among keratin bundles accumulating in cortical and cuticle cells but these proteins undergo changes during the following cornification that alter the epitopes tagged by the antibodies.

  15. Macroscopic, histologic, and ultrastructural lesions associated with avian keratin disorder in Black-capped Chickadees (Poecile atricapillus)

    USGS Publications Warehouse

    Van Hemert, C.; Armién, A. G.; Blake, J.E.; Handel, C.M.; O'Hara, T. M.

    2013-01-01

    An epizootic of beak abnormalities (avian keratin disorder) was recently detected among wild birds in Alaska. Here we describe the gross, histologic, and ultrastructural features of the disease in 30 affected adult black-capped chickadees (Poecile atricapillus). Grossly, there was elongation of the rhamphotheca, with varying degrees of lateral deviation, crossing, and gapping between the upper and lower beak. Not uncommonly, the claws were overgrown, and there was alopecia, scaling, and crusting of the skin. The most prominent histopathologic features in the beak included epidermal hyperplasia, hyperkeratosis, and core-like intrusions of necrotic debris. In affected birds, particularly those with moderate to severe beak overgrowth, there was remodeling of premaxillary and mandibular bones and various dermal lesions. Lesions analogous to those found in beaks were present in affected claws, indicating that this disorder may target both of these similar tissues. Mild to moderate hyperkeratosis occurred in other keratinized tissues, including skin, feather follicles, and, occasionally, sinus epithelium, but typically only in the presence of microbes. We did not find consistent evidence of a bacterial, fungal, or viral etiology for the beak lesions. The changes observed in affected birds did not correspond with any known avian diseases, suggesting a potentially novel hyperkeratotic disorder in wild birds.

  16. Macroscopic, Histologic, and Ultrastructural Lesions Associated with Avian Keratin Disorder in Black-capped Chickadees (Poecile atricapillus)

    PubMed Central

    Van Hemert, C.; Armién, A. G.; Blake, J. E.; Handel, C. M.; O’Hara, T. M.

    2015-01-01

    An epizootic of beak abnormalities (avian keratin disorder) was recently detected among wild birds in Alaska. Here we describe the gross, histologic, and ultrastructural features of the disease in 30 affected adult black-capped chickadees (Poecile atricapillus). Grossly, there was elongation of the rhamphotheca, with varying degrees of lateral deviation, crossing, and gapping between the upper and lower beak. Not uncommonly, the claws were overgrown and there was alopecia, scaling, and crusting of the skin. The most prominent histopathologic features in the beak included epidermal hyperplasia, hyperkeratosis, and core-like intrusions of necrotic debris. In affected birds, particularly those with moderate to severe beak overgrowth, there was remodeling of premaxillary and mandibular bones and various dermal lesions. Lesions analogous to those found in beaks were present in affected claws, indicating that this disorder may target both of these similar tissues. Mild to moderate hyperkeratosis occurred in other keratinized tissues, including skin, feather follicles, and, occasionally, sinus epithelium, but typically only in the presence of microbes. We did not find consistent evidence of a bacterial, fungal, or viral etiology for the beak lesions. The changes observed in affected birds did not correspond with any known avian diseases, suggesting a potentially novel hyperkeratotic disorder in wild birds. PMID:23399850

  17. The Weight of Iron and Feathers

    ERIC Educational Resources Information Center

    Zendri, G.; Gratton, L. M.; Oss, S.

    2014-01-01

    We discuss the popular question concerning the difference in weight between 1 kg of iron and 1 kg of feathers, by taking into account the non-trivial aspect of the semantic interpretation of "weight" and the weighting procedure. The inclusion of air buoyancy makes the correct answer an interesting one. We describe and comment on the…

  18. Scaling of Avian Primary Feather Length

    PubMed Central

    Nudds, Robert L.; Kaiser, Gary W.; Dyke, Gareth J.

    2011-01-01

    The evolution of the avian wing has long fascinated biologists, yet almost no work includes the length of primary feathers in consideration of overall wing length variation. Here we show that the length of the longest primary feather () contributing to overall wing length scales with negative allometry against total arm (ta = humerus+ulna+manus). The scaling exponent varied slightly, although not significantly so, depending on whether a species level analysis was used or phylogeny was controlled for using independent contrasts: . The scaling exponent was not significantly different from that predicted (0.86) by earlier work. It appears that there is a general trend for the primary feathers of birds to contribute proportionally less, and ta proportionally more, to overall wingspan as this dimension increases. Wingspan in birds is constrained close to mass (M1/3) because of optimisation for lift production, which limits opportunities for exterior morphological change. Within the wing, variations in underlying bone and feather lengths nevertheless may, in altering the joint positions, permit a range of different flight styles by facilitating variation in upstroke kinematics. PMID:21347413

  19. Modelling the growth of feather crystals

    SciTech Connect

    Wood, H.J.; Hunt, J.D.; Evans, P.V.

    1997-02-01

    An existing numerical model of dendritic growth has been adapted to model the growth of twinned columnar dendrites (feather crystals) in a binary aluminium alloy, Examination of the effect of dendrite tip angle on growth has led to an hypothesis regarding the stability of a pointed tip morphology in these crystals.

  20. Windmill with direction-controlled feathering

    SciTech Connect

    Weiss, H. G.

    1984-10-02

    A windmill employs a separate wind vane pivotably mounted on the chassis of the windmill. An internal sensor detects the relative angle between the wind vane and the windmill and activates the pitch-control mechanism of the windmill to feather the windmill blades whenever the angle exceeds a predetermined maximum.

  1. A New Primer for Sex Identification of Ducks and a Minimally Invasive Technique for Sampling of Allantoic Fluid to Detect Sex during Bird Embryo Development.

    PubMed

    Li, Huifang; Hu, Yan; Song, Chi; Ji, Gaige; Liu, Hongxiang; Xu, Wenjuan; Ding, Jing

    2015-01-01

    During the early incubation period of the duck, from embryonic day 1 to 13, a precise identification of the sex may be difficult. In a preliminary test, we found a defect in the use of the classical P2/P8, 1237L/1272H, and 2550F/2718R primers for chromo-helicase-DNA-binding 1 gene (CHD1) as a PCR-based test to identify sex in ducks. Therefore, universal PCR primers HPF/HPR for sexing ducks were designed. The PCR product was cloned, sequenced, and analyzed using GenBank. The effectiveness of the primers was compared using samples of blood and feathers from adult birds and chorioallantoic membranes and allantoic fluid (AF) of embryos as a source of DNA. The 495-bp CHD1-Z and the 351-bp CHD1-W PCR amplicons could be easily distinguished on a 3% agarose gel, and females (ZW) displayed 2 visible bands whereas only a single band was found in males (ZZ). The results indicated that HPF/HPR primers were highly efficient and more reliable than the classical primers used for sexing ducks. During the design of the new primers, an AF sampling technique was established to collect a very small amount of AF from free-living birds. This technique, which was minimally invasive, had no adverse effects on either embryos or the post-hatching survival of young ducks and could be used in developmental biology research in birds.

  2. Feather-pecking response of laying hens to feather and cellulose-based rations fed during rearing.

    PubMed

    Kriegseis, I; Bessei, W; Meyer, B; Zentek, J; Würbel, H; Harlander-Matauschek, A

    2012-07-01

    Recent studies in laying hens have shown that feather peckers eat more feathers than nonpeckers. We hypothesized that food pellets containing feathers would decrease the birds' appetite for feathers and thereby also decrease feather pecking. To separate the effect of feathers from that of insoluble fiber per se, additional control groups were fed pellets containing similar amounts of cellulose. Sixty (experiment 1) and 180 (experiment 2) 1-d-old Lohmann-Selected Leghorn birds were divided into 12 groups of 5 (experiment 1) and 15 (experiment 2) birds, respectively, and kept on slatted floors. During the rearing period, 4 groups each had ad libitum access to either a commercial pelleted diet, a pelleted diet containing 5% (experiment 1) or 10% (experiment 2) of chopped feathers, respectively, or a pelleted diet containing 5% (experiment 1) or 10% (experiment 2) of cellulose, respectively. In the consecutive laying period, all groups received a commercial pelleted diet. In experiment 1, feather pecking was recorded weekly from wk 5 to wk 16. In the laying period, observations were made in wk 18, 20, 22, 23, 24, 25, 26, 27, 28, and 30. In experiment 2, feather pecking was recorded weekly from wk 5 to 11, in wk 16 to wk 18, and in wk 20 and 21. At the end of the rearing period, plumage condition per individual hen was scored. Scores from 1 (denuded) to 4 (intact) were given for each of 6 body parts. The addition of 10% of feathers to the diet reduced the number of severe feather-pecking bouts (P < 0.0129) and improved plumage condition of the back area (P < 0.001) significantly compared with control diets. The relationship between feather pecking/eating and the gastrointestinal consequences thereof, which alter feather pecking-behavior, are unclear. Understanding this relationship might be crucial for understanding the causation of feather pecking in laying hens.

  3. Duck shooting injuries in Southland, New Zealand.

    PubMed

    Watts, Martin; Densie, Ian

    2013-05-10

    Duck shooting is a common sport in New Zealand. The opening weekend is anticipated and celebrated, often with significant alcohol intake which is cause for concern, and potentially very dangerous. Hunters are annually warned about the dangers. There have been few duck shooting incidents which lead to injury or death. In the last decade two duck shooters in New Zealand have been killed, while 16 suffered non fatal gunshot injuries. We present a series of injuries identified during the 2012 duck shooting season in Southland Province.

  4. Keratins Are Altered in Intestinal Disease-Related Stress Responses

    PubMed Central

    Helenius, Terhi O.; Antman, Cecilia A.; Asghar, Muhammad Nadeem; Nyström, Joel H.; Toivola, Diana M.

    2016-01-01

    Keratin (K) intermediate filaments can be divided into type I/type II proteins, which form obligate heteropolymers. Epithelial cells express type I-type II keratin pairs, and K7, K8 (type II) and K18, K19 and K20 (type I) are the primary keratins found in the single-layered intestinal epithelium. Keratins are upregulated during stress in liver, pancreas, lung, kidney and skin, however, little is known about their dynamics in the intestinal stress response. Here, keratin mRNA, protein and phosphorylation levels were studied in response to murine colonic stresses modeling human conditions, and in colorectal cancer HT29 cells. Dextran sulphate sodium (DSS)-colitis was used as a model for intestinal inflammatory stress, which elicited a strong upregulation and widened crypt distribution of K7 and K20. K8 levels were slightly downregulated in acute DSS, while stress-responsive K8 serine-74 phosphorylation (K8 pS74) was increased. By eliminating colonic microflora using antibiotics, K8 pS74 in proliferating cells was significantly increased, together with an upregulation of K8 and K19. In the aging mouse colon, most colonic keratins were upregulated. In vitro, K8, K19 and K8 pS74 levels were increased in response to lipopolysaccharide (LPS)-induced inflammation in HT29 cells. In conclusion, intestinal keratins are differentially and dynamically upregulated and post-translationally modified during stress and recovery. PMID:27626448

  5. Keratins Stabilize Hemidesmosomes through Regulation of β4-Integrin Turnover.

    PubMed

    Seltmann, Kristin; Cheng, Fang; Wiche, Gerhard; Eriksson, John E; Magin, Thomas M

    2015-06-01

    Epidermal integrity and wound healing depend on remodeling of cell-matrix contacts including hemidesmosomes. Mutations in β4-integrin and plectin lead to severe epidermolysis bullosa (EB). Whether mutations in keratins K5 or K14, which cause EB simplex, also compromise cell-matrix adhesion through altering hemidesmosomal components is not well investigated. In particular, the dependence of β4-integrin endocytosis and turnover on keratins remains incompletely understood. Here, we show that the absence of keratins causes loss of plectin-β4-integrin interaction and elevated β4-integrin phosphorylation at Ser1354 and Ser1362. This triggered a caveolin-dependent endocytosis of β4-integrin but not of other integrins through Rab5 and Rab11 compartments in keratinocytes. Expressing a phospho-deficient β4-integrin mutant reduces β4-integrin endocytosis and rescues plectin localization in keratin-free cells. β4-integrin phosphorylation in the absence of keratins resulted from elevated Erk1/2 activity downstream of increased EGFR and PKCα signaling. Further, increased Erk1/2 phosphorylation and altered plectin localization occur in keratin-deficient mouse epidermis in vivo. Strikingly, expression of the K14-R125P EBS mutant also resulted in plectin mislocalization and elevated β4-integrin turnover, suggesting disease relevance. Our data underscore a major role of keratins in controlling β4-integrin endocytosis involving a plectin-Erk1/2-dependent mechanism relevant for epidermal differentiation and pathogenesis.

  6. Keratin cytoskeletons in epithelial cells of internal organs

    PubMed Central

    Sun, Tung-Tien; Shih, Chiaho; Green, Howard

    1979-01-01

    An antiserum against human epidermal keratins was used to detect keratins in frozen sections of various rabbit and human tissues by indirect immunofluorescence. Strong staining was observed in all stratified squamous epithelia (epidermis, cornea, conjunctiva, tongue, esophagus, vagina, and anus), in epidermal appendages (hair follicle, sebaceous gland, ductal and myoepithelial cells of sweat glands), as well as in Hassall's corpuscles of the thymus, indicating that all contain abundant keratins. No staining by the antiserum was observed in fibroblasts, muscle of any type, cartilage, blood vessel, nerve tissue, iris or lens epithelium, or the glomerular or tubular cells of the kidney. In contrast, the antiserum stained the cells of most epithelia of the intestinal tract, urinary tract (urethra, bladder, ureter, collecting ducts of kidney), female genital tract (cervix, cervical glands, uterus, and oviduct), and respiratory tract (trachea and bronchi). Epithelial cells of the fine ductal system in the pancreas and submaxillary gland also stained well. When primary cultures of epithelial cells derived from bladder, intestine, kidney, and trachea were grown on glass coverslips and stained with anti-keratin, fiber networks similar to those of cultured keratinocytes were observed. These results show that keratins constitute a cytoskeleton in epithelial cells of diverse morphology and embryological origin. The stability of keratin filaments probably confers the structural strength necessary for cells covering a free surface. Keratin staining can be used to obtain information about the origin of cell lines. Images PMID:111242

  7. Expressed miRNAs target feather related mRNAs involved in cell signaling, cell adhesion and structure during chicken epidermal development.

    PubMed

    Bao, Weier; Greenwold, Matthew J; Sawyer, Roger H

    2016-10-15

    MicroRNAs (miRNAs) are small non-coding RNAs that regulate gene expression at the post-transcriptional level. Previous studies have shown that miRNA regulation contributes to a diverse set of processes including cellular differentiation and morphogenesis which leads to the creation of different cell types in multicellular organisms and is thus key to animal development. Feathers are one of the most distinctive features of extant birds and are important for multiple functions including flight, thermal regulation, and sexual selection. However, the role of miRNAs in feather development has been woefully understudied despite the identification of cell signaling pathways, cell adhesion molecules and structural genes involved in feather development. In this study, we performed a microarray experiment comparing the expression of miRNAs and mRNAs among three embryonic stages of development and two tissues (scutate scale and feather) of the chicken. We combined this expression data with miRNA target prediction tools and a curated list of feather related genes to produce a set of 19 miRNA-mRNA duplexes. These targeted mRNAs have been previously identified as important cell signaling and cell adhesion genes as well as structural genes involved in feather and scale morphogenesis. Interestingly, the miRNA target site of the cell signaling pathway gene, Aldehyde Dehydrogenase 1 Family, Member A3 (ALDH1A3), is unique to birds indicating a novel role in Aves. The identified miRNA target site of the cell adhesion gene, Tenascin C (TNC), is only found in specific chicken TNC splice variants that are differentially expressed in developing scutate scale and feather tissue indicating an important role of miRNA regulation in epidermal differentiation. Additionally, we found that β-keratins, a major structural component of avian and reptilian epidermal appendages, are targeted by multiple miRNA genes. In conclusion, our work provides quantitative expression data on miRNAs and m

  8. Structural resonance and mode of flutter of hummingbird tail feathers.

    PubMed

    Clark, Christopher J; Elias, Damian O; Girard, Madeline B; Prum, Richard O

    2013-09-15

    Feathers can produce sound by fluttering in airflow. This flutter is hypothesized to be aeroelastic, arising from the coupling of aerodynamic forces to one or more of the feather's intrinsic structural resonance frequencies. We investigated how mode of flutter varied among a sample of hummingbird tail feathers tested in a wind tunnel. Feather vibration was measured directly at ~100 points across the surface of the feather with a scanning laser Doppler vibrometer (SLDV), as a function of airspeed, Uair. Most feathers exhibited multiple discrete modes of flutter, which we classified into types including tip, trailing vane and torsional modes. Vibratory behavior within a given mode was usually stable, but changes in independent variables such as airspeed or orientation sometimes caused feathers to abruptly 'jump' from one mode to another. We measured structural resonance frequencies and mode shapes directly by measuring the free response of 64 feathers stimulated with a shaker and recorded with the SLDV. As predicted by the aeroelastic flutter hypothesis, the mode shape (spatial distribution) of flutter corresponded to a bending or torsional structural resonance frequency of the feather. However, the match between structural resonance mode and flutter mode was better for tip or torsional mode shapes, and poorer for trailing vane modes. Often, the 3rd bending structural harmonic matched the expressed mode of flutter, rather than the fundamental. We conclude that flutter occurs when airflow excites one or more structural resonance frequencies of a feather, most akin to a vibrating violin string.

  9. Spectroscopic analysis of keratin endogenous signal for skin multiphoton microscopy

    NASA Astrophysics Data System (ADS)

    Pena, A.-M.; Strupler, M.; Boulesteix, T.; Schanne-Klein, M.-C.

    2005-08-01

    We recorded one-photon excited fluorescence (1PEF) and two-photon excited fluorescence (2PEF) spectra of purified keratin from human epidermis, and determined the action cross section of this endogenous chromophore. We used this spectroscopic analysis to analyse multiphoton images of skin biopsies and assign the intrinsic fluorescence signals in the epidermis. We observed a good agreement between in situ and in vitro 2PEF spectra of keratin. This study provides a comprehensive characterization of the 2PEF signal of the keratins from the epidermis, and will be of practical interest for multiphoton imaging of the skin.

  10. Hydrodynamic drag of diving birds: effects of body size, body shape and feathers at steady speeds.

    PubMed

    Lovvorn, J; Liggins, G A; Borstad, M H; Calisal, S M; Mikkelsen, J

    2001-05-01

    For birds diving to depths where pressure has mostly reduced the buoyancy of air spaces, hydrodynamic drag is the main mechanical cost of steady swimming. Drag is strongly affected by body size and shape, so such differences among species should affect energy costs. Because flow around the body is complicated by the roughness and vibration of feathers, feathers must be considered in evaluating the effects of size and shape on drag. We investigated the effects of size, shape and feathers on the drag of avian divers ranging from wing-propelled auklets weighing 75 g to foot-propelled eiders weighing up to 2060 g. Laser scanning of body surfaces yielded digitized shapes that were averaged over several specimens per species and then used by a milling machine to cut foam models. These models were fitted with casts of the bill area, and their drag was compared with that of frozen specimens. Because of the roughness and vibration of the feathers, the drag of the frozen birds was 2-6 times that of the models. Plots of drag coefficient (C(D)) versus Reynolds number (Re) differed between the model and the frozen birds, with the pattern of difference varying with body shape. Thus, the drag of cast models or similar featherless shapes can differ both quantitatively and qualitatively from that of real birds. On the basis of a new towing method with no posts or stings that alter flow or angles of attack, the dimensionless C(D)/Re curves differed among a size gradient of five auklet species (75-100g) with similar shapes. Thus, extrapolation of C(D)/Re curves among related species must be performed with caution. At lower speeds, the C(D) at a given Re was generally higher for long-necked birds that swim with their neck extended (cormorants, grebes, some ducks) than for birds that swim with their head retracted (penguins, alcids), but this trend was reversed at high speeds. Because swimming birds actually travel at a range of instantaneous speeds during oscillatory strokes, species

  11. Blood parasites of wood ducks

    USGS Publications Warehouse

    Herman, C.M.; Knisley, J.O.; Knipling, G.D.

    1971-01-01

    Examination of blood films from wood ducks (Aix sponsa) from several northeastern states revealed Haemoproteus, Leucocytozoon, Plasmodium and a typanosome. Haemoproteus occurred in all areas sampled and birds of the year from Massachusetts demonstrated the highest incidence during the last 2 weeks in August. Leucocytozoon was most prevalent in more northern areas. P. circumflexum and a trypanosome are reported for the first time from this host.

  12. Hybridization between white-headed ducks and introduced ruddy ducks in Spain.

    PubMed

    Muñoz-Fuentes, V; Vilà, C; Green, A J; Negro, J J; Sorenson, M D

    2007-02-01

    The ruddy duck, Oxyura jamaicensis, was introduced to Great Britain in the mid-20th century and has recently spread to other Western European countries. In Spain, ruddy ducks hybridize with the globally endangered white-headed duck, Oxyura leucocephala. We assessed the effects of hybridization on the Spanish white-headed ducks, which constitute 25% of the global population of this species, using a panel of eight nuclear intron markers, 10 microsatellite loci, and mtDNA control region sequences. These data allowed parental individuals, F(1) hybrids, and the progeny of backcrossing to be reliably distinguished. We show that hybrids between the two species are fertile and produce viable offspring in backcrosses with both parental species. To date, however, we found no extensive introgression of ruddy duck genes into the Spanish white-headed duck population, probably due to the early implementation of an effective ruddy duck and hybrid control programme. We also show that genetic diversity in the expanding European ruddy duck population, which was founded by just seven individuals, exceeds that of the native Spanish white-headed duck population, which recently recovered from a severe bottleneck. Unless effective control of ruddy ducks is continued, genetic introgression will compromise the unique behavioural and ecological adaptations of white-headed ducks and consequently their survival as a genetically and evolutionary distinct species.

  13. Survival and reproductive success of black ducks fed methyl mercury

    USGS Publications Warehouse

    Finley, M.T.; Stendell, R.C.

    1978-01-01

    A diet containing 3 ppm mercury was fed to black ducks (Anas rubripes) for periods of 28 weeks during two consecutive breeding seasons. Clutch size, egg production, number of eggs incubated, hatchability and survival of ducklings were lower during both years in hens fed mercury. Reduced hatchability and poor duckling survival were the most harmful effects. During 2 years, 13 pairs of breeders fed mercury produced only 16 ducklings that survived 1 week compared with 73 ducklings from 13 pairs of controls. Mercury residues in eggs, embryos and ducklings averaged about 30% lower during the second breeding season compared with first year results. Third eggs laid by treated hens contained a mean of 6?14 and 3?86 ppm mercury during the first and second years. Whole embryos that failed to hatch contained means of 9?62 and 6?08 ppm mercury during the first and second years. Brains of dead ducklings contained between 3?25 and 6?98 ppm mercury and exhibited lesions characteristic of mercury poisoning. Relative tissue mercury levels for treated adult breeders were: feathers > liver > kidney > breast muscle > brain. Mercury levels in males and females did not differ.

  14. A feather disease in Senegal doves (Streptopelia senegalensis) morphologically similar to psittacine beak and feather disease.

    PubMed

    Raidal, S R; Riddoch, P A

    1997-01-01

    The pathogenesis and epidemiology of a feather disease in wild Senegal doves (Streptopelia senegalensis) which is morphologically similar to psittacine beak and feather disease (PBFD) was investigated. Although the lesions in doves resembled PBFD there was little evidence for the presence of psittacine circovirus (PsCV). Haemagglutination activity (HA) using type A galah (Eolophus roseicapillus) erythro-cytes was not detected in feathers or livers of affected doves as would occur in PBFD. Low concentrations of HA excreted in the faeces of affected doves was not caused by psittacine circovirus (PsCV) because the antigen in faeces also caused haemagglutination of PsCV-insensitive type B galah erythrocyte and was not inhibited by anti-PsCV antibody. Similar HA of unknown cause was also detected in faeces from clinically normal Senegal doves. Anti-PsCV haemagglutination inhibiting (HI) antibody was not detected in the serum of affected doves or in the blood of 206 clinically normal wild Senegal doves or 17 captive columbid birds in close contact with a flock of psittacine birds that was known to be PsCV-infected. Senegal doves also failed to seroconvert after two inoculations with PsCV purified from the feathers of a PBFD-affected long-billed corella (Cacatua tenuirostris). The results indicate that the feather disease seen in feral Senegal doves in Perth is not due to PsCV although the possibility that it is due to another antigenically distinct circovirus was not eliminated.

  15. Effect of age on the pathogenesis of duck tembusu virus in Cherry Valley ducks.

    PubMed

    Li, Ning; Lv, Chuanwei; Yue, Ruichao; Shi, Ying; Wei, Liangmeng; Chai, Tongjie; Liu, Sidang

    2015-01-01

    The effect of host age on the outcome of duck tembusu virus (DTMUV) infection was studied in ducks. Three groups of Cherry Valley ducks at 1, 3, and 7 weeks of age were intramuscularly infected with DTMUV to systematically observe the clinical symptoms, pathological changes, tissue viral loads, and immune responses. Severe clinical symptoms and neurological dysfunction were observed in 1-week-old ducks as early as 2 days post infection (dpi) and some died at 5-7 dpi. Three weeks-old ducks showed similar but milder symptoms and no deaths. However, 7-weeks-old ducks showed only transient loss of appetite. Gross lesions gradually reduced in severity as ducks matured. One-week-old ducks showed endocardial hemorrhage, splenomegaly, swelling in the lymph follicles of the ileum, liver, and kidney swelling with degeneration, and meningeal hyperemia. Three-weeks-old ducks showed only mild pathological lesions. No visible lesions were observed in 7-weeks-old ducks. However, pathological histology analysis demonstrated all infected ducks displayed viral encephalitis. DTMUV could be detected in the brains of 1-week-old ducks as early as 1 dpi and virus titers of most organs in 1-week-old ducks were significantly higher than that of 3- and 7-weeks-old ducks at 3-5 dpi. The patterns of IFN-γ, IL-2, and serum neutralizing antibodies were similar, and there were significant difference between the youngest ducks and the older ducks at early infection stage (P < 0.05). More important is that although the antibody titers of all infected ducks were similar from 9 to 17 dpi, reduced clearance of virus was observed in the youngest groups comparing with the other two groups, indicating that immune system maturity was more important than the presence of neutralizing antibody. In summary, this study demonstrates that viral pathogenesis is strongest in 1-week-old ducks and the age-related immune response plays an important role in the pathogenesis of DTMUV in ducks.

  16. Selection and Crossbreeding in Relation to Plumage Color Inheritance in Three Chinese Egg Type Duck Breeds (Anas Platyrhynchos)

    PubMed Central

    Lin, R. L.; Chen, H. P.; Rouvier, R.; Poivey, J. P.

    2014-01-01

    could provide a solution for producing 3-way crossbred ducks Putian White×(Putian-Ma ×Shan Ma) and Putian White×(Shan Ma×Putian-Ma), with the desired Shan Ma feather color. PMID:25083099

  17. Outer root sheath keratinization in anagen and catagen of the mammalian hair follicle. A seventh distinct type of keratinization in the hair follicle: trichilemmal keratinization.

    PubMed

    Pinkus, H; Iwasaki, T; Mishima, Y

    1981-08-01

    Trichilemmal keratinization, first described in Maurer in 1895 and rediscovered by Holmes (1968) and Pinkus (1968) converts the stratified epithelium of the outer root sheath into anuclear keratin without an intervening keratohyalin layer. It is a distinct seventh type of keratinization in the hair follicle, not derived from the hair matrix. It occurs wherever outer root sheath is not apposed to inner root sheath, in anagen in the zone of sloughing just below the opening of the sebaceous duct, in catagen in the trichilemmal sac surrounding the lower end of the dying hair shaft where it forms the club of the telogen hair. Electron microscopic study of the thick hairs of dogs (but not the tiny hairs of rodents) reveals intricate infoldings of non-keratinized and keratinized cells. It also shows unique ladder-like membrane coating granules in anagen, which are strongly acid phosphatase-positive and are suggested to be the source of enzyme involved with disintegration of the inner root sheath.

  18. Mercury levels in feathers of Magellanic penguins.

    PubMed

    Frias, Jorgelina E; Gil, Mónica N; Esteves, José L; García Borboroglu, Pablo; Kane, Olivia J; Smith, Jeff R; Boersma, P Dee

    2012-06-01

    Feathers are useful to determine mercury (Hg) contamination. We evaluated the mercury concentration in feathers of Magellanic penguins (Spheniscus magellanicus) age 1.5 years to 25 years at Punta Tombo, Argentina before and during their molt. Mercury ranged between <1.4 and 367 ng/g dry weight, with three extreme high values (8996 ng/g, 3011 ng/g and 1340 ng/g) all in young adults. The median concentration was lowest for juveniles and significantly higher for adults but with high variation among older adults. Males and females had similar mercury loads. Compared with other penguin species, concentrations in Magellanic penguins were low. Mercury levels for Magellanic penguins in the Southwest Atlantic for older adults averaged 206±98 ng/g, and serve as a baseline for biomonitoring and/or ecotoxicological studies.

  19. "Panta rhei": Perpetual cycling of the keratin cytoskeleton.

    PubMed

    Leube, Rudolf E; Moch, Marcin; Kölsch, Anne; Windoffer, Reinhard

    2011-01-01

    The filamentous cytoskeletal systems fulfil seemingly incompatible functions by maintaining a stable scaffolding to ensure tissue integrity and simultaneously facilitating rapid adaptation to intracellular processes and environmental stimuli. This paradox is particularly obvious for the abundant keratin intermediate filaments in epithelial tissues. The epidermal keratin cytoskeleton, for example, supports the protective and selective barrier function of the skin while enabling rapid growth and remodelling in response to physical, chemical and microbial challenges. We propose that these dynamic properties are linked to the perpetual re-cycling of keratin intermediate filaments that we observe in cultured cells. This cycle of assembly and disassembly is independent of protein biosynthesis and consists of distinct, temporally and spatially defined steps. In this way, the keratin cytoskeleton remains in constant motion but stays intact and is also able to restructure rapidly in response to specific regulatory cues as is needed, e.g., during division, differentiation and wound healing.

  20. Body molt of male long-tailed ducks in the nearshore waters of the north slope, Alaska

    USGS Publications Warehouse

    Howell, M.D.; Grand, J.B.; Flint, P.L.

    2003-01-01

    We examined the timing and intensity of body molt in relation to stage of remige growth for postbreeding adult male Long-tailed Ducks (Clangula hyemalis) off the coast of northern Alaska. During this period, remige and rectrix feathers are molted simultaneously with body feathers during the prebasic molt, which results in a period of increased energetic and nutritional demands. We collected birds from late July through mid-August and recorded intensity of molt in eight regions: head and neck, back and rump, greater coverts, lesser coverts, flank and sides, breast, belly, and tail. Using nonlinear regression, we estimated the peak intensity and variation for each region in relation to ninth primary length. We found little evidence of molt in the head and neck region. The greater and lesser coverts, and back and rump reached peak molt intensities earliest and were followed by tail, breast, and belly. Molt intensity in the flank and side region was highly variable and indicated a more prolonged molting pattern in relation to other regions. While body molt occurs simultaneously with wing molt, we found that molt among regions occurred in a staggered pattern. Long-tailed Ducks may employ this staggered molting pattern to minimize the energetic and nutritional requirements of molt.

  1. Typhlocolitis associated with spirochaetes in duck flocks.

    PubMed

    Glávits, Róbert; Ivanics, Eva; Thuma, Akos; Kaszanyitzky, Eva; Samu, Péterné; Ursu, Krisztina; Dencso, László; Dán, Adám

    2011-02-01

    The aetiology of increased mortality observed in two breeder duck flocks (Flock A consisting of 3500 laying ducks and Flock B comprising 4300 laying ducks) during the first egg-laying season was studied. In Flocks A and B, 773 ducks and 715 ducks (18.4% and 16.6%) died within a 24-week and a 20-week period, respectively. Death was preceded by clinical signs including movement difficulties, lack of appetite and depression lasting for 1 to 2 days. Diarrhoea was not observed. On gross pathological examination, the ducks were found to have haemorrhagic to fibrinonecrotic typhlocolitis, renal degeneration accompanied by fibrosis and mineralization, hepatic and splenic amyloidosis, and swelling of some of the metatarsal and phalangeal joints. Histopathological and immunohistochemical examination consistently demonstrated spirochaetes in the mucous membrane of the affected large intestine. On the basis of their cultural and biochemical properties and polymerase chain reaction sequencing analysis, four out of seven spirochaete strains isolated from the ducks (Flock A) by culture on special media under anaerobic conditions were identified as Brachyspira hyodysenteriae, and five out of eight strains (Flock B) were identified as Brachyspira pilosicoli. This is the first report on the isolation of B. hyodysenteriae and B. pilosicoli from laying ducks affected by fibrinonecrotic typhlocolitis.

  2. D.U.C.K. Walking.

    ERIC Educational Resources Information Center

    Steller, Jenifer J.

    This manual presents a schoolwide walking program that includes aerobic fitness information, curriculum integration, and walking tours. "Discover and Understand Carolina Kids by Walking" is D.U.C.K. Walking. An aerobic walking activity, D.U.C.K. Walking has two major goals: (1) to promote regular walking as a way to exercise at any age;…

  3. Blood parasites from California ducks and geese

    USGS Publications Warehouse

    Herman, C.M.

    1951-01-01

    Blood smears were procured from 1,011 geese and ducks of 19 species from various locations in California. Parasites were found in 28 individuals. The parasites observed included Haemoproteus hermani, Leucocytozoon simondi, microfilaria, Plasmodium relictum (=P. biziurae), and Plasmodium sp. with elongate gametocytes. This is the first report of a natural infection with a Plasmodium in North American wild ducks.

  4. Propeller/fan-pitch feathering apparatus

    NASA Technical Reports Server (NTRS)

    Schilling, Jan C. (Inventor); Adamson, Arthur P. (Inventor); Bathori, Julius (Inventor); Walker, Neil (Inventor)

    1990-01-01

    A pitch feathering system for a gas turbine driven aircraft propeller having multiple variable pitch blades utilizes a counter-weight linked to the blades. The weight is constrained to move, when effecting a pitch change, only in a radial plane and about an axis which rotates about the propeller axis. The system includes a linkage allowing the weight to move through a larger angle than the associated pitch change of the blade.

  5. Multicenter Clinical Trial of Keratin Biomaterials for Peripheral Nerve Regeneration

    DTIC Science & Technology

    2013-10-01

    purity (size exclusion chromatography for molecular weight, amino acids analysis, ELISA for protein identification, and gel rheology ) and 2) a cell...distribution study. Labeled keratin gel will be placed inside nerve conduits. The ends of the conduits will be closed, and the conduits will be implanted in...Marra KG. Keratin gel filler for peripheral nerve repair in a rodent sciatic nerve injury model. Plast Reconstr Surg 2012;129:67-78. Pace LA

  6. Epiplakin attenuates experimental mouse liver injury by chaperoning keratin reorganization

    PubMed Central

    Szabo, Sandra; Wögenstein, Karl L.; Österreicher, Christoph H.; Guldiken, Nurdan; Chen, Yu; Doler, Carina; Wiche, Gerhard; Boor, Peter; Haybaeck, Johannes; Strnad, Pavel; Fuchs, Peter

    2015-01-01

    Background & Aims Epiplakin is a member of the plakin protein family and exclusively expressed in epithelial tissues where it binds to keratins. Epiplakin-deficient (Eppk1−/−) mice displayed no obvious spontaneous phenotype, but their keratinocytes showed a faster keratin network breakdown in response to stress. The role of epiplakin in the stressed liver remained to be elucidated. Methods Wild-type (WT) and Eppk1−/− mice were subjected to common bile duct ligation (CBDL) or fed with a 3,5-diethoxycarbonyl-1,4-dihydrocollidine (DDC)-containing diet. The importance of epiplakin during keratin reorganization was assessed in primary hepatocytes. Results Our experiments revealed that epiplakin is expressed in hepatocytes and cholangiocytes, and binds to keratin 8 (K8) and K18 via multiple domains. In several liver stress models epiplakin and K8 genes displayed identical expression patterns and transgenic K8 overexpression resulted in elevated hepatic epiplakin levels. After CBDL and DDC treatment, Eppk1−/− mice developed a more pronounced liver injury and their livers contained larger amounts of hepatocellular keratin granules, indicating impaired disease-induced keratin network reorganization. In line with these findings, primary Eppk1−/− hepatocytes showed increased formation of keratin aggregates after treatment with the phosphatase inhibitor okadaic acid, a phenotype which was rescued by the chemical chaperone trimethylamine N-oxide (TMAO). Finally, transfection experiments revealed that Eppk1−/− primary hepatocytes were less able to tolerate forced K8 overexpression and that TMAO treatment rescued this phenotype. Conclusion Our data indicate that epiplakin plays a protective role during experimental liver injuries by chaperoning disease-induced keratin reorganization. PMID:25617501

  7. Water in keratin. Piezoelectric, dielectric, and elastic experiments.

    PubMed Central

    Maeda, H

    1989-01-01

    To investigate actions of water in keratin, the piezoelectric, dielectric, and elastic constants are measured at 10 Hz, at temperatures between -160 and 150 degrees C, and at various hydration levels. From changes in the piezoelectric, dielectric, and dynamic mechanical parameters with moisture content (m.c.), we have identified three regimes (I, II, and III) in the hydration of water for keratin. At high hydration (21% m.c.) around 0 degree C, the piezoelectric constants for keratin steeply decrease with increasing temperature. This may be attributed to interfacial polarization which is strongly related to self-associated water molecules (particularly regime III water) just around crystalline helical regions which can exhibit the stress-induced, i.e., piezoelectric, polarization and may be attributed to electrode polarization induced by the increase of mobile ions in the amorphous matrix region, some of which would be released from their trapped states just around the piezoelectric phase by the regime III water. With increasing hydration, the elastic constants for keratin are found to increase below -70 degrees C and decrease above -70 degrees C. This suggests a viscoelastic transition of the keratin structure due to bound water (regime II water). The piezoelectric, dielectric, and elastic loss peaks are found at around -120 degrees C for hydrated keratin, believed to be due to tightly bound water (regime I water), which acts only to stiffen the keratin structure. The adsorption regions of water in keratin are discussed by a piezoelectric two-phase model, which consists of piezoelectric and nonpiezoelectric phases. It is proposed that water molecule would at least adsorb in the nonpiezoelectric phase. PMID:2481512

  8. From feathers to syngas - technologies and devices.

    PubMed

    Dudyński, Marek; Kwiatkowski, Kamil; Bajer, Konrad

    2012-04-01

    The poultry waste produced by industrial slaughterhouses typically contains not only feathers, but also a mixture of animal entrails, nails, blood, beaks and whole carcasses. Economical utilisation of this mixture, varying strongly in composition and moisture content, is, in general, difficult. We demonstrate that this awkward material can be successfully used for gasification in a simple, fixed-bed gasifier. The method of gasification, which we developed, enables control of the gasification process and ensures its stability in the operational regime of a working poultry processing plant. The installation, which has been working in Poland for 2 years, utilises 2 tons of feathers per hour and produces syngas of stable composition and fairly high quality. The syngas is burnt in the combustion chamber adjacent to the gasifier. Heat is recuperated in a boiler producing 3.5 tons per hour of technological steam continuously used for the operation of the slaughterhouse. The whole process complies with the stringent emission standards. In the paper we present the end-use device for feather utilisation and describe the underlying gasification and syngas combustion processes. Key elements of the whole installation are briefly discussed. The environmental impacts of the installation are summarized.

  9. Synthesis of Keratin-based Nanofiber for Biomedical Engineering.

    PubMed

    Thompson, Zanshe S; Rijal, Nava P; Jarvis, David; Edwards, Angela; Bhattarai, Narayan

    2016-02-07

    Electrospinning, due to its versatility and potential for applications in various fields, is being frequently used to fabricate nanofibers. Production of these porous nanofibers is of great interest due to their unique physiochemical properties. Here we elaborate on the fabrication of keratin containing poly (ε-caprolactone) (PCL) nanofibers (i.e., PCL/keratin composite fiber). Water soluble keratin was first extracted from human hair and mixed with PCL in different ratios. The blended solution of PCL/keratin was transformed into nanofibrous membranes using a laboratory designed electrospinning set up. Fiber morphology and mechanical properties of the obtained nanofiber were observed and measured using scanning electron microscopy and tensile tester. Furthermore, degradability and chemical properties of the nanofiber were studied by FTIR. SEM images showed uniform surface morphology for PCL/keratin fibers of different compositions. These PCL/keratin fibers also showed excellent mechanical properties such as Young's modulus and failure point. Fibroblast cells were able to attach and proliferate thus proving good cell viability. Based on the characteristics discussed above, we can strongly argue that the blended nanofibers of natural and synthetic polymers can represent an excellent development of composite materials that can be used for different biomedical applications.

  10. Exceptional dinosaur fossils show ontogenetic development of early feathers.

    PubMed

    Xu, Xing; Zheng, Xiaoting; You, Hailu

    2010-04-29

    Recent discoveries of feathered dinosaur specimens have greatly improved our understanding of the origin and early evolution of feathers, but little information is available on the ontogenetic development of early feathers. Here we describe an early-juvenile specimen and a late-juvenile specimen, both referable to the oviraptorosaur Similicaudipteryx, recovered from the Lower Cretaceous Yixian Formation of western Liaoning, China. The two specimens have strikingly different remiges and rectrices, suggesting that a radical morphological change occurred during feather development, as is the case for modern feathers. However, both the remiges and the rectrices are proximally ribbon-like in the younger specimen but fully pennaceous in the older specimen, a pattern not known in any modern bird. In combination with the wide distribution of proximally ribbon-like pennaceous feathers and elongate broad filamentous feathers among extinct theropods, this find suggests that early feathers were developmentally more diverse than modern ones and that some developmental features, and the resultant morphotypes, have been lost in feather evolution.

  11. Global associations between birds and vane-dwelling feather mites.

    PubMed

    Doña, Jorge; Proctor, Heather; Mironov, Sergey; Serrano, David; Jovani, Roger

    2016-11-01

    Understanding host-symbiont networks is a major question in evolutionary ecology. Birds host a great diversity of endo- and ectosymbiotic organisms, with feather mites (Arachnida: Acariformes: Analgoidea, Pterolichoidea) being among the most diverse of avian symbionts. A global approach to the ecology and evolution of bird-feather-mite associations has been hampered because of the absence of a centralized data repository. Here we present the most extensive data set of associations between feather mites and birds. Data include 12 036 records of 1887 feather mite species located on the flight feathers of 2234 bird species from 147 countries. Feather mites typically located inside quills, on the skin, or on downy body feathers are not included. Data were extracted from 493 published sources dating from 1882 to 2015. Data exploration shows that although most continents and bird families are represented, most bird species remain unexplored for feather mites. Nevertheless, this is the most comprehensive data set available for enabling global macroecological analyses of feather mites and their hosts, such as ecological network analyses. This metadata file outlines the structure of these data and provides primary references for all records used.

  12. Primitive wing feather arrangement in Archaeopteryx lithographica and Anchiornis huxleyi.

    PubMed

    Longrich, Nicholas R; Vinther, Jakob; Meng, Qingjin; Li, Quangguo; Russell, Anthony P

    2012-12-04

    In modern birds (Neornithes), the wing is composed of a layer of long, asymmetrical flight feathers overlain by short covert feathers. It has generally been assumed that wing feathers in the Jurassic bird Archaeopteryx and Cretaceous feathered dinosaurs had the same arrangement. Here, we redescribe the wings of the archaic bird Archaeopteryx lithographica and the dinosaur Anchiornis huxleyi and show that their wings differ from those of Neornithes in being composed of multiple layers of feathers. In Archaeopteryx, primaries are overlapped by long dorsal and ventral coverts. Anchiornis has a similar configuration but is more primitive in having short, slender, symmetrical remiges. Archaeopteryx and Anchiornis therefore appear to represent early experiments in the evolution of the wing. This primitive configuration has important functional implications: although the slender feather shafts of Archaeopteryx and Anchiornis make individual feathers weak, layering of the wing feathers may have produced a strong airfoil. Furthermore, the layered arrangement may have prevented the feathers from forming a slotted tip or separating to reduce drag on the upstroke. The wings of early birds therefore may have lacked the range of functions seen in Neornithes, limiting their flight ability.

  13. Survival and movements of molting male black ducks in Labrador

    USGS Publications Warehouse

    Bowman, T.D.; Longcore, J.R.

    1989-01-01

    We marked 26 flightless male American black ducks with transmitters during the post-nuptial molt in northern Labrabor to determine survival and movements. Twelve ducks remained in the watershed where marked and 11 ducks moved to different watersheds. The period survival rate (PSR) for these flightless males was 0.89 using the Kaplan-Meier estimator. Only 2 ducks were killed by predators. Death of these 2 ducks might have been influenced by our disturbance, thus we considered the PSR minimal.

  14. Rachis morphology cannot accurately predict the mechanical performance of primary feathers in extant (and therefore fossil) feathered flyers

    PubMed Central

    Garner, Terence; Cooper, Glen; Nudds, Robert

    2017-01-01

    It was previously suggested that the flight ability of feathered fossils could be hypothesized from the diameter of their feather rachises. Central to the idea is the unvalidated assumption that the strength of a primary flight feather (i.e. its material and structural properties) may be consistently calculated from the external diameter of the feather rachis, which is the only dimension that is likely to relate to structural properties available from fossils. Here, using three-point bending tests, the relationship between feather structural properties (maximum bending moment, Mmax and Young's modulus, Ebend) and external morphological parameters (primary feather rachis length, diameter and second moment of area at the calamus) in 180 primary feathers from four species of bird of differing flight style was investigated. Intraspecifically, both Ebend and Mmax were strongly correlated with morphology, decreasing and increasing, respectively, with all three morphological measures. Without accounting for species, however, external morphology was a poor predictor of rachis structural properties, meaning that precise determination of aerial performance in extinct, feathered species from external rachis dimensions alone is not possible. Even if it were possible to calculate the second moment of area of the rachis, our data suggest that feather strength could still not be reliably estimated. PMID:28386445

  15. A novel alkaline surfactant-stable keratinase with superior feather-degrading potential based on library screening strategy.

    PubMed

    Su, Chang; Gong, Jin-Song; Zhang, Rong-Xian; Tao, Li-Yan; Dou, Wen-Fang; Zhang, Dan-Dan; Li, Heng; Lu, Zhen-Ming; Xu, Zheng-Hong; Shi, Jin-Song

    2017-02-01

    A novel keratinase was mined and expressed in Escherichia coli BL21 (DE3) via function-driven screening with fosmid library. The catalytic properties of purified keratinase were investigated in detail following enzyme purification. The recombinant keratinase was purified to homogeneity with an estimated molecular weight of 26kDa using nickel affinity chromatography, of which the optimal reaction pH and temperature were 10.0 and 55°C, respectively. It could remain stable at pH 5.0-12.0 and 40-60°C. Metal ions such as Ca(2+), Mn(2+), Ag(+), Na(+), Mg(2+), Li(+), Sn(2+) (1mM) displayed positive influence on keratinase, and particularly, Ca(2+) exhibited remarkable improvement effect by 2.6 folds. It was strongly inhibited by PMSF as a protease inhibitor. On the contrary, it could be obviously activated by various surfactants, such as Tween 40 and Triton X-114. The recombinant keratinase showed high specificity towards casein, soluble keratin, BSA, and wool. The keratinase could efficiently degrade the feathers, which demonstrated its applicable potential for biodegradation of keratin wastes and regeneration of soluble protein.

  16. Keratins as the main component for the mechanical integrity of keratinocytes.

    PubMed

    Ramms, Lena; Fabris, Gloria; Windoffer, Reinhard; Schwarz, Nicole; Springer, Ronald; Zhou, Chen; Lazar, Jaroslav; Stiefel, Simone; Hersch, Nils; Schnakenberg, Uwe; Magin, Thomas M; Leube, Rudolf E; Merkel, Rudolf; Hoffmann, Bernd

    2013-11-12

    Keratins are major components of the epithelial cytoskeleton and are believed to play a vital role for mechanical integrity at the cellular and tissue level. Keratinocytes as the main cell type of the epidermis express a differentiation-specific set of type I and type II keratins forming a stable network and are major contributors of keratinocyte mechanical properties. However, owing to compensatory keratin expression, the overall contribution of keratins to cell mechanics was difficult to examine in vivo on deletion of single keratin genes. To overcome this problem, we used keratinocytes lacking all keratins. The mechanical properties of these cells were analyzed by atomic force microscopy (AFM) and magnetic tweezers experiments. We found a strong and highly significant softening of keratin-deficient keratinocytes when analyzed by AFM on the cell body and above the nucleus. Magnetic tweezers experiments fully confirmed these results showing, in addition, high viscous contributions to magnetic bead displacement in keratin-lacking cells. Keratin loss neither affected actin or microtubule networks nor their overall protein concentration. Furthermore, depolymerization of actin preserves cell softening in the absence of keratin. On reexpression of the sole basal epidermal keratin pair K5/14, the keratin filament network was reestablished, and mechanical properties were restored almost to WT levels in both experimental setups. The data presented here demonstrate the importance of keratin filaments for mechanical resilience of keratinocytes and indicate that expression of a single keratin pair is sufficient for almost complete reconstitution of their mechanical properties.

  17. Duck plague: carrier state and gross pathology in black ducks

    USGS Publications Warehouse

    Ossa, Jorge E.

    1975-01-01

    Duck plague (UP) is a highly fatal disease of ducks, geese, and swans (family Anatidae), produced by a reticulo-endotheliotrophic virus classified as a member of the Herpesvirus group. The disease was recognized in Europe in 1949. On the American continent, the disease was first diagnosed in the United States in 1967. Very little is known of DP virus ecology, particularly of the mechanisms of interepizootic survival and movement. The tendency of the IIerpesviruses to enter into a quiescent state after an overt or inapparent infection is a proven characteristic for most of the members of this group. Herpes simplex, which is the model of the Herpesviruses, is said to be the classical example of a persistent recurrent viral infection. Burnet and Williams (4) were the first to recognize this kind of relationship between herpes simplex and its host in 1939. Later, it was found that the reactivation of the virus can be brought on by a variety of stimuli either physiological (menstruation), pathological (anaphylactic shock), chemical (pesticides) or physical (sunburn). This same latency property has been proved for every member of this group of viruses which has been studied adequately, DP is among the few Herpesviruses for which the carrier state has not been demonstrated, but there is circumstantial evidence suggesting it. The carrier state for DP seems to be a likely explanation for the persistence and the particular pattern of movement of this disease.

  18. Avian influenza ecology in North Atlantic sea ducks: Not all ducks are created equal

    USGS Publications Warehouse

    Hall, Jeffrey S.; Russell, Robin E.; Franson, J. Christian; Soos, Catherine; Dusek, Robert J.; Allen, R. Bradford; Nashold, Sean W.; Teslaa, Joshua L.; Jónsson, Jón Einar; Ballard, Jennifer R.; Harms, Naomi Jnae; Brown, Justin D.

    2015-01-01

    Wild waterfowl are primary reservoirs of avian influenza viruses (AIV). However the role of sea ducks in the ecology of avian influenza, and how that role differs from freshwater ducks, has not been examined. We obtained and analyzed sera from North Atlantic sea ducks and determined the seroprevalence in those populations. We also tested swab samples from North Atlantic sea ducks for the presence of AIV. We found relatively high serological prevalence (61%) in these sea duck populations but low virus prevalence (0.3%). Using these data we estimated that an antibody half-life of 141 weeks (3.2 years) would be required to attain these prevalences. These findings are much different than what is known in freshwater waterfowl and have implications for surveillance efforts, AIV in marine environments, and the roles of sea ducks and other long-lived waterfowl in avian influenza ecology.

  19. Avian Influenza Ecology in North Atlantic Sea Ducks: Not All Ducks Are Created Equal

    PubMed Central

    Hall, Jeffrey S.; Russell, Robin E.; Franson, J. Christian; Soos, Catherine; Dusek, Robert J.; Allen, R. Bradford; Nashold, Sean W.; TeSlaa, Joshua L.; Jónsson, Jón Eínar; Ballard, Jennifer R.; Harms, Naomi Jane; Brown, Justin D.

    2015-01-01

    Wild waterfowl are primary reservoirs of avian influenza viruses (AIV). However the role of sea ducks in the ecology of avian influenza, and how that role differs from freshwater ducks, has not been examined. We obtained and analyzed sera from North Atlantic sea ducks and determined the seroprevalence in those populations. We also tested swab samples from North Atlantic sea ducks for the presence of AIV. We found relatively high serological prevalence (61%) in these sea duck populations but low virus prevalence (0.3%). Using these data we estimated that an antibody half-life of 141 weeks (3.2 years) would be required to attain these prevalences. These findings are much different than what is known in freshwater waterfowl and have implications for surveillance efforts, AIV in marine environments, and the roles of sea ducks and other long-lived waterfowl in avian influenza ecology. PMID:26677841

  20. Avian Influenza Ecology in North Atlantic Sea Ducks: Not All Ducks Are Created Equal.

    PubMed

    Hall, Jeffrey S; Russell, Robin E; Franson, J Christian; Soos, Catherine; Dusek, Robert J; Allen, R Bradford; Nashold, Sean W; TeSlaa, Joshua L; Jónsson, Jón Eínar; Ballard, Jennifer R; Harms, Naomi Jane; Brown, Justin D

    2015-01-01

    Wild waterfowl are primary reservoirs of avian influenza viruses (AIV). However the role of sea ducks in the ecology of avian influenza, and how that role differs from freshwater ducks, has not been examined. We obtained and analyzed sera from North Atlantic sea ducks and determined the seroprevalence in those populations. We also tested swab samples from North Atlantic sea ducks for the presence of AIV. We found relatively high serological prevalence (61%) in these sea duck populations but low virus prevalence (0.3%). Using these data we estimated that an antibody half-life of 141 weeks (3.2 years) would be required to attain these prevalences. These findings are much different than what is known in freshwater waterfowl and have implications for surveillance efforts, AIV in marine environments, and the roles of sea ducks and other long-lived waterfowl in avian influenza ecology.

  1. Exocrine pancreatic disorders in transsgenic mice expressing human keratin 8

    PubMed Central

    Casanova, M. Llanos; Bravo, Ana; Ramírez, Angel; Escobar, Gabriela Morreale de; Were, Felipe; Merlino, Glenn; Vidal, Miguel; Jorcano, José L.

    1999-01-01

    Keratins K8 and K18 are the major components of the intermediate-filament cytoskeleton of simple epithelia. Increased levels of these keratins have been correlated with various tumor cell characteristics, including progression to malignancy, invasive behavior, and drug sensitivity, although a role for K8/K18 in tumorigenesis has not yet been demonstrated. To examine the function of these keratins, we generated mice expressing the human K8 (hk8) gene, which leads to a moderate keratin-content increase in their simple epithelia. These mice displayed progressive exocrine pancreas alterations, including dysplasia and loss of acinar architecture, redifferentiation of acinar to ductal cells, inflammation, fibrosis, and substitution of exocrine by adipose tissue, as well as increased cell proliferation and apoptosis. Histological changes were not observed in other simple epithelia, such as the liver. Electron microscopy showed that transgenic acinar cells have keratins organized in abundant filament bundles dispersed throughout the cytoplasm, in contrast to control acinar cells, which have scarce and apically concentrated filaments. The phenotype found was very similar to that reported for transgenic mice expressing a dominant-negative mutant TGF-β type II receptor (TGFβRII mice). We show that these TGFβRII mutant mice also have elevated K8/K18 levels. These results indicate that simple epithelial keratins play a relevant role in the regulation of exocrine pancreas homeostasis and support the idea that disruption of mechanisms that normally regulate keratin expression in vivo could be related to inflammatory and neoplastic pancreatic disorders. PMID:10359568

  2. Keratins as components of the enamel organic matrix.

    PubMed

    Duverger, Olivier; Beniash, Elia; Morasso, Maria I

    2016-01-01

    Dental enamel is the hardest tissue in the human body, and although it starts as a tissue rich in proteins, by the time of eruption of the tooth in the oral cavity only a small fraction of the protein remains. While this organic matrix of enamel represents less than 1% by weight it plays essential roles in improving both toughness and resilience to chemical attacks. Despite the fact that the first studies of the enamel matrix began in the 19th century, its exact composition and mechanisms of its function remain poorly understood. It was proposed that keratin or a keratin-like primitive epithelial component exists in mature enamel, however due to the extreme insolubility of its organic matrix the presence of keratins there was never clearly established. We have recently identified expression of a number of hair keratins in ameloblasts, the enamel secreting cells, and demonstrated their incorporation into mature enamel. Mutation in epithelial hair keratin KRT75 leads to a skin condition called pseudofollicularis barbae. Carriers of this mutation have an altered enamel structure and mechanical properties. Importantly, these individuals have a much higher prevalence of caries. To the best of our knowledge, this is the first study showing a direct link between a mutation in a protein-coding region of a gene and increased caries rates. In this paper we present an overview of the evidence of keratin-like material in enamel that has accumulated over the last 150years. Furthermore, we propose potential mechanisms of action of KTR75 in enamel and highlight the clinical implications of the link between mutations in KRT75 and caries. Finally, we discuss the potential use of keratins for enamel repair.

  3. Habitats of North American sea ducks.

    USGS Publications Warehouse

    Derksen, Dirk V.; Petersen, Margaret R.; Savard, Jean-Pierre L.

    2015-01-01

    Breeding, molting, fall and spring staging, and wintering habitats of the sea duck tribe Mergini are described based on geographic locations and distribution in North America, geomorphology, vegetation and soil types, and fresh water and marine characteristics. The dynamics of habitats are discussed in light of natural and anthropogenic events that shape areas important to sea ducks. Strategies for sea duck habitat management are outlined and recommendations for international collaboration to preserve key terrestrial and aquatic habitats are advanced. We follow the definition of habitat advanced by Odum (1971), which is the place or space where an organism lives. Weller (1999) emphasized that habitats for waterbirds required presence of sufficient resources (i.e., food, water, cover, space) for maintenance during a portion of their annual cycle. Habitats exploited by North American sea ducks are diverse, widespread across the continent and adjacent marine waters and until recently, most were only superficially known. Even following a 15-year-long effort through the Sea Duck Joint Venture and U.S. and Canadian Endangered/Threatened Species programs to fund research focused on sea duck habitats there are still important gaps in our understanding of key elements required by some species during various life stages. Importantly, many significant habitats, especially staging and wintering sites, have been and continue to be destroyed or altered, largely as a result of anthropogenic effects. Our goal here is to develop a comprehensive summary of marine, freshwater, and terrestrial habitats and their characteristics by considering sea duck species with similar needs as groups (e.g., eiders) within the tribe Mergini. Additionally, this chapter will examine threats and changes to sea duck habitats from human-caused and natural events. Finally, we will evaluate conservation and management programs underway or available for maintenance and enhancement of habitats critical for

  4. Corvidae feather pulp and West Nile virus detection

    USGS Publications Warehouse

    Docherty, D.E.; Romaine Long, R.; Griffin, Katie M.; Saito, E.K.

    2004-01-01

    We evaluated cloacal swab, vascular pulp of flight feather, and kidney and spleen pool samples from carcasses of members of the family Corvidae as sources of West Nile virus (WNV). The cloacal swab, kidney and spleen pool, and feather pulp were the source of WNV in 38%, 43%, and 77%, respectively, of the carcasses.

  5. 14 CFR 23.1153 - Propeller feathering controls.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Propeller feathering controls. 23.1153... AIRCRAFT AIRWORTHINESS STANDARDS: NORMAL, UTILITY, ACROBATIC, AND COMMUTER CATEGORY AIRPLANES Powerplant Powerplant Controls and Accessories § 23.1153 Propeller feathering controls. If there are...

  6. Fish oil disrupts seabird feather microstructure and waterproofing.

    PubMed

    Morandin, Lora A; O'Hara, Patrick D

    2014-10-15

    Seabirds and other aquatic avifauna are highly sensitive to exposure to petroleum oils. A small amount of oil is sufficient to break down the feather barrier that is necessary to prevent water penetration and hypothermia. Far less attention has been paid to potential effects on aquatic birds of so called 'edible oils', non-petroleum oils such as vegetable and fish oils. In response to a sardine oil discharge by a vessel off the coast of British Columbia, we conducted an experiment to assess if feather exposure to sheens of sardine oil (ranging from 0.04 to 3 μm in thickness) resulted in measurable oil and water uptake and significant feather microstructure disruption. We designed the experiment based on a previous experiment on effects of petroleum oils on seabird feathers. Feathers exposed to the thinnest fish oil sheens (0.04 μm) resulted in measurable feather weight gain (from oil and water uptake) and significant feather microstructure disruption. Both feather weight gain and microstructure disruption increased with increasing fish oil thickness. Because of the absence of primary research on effects of edible oils on sea birds, we conducted interviews with wildlife rehabilitation professionals with experience rehabilitating sea birds after edible oil exposure. The consensus from interviews and our experiment indicated that physical contact with fish and other 'edible oils' in the marine environment is at least as harmful to seabirds as petroleum oils.

  7. Habitat Suitability Index Models: Mottled duck

    USGS Publications Warehouse

    Rorabaugh, James C.; Zwank, Phillip J.

    1983-01-01

    The mottled duck is a mallard-like resident species of the Gulf of Mexico coast, from the marshes of Pearl River on the Lou i si ana-Ht ss t ss ipp i border to the Al varado Lagoon near Veracruz, Mexico (Bell rose 1976). The highest densities of nesting mottl ed ducks are found in brackish to fresh coastal marshes (H. Bateman, Louisiana Department of Wildl ife and Fisheries, Baton Rouge; pers , comm.). Mottled ducks also inhabit prairie land near prairie potholes in Texas and flooded rice fields in Texas (Engel ing 1950) and Louisiana (Linscombe 1972).

  8. Hawaiian Duck's Future Threatened by Feral Mallards

    USGS Publications Warehouse

    Uyehara, Kimberly J.; Engilis, Andrew; Reynolds, Michelle

    2007-01-01

    Nearly 70 percent of Hawaii's native bird species are found nowhere else on Earth, and many of these species are declining or in danger of extinction. Although the Hawaiian Islands were once home to a remarkable diversity of waterfowl, only three species remain-the Hawaiian Goose (Nene), Laysan Duck, and Hawaiian Duck (Koloa maoli)-all Federally endangered. The Koloa maoli is the only Hawaiian bird threatened by 'genetic extinction' from hybridization with an invasive species-feral Mallard ducks. U.S. Geological Survey (USGS) biologists in Hawaii are working to find the causes of bird endangerment and ways to prevent extinction of the Koloa maoli and other threatened birds.

  9. An outbreak of duck virus enteritis (duck plague) in a captive flock of mixed waterfowl

    USGS Publications Warehouse

    Montgomery, R.D.; Stein, G.; Novilla, M.N.; Hurley, Sarah S.; Fink, R.J.

    1981-01-01

    An outbreak of duck virus enteritis occurred in a flock of captive waterfowl composed of mallards (Anas platyrhynchos), black ducks (Anas rubripes), and Canada geese (Branta canadensis). Although all three species were housed together, morbidity and mortality were confined to the 227 black ducks and Canada geese, of which 180 died and the rest were left in a weakened condition. Lesions are given for 20 black ducks and 4 Canada geese dying from DVE. In addition, both horizontal and vertical transmission are discussed as possible sources of the virus that caused this outbreak.

  10. Selection for Duration of Fertility and Mule Duck White Plumage Colour in a Synthetic Strain of Ducks (Anas platyrhynchos)

    PubMed Central

    Liu, H. C.; Huang, J. F.; Lee, S. R.; Liu, H. L.; Hsieh, C. H.; Huang, C. W.; Huang, M. C.; Tai, C.; Poivey, J. P.; Rouvier, R.; Cheng, Y. S.

    2015-01-01

    average predicted genetic response for F was 40% of genetic standard deviation per generation of selection. The mule ducklings’ feather colour also was improved. It was concluded that this study provided results for a better understanding of the genetics of the duration of fertility traits in the common female duck bred for mule and that the selection of a synthetic strain was effective method of improvement. PMID:25715691

  11. Selection for Duration of Fertility and Mule Duck White Plumage Colour in a Synthetic Strain of Ducks (Anas platyrhynchos).

    PubMed

    Liu, H C; Huang, J F; Lee, S R; Liu, H L; Hsieh, C H; Huang, C W; Huang, M C; Tai, C; Poivey, J P; Rouvier, R; Cheng, Y S

    2015-05-01

    rate. The average predicted genetic response for F was 40% of genetic standard deviation per generation of selection. The mule ducklings' feather colour also was improved. It was concluded that this study provided results for a better understanding of the genetics of the duration of fertility traits in the common female duck bred for mule and that the selection of a synthetic strain was effective method of improvement.

  12. Disruption of the keratin filament network during epithelial cell division.

    PubMed Central

    Lane, E B; Goodman, S L; Trejdosiewicz, L K

    1982-01-01

    The behaviour of keratin filaments during cell division was examined in a wide range of epithelial lines from several species. Almost half of them show keratin disruption as described previously: by immunofluorescence, filaments are replaced during mitosis by a 'speckled' pattern of discrete cytoplasmic dots. In the electron microscope these ' speckles ' are seen as granules around the cell periphery, just below the actin cortical mesh, with no detectable 10 nm filament structure inside them and no keratin filament bundles in the rest of the cytoplasm. A time course of the filament reorganization was constructed from double immunofluorescence data; filaments are disrupted in prophase, and the filament network is intact again by cytokinesis. The phenomenon is restricted to cells rich in keratin filaments, such as keratinocytes; it is unrelated to the co-existence of vimentin in many of these cells, and vimentin is generally maintained as filaments while the keratin is restructured. Some resistance to the effect may be conferred by an extended cycle time. Filament reorganization takes place within minutes, so that a reversible mechanism seems more likely than one involving de novo protein synthesis, at this metabolically quiet stage of the cell cycle. Images Fig. 1. Fig. 2. Fig. 3. Fig. 4. Fig. 5. Fig. 6. PMID:6202508

  13. Role of keratin 24 in human epidermal keratinocytes

    PubMed Central

    Min, Min; Chen, Xi-Bei; Wang, Ping; Landeck, Lilla; Chen, Jia-Qi; Li, Wei; Cai, Sui-Qing; Zheng, Min; Man, Xiao-Yong

    2017-01-01

    Keratin 24 (K24) is a new kind of keratin genes, which encodes a novel keratin protein, K24 that bears high similarity to the type I keratins and displays a unique expression profile. However, the role of K24 is incompletely understood. In our study, we investigated the localization of K24 within the epidermis and possible functions. Keratin 24 was found to be modestly overexpressed in senescent keratinocytes and was mainly restricted to the upper stratum spinosum of epidermis. The protein was required for terminal differentiation upon CaCl2-induced differentiation. In vitro results showed that increased K24 in keratinocytes dramatically changed the differentiation of primary keratinocytes. It also inhibited cell survival by G1/S phase cell cycle arrest and induced senescence, autophagy and apoptosis of keratinocytes. In addition, K24 activated PKCδ signal pathway involving in cellular survival. In summary, K24 may be suggested as a potential differentiation marker and anti-proliferative factor in the epidermis. PMID:28362807

  14. Peptide-protein interactions within human hair keratins.

    PubMed

    Cruz, Célia F; Matamá, Teresa; Cavaco-Paulo, Artur

    2017-03-15

    We selected 1235 decapeptides from human hair proteins encoded by human genes of keratins and keratin associated proteins. The peptides were linked to glass arrays and screened for their affinity towards a solution of human hair extracted keratin fraction. Based on the physicochemical properties of the peptides, ten variables were studied: content of different types of amino acid side chains (cysteine, hydrophobic, polar, basic, acidic, aromatic rings, amide, alcohol side chains), isoelectric point, and net charge. We found differences statistically significant on the binding affinity of peptides based on their content of cysteine, hydrophobic and polar amino acids, mainly containing alcohols. These results point to the formation of hydrophobic interactions and disulfide bonds between small peptides and human hair keratins as the main driving forces for the interaction of possible cosmetic peptides, namely designed to strength human hair. As so, our results enlighten the nature of the interaction of keratin based materials with human hair, which are claimed to enhance hair fiber strength, and enable a more directed and sustained hair care peptide design.

  15. Autoantibodies in Scurfy Mice and IPEX Patients Recognize Keratin 14

    PubMed Central

    Huter, Eva N.; Natarajan, Kannan; Torgerson, Troy R.; Glass, Deborah D.; Shevach, Ethan M.

    2013-01-01

    Scurfy mice have a deletion in the Foxp3 gene, resulting in a failure to generate Foxp3+ regulatory T cells, and they subsequently develop severe CD4+ T-cell-mediated autoimmune inflammation. Multiple organs are involved, but the skin is one of the main organs affected. During the course of disease, Scurfy mice develop autoantibodies; however, the targeted antigens are unknown. In this study, we show that Scurfy mice develop autoantibodies directed against skin antigens. Using western blot analysis, we found that Scurfy serum reacted with proteins in total skin lysate, as well as in a keratinocyte lysate. Most of the Scurfy sera tested identified a major band at 50 kDa. Transfer of Scurfy CD4+ T cells into nu/nu mice yielded autoantibodies with similar reactivity. Further analysis using 2D western blots, followed by peptide mass fingerprinting, identified several keratins as targets. To confirm this observation, we chose one of the identified targets, keratin 14, and prepared recombinant proteins encompassing the N-terminal, middle, and C-terminal portions of the keratin 14 protein. Scurfy serum predominantly recognized the C-terminal fragment. Sera from patients with immunodysregulation, polyendocrinopathy, enteropathy, X-linked (IPEX) syndrome, the human disease resulting from FOXP3 mutations, also recognized skin antigens, including keratin 14. Thus, the results of our study indicate that autoantibodies in Scurfy mice and patients with IPEX target keratins. PMID:20147963

  16. Autoantibodies in scurfy mice and IPEX patients recognize keratin 14.

    PubMed

    Huter, Eva N; Natarajan, Kannan; Torgerson, Troy R; Glass, Deborah D; Shevach, Ethan M

    2010-05-01

    Scurfy mice have a deletion in the Foxp3 gene, resulting in a failure to generate Foxp3(+) regulatory T cells, and they subsequently develop severe CD4(+) T-cell-mediated autoimmune inflammation. Multiple organs are involved, but the skin is one of the main organs affected. During the course of disease, Scurfy mice develop autoantibodies; however, the targeted antigens are unknown. In this study, we show that Scurfy mice develop autoantibodies directed against skin antigens. Using western blot analysis, we found that Scurfy serum reacted with proteins in total skin lysate, as well as in a keratinocyte lysate. Most of the Scurfy sera tested identified a major band at 50 kDa. Transfer of Scurfy CD4(+) T cells into nu/nu mice yielded autoantibodies with similar reactivity. Further analysis using 2D western blots, followed by peptide mass fingerprinting, identified several keratins as targets. To confirm this observation, we chose one of the identified targets, keratin 14, and prepared recombinant proteins encompassing the N-terminal, middle, and C-terminal portions of the keratin 14 protein. Scurfy serum predominantly recognized the C-terminal fragment. Sera from patients with immunodysregulation, polyendocrinopathy, enteropathy, X-linked (IPEX) syndrome, the human disease resulting from FOXP3 mutations, also recognized skin antigens, including keratin 14. Thus, the results of our study indicate that autoantibodies in Scurfy mice and patients with IPEX target keratins.

  17. Mercury concentrations in feathers of wading birds from Florida

    USGS Publications Warehouse

    Beyer, W.N.; Spalding, M.; Morrison, D.

    1997-01-01

    Primary or tail feathers were collected from 92 wading birds in Florida from Lake Okeechobee and wetlands farther south, from 1987 to 1990. Mean concentrations detected in feathers of nestlings were 2.0 ppm Hg in roseate spoonbills (Ajaia ajaja), 3.5 ppm Hg in great blue herons (Ardea herodias), 4.7 ppm Hg in great white herons (Ardea herodias occidentalis), and 7.1 ppm Hg in great egrets (Casmerodius albus). Concentrations in feathers of great white herons increased with the age of the bird, from 4.7 ppm Hg in nestlings, to 6.7 ppm Hg in juveniles, and 8.2 ppm Hg in adults. Mercury concentrations were greatest in species consuming large fish. Feathers collected from wood storks (Mycteria americana) contained an average of 3.3 ppm Hg. Mercury concentrations in feathers of wading birds from southern Florida were greater than those reported in feathers of wading birds from Asia. Both liver and feather Hg concentrations were known for 25 wading birds. The regression of liver (wet weight) Hg concentrations (Y) on feather Hg concentrations (X) was: log(Y) = 1.52 log(X) - 0.722. The correlation coefficient was 0.84. If reproductive disorders are expected when concentrations in feathers of adult birds average 9 ppm Hg, as might be inferred from a published laboratory study on mallards (Anas platyrhynchos), then Hg in southern Florida may be high enough to reduce productivity of wading bird populations. However, additional controlled studies are needed before a minimum toxic concentration in feathers can be designated with confidence.

  18. Effects of oxidative treatments on human hair keratin films.

    PubMed

    Fujii, T; Ito, Y; Watanabe, T; Kawasoe, T

    2012-01-01

    The effects of hydrogen peroxide and commercial bleach on hair and human hair keratin films were examined by protein solubility, scanning electron microscopy (SEM), immunofluorescence microscopy, immunoblotting, and Fourier-transform infrared spectroscopy. Protein solubility in solutions containing urea decreased when the keratin films were treated with hydrogen peroxide or bleach. Oxidative treatments promoted the urea-dependent morphological change by turning films from opaque to transparent in appearance. Immunofluorescence microscopy and immunoblotting showed that the oxidation of amino acids and proteins occurred due to the oxidative treatments, and such occurrence was more evident in the bleach-treated films than in the hydrogen peroxide-treated films. Compared with hair samples, the formation of cysteic acid was more clearly observed in the keratin films after the oxidative treatments.

  19. Floods on Duck and Little Duck Rivers and Grindstone Hollow, Hunt, Hickory Flat, and Wolf Creeks in the vicinity of Manchester, Tennessee. [Duck River; Little Duck River

    SciTech Connect

    Not Available

    1984-09-01

    This flood hazard report describes the extent and severity of the flood potential along selected reaches of the Duck and Little Duck Rivers, and Grindstone Hollow, Hunt, Hickory Flat, and Wolf Creeks in the vicinity of Manchester, Tennessee. The report was prepared by TVA as a result of a request from the city of Manchester for TVA technical assistance in evaluating alternative solutions to local flood problems. 5 references, 12 figures, 12 tables.

  20. Breeding productivity of Smith Island black ducks

    USGS Publications Warehouse

    Haramis, G.M.; Jorde, D.G.; Olsen, G.H.; Stotts, D.B.; Harrison, M.K.; Perry, M.C.

    2002-01-01

    We investigated the breeding performance of American black ducks (Anas rubripes) on Smith Island, Chesapeake Bay, to improve our understanding of island black duck breeding ecology and to make management recommendations to enhance productivity. During 1995-96, we implanted 56 female black ducks with 20-g radio transmitters and tracked 35 of the individuals through the breeding season to locate nests, determine nest fate, and identify brood habitat. We also increased preseason banding efforts and compared capture characteristics over 12 years with those from the Deal Island Wildlife Management Area, a banding site on the mainland of Tangier Sound. A low rate of nesting (37%), lack of renesting, and poor hatching success (31%) indicated that island salt marsh habitats present a harsh environment for breeding black ducks. Black ducks located 11 of 13 nests (85%) in black needlerush (Juncus roemerianus) marsh where they were vulnerable to flooding from extreme tides and to egg predators. No nests were found on forested tree hammocks, a feature that distinguishes Smith Island from nearby South Marsh and Bloodsworth Islands. Nest predators included red foxes (Vulpes vulpes), herring gulls (Larus argentams), fish crows (Corvus ossifragus), and, potentially, Norway rats (Rattus norvegicus). Unlike mainland red foxes, foxes radio tracked on Smith Island were found to be capable swimmers and effective low marsh predators. We found shoreline meadows of widgeon grass (Ruppia maritima) to be important foraging sites for black ducks and suspected that the virtual absence of fresh water in this high salinity environment (1217+ ppt) to incur some cost in terms of growth and survival of ducklings. Preseason bandings revealed a high proportion of banded adults and a strong positive correlation in age ratios with the Deal Island banding site. This latter finding strongly suggests a negative universal effect of storm tides on nest success for Tangier Sound black ducks. Management to

  1. Black ducks and DDE: Review and status

    USGS Publications Warehouse

    Longcore, J.R.; Stendell, R.C.

    1982-01-01

    Residues of DDE in wild black duck (Anas rubripes) wings or eggs are lower now than they were in the 1960s, and the mean shell thickness of eggs collected in 1978 has recovered to the pre-DDT use thickness. Mean DDE residues (ppm, wet wt) for eggs were: 1964, 2.93; 1971, 1.22; 1978, 0.65. Average DDE residues in wing pools were: 1965-66 and 1966-67 combined, 1.23; 1969-70, 1.42; 1972-73, 0.35 and 1976-77, 0.39. The threshold level of DDE in black duck foods for causing shell thinning is about 0.6 ppm, wet wt. Captive black ducks fed this dietary amount laid eggs with shells that were lighter in wt (-11.3%; P 0.05) for DDE-dosed birds, but this was caused by 1 unusually thin (0.283 mm) eggshell from a control hen. Our ad libitum diet, which equals the amount of DDE detected in some black duck foods, resulted in a mean DDE egg residue that was 4-6 ppm above the highest DDE residues detected in field-collected black duck eggs in 1964 (12.1 ppm) and 1971 (14.0). A comparison of documented effects of DDE in captive black ducks with DDE residues reported from wild black duck wing pools and eggs collected during 1964-78 suggests that reproductive success in wild black duck females was impaired in the 1960s and perhaps earlier.

  2. Duodenal perforation caused by a bird feather.

    PubMed

    Sahoo, Manash Ranjan; Kumar, Anil

    2013-02-15

    Ingestion of gastrointestinal (GI) foreign bodies represents a challenging clinical scenario. The greater risk is at extremes of age, in those wearing dentures, alcoholics and mentally handicapped. We present a case of duodenal perforation caused by a bird feather. A 64-year-old man was presented with abdominal pain for 4 days. Abdominal examination showed signs of peritonitis. The erect abdominal x-ray showed free gas under diaphragm. Exploratory laparotomy showed purulent fluid, but no definite site of perforation could be found. So the abdomen was closed with a drain in Morison's pouch. The postoperative recovery was uneventful. He came for a repeat check-up at 4 weeks with dull aching pain in the upper abdomen and was advised for a routine upper GI endoscopy which revealed a feather penetrating the first part of the duodenum, which was removed with a foreign body removing forceps. GI foreign bodies represent a significant problem and an increased level of suspicion is important for timely diagnosis and treatment.

  3. Classification of epidermal keratins according to their immunoreactivity, isoelectric point, and mode of expression

    PubMed Central

    1984-01-01

    Human epidermal keratinocytes express under various growth conditions a total of at least nine keratins that can be divided into two subfamilies. Subfamily A comprises 40-, 46-, 48-, 50-/50'-, and 56.5- kilodalton (kd) keratins which are relatively acidic (pI less than 5.5) and, with the exception of 46-kd keratin, are recognized by AE1 monoclonal antibody. Subfamily B comprises 52-, 56-, 58-, and 65-67-kd keratins which are relatively basic (pI greater than 6) and are recognized by AE3 monoclonal antibody. Within each keratin subfamily, there is a constant member (50-/50'- and 58-kd keratins of the subfamilies A and B, respectively) that is always expressed. The other seven keratins of both subfamilies are variable members whose expression depends upon the cellular differentiated state, which is in turn modulated by the growth environment. The 56.5-kd keratin (subfamily A) and the 65-67-kd keratins (subfamily B) are coordinately expressed during keratinization. In contrast, the 40-, 46-, and 48-kd keratins (subfamily A) and the 52- and 56-kd keratins (subfamily B) are characteristic of cultured epidermal cells forming nonkeratinized colonies. These results demonstrate that human epidermal keratins can be classified according to their reactivity with monoclonal antikeratin antibodies, isoelectric point, and mode of expression. The classification of keratins into various subgroups may have important implications for the mechanisms of epidermal differentiation, the evolution of keratin heterogeneity, and the use of keratin markers for tumor diagnosis. PMID:6201491

  4. Study on the conversion of wool keratin by steam explosion.

    PubMed

    Tonin, Claudio; Zoccola, Marina; Aluigi, Annalisa; Varesano, Alessio; Montarsolo, Alessio; Vineis, Claudia; Zimbardi, Francesco

    2006-12-01

    A wool fiber sample was submitted to chemical-free steam explosion in view of potential exploitation of keratin-based industrial and farm wastes. Fiber keratin was converted into a dark-yellow sludge that was submitted to phase separation by filtration, centrifugation, and precipitation of the soluble materials from the supernatant liquid. The resulting products, when compared with the original wool, showed the extent of disruption of the histology structure, reduction of the molecular weight to water-soluble peptides and free amino acids, and change of the structure of the remainder of the protein associated with breaking of disulfide bonds and decomposition of the high-sulfur-content protein fraction.

  5. 'Victoria Crater' from 'Duck Bay'

    NASA Technical Reports Server (NTRS)

    2006-01-01

    NASA's Mars rover Opportunity edged 3.7 meters (12 feet) closer to the top of the 'Duck Bay' alcove along the rim of 'Victoria Crater' during the rover's 952nd Martian day, or sol (overnight Sept. 27 to Sept. 28), and gained this vista of the crater. The rover's navigation camera took the seven exposures combined into this mosaic view of the crater's interior. This crater has been the mission's long-term destination for the past 21 Earth months.

    The far side of the crater is about 800 meters (one-half mile) away. The rim of the crater is composed of alternating promontories, rocky points towering approximately 70 meters (230 feet) above the crater floor, and recessed alcoves, such as Duck Bay. The bottom of the crater is covered by sand that has been shaped into ripples by the Martian wind. The rocky cliffs in the foreground have been informally named 'Cape Verde,' on the left, and 'Cabo Frio,' on the right.

    Victoria Crater is about five times wider than 'Endurance Crater,' which Opportunity spent six months examining in 2004, and about 40 times wider than 'Eagle Crater,' where Opportunity first landed. The great lure of Victoria is an expectation that the thick stack of geological layers exposed in the crater walls could reveal the record of past environmental conditions over a much greater span of time than Opportunity has read from rocks examined earlier in the mission.

    This view is presented as a cylindrical projection with geometric seam correction.

  6. Thermal and chemical effects of turkey feathers pyrolysis.

    PubMed

    Kluska, Jacek; Kardaś, Dariusz; Heda, Łukasz; Szumowski, Mateusz; Szuszkiewicz, Jarosław

    2016-03-01

    This study examines the thermal and chemical effects of the pyrolysis of turkey feathers. Research of feathers pyrolysis is important because of their increasing production and difficulties of their utilization. The experiments were carried out by means of thermogravimetric analysis (TGA), differential scanning calorimetry (DSC) and two pyrolytic reactors. The experimental investigation indicated that the feather material liquefies at temperatures between 210 and 240°C. This liquefaction together with the agglomeration of various dispersed and porous elements of the feathers into larger droplets leads to the volume reduction. Moreover, this work presents characteristics of the composition of the solid, liquid and gaseous products of turkey feathers pyrolysis at different temperatures. The higher heating value (HHV) of gaseous products in temperature 900°C equals 19.28 MJ/Nm(3) making the gases suitable for use as a fuel. The thermochemical conversion of turkey feathers leads to the formation of poisonous compounds such as hydrogen cyanide (HCN) in the liquid (0.13%) and gaseous (88 mg/Nm(3)) products. The phenomenon of liquefaction of feathers is important because it can lead to rapid degradation of the walls of reactors, and the formation of deposits.

  7. The role of allogenic keratin - derived dressing in wound healing in a mouse model.

    PubMed

    Konop, Marek; Sulejczak, Dorota; Czuwara, Joanna; Kosson, Piotr; Misicka, Aleksandra; Lipkowski, Aandrzej W; Rudnicka, Lidia

    2016-12-20

    Keratin is an interesting protein needed for wound healing and tissue recovery. We have recently proposed a new, simple and inexpensive method to obtain fur and hair keratin-derived biomaterials suitable for medical application. The aim of the study was to evaluate the role of the fur keratin derived protein (FKDP) dressing in the allogenic full-thickness surgical skin wound model.

  8. Keratin capped silver nanoparticles - synthesis and characterization of a nanomaterial with desirable handling properties

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Silver nanoparticles (NPs) were produced with keratin stabilizer and the NPs exhibited unimodal Gaussian distribution with average diameter of 3.5nm +/- 0.7 nm. The molecular mass of keratin stabilizer was 6-8 kDa. The mass of keratin capped NPs was >250 kDa to indicate the formation of crosslinked...

  9. Methodological considerations for measuring glucocorticoid metabolites in feathers

    PubMed Central

    Berk, Sara A.; McGettrick, Julie R.; Hansen, Warren K.; Breuner, Creagh W.

    2016-01-01

    In recent years, researchers have begun to use corticosteroid metabolites in feathers (fCORT) as a metric of stress physiology in birds. However, there remain substantial questions about how to measure fCORT most accurately. Notably, small samples contain artificially high amounts of fCORT per millimetre of feather (the small sample artefact). Furthermore, it appears that fCORT is correlated with circulating plasma corticosterone only when levels are artificially elevated by the use of corticosterone implants. Here, we used several approaches to address current methodological issues with the measurement of fCORT. First, we verified that the small sample artefact exists across species and feather types. Second, we attempted to correct for this effect by increasing the amount of methanol relative to the amount of feather during extraction. We consistently detected more fCORT per millimetre or per milligram of feather in small samples than in large samples even when we adjusted methanol:feather concentrations. We also used high-performance liquid chromatography to identify hormone metabolites present in feathers and measured the reactivity of these metabolites against the most commonly used antibody for measuring fCORT. We verified that our antibody is mainly identifying corticosterone (CORT) in feathers, but other metabolites have significant cross-reactivity. Lastly, we measured faecal glucocorticoid metabolites in house sparrows and correlated these measurements with corticosteroid metabolites deposited in concurrently grown feathers; we found no correlation between faecal glucocorticoid metabolites and fCORT. We suggest that researchers should be cautious in their interpretation of fCORT in wild birds and should seek alternative validation methods to examine species-specific relationships between environmental challenges and fCORT. PMID:27335650

  10. Aerodynamic performance of the feathered dinosaur Microraptor and the evolution of feathered flight.

    PubMed

    Dyke, Gareth; de Kat, Roeland; Palmer, Colin; van der Kindere, Jacques; Naish, Darren; Ganapathisubramani, Bharathram

    2013-01-01

    Understanding the aerodynamic performance of feathered, non-avialan dinosaurs is critical to reconstructing the evolution of bird flight. Here we show that the Early Cretaceous five-winged paravian Microraptor is most stable when gliding at high-lift coefficients (low lift/drag ratios). Wind tunnel experiments and flight simulations show that sustaining a high-lift coefficient at the expense of high drag would have been the most efficient strategy for Microraptor when gliding from, and between, low elevations. Analyses also demonstrate that anatomically plausible changes in wing configuration and leg position would have made little difference to aerodynamic performance. Significant to the evolution of flight, we show that Microraptor did not require a sophisticated, 'modern' wing morphology to undertake effective glides. This is congruent with the fossil record and also with the hypothesis that symmetric 'flight' feathers first evolved in dinosaurs for non-aerodynamic functions, later being adapted to form lifting surfaces.

  11. The effects of season and sex upon the morphology and material properties of keratin in the Svalbard rock ptarmigan (Lagopus muta hyperborea).

    PubMed

    Lees, John J; Folkow, Lars P; Nudds, Robert L; Codd, Jonathan R

    2014-08-01

    The material properties and morphologies of the modified integumentary organs of birds (the keratinous bills, claws and feathers) have evolved to withstand the variety of mechanical stresses imposed by their interaction with the environment. These stresses are likely to vary temporally in seasonal environments and may also differ between the sexes as a result of behavioural dimorphism. Here we investigate the morphology and material properties of the claws of male and female Svalbard ptarmigan (Lagopus muta hyperborea) during the summer and winter using nanoindentation. Despite differences in locomotor demands between the sexes and pronounced seasonal differences in environmental conditions, like ground substrate, ambient temperature and day length, there was no significant difference in Young׳s modulus or hardness between the seasons for each sex. However, when comparing males and females, female claws were significantly harder than those of males and both sexes had significantly wider claws during winter. We propose that wider claws may follow winter claw moulting as the claws are regrown and form an important part of the ptarmigan׳s snowshoe-like foot that is an adaptation to locomotion on snow. Future work focusing on growth rates and more broad measures of material properties in both captive and wild birds is required to determine the extent of seasonal and sex differences in the material properties of their keratinous structures.

  12. Palaeontology: leg feathers in an Early Cretaceous bird.

    PubMed

    Zhang, Fucheng; Zhou, Zhonghe

    2004-10-21

    Here we describe a fossil of an enantiornithine bird from the Early Cretaceous period in China that has substantial plumage feathers attached to its upper leg (tibiotarsus). The discovery could be important in view of the relative length and aerodynamic features of these leg feathers compared with those of the small 'four-winged' gliding dinosaur Microraptor and of the earliest known bird, Archaeopteryx. They may be remnants of earlier long, aerodynamic leg feathers, in keeping with the hypothesis that birds went through a four-winged stage during the evolution of flight.

  13. Campylobacter populations in wild and domesticated Mallard ducks (Anas platyrhynchos).

    PubMed

    Colles, Frances M; Ali, Jan S; Sheppard, Samuel K; McCarthy, Noel D; Maiden, Martin C J

    2011-10-01

    Identifying the Campylobacter genotypes that colonize farmed and wild ducks will help to assess the proportion of human disease that is potentially attributable to the consumption of duck meat and environmental exposure to duck faeces. Comparison of temporally and geographically matched farmed and wild ducks showed that they had different Campylobacter populations in terms of: (i) prevalence, (ii) Campylobacter species and (iii) diversity of genotypes. Furthermore, 92.4% of Campylobacter isolates from farmed ducks were sequence types (STs) commonly associated with human disease, in contrast to just one isolate from the wild ducks. Only one ST, ST-45, was shared between the two sources, accounting for 0.9% of wild duck isolates and 5% of farmed duck isolates. These results indicate that domestic 'niche' as well as host type may affect the distribution of Campylobacter, and that husbandry practises associated with intensive agriculture may be involved in generating a reservoir of human disease associated lineages.

  14. Campylobacter populations in wild and domesticated Mallard ducks (Anas platyrhynchos)

    PubMed Central

    Colles, Frances M; Ali, Jan S; Sheppard, Samuel K; McCarthy, Noel D; Maiden, Martin C J

    2011-01-01

    Identifying the Campylobacter genotypes that colonize farmed and wild ducks will help to assess the proportion of human disease that is potentially attributable to the consumption of duck meat and environmental exposure to duck faeces. Comparison of temporally and geographically matched farmed and wild ducks showed that they had different Campylobacter populations in terms of: (i) prevalence, (ii) Campylobacter species and (iii) diversity of genotypes. Furthermore, 92.4% of Campylobacter isolates from farmed ducks were sequence types (STs) commonly associated with human disease, in contrast to just one isolate from the wild ducks. Only one ST, ST-45, was shared between the two sources, accounting for 0.9% of wild duck isolates and 5% of farmed duck isolates. These results indicate that domestic ‘niche’ as well as host type may affect the distribution of Campylobacter, and that husbandry practises associated with intensive agriculture may be involved in generating a reservoir of human disease associated lineages. PMID:22164198

  15. 1. OVERALL VIEW OF BROWN DUCK LAKE, LOOKING SOUTHWEST ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    1. OVERALL VIEW OF BROWN DUCK LAKE, LOOKING SOUTHWEST - High Mountain Dams in Upalco Unit, Brown Duck Lake Dam, Ashley National Forest, 4.4 miles North of Miners Gulch Campground, Mountain Home, Duchesne County, UT

  16. 2. OVERALL VIEW OF BROWN DUCK LAKE, LOOKING WEST ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    2. OVERALL VIEW OF BROWN DUCK LAKE, LOOKING WEST - High Mountain Dams in Upalco Unit, Brown Duck Lake Dam, Ashley National Forest, 4.4 miles North of Miners Gulch Campground, Mountain Home, Duchesne County, UT

  17. Keratinase Production by Three Bacillus spp. Using Feather Meal and Whole Feather as Substrate in a Submerged Fermentation

    PubMed Central

    Mazotto, Ana Maria; Coelho, Rosalie Reed Rodrigues; Cedrola, Sabrina Martins Lage; de Lima, Marcos Fábio; Couri, Sonia; Paraguai de Souza, Edilma; Vermelho, Alane Beatriz

    2011-01-01

    Three Bacillus species (B. subtilis LFB-FIOCRUZ 1270, B. subtilis LFB-FIOCRUZ 1273, and B. licheniformis LFB-FIOCRUZ 1274), isolated from the poultry industry, were evaluated for keratinase production using feathers or feather meal as the sole carbon and nitrogen sources in a submerged fermentation. The three Bacillus spp. produced extracellular keratinases and peptidases after 7 days. Feather meal was the best substrate for keratinase and peptidase production in B. subtilis 1273, with 412 U/mL and 463 U/ml. The three strains were able to degrade feather meal (62–75%) and feather (40–95%) producing 3.9–4.4 mg/ml of soluble protein in feather meal medium and 1.9–3.3 mg/ml when feather medium was used. The three strains produced serine peptidases with keratinase and gelatinase activity. B. subtilis 1273 was the strain which exhibited the highest enzymatic activity. PMID:21822479

  18. Mutation of human keratin 18 in association with cryptogenic cirrhosis.

    PubMed Central

    Ku, N O; Wright, T L; Terrault, N A; Gish, R; Omary, M B

    1997-01-01

    Mutations in 11 of the more than 20 keratin intermediate filaments cause several epidermal and oral associated diseases. No disease-associated mutations have been described in keratin 8 or 18 (K8/18) which are the major keratin pair in simple-type epithelia, as found in the liver, pancreas, and intestine. However, transgenic mice that express mutant keratin 18 develop chronic hepatitis, and have an increased susceptibility to drug-induced hepatotoxicity. Also, ectopic expression of epidermal K14 in mouse liver results in chronic hepatitis, and disruption of mouse K8 leads to embryo lethality with extensive liver hemorrhage. We tested if patients with liver disease of unknown cause may harbor mutations in K18. We describe a his127-->leu (H127L) K18 mutation in a patient with cryptogenic cirrhosis that is germline transmitted. The K18 H127L isolated from the liver explant, or after expression in bacteria, showed an altered migration on two-dimensional gel analysis as compared with normal human liver or bacterially expressed K18. Electron microscopy of in vitro assembled K18 H127L and wild type K8 showed an assembly defect as compared with normal K8/18 assembly. Our results suggest that mutations in K18 may be predispose to, or result in cryptogenic cirrhosis in humans. PMID:9011570

  19. Keratin sponge/hydrogel II, active agent delivery

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Keratin sponge/hydrogels from oxidation and reduction hydrolysis of fine and coarse wool fibers were formed to behave as cationic hydrogels to swell and release active agents in the specific region of the gastro-intestinal (GI) tract. Their porous, interpenetrating networks (IPN) were effective for...

  20. Keratin sponge/hydrogel part 1. fabrication and characterization

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Keratin sponge/hydrogel products formed by either the oxidation or reduction of U.S. domestic fine- or coarse-grade wool exhibited distinctively different topologies and molecular weights of 6- 8 kDa and 40-60 kDa, each with unique macro-porous structure and microstructural behaviors. The sponge/ ...

  1. Pathogenicity of duck plague and innate immune responses of the Cherry Valley ducks to duck plague virus.

    PubMed

    Li, Ning; Hong, Tianqi; Li, Rong; Guo, Mengjiao; Wang, Yao; Zhang, Jinzhou; Liu, Jiyuan; Cai, Yumei; Liu, Sidang; Chai, Tongjie; Wei, Liangmeng

    2016-08-24

    Duck plague caused by duck plague virus (DPV) is an acute and contagious disease. To better understand the pathogenic mechanism of duck plague virus in ducklings, an infection experiment was performed. Our results showed that typical symptoms were observed in the infected ducklings. DPV could replicate quickly in many tissues, leading to pathological lesions, especially on the spleen. Real-time quantitative PCR demonstrated that expression of many innate immune-related genes was mostly up-regulated in the brain, and the antiviral innate immune response was established, but not sufficient to restrict viral replication. In contrast, although the expression of many major pattern recognition receptors (PRRs) increased in the spleen, the expression of most cytokines was declined. Our study indicates that DPV is a pantropic virus that can replicate rapidly in tissues, causing serious pathological lesions but the immune responses are different in the spleen and brain. To our knowledge, this is the first report to systematically explore the expression profiles of the immune genes in the DPV-infected ducks. Our data provide a foundation for further study of the pathogenicity of duck plague.

  2. Temporal overlap and repeatability of feather corticosterone levels: practical considerations for use as a biomarker

    PubMed Central

    Harris, Christopher M.; Madliger, Christine L.; Love, Oliver P.

    2016-01-01

    The measurement of corticosterone (CORT) levels in feathers has recently become an appealing tool for the conservation toolbox, potentially providing a non-invasive, integrated measure of stress activity throughout the time of feather growth. However, because the mechanism of CORT deposition, storage and stability in feathers is not fully understood, it is unclear how reliable this measure may be, especially when there is an extended interval between growth and feather collection. We compared CORT levels of naturally grown feathers from tree swallows (Tachycineta bicolor) that were moulted and regrown concurrently and therefore expected to have similar CORT levels. Specifically, we compared the same feather from the left and right wing (moulted symmetrically) and different types of feathers (wing, back and tail) expected to have been moulted within the same time period. We found that larger, heavier feathers held more CORT per unit length. In addition, we found a lack of concordance in CORT levels both within the same feather type and between different feather types, even after taking into account differences in feather density. Our results indicate that naturally grown feathers may not consistently provide an indication of stress status. Additionally, conflict in results may arise depending on the feather assayed, and total feather volume may be an important consideration when interpreting feather CORT levels. Future work is necessary to determine explicitly the mechanisms of CORT deposition, the effects of environmental exposure and feather wear on the permanence of the feather CORT signal, and the influence of responses to wild stressors on feather CORT levels, before feather CORT can be implemented effectively as a tool for ecological and conservation applications. PMID:27933163

  3. Theory of the development of curved barbs and their effects on feather morphology.

    PubMed

    Feo, Teresa J; Simon, Emma; Prum, Richard O

    2016-08-01

    Feathers exhibit an extraordinary diversity of shapes, which are used by birds to accomplish a diverse set of functions. Pennaceous feathers have a double branched morphology that develops from a tube of epidermis, and variation in branch geometry determines feather shape. Feather development is both complex (i.e., a simple developmental modification can have multiple effects on mature feather shape), and redundant (i.e., different developmental modifications can create the same shape). Due to this, it is not readily apparent how different feather shapes develop. In many feathers, barbs are not straight, but instead curve in toward, or away, from the feather tip. Barb curvature can affect the shape of mature feathers but the development of curved barbs is unknown. Previous research has hypothesized that barb curvature could develop either during the helical growth of barb ridges in the tubular feather germ, or during barb angle expansion as the feather unfurls from the sheath. To better understand the development of curved barbs and their effects on mature feathers we present a theoretical model of curved barb development and test the model with empirical investigations of feathers. We find that curved barbs affect many aspects of feather morphology including vane width, barb length, and barb spacing. In real feathers, curved barbs can develop both during helical barb ridge growth and during barb angle expansion, with most of the observed curvature due to barb angle expansion. Our results demonstrate that barb angle expansion as a feather unfurls from the sheath is a complex and dynamic process that plays an important role in determining the shape and structure of mature feathers. Curved barbs create heterogeneity in barb geometry within the feather vane, which could have important implications for aerodynamic function and the development of within feather pigmentation patterns. J. Morphol. 277:995-1013, 2016. © 2016 Wiley Periodicals, Inc.

  4. Temporal overlap and repeatability of feather corticosterone levels: practical considerations for use as a biomarker.

    PubMed

    Harris, Christopher M; Madliger, Christine L; Love, Oliver P

    2016-01-01

    The measurement of corticosterone (CORT) levels in feathers has recently become an appealing tool for the conservation toolbox, potentially providing a non-invasive, integrated measure of stress activity throughout the time of feather growth. However, because the mechanism of CORT deposition, storage and stability in feathers is not fully understood, it is unclear how reliable this measure may be, especially when there is an extended interval between growth and feather collection. We compared CORT levels of naturally grown feathers from tree swallows (Tachycineta bicolor) that were moulted and regrown concurrently and therefore expected to have similar CORT levels. Specifically, we compared the same feather from the left and right wing (moulted symmetrically) and different types of feathers (wing, back and tail) expected to have been moulted within the same time period. We found that larger, heavier feathers held more CORT per unit length. In addition, we found a lack of concordance in CORT levels both within the same feather type and between different feather types, even after taking into account differences in feather density. Our results indicate that naturally grown feathers may not consistently provide an indication of stress status. Additionally, conflict in results may arise depending on the feather assayed, and total feather volume may be an important consideration when interpreting feather CORT levels. Future work is necessary to determine explicitly the mechanisms of CORT deposition, the effects of environmental exposure and feather wear on the permanence of the feather CORT signal, and the influence of responses to wild stressors on feather CORT levels, before feather CORT can be implemented effectively as a tool for ecological and conservation applications.

  5. Do All Ducks Lay Eggs? The Generic Overgeneralization Effect

    ERIC Educational Resources Information Center

    Leslie, Sarah-Jane; Khemlani, Sangeet; Glucksberg, Sam

    2011-01-01

    Generics are statements such as "tigers are striped" and "ducks lay eggs". They express general, though not universal or exceptionless, claims about kinds (Carlson & Pelletier, 1995). For example, the generic "ducks lay eggs" seems true even though many ducks (e.g. the males) do not lay eggs. The universally quantified version of the statement…

  6. Yellow Ducks Overboard! A Lesson in Geography and World Citizenship

    ERIC Educational Resources Information Center

    Nagel, Paul; Beauboeuf, Donna

    2012-01-01

    This lesson was inspired by the book, "10 Little Rubber Ducks" by Eric Carle, which discusses ocean pollution. The book was inspired by an incident in 1992: A shipping container tumbled into the North Pacific Ocean, broke open, and 28,800 little rubber ducks (and other plastic bath toys) were lost at sea. The ducks were manufactured in China, and…

  7. Feathers of archaeopteryx: asymmetric vanes indicate aerodynamic function.

    PubMed

    Feduccia, A; Tordoff, H B

    1979-03-09

    Vanes in the primary flight feathers of Archaeopteryx conform to the asymmetric pattern in modern flying birds. The asymmetry has aerodynamic functions and can be assumed to have evolved in the selective context of flight.

  8. Changing patterns of keratin expression during progression of cervical intraepithelial neoplasia.

    PubMed Central

    Smedts, F.; Ramaekers, F.; Robben, H.; Pruszczynski, M.; van Muijen, G.; Lane, B.; Leigh, I.; Vooijs, P.

    1990-01-01

    The expression of keratins in normal cervical epithelia, metaplastic epithelium, and cervical intraepithelial neoplasia (CIN) grades I, II, and III is investigated with a panel of keratin polypeptide-specific monoclonal antibodies. This approach allowed the detection of individual keratins 4, 7, 8, 10, 13, 14, 18, and 19 at the single-cell level. By using an antibody recognizing keratins 5 and 8 (RCK 102) and two antibodies specific for keratin 8 (CAM 5.2 and M 20), it was also possible to derive information on the distribution of keratin 5. Our results show that during immature squamous metaplasia there is an acquisition of keratins typical of squamous epithelium, ie, keratins 4, 5, 13, and 14. This process continues during further differentiation to mature squamous metaplasia. In premalignant lesions the expression pattern of the progenitor reserve cells and immature squamous metaplastic epithelium is partly conserved. However, in most cases an induction in the expression of the keratins 4, 13, and 14 was observed. Furthermore, CIN III shows a more extensive expression of keratins typical of simple epithelia, ie, keratins 8 and 18, as compared to CIN I and CIN II. Images Figure 1 Figure 3 Figure 4 Figure 5 Figure 6 PMID:1690513

  9. Phosphorylation and Reorganization of Keratin Networks: Implications for Carcinogenesis and Epithelial Mesenchymal Transition

    PubMed Central

    Kim, Hyun Ji; Choi, Won Jun; Lee, Chang Hoon

    2015-01-01

    Metastasis is one of hallmarks of cancer and a major cause of cancer death. Combatting metastasis is highly challenging. To overcome these difficulties, researchers have focused on physical properties of metastatic cancer cells. Metastatic cancer cells from patients are softer than benign cancer or normal cells. Changes of viscoelasticity of cancer cells are related to the keratin network. Unexpectedly, keratin network is dynamic and regulation of keratin network is important to the metastasis of cancer. Keratin is composed of heteropolymer of type I and II. Keratin connects from the plasma membrane to nucleus. Several proteins including kinases, and protein phosphatases bind to keratin intermediate filaments. Several endogenous compounds or toxic compounds induce phosphorylation and reorganization of keratin network in cancer cells, leading to increased migration. Continuous phosphorylation of keratin results in loss of keratin, which is one of the features of epithelial mesenchymal transition (EMT). Therefore, several proteins involved in phosphorylation and reorganization of keratin also have a role in EMT. It is likely that compounds controlling phosphorylation and reorganization of keratin are potential candidates for combating EMT and metastasis. PMID:26157545

  10. Evidence for novel functions of the keratin tail emerging from a mutation causing ichthyosis hystrix.

    PubMed

    Sprecher, E; Ishida-Yamamoto, A; Becker, O M; Marekov, L; Miller, C J; Steinert, P M; Neldner, K; Richard, G

    2001-04-01

    Unraveling the molecular basis of inherited disorders of epithelial fragility has led to understanding of the complex structure and function of keratin intermediate filaments. Keratins are organized as a central alpha-helical rod domain flanked by nonhelical, variable end domains. Pathogenic mutations in 19 different keratin genes have been identified in sequences corresponding to conserved regions at the beginning and end of the rod. These areas have been recognized as zones of overlap between aligned keratin proteins and are thought to be crucial for proper assembly of keratin intermediate filaments. Consequently, all keratin disorders of skin, hair, nail, and mucous membranes caused by mutations in rod domain sequences are characterized by perinuclear clumping of fragmented keratin intermediate filaments, thus compromising mechanical strength and cell integrity. We report here the first mutation in a keratin gene (KRT1) that affects the variable tail domain (V2) and results in a profoundly different abnormality of the cytoskeletal architecture leading to a severe form of epidermal hyperkeratosis known as ichthyosis hystrix Curth-Macklin. Structural analyses disclosed a failure in keratin intermediate filament bundling, retraction of the cytoskeleton from the nucleus, and failed translocation of loricrin to the desmosomal plaques. These data provide the first in vivo evidence for the crucial role of a keratin tail domain in supramolecular keratin intermediate filament organization and barrier formation.

  11. Occurrence of Campylobacter and Salmonella in ducks and duck eggs in Selangor, Malaysia.

    PubMed

    Nor Faiza, S; Saleha, A A; Jalila, A; Fauziah, N

    2013-03-01

    The importance of Campylobacter and Salmonella as foodborne pathogens is well recognised globally. A recent work in Penang found ducks in commercial farms were infected with these organisms. The aim of the study was to detect the presence of Campylobacter and Salmonella in ducks and Salmonella in duck eggs in farms in a small part of Selangor. Cloacal swabs were obtained from 75 ducks and 30 duck eggs from three farms. The isolation and identification of Campylobacter and Salmonella were done using conventional methods. Twelve percent of Campylobacter and 16.0% of Salmonella were isolated from the ducks sampled. Salmonella was absent on and in eggs. Campylobacter isolates consisted of 22% Campylobacter jejuni and the remaining was Campylobacter coli. Three Salmonella serovars identified were Salmonella Agona, S. Braenderup and S. Corvallis. The presence of Campylobacter and Salmonella in ducks may cause contamination of the meat during processing and handling which can constitute public health hazard. Moreover, the farm workers may be exposed to the organisms through contact with the infected animals.

  12. Prevalence of duck circovirus infection of subclinical pekin ducks in South Korea.

    PubMed

    Cha, Se-Yeoun; Song, Eu-Tteum; Kang, Min; Wei, Bai; Seo, Hye-Suk; Roh, Jae-Hee; Yoon, Ran-Hee; Moon, Oun-Kyoung; Jang, Hyung-Kwan

    2014-04-01

    An investigation was carried out to determine the prevalence and infection pattern of duck circovirus (DuCV) in subclinical Pekin ducks on South Korean duck farms. A total of 147 samples collected from 92 duck farms in five provinces were examined from 2011 to 2012. The overall prevalence of DuCV PCR-positive pooled bursa of Fabricius and liver samples was 21.8% (32/147). The prevalence of DuCV PCR-positive samples increased significantly in 3-week-old ducks compared with that in 1-week-old ducks (P<0.05). DuCV in association with Riemerella and Salmonella infections (10.9%; 16/147) occurred at the same level as infection with DuCV alone (10.9%; 16/147). In comparison of the relationship between bacterial diseases (salmonellosis, Riemerella infection) and morbidity in farms with and without DuCV, morbidity was higher in circovirus-positive farms (50%; 16/32) than in circovirus-negative farms (26.1%; 30/115). Our findings provide baseline information on the degree of DuCV infection and distribution and pattern of DuCV in ducks, and it is evident that DuCV can be associated with subclinical diseases and that subclinical infection could be economically important.

  13. Mycoplasma infection of ducks and geese.

    PubMed

    Stipkovits, L; Szathmary, S

    2012-11-01

    Production of ducks and geese in certain parts of the world is very important. Mycoplasma diseases cause significant losses to the duck and goose industry. This review summarizes the epidemiological, clinical, and pathomorphological characteristics of mycoplasma diseases of ducks and geese and the involvement of the various mycoplasma species in their pathogenesis. The role of mycoplasma infections in the development of clinical signs, pathological lesions, and mortality of challenged birds is demonstrated in challenge experiments. Transmission of mycoplasma in the ovary and eggs resulting in the reduction of egg production and an increase of embryo mortality has been shown in challenge experiments as well as in field studies. The susceptibility of many mycoplasma isolates of the most important mycoplasma species of duck and goose origin were tested and showed relatively high average minimum inhibitory concentrations of lincomycin, tilosin, oxytetracycline, chlortetracycline, and enrofloxacin but not for tiamulin. The successful treatment of mycoplasma infections with antibiotics in ducks and geese should be selected based on the minimum inhibitory concentration values against the mycoplasmas isolated from the flock.

  14. Feather growth influences blood mercury level of young songbirds.

    PubMed

    Condon, Anne M; Cristol, Daniel A

    2009-02-01

    Dynamics of mercury in feathers and blood of free-living songbirds is poorly understood. Nestling eastern bluebirds (Sialia sialis) living along the mercury-contaminated South River (Virginia, USA) had blood mercury levels an order of magnitude lower than their parents (nestling: 0.09 +/- 0.06 mg/kg [mean +/- standard deviation], n = 156; adult: 1.21 +/- 0.57 mg/kg, n = 86). To test whether this low blood mercury was the result of mercury sequestration in rapidly growing feathers, we repeatedly sampled free-living juveniles throughout the period of feather growth and molt. Mean blood mercury concentrations increased to 0.52 +/- 0.36 mg/kg (n = 44) after the completion of feather growth. Some individuals had reached adult blood mercury levels within three months of leaving the nest, but levels dropped to 0.20 +/- 0.09 mg/kg (n = 11) once the autumn molt had begun. Most studies of mercury contamination in juvenile birds have focused on recently hatched young with thousands of rapidly growing feathers. However, the highest risk period for mercury intoxication in young birds may be during the vulnerable period after fledging, when feathers no longer serve as a buffer against dietary mercury. We found that nestling blood mercury levels were not indicative of the extent of contamination because a large portion of the ingested mercury ended up in feathers. The present study demonstrates unequivocally that in songbirds blood mercury level is influenced strongly by the growth and molt of feathers.

  15. Fossil evidence for evolution of the shape and color of penguin feathers.

    PubMed

    Clarke, Julia A; Ksepka, Daniel T; Salas-Gismondi, Rodolfo; Altamirano, Ali J; Shawkey, Matthew D; D'Alba, Liliana; Vinther, Jakob; DeVries, Thomas J; Baby, Patrice

    2010-11-12

    Penguin feathers are highly modified in form and function, but there have been no fossils to inform their evolution. A giant penguin with feathers was recovered from the late Eocene (~36 million years ago) of Peru. The fossil reveals that key feathering features, including undifferentiated primary wing feathers and broad body contour feather shafts, evolved early in the penguin lineage. Analyses of fossilized color-imparting melanosomes reveal that their dimensions were similar to those of non-penguin avian taxa and that the feathering may have been predominantly gray and reddish-brown. In contrast, the dark black-brown color of extant penguin feathers is generated by large, ellipsoidal melanosomes previously unknown for birds. The nanostructure of penguin feathers was thus modified after earlier macrostructural modifications of feather shape linked to aquatic flight.

  16. Study of temporal trends in mercury concentrations in the primary flight feathers of Strix aluco.

    PubMed

    Varela, Z; García-Seoane, R; Fernández, J A; Carballeira, A; Aboal, J R

    2016-08-01

    Temporal trends in Hg concentrations were determined in the primary flight feathers of 146 specimens of Strix aluco which had died in various Wildlife Recovery Centres in Galicia (NW Spain) between 1997 and 2014. The aim of the study was to determine whether standardization of a primary flight feather (or feathers) in this species is essential for identifying temporal trends in Hg concentrations. For this purpose, we had to first standardize the feather(s) analyzed to enable comparison of the levels of Hg detected in different feathers. The results show a high degree of both inter and intra-individual variability but despite that, it was possible to identify P5 as the most representative feather taking into account the amount of metal excreted in each feather and the intra-individual variability: its median was 133ng, which represents 15% (from 7% to 15%) of the total Hg present in all the primary feathers. However, this "standard feather" did not reveal any temporal trend in Hg concentrations for the study period. This lack of trend was found irrespective of the feather considered and it is expected that detection of any existing trend would also not depend on the feather considered. We conclude that use of any particular feather is not essential for identifying temporal trends in Hg concentrations, because the pattern will be identified regardless of the feather selected.

  17. Do feather-degrading bacteria affect sexually selected plumage color?

    NASA Astrophysics Data System (ADS)

    Shawkey, Matthew D.; Pillai, Shreekumar R.; Hill, Geoffrey E.

    2009-01-01

    Models of parasite-mediated sexual selection propose that males with more elaborate sexual traits will have fewer parasites. These models have generally been tested using metazoan or protozoan parasites of the blood, gut, or integument. Fewer studies have examined sexual ornaments in relation to bacterial infections. While most surface bacteria are harmless or beneficial, feather-degrading bacteria may have detrimental effects. In this study, we examined the relationships between overall bacterial load, feather-degrading bacterial load, and sexually selected carotenoid-based plumage color in a wild population of house finches ( Carpodacus mexicanus). We found that males with the redder plumage preferred by females had similar overall bacterial loads, but lower feather-degrading bacterial loads, than males with less red plumage. These data suggest that plumage color can signal abundance of feather-degrading bacteria to potential mates. It remains unclear whether feather-degrading bacteria directly or indirectly affect plumage color, but the observed correlations suggest that feather-degrading bacteria may play some role in sexual selection.

  18. Distribution of unique red feather pigments in parrots

    PubMed Central

    McGraw, Kevin J; Nogare, Mary C

    2005-01-01

    In many birds, red, orange and yellow feathers are coloured by carotenoid pigments, but parrots are an exception. For over a century, biochemists have known that parrots use an unusual set of pigments to produce their rainbow of plumage colours, but their biochemical identity has remained elusive until recently. Here, we use high-performance liquid chromatography to survey the pigments present in the red feathers of 44 species of parrots representing each of the three psittaciform families. We found that all species used the same suite of five polyenal lipochromes (or psittacofulvins) to colour their plumage red, indicating that this unique system of pigmentation is remarkably conserved evolutionarily in parrots. Species with redder feathers had higher concentrations of psittacofulvins in their plumage, but neither feather colouration nor historical relatedness predicted the ratios in which the different pigments appeared. These polyenes were absent from blood at the time when birds were replacing their colourful feathers, suggesting that parrots do not acquire red plumage pigments from the diet, but instead manufacture them endogenously at growing feathers. PMID:17148123

  19. Feathering instability of spiral arms. II. Parameter study

    SciTech Connect

    Lee, Wing-Kit

    2014-09-10

    We report the results of a parameter study of the feathering stability in the galactic spiral arms. A two-dimensional, razor-thin magnetized self-gravitating gas disk with an imposed two-armed stellar spiral structure is considered. Using the formulation developed previously by Lee and Shu, a linear stability analysis of the spiral shock is performed in a localized Cartesian geometry. Results of the parameter study of the base state with a spiral shock are also presented. The single-mode feathering instability that leads to growing perturbations may explain the feathering phenomenon found in nearby spiral galaxies. The self-gravity of the gas, characterized by its average surface density, is an important parameter that (1) shifts the spiral shock farther downstream and (2) increases the growth rate and decreases the characteristic spacing of the feathering structure due to the instability. On the other hand, while the magnetic field suppresses the velocity fluctuation associated with the feathers, it does not strongly affect their growth rate. Using a set of typical parameters of the grand-design spiral galaxy M51 at 2 kpc from the center, the spacing of the feathers with the maximum growth rate is found to be 530 pc, which agrees with the previous observational studies.

  20. Toxic metals and associated sporulated bacteria on Andean hummingbird feathers.

    PubMed

    Góngora, Esteban; Cadena, Carlos Daniel; Dussán, Jenny

    2016-11-01

    Human activities in the Sabana de Bogotá, Colombia, release toxic metals such as lead (Pb) and chromium (Cr) into the environment polluting the air, water, and soil. Because birds are in contact with these pollutants and their sources, they may serve as bioindicator organisms. We evaluated the use of hummingbird feathers obtained from individuals captured in three sites of the Sabana de Bogotá as bioindicators of toxic metal pollution using spectrophotometric and spectroscopic methods based on single-feather samples. We also characterized the bacterial microbiota associated with hummingbird feathers by molecular identification using the 16S rRNA with a special focus on sporulated bacteria. Finally, we described the interactions which naturally occur among the feathers, their associated bacteria, and pollutants. We found differences in Pb and Cr concentrations between sampling sites, which ranged from 2.11 to 4.69 ppm and 0.38 to 3.00 ppm, respectively. This may reflect the impact of the activities held in those sites which release pollutants to the environment. Bacterial assemblages mainly consisted of sporulated bacilli in the Bacillaceae family (65.7 % of the identified morphotypes). We conclude that the feathers of wild tropical birds, including hummingbirds, can be used as lead and chromium bioindicators and that bacteria growing on feathers may in fact interact with these two toxic metals.

  1. Complete genome sequence of duck Tembusu virus, isolated from Muscovy ducks in southern China.

    PubMed

    Zhu, Wanjun; Chen, Jidang; Wei, Chunya; Wang, Heng; Huang, Zhen; Zhang, Minze; Tang, Fengfeng; Xie, Jiexiong; Liang, Huanbin; Zhang, Guihong; Su, Shuo

    2012-12-01

    We report here the complete genomic sequence of the duck Tembusu virus (DTMUV) WJ-1 strain, isolated from Muscovy ducks. This is the first complete genome sequence of DTMUV reported in southern China. Compared with the other strains (TA, GH-2, YY5, and ZJ-407) that were previously found in eastern China, WJ-1 bears a few differences in the nucleotide and amino acid sequences. We found that there are 47 mutations of amino acids encoded by the whole open reading frame (ORF) among these five strains. The whole-genome sequence of DTMUV will help in understanding the epidemiology and molecular characteristics of duck Tembusu virus in southern China.

  2. Complete genome sequence analysis of a duck circovirus from Guangxi pockmark ducks.

    PubMed

    Xie, Liji; Xie, Zhixun; Zhao, Guangyuan; Liu, Jiabo; Pang, Yaoshan; Deng, Xianwen; Xie, Zhiqin; Fan, Qing

    2012-12-01

    We report here the complete genomic sequence of a novel duck circovirus (DuCV) strain, GX1104, isolated from Guangxi pockmark ducks in Guangxi, China. The whole nucleotide sequence had the highest homology (97.2%) with the sequence of strain TC/2002 (GenBank accession number AY394721.1) and had a low homology (76.8% to 78.6%) with the sequences of other strains isolated from China, Germany, and the United States. This report will help to understand the epidemiology and molecular characteristics of Guangxi pockmark duck circovirus in southern China.

  3. Quantification of feather structure, wettability and resistance to liquid penetration

    PubMed Central

    Srinivasan, Siddarth; Chhatre, Shreerang S.; Guardado, Jesus O.; Park, Kyoo-Chul; Parker, Andrew R.; Rubner, Michael F.; McKinley, Gareth H.; Cohen, Robert E.

    2014-01-01

    Birds in the cormorant (Phalacrocoracidae) family dive tens of metres into water to prey on fish while entraining a thin layer of air (a plastron film) within the microstructures of their feathers. In addition, many species within the family spread their wings for long periods of time upon emerging from water. To investigate whether wetting and wing-spreading are related to feather structure, microscopy and photographic studies have previously been used to extract structural parameters for barbs and barbules. In this work, we describe a systematic methodology to characterize the quasi-hierarchical topography of bird feathers that is based on contact angle measurements using a set of polar and non-polar probing liquids. Contact angle measurements on dip-coated feathers of six aquatic bird species (including three from the Phalacrocoracidae family) are used to extract two distinguishing structural parameters, a dimensionless spacing ratio of the barbule (D*) and a characteristic length scale corresponding to the spacing of defect sites. The dimensionless spacing parameter can be used in conjunction with a model for the surface topography to enable us to predict a priori the apparent contact angles of water droplets on feathers as well as the water breakthrough pressure required for the disruption of the plastron on the feather barbules. The predicted values of breakthrough depths in water (1–4 m) are towards the lower end of typical diving depths for the aquatic bird species examined here, and therefore a representative feather is expected to be fully wetted in a typical deep dive. However, thermodynamic surface energy analysis based on a simple one-dimensional cylindrical model of the feathers using parameters extracted from the goniometric analysis reveals that for water droplets on feathers of all six species under consideration, the non-wetting ‘Cassie–Baxter’ composite state represents the global energy minimum of the system. By contrast, for other

  4. Quantification of feather structure, wettability and resistance to liquid penetration.

    PubMed

    Srinivasan, Siddarth; Chhatre, Shreerang S; Guardado, Jesus O; Park, Kyoo-Chul; Parker, Andrew R; Rubner, Michael F; McKinley, Gareth H; Cohen, Robert E

    2014-07-06

    Birds in the cormorant (Phalacrocoracidae) family dive tens of metres into water to prey on fish while entraining a thin layer of air (a plastron film) within the microstructures of their feathers. In addition, many species within the family spread their wings for long periods of time upon emerging from water. To investigate whether wetting and wing-spreading are related to feather structure, microscopy and photographic studies have previously been used to extract structural parameters for barbs and barbules. In this work, we describe a systematic methodology to characterize the quasi-hierarchical topography of bird feathers that is based on contact angle measurements using a set of polar and non-polar probing liquids. Contact angle measurements on dip-coated feathers of six aquatic bird species (including three from the Phalacrocoracidae family) are used to extract two distinguishing structural parameters, a dimensionless spacing ratio of the barbule (D*) and a characteristic length scale corresponding to the spacing of defect sites. The dimensionless spacing parameter can be used in conjunction with a model for the surface topography to enable us to predict a priori the apparent contact angles of water droplets on feathers as well as the water breakthrough pressure required for the disruption of the plastron on the feather barbules. The predicted values of breakthrough depths in water (1-4 m) are towards the lower end of typical diving depths for the aquatic bird species examined here, and therefore a representative feather is expected to be fully wetted in a typical deep dive. However, thermodynamic surface energy analysis based on a simple one-dimensional cylindrical model of the feathers using parameters extracted from the goniometric analysis reveals that for water droplets on feathers of all six species under consideration, the non-wetting 'Cassie-Baxter' composite state represents the global energy minimum of the system. By contrast, for other wetting

  5. The sequential tissue distribution of duck Tembusu virus in adult ducks.

    PubMed

    Wu, Li; Liu, Jinxiong; Chen, Pucheng; Jiang, Yongping; Ding, Leilei; Lin, Yuan; Li, Qimeng; He, Xijun; Chen, Qiusheng; Chen, Hualan

    2014-01-01

    In 2010, a novel Tembusu virus (TMUV) that caused a severe decrease in the egg production of ducks was isolated in southeast China. Given the novelty of this duck pathogen, little information is available regarding its pathogenesis. Here, we systematically investigated the replication kinetics of TMUV PTD2010 in adult male and female ducks. We found that PTD2010 was detectable in most of the parenchymatous organs as well as the oviduct and intestinal tract from days 1 to 7 after inoculation. Viral titers were maintained at high levels for at least 9 days in the spleen, kidney, bursa of Fabricius, brain, and ovary. No virus was detected in any of these organs or tissues at 18 days after inoculation. PTD2010, thus, causes systemic infections in male and female ducks; its replication kinetics show similar patterns in most organs, with the exception of the ovaries and testes.

  6. Organization of the human keratin type II gene cluster at 12q13

    SciTech Connect

    Yoon, S.J.; LeBlanc-Straceski, J.; Krauter, K.

    1994-12-01

    Keratin proteins constitute intermediate filaments and are the major differentiation products of mammalian epithelial cells. The epithelial keratins are classified into two groups, type I and type II, and one member of each group is expressed in a given epithelial cell differentiation stage. Mutations in type I and type II keratin genes have now been implicated in three different human genetic disorders, epidermolysis bullosa simplex, epidermolytic hyperkeratosis, and epidermolytic palmoplantar keratoderma. Members of the type I keratins are mapped to human chromosome 17, and the type II keratin genes are mapped to chromosome 12. To understand the organization of the type II keratin genes on chromosome 12, we isolated several yeast artificial chromosomes carrying these keratin genes and examined them in detail. We show that eight already known type II keratin genes are located in a cluster at 12q13, and their relative organization reflects their evolutionary relationship. We also determined that a type I keratin gene, KRT8, is located next to its partner, KRT18, in this cluster. Careful examination of the cluster also revealed that there may be a number of additional keratin genes at this locus that have not been described previously. 41 refs., 3 figs., 1 tab.

  7. Distinct Impact of Two Keratin Mutations Causing Epidermolysis Bullosa Simplex on Keratinocyte Adhesion and Stiffness.

    PubMed

    Homberg, Melanie; Ramms, Lena; Schwarz, Nicole; Dreissen, Georg; Leube, Rudolf E; Merkel, Rudolf; Hoffmann, Bernd; Magin, Thomas M

    2015-10-01

    Keratin filaments constitute the major component of the epidermal cytoskeleton from heterodimers of type I and type II keratin subunits. Missense mutations in keratin 5 or keratin 14, highly expressed in the basal epidermis, cause the severe skin blistering disease epidermolysis bullosa simplex (EBS) in humans by rendering the keratin cytoskeleton sensitive to mechanical stress; yet, the mechanisms by which individual mutations cause cell fragility are incompletely understood. Here, we compared the K14p.Arg125Pro with the K5p.Glu477Asp mutation, both giving rise to severe generalized EBS, by stable expression in keratin-free keratinocytes. This revealed distinctly different effects on keratin cytoskeletal organization, in agreement with in vivo observations, thus validating the cell system. Although the K14p.Arg125Pro mutation led to impaired desmosomes, downregulation of desmosomal proteins, and weakened epithelial sheet integrity upon shear stress, the K5p.Glu477Asp mutation did not impair these functions, although causing EBS with squamous cell carcinoma in vivo. Atomic force microscopy demonstrated that K14 mutant cells were even less resistant against deformation compared with keratin-free keratinocytes. Thus, a keratin mutation causing EBS compromises cell stiffness to a greater extent than the lack of keratins. Finally, re-expression of K14 in K14 mutant cells did not rescue the above defects. Collectively, our findings have implications for EBS therapy approaches.

  8. Absence of keratin 19 in mice causes skeletal myopathy with mitochondrial and sarcolemmal reorganization.

    PubMed

    Stone, Michele R; O'Neill, Andrea; Lovering, Richard M; Strong, John; Resneck, Wendy G; Reed, Patrick W; Toivola, Diana M; Ursitti, Jeanine A; Omary, M Bishr; Bloch, Robert J

    2007-11-15

    Intermediate filaments, composed of desmin and of keratins, play important roles in linking contractile elements to each other and to the sarcolemma in striated muscle. We examined the contractile properties and morphology of fast-twitch skeletal muscle from mice lacking keratin 19. Tibialis anterior muscles of keratin-19-null mice showed a small but significant decrease in mean fiber diameter and in the specific force of tetanic contraction, as well as increased plasma creatine kinase levels. Costameres at the sarcolemma of keratin-19-null muscle, visualized with antibodies against spectrin or dystrophin, were disrupted and the sarcolemma was separated from adjacent myofibrils by a large gap in which mitochondria accumulated. The costameric dystrophin-dystroglycan complex, which co-purified with gamma-actin, keratin 8 and keratin 19 from striated muscles of wild-type mice, co-purified with gamma-actin but not keratin 8 in the mutant. Our results suggest that keratin 19 in fast-twitch skeletal muscle helps organize costameres and links them to the contractile apparatus, and that the absence of keratin 19 disrupts these structures, resulting in loss of contractile force, altered distribution of mitochondria and mild myopathy. This is the first demonstration of a mammalian phenotype associated with a genetic perturbation of keratin 19.

  9. Do spotless starlings place feathers at their nests by ultraviolet color?

    PubMed

    Avilés, Jesús M; Parejo, Deseada; Pérez-Contreras, Tomás; Navarro, Carlos; Soler, Juan J

    2010-02-01

    A considerable number of bird species carry feathers to their nests. Feathers' presence in the nests has traditionally been explained by their insulating properties. Recently, however, it has been suggested that feathers carried to the nests by females of the spotted starling (Sturnus unicolor L.) could have an ornamental function based on their ultraviolet (300-400 nm) and human-visible longer wavelength (400-700 nm) coloration. In our population, 95.7% of feathers found inside next-boxes occupied by nesting starlings were rock dove fly feathers. Of these feathers, 82.7% were naturally positioned with their reverse side oriented toward the entrance hole and 42.4% of all found feathers were situated within the nest-cup. Here we experimentally assess the signaling function of ultraviolet coloration of feathers in nests of spotless starlings by providing nests with a number of pigeon flight feathers that were respectively treated on their obverse, reverse, both, or neither side with a UV blocker. Starlings placed 42.5% of the experimental feathers in the nest-cup irrespective of the UV block treatment. Orientation of feathers toward the entrance hole was not related with their ultraviolet radiation. However, feathers placed within the nest-cup were more likely found with their reverse side oriented toward the entrance hole confirming our correlative findings. These results suggest a minor role of ultraviolet coloration on feather location by spotless starlings.

  10. Molecular evidence for an activator–inhibitor mechanism in development of embryonic feather branching

    PubMed Central

    Harris, Matthew P.; Williamson, Scott; Fallon, John F.; Meinhardt, Hans; Prum, Richard O.

    2005-01-01

    The developmental basis of morphological complexity remains a central question in developmental and evolutionary biology. Feathers provide a unique system to analyze the development of complex morphological novelties. Here, we describe the interactions between Sonic hedgehog (Shh) and bone morphogenetic protein 2 (Bmp2) signaling during feather barb ridge morphogenesis. We demonstrate that activator–inhibitor models of Shh and Bmp2 signaling in the tubular feather epithelium are sufficient to explain the initial formation of a meristic pattern of barb ridges and the observed variation in barb morphogenesis in chick natal down feathers. Empirical tests support the assumptions of the model that, within the feather ectoderm, Shh (activator) up-regulates its own transcription and that of Bmp2 (inhibitor), whereas Bmp2 signaling down-regulates Shh expression. More complex models incorporating a second activator and dorsal/ventral polarized modification of activator signaling can produce all of the barb morphogenesis patterns observed during the growth of more complex branched pennaceous feathers: new barb ridge formation, helical growth, and barb ridge fusion. An integrated model of feather morphogenesis and evolution suggests that plumulaceous feather structure evolved by the establishment of activator–inhibitor interactions between Shh and Bmp2 signaling in the basal epithelium of the feather germ. Subsequently, pennaceous feather structure evolved through the integration of barb ridge morphogenesis with a second, local inhibitor and a dorsal/ventral signal gradient within the feather. The model is congruent with paleontological evidence that plumulaceous feathers are primitive to pennaceous feathers. PMID:16087884

  11. Study of Methylene Blue adsorption on keratin nanofibrous membranes.

    PubMed

    Aluigi, A; Rombaldoni, F; Tonetti, C; Jannoke, L

    2014-03-15

    In this work, keratin nanofibrous membranes (mean diameter of about 220nm) were prepared by electrospinning and tested as adsorbents for Methylene Blue through batch adsorption tests. The adsorption capacity of the membranes was evaluated as a function of initial dye concentration, pH, adsorbent dosage, time and temperature. The adsorption capacity increased with increasing the initial dye concentration and pH, while it decreased with increasing the adsorbent dosage and temperature, indicating an exothermic process. The adsorption results indicated that the Langmuir isotherm fitted the experimental data better than the Freundlich and Temkin isotherm models. A mean free energy evaluated through the Dubinin-Radushkevich model of about 16kJmol(-1), indicated a chemisorption process which occurred by ion exchange. The kinetic data were found to fit the pseudo-second-order model better than the pseudo-first-order model. The obtained results suggest that keratin nanofibrous membranes could be promising candidates as dye adsorption filters.

  12. Keratinization Disorders and Genetic Aspects in Palmar and Plantar Keratodermas.

    PubMed

    Stypczyńska, Ewa; Placek, Waldemar; Zegarska, Barbara; Czajkowski, Rafał

    2016-06-01

    Palmoplantar keratoderma (PPK) is a heterogeneous group of hereditary and acquired disorders characterized by abnormal thickening of the palms and soles. There are three clinical patterns: diffuse, focal, and punctuate. Palmoplantar keratodermas can be divided into the following functional subgroups: disturbed gene functions in structural proteins (keratins), cornified envelope (loricrin, transglutaminase), cohesion (plakophilin, desmoplakin, desmoglein 1), cell-to-cell communication (connexins) and transmembrane signal transduction (cathepsin C). Unna-Thost disease is the most common variety of hereditary PPK. Mutations in keratin 1 have been reported in Unna-Thost disease. We report 12 cases in which Unna-Thost disease was diagnosed. Genealogical study demonstrated that the genodermatosis was a familial disease inherited as an autosomal dominant disorder. Dermatological examination revealed yellowish hyperkeratosis on the palms and soles. Oral mucosa, teeth, and nails remained unchanged. Histopathological examination of the biopsy sample taken from the soles of the patients showed orthokeratotic keratosis, hypergranulosis, and acanthosis without epidermolysis.

  13. Influence of microemulsion structure on cystine reactivity with keratin fibres.

    PubMed

    Solans, C; Parra, J L; Erra, P; Azemar, N; Clausse, M; Touraud, D

    1987-10-01

    Summary The activity of thioglycolic acid, incorporated in a microemulsion, towards cystine residues present in keratin proteins has been investigated. In an attempt to relate the structural state of the microemulsions to cystine reactivity, an appropriate model system showing a large microemulsion domain with diverse structures was chosen. The realm of preferentially hydrocarbon-continuous microemulsion-type media was found to induce the highest activity.

  14. An updated nomenclature for keratin-associated proteins (KAPs).

    PubMed

    Gong, Hua; Zhou, Huitong; McKenzie, Grant W; Yu, Zhidong; Clerens, Stefan; Dyer, Jolon M; Plowman, Jeffrey E; Wright, Mathew W; Arora, Reena; Bawden, C Simon; Chen, Yulin; Li, Jinquan; Hickford, Jonathan G H

    2012-01-01

    Most protein in hair and wool is of two broad types: keratin intermediate filament-forming proteins (commonly known as keratins) and keratin-associated proteins (KAPs). Keratin nomenclature was reviewed in 2006, but the KAP nomenclature has not been revised since 1993. Recently there has been an increase in the number of KAP genes (KRTAPs) identified in humans and other species, and increasingly reports of variation in these genes. We therefore propose that an updated naming system is needed to accommodate the complexity of the KAPs. It is proposed that the system is founded in the previous nomenclature, but with the abbreviation sp-KAPm-nL*x for KAP proteins and sp-KRTAPm-n(p/L)*x for KAP genes. In this system "sp" is a unique letter-based code for different species as described by the protein knowledge-based UniProt. "m" is a number identifying the gene or protein family, "n" is a constituent member of that family, "p" signifies a pseudogene if present, "L" if present signifies "like" and refers to a temporary "place-holder" until the family is confirmed and "x" signifies a genetic variant or allele. We support the use of non-italicised text for the proteins and italicised text for the genes. This nomenclature is not that different to the existing system, but it includes species information and also describes genetic variation if identified, and hence is more informative. For example, GenBank sequence JN091630 would historically have been named KRTAP7-1 for the gene and KAP7-1 for the protein, but with the proposed nomenclature would be SHEEP-KRTAP7-1*A and SHEEP-KAP7-1*A for the gene and protein respectively. This nomenclature will facilitate more efficient storage and retrieval of data and define a common language for the KAP proteins and genes from all mammalian species.

  15. Does Water Temperature Affect the Timing and Duration of Remigial Moult in Sea Ducks? An Experimental Approach.

    PubMed

    Viain, Anouck; Guillemette, Magella

    2016-01-01

    Aquatic birds have high cost of thermoregulation, especially during the moulting period, yet the effect of water temperature on the moulting strategy of aquatic birds has rarely been studied. Our general hypothesis is that energy savings associated with lower thermoregulation costs would be allocated to moulting processes. We predicted that aquatic birds moulting in warm water would have a higher level of body reserves, a faster growth rate of feathers, and an earlier remigial moult onset compared with birds moulting in cold water. We used the common eider (Somateria mollissima dresseri), a large sea duck, as the model species. Captive individuals were experimentally exposed to warm (18°C) and cold (8°C) water treatments during a three year period with individuals swapped between treatments. We found a similar feather growth rate for the two water temperature treatments and in contrast to our predictions, eiders exposed to warm water had a lower body mass and showed a delayed onset of remigial moult of approximately 7 days compared with those exposed to cold water. Our data indicate that body mass variations influence the timing of moult in unexpected ways and we suggest that it likely controls the occurrence of wing moult through a hormonal cascade. This study emphasizes the importance of improving our knowledge of the effects of water temperature on remigial moult of aquatic birds, to better assert the potential effects of global warming on their survival.

  16. Does Water Temperature Affect the Timing and Duration of Remigial Moult in Sea Ducks? An Experimental Approach

    PubMed Central

    Viain, Anouck; Guillemette, Magella

    2016-01-01

    Aquatic birds have high cost of thermoregulation, especially during the moulting period, yet the effect of water temperature on the moulting strategy of aquatic birds has rarely been studied. Our general hypothesis is that energy savings associated with lower thermoregulation costs would be allocated to moulting processes. We predicted that aquatic birds moulting in warm water would have a higher level of body reserves, a faster growth rate of feathers, and an earlier remigial moult onset compared with birds moulting in cold water. We used the common eider (Somateria mollissima dresseri), a large sea duck, as the model species. Captive individuals were experimentally exposed to warm (18°C) and cold (8°C) water treatments during a three year period with individuals swapped between treatments. We found a similar feather growth rate for the two water temperature treatments and in contrast to our predictions, eiders exposed to warm water had a lower body mass and showed a delayed onset of remigial moult of approximately 7 days compared with those exposed to cold water. Our data indicate that body mass variations influence the timing of moult in unexpected ways and we suggest that it likely controls the occurrence of wing moult through a hormonal cascade. This study emphasizes the importance of improving our knowledge of the effects of water temperature on remigial moult of aquatic birds, to better assert the potential effects of global warming on their survival. PMID:27177039

  17. Humid microclimates within the plumage of mallard ducks (Anas platyrhynchos) can potentially facilitate long distance dispersal of propagules

    NASA Astrophysics Data System (ADS)

    Coughlan, Neil E.; Kelly, Tom C.; Davenport, John; Jansen, Marcel A. K.

    2015-05-01

    Birds as carriers of propagules are major agents in the dispersal of plants, animals, fungi and microbes. However, there is a lack of empirical data in relation to bird-mediated, epizoochorous dispersal. The microclimate found within the plumage likely plays a pivotal role in survival during flight conditions. To investigate the potential of epizoochory, we have analysed the microclimatic conditions within the plumage of mallard ducks (Anas platyrhynchos). Under similar ambient conditions of humidity and temperature, a sample of mallards showed a consistent microclimatic regime with variation across the body surface. The highest (mean) temperature and specific humidity occurred between feathers of the postpatagium. The lowest humidity was found between feathers of the centre back and the lowest temperature in the crissum. Observed differences in plumage depth and density, and distance from the skin, are all likely to be determining factors of microclimate condition. Specific humidity found within the plumage was on average 1.8-3.5 times greater than ambient specific humidity. Thus, the plumage can supply a microclimate buffered from that of the exterior environment. Extrapolating survival data for Lemna minor desiccation at various temperature and humidity levels to the measured plumage microclimatic conditions of living birds, survival for up to 6 h can be anticipated, especially in crissum, crural and breast plumage. The results are discussed in the context of potential long distance epizoochorous dispersal by A. platyrhynchos and similar species.

  18. Flight feather attachment in rock pigeons (Columba livia): covert feathers and smooth muscle coordinate a morphing wing.

    PubMed

    Hieronymus, Tobin L

    2016-11-01

    Mechanisms for passively coordinating forelimb movements and flight feather abduction and adduction have been described separately from both in vivo and ex vivo studies. Skeletal coordination has been identified as a way for birds to simplify the neuromotor task of controlling flight stroke, but an understanding of the relationship between skeletal coordination and the coordination of the aerodynamic control surface (the flight feathers) has been slow to materialize. This break between the biomechanical and aerodynamic approaches - between skeletal kinematics and airfoil shape - has hindered the study of dynamic flight behaviors. Here I use dissection and histology to identify previously overlooked interconnections between musculoskeletal elements and flight feathers. Many of these structures are well-placed to directly link elements of the passive musculoskeletal coordination system with flight feather movements. Small bundles of smooth muscle form prominent connections between upper forearm coverts (deck feathers) and the ulna, as well as the majority of interconnections between major flight feathers of the hand. Abundant smooth muscle may play a role in efficient maintenance of folded wing posture, and may also provide an autonomically regulated means of tuning wing shape and aeroelastic behavior in flight. The pattern of muscular and ligamentous linkages of flight feathers to underlying muscle and bone may provide predictable passive guidance for the shape of the airfoil during flight stroke. The structures described here provide an anatomical touchstone for in vivo experimental tests of wing surface coordination in an extensively researched avian model species.

  19. Evaluation and experimentation with duck management strategies

    USGS Publications Warehouse

    Nichols, J.D.; Johnson, F.A.

    1989-01-01

    Our knowledge of the effects of hunting regulations on duck populations has been based largely on retrospective studies of historical data. We have reached the limits of what can be learned in this way. Future knowledge gains will likely come about only through experimentation and adaptive management.

  20. A feather precipitation hydrogen isoscape for New Zealand

    NASA Astrophysics Data System (ADS)

    Rogers, K. M.; Wassenaar, L. I.; Soto, D. X.; Bartle, J. A.

    2012-04-01

    Forensic isotopic assays of feathers from historical Maori cloaks are a potential tool to link historical artefacts back to their native locales (Iwi) in New Zealand. In order to test this approach, we sampled feathers from extant museum archived birds of known origin for their feather hydrogen isotopes (δyHf) to assign their regional origin and location over time. We obtained feathers from two non-migratory bird species widely distributed around New Zealand, tui (Prosthemadera novaeseelandiae) and quail (Callipepla californica). Feathers were sampled from archived birds collected between 1880-2002 held in 3 New Zealand museum collections. We determined regression coefficients of δ2H on location, latitude, δ2Hprecipitation, and age. The data showed that ground dwelling quail had higher regression coefficients with respect to latitude (r2=0.46) than the nectar feeding tui (r2=0.39). On the whole, both resident birds showed promise as regional geographical indicators of their habitat (r2=0.58). Year of collection had no meaningful effect on isotopic composition. We conclude that isotopic assays may therefore be used to aid in regional assignments relevant to the interpretation of historical artefacts.

  1. Seeking carotenoid pigments in amber-preserved fossil feathers

    NASA Astrophysics Data System (ADS)

    Thomas, Daniel B.; Nascimbene, Paul C.; Dove, Carla J.; Grimaldi, David A.; James, Helen F.

    2014-06-01

    Plumage colours bestowed by carotenoid pigments can be important for visual communication and likely have a long evolutionary history within Aves. Discovering plumage carotenoids in fossil feathers could provide insight into the ecology of ancient birds and non-avian dinosaurs. With reference to a modern feather, we sought chemical evidence of carotenoids in six feathers preserved in amber (Miocene to mid-Cretaceous) and in a feather preserved as a compression fossil (Eocene). Evidence of melanin pigmentation and microstructure preservation was evaluated with scanning electron and light microscopies. We observed fine microstructural details including evidence for melanin pigmentation in the amber and compression fossils, but Raman spectral bands did not confirm the presence of carotenoids in them. Carotenoids may have been originally absent from these feathers or the pigments may have degraded during burial; the preservation of microstructure may suggest the former. Significantly, we show that carotenoid plumage pigments can be detected without sample destruction through an amber matrix using confocal Raman spectroscopy.

  2. Hormonal treatment and flight feather molt in immature Sandhill Cranes

    USGS Publications Warehouse

    Gee, G.F.; Lewis, J.C.

    1982-01-01

    Molt, the production of a new generation of feathers, is a poorly understood physiological phenomenon in nondomestic birds. Often in large birds like geese, flight is restricted by clipping the primary remiges on 1 wing and flight is restored after the molt when the primaries are replaced. A similar technique would be desirable for use with cranes conditioned for release to the native habitat. However, immature sandhill cranes (Grus canadensis) did not appear to replace their primaries annually; therefore, we studied their flight feather molt (from 4 months to 3.5 years of age) and attempted to influence molting. Under natural conditions tail feathers (rectrices) were replaced annually and all secondaries replaced in 2.5-year-old birds. However, replacement of primaries in immature sandhill cranes appears to be a gradual process beginning the 2nd year; about 33% of the original primaries (present at 10 months of age) persisted in the 3.5-year-oId birds. Pulling out the primaries of immature sandhill cranes induces the growth of new primaries, as is true of many other birds. However, the new primaries were incapable of supporting flight, fell out repeatedly, and those that remained were often deformed. Pulling the primaries, under the influence of tranquilizers and anesthetics to relax the feather papillae, also did not induce normal growth of the replacement primaries. Progesterone (including excessively high doses), thyroxine, and follicle stimulating hormone, although effective in inducing feather replacement in domestic poultry, had no effect on crane molt.

  3. Observations on the Growth of Roughness Elements Into Icing Feathers

    NASA Technical Reports Server (NTRS)

    Vargas, Mario; Tsao, Jen, Ching

    2007-01-01

    This work presents the results of an experiment conducted in the Icing Research Tunnel at NASA Glenn Research Center to understand the process by which icing feathers are formed in the initial stages of ice accretion formation on swept wings. Close-up photographic data were taken on an aluminum NACA 0012 swept wing tip airfoil. Two types of photographic data were obtained: time sequence close-up photographic data during the run and close-up photographic data of the ice accretion at the end of each run. Icing runs were conducted for short ice accretion times from 10 to 180 sec. The time sequence close-up photographic data was used to study the process frame by frame and to create movies of how the process developed. The movies confirmed that at glaze icing conditions in the attachment line area icing feathers develop from roughness elements. The close-up photographic data at the end of each run showed that roughness elements change into a pointed shape with an upstream facet and join on the side with other elements having the same change to form ridges with pointed shape and upstream facet. The ridges develop into feathers when the upstream facet grows away to form the stem of the feather. The ridges and their growth into feathers were observed to form the initial scallop tips present in complete scallops.

  4. Dynamics of mercury in blood and feathers of great skuas

    SciTech Connect

    Bearhop, S.; Ruxton, G.D.; Furness, R.W.

    2000-06-01

    Mercury dynamics in the blood and feathers of captive great skuas, Catharacta skua, were monitored over 56 weeks. Prior to the onset of molt, mercury intake was solely from their maintenance ration of sprats, Sprattus sprattus. For the first half of molt, in addition to mercury intake from sprats, birds were fed different doses of methylmercuric chloride weekly for 20 weeks. During the second half of molt, dosing was stopped and mercury intake was solely from sprats. Blood was sampled throughout the study and feather growth was monitored. Prior to the onset of molt, mercury concentrations increased over the first 51 to 71 d and appeared to level off after this period. Repeated dosing models based on mammalian pharmacokinetics were, in general, too simplistic to be applicable to the birds in the study. During molt, the elimination of mercury from the blood is probably best described by a three-compartment model. Mercury concentrations in feathers were significantly correlated with those in blood at the time of their growth, suggesting that blood and feathers reflect mercury intake over the same time period. Individuals varied in their ability to excrete ingested mercury into the feathers.

  5. [The location of keratins 17 and 8 in the metaplastic proliferates of the endocervix].

    PubMed

    Bulanova, E A; Chipysheva, T A; Ermilova, V D; Gel'shteĭn, V I

    1994-01-01

    Monoclonal antibodies to keratin 8 which is characteristic for glandular epithelium and those to keratin 17 characteristic of basal cells of complex epithelium were used. Material from 14 females after surgery because of ovarian tumours and uterine carcinoma and from 10 females with dysplasias of various degree and uterine carcinoma was investigated. In addition, ectocervix of vaginal portion at a distance from the point of two epithelia junction was studied in 42 samples. It is shown that keratins 8 and 17 are expressed in the ectocervix sporadically and have a basal location. Keratin 8 is expressed in column epithelium of the areas having normal structure of endocervix. Proliferation of subcolumn reserve cells is followed by an active expression of keratin 17. Proliferative multilayer areas with foci of the immature metaplasia, dysplasias and carcinoma in situ are characterized by cells with coexpression of both keratins, i.e. cells with double differentiation (glandular and squamous).

  6. The use of keratin-based wound products on refractory wounds.

    PubMed

    Batzer, Annette T; Marsh, Clive; Kirsner, Robert S

    2016-02-01

    Keratin proteins have been shown to play a key role in wound healing. Controlled keratin gene (KRT) expression promotes cell growth, migration and differentiation, and as an example of the importance of keratin proteins, absence of KRT17 has been shown to delay wound closure. In addition, downregulation of KRT6 and KRT16 in non-healing chronic venous ulcers suggests that deregulation of keratin expression contributes to non-healing phenotype. A sample of 45 chronic wounds of mixed aetiologies presenting in 31 patients were treated with keratin-based novel topical wound healing products. Thirty-seven wounds or 82% of wounds were either healed or reduced in size of >50% during treatment, with 29 (64%) healing completely and an additional 8 wounds experiencing 50% wound size reduction or greater. Of the wounds that responded, 15 required antimicrobial treatment during their course of treatment, suggesting that keratin dressing treatment should be interrupted briefly and then restarted when wound infection occur.

  7. Factors limiting traditional household duck production in Bangladesh.

    PubMed

    Hoque, M A; Skerratt, L F; Rahman, M A; Beg, A B M Rabiul Alam; Debnath, N C

    2010-10-01

    A cross sectional survey of duck production was carried out in 2002 on 771 traditional, semiscavenging household duck farms on the coastal Island of Hatia. We determined the socioeconomic characteristics of duck farmers and their management systems, identified the factors associated with egg production, and measured the level of selected duck diseases and current preventive strategies. Household family size varied from 1 to 14 individuals and women were the main caretakers of ducks. Around 34% of keepers were illiterate. Most duck products (eggs and meat; 85%) were sold at the local market. Duck houses were poorly ventilated and a variety of bedding materials were used. Feed was available in nearby scavenging areas; however, additional feed was frequently supplied by farmers. Almost all farmers (96%) ranked the rainy season as the best time for rearing ducks due to greater feed availability. The annual egg production was 79 eggs per layer with a weight of 48 g and a hatchability rate of 87%. Egg production varied by zone (p < 0.05). The odds of suboptimal egg production was 0.5 times lower in educated farmers (p = 0.001). The odds of suboptimal egg production was 2.5 times more likely in ducks that attained sexual maturity at >22 weeks (p<0.001). Most farmers ranked duck plague as the most important disease, followed by duck cholera, botulism, and duck viral hepatitis. Preventive vaccination was sporadic and used by few farmers (28%). There are significant opportunities for improved duck production on the Island of Hatia and in Bangladesh generally.

  8. Barn owl feathers as biomonitors of mercury: sources of variation in sampling procedures.

    PubMed

    Roque, Inês; Lourenço, Rui; Marques, Ana; Coelho, João Pedro; Coelho, Cláudia; Pereira, Eduarda; Rabaça, João E; Roulin, Alexandre

    2016-04-01

    Given their central role in mercury (Hg) excretion and suitability as reservoirs, bird feathers are useful Hg biomonitors. Nevertheless, the interpretation of Hg concentrations is still questioned as a result of a poor knowledge of feather physiology and mechanisms affecting Hg deposition. Given the constraints of feather availability to ecotoxicological studies, we tested the effect of intra-individual differences in Hg concentrations according to feather type (body vs. flight feathers), position in the wing and size (mass and length) in order to understand how these factors could affect Hg estimates. We measured Hg concentration of 154 feathers from 28 un-moulted barn owls (Tyto alba), collected dead on roadsides. Median Hg concentration was 0.45 (0.076-4.5) mg kg(-1) in body feathers, 0.44 (0.040-4.9) mg kg(-1) in primary and 0.60 (0.042-4.7) mg kg(-1) in secondary feathers, and we found a poor effect of feather type on intra-individual Hg levels. We also found a negative effect of wing feather mass on Hg concentration but not of feather length and of its position in the wing. We hypothesize that differences in feather growth rate may be the main driver of between-feather differences in Hg concentrations, which can have implications in the interpretation of Hg concentrations in feathers. Finally, we recommend that, whenever possible, several feathers from the same individual should be analysed. The five innermost primaries have lowest mean deviations to both between-feather and intra-individual mean Hg concentration and thus should be selected under restrictive sampling scenarios.

  9. Feather Vibration as a Stimulus for Sensing Incipient Separation in Falcon Diving Flight

    DTIC Science & Technology

    2016-07-07

    V-shape some feathers tips may elevate in certain regions of the body. These regions were identi- fied in wind tunnel tests for typical diving...was studied in a wind tunnel to focus on the fluid-structure interaction of feathers located in this sec- tor. The distal ends of the feathers show...feather vibration during flight and the local flow situation. A possible way is to study the bird flight under controlled situation in a wind

  10. Different outcomes of infection of chickens and ducks with a duck-origin H9N2 influenza A virus.

    PubMed

    Wang, J; Li, C C; Diao, Y X; Sun, X Y; Hao, D M; Liu, X; Ge, P P

    2014-01-01

    As the major aquatic and terrestrial hosts for avian influenza viruses (AIVs), ducks and chickens play a critical role in the evolution and spread of the H9N2 virus. However, the outcomes of infection of ducks and chickens with the H9N2 virus are not sufficiently documented. In this study, we compared the outcomes of infection of chickens and Peking ducks with a duck-origin H9N2 virus. The results showed that this virus caused more pronounced clinical signs and histological lesions in chickens. As for the virus shedding, chickens shed more virus in the trachea and less virus in the cloaca in levels of interferon (IFN) γ were found in the trachea of ducks compared with chickens, while comparison with ducks. As for cytokines, namely IFNs and interleukins (IL), higher higher levels of IFN-β, IFN-γ, IL-1β, and IL-6 were observed in the ileum of chickens compared with ducks. Eventually, serum hemagglutination-inhibition (HI) antibody titers were higher in chickens than in ducks. Taken together, ducks and chickens use different strategies in response to the H9N2 virus infection in tissues representing main replication sites of low-pathogenic AIVs. Given the different outcomes of the H9N2 virus infection in ducks and chickens, different measures should be taken in vaccination and treatment.

  11. 50 CFR 20.92 - Personal use of feathers or skins.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 50 Wildlife and Fisheries 6 2010-10-01 2010-10-01 false Personal use of feathers or skins. 20.92... WILDLIFE AND PLANTS (CONTINUED) MIGRATORY BIRD HUNTING Feathers or Skins § 20.92 Personal use of feathers or skins. Any person for his own use may possess, transport, ship, import, and export without...

  12. Do spotless starlings place feathers at their nests by ultraviolet color?

    NASA Astrophysics Data System (ADS)

    Avilés, Jesús M.; Parejo, Deseada; Pérez-Contreras, Tomás; Navarro, Carlos; Soler, Juan J.

    2010-02-01

    A considerable number of bird species carry feathers to their nests. Feathers’ presence in the nests has traditionally been explained by their insulating properties. Recently, however, it has been suggested that feathers carried to the nests by females of the spotted starling ( Sturnus unicolor L.) could have an ornamental function based on their ultraviolet (300-400 nm) and human-visible longer wavelength (400-700 nm) coloration. In our population, 95.7% of feathers found inside next-boxes occupied by nesting starlings were rock dove fly feathers. Of these feathers, 82.7% were naturally positioned with their reverse side oriented toward the entrance hole and 42.4% of all found feathers were situated within the nest-cup. Here we experimentally assess the signaling function of ultraviolet coloration of feathers in nests of spotless starlings by providing nests with a number of pigeon flight feathers that were respectively treated on their obverse, reverse, both, or neither side with a UV blocker. Starlings placed 42.5% of the experimental feathers in the nest-cup irrespective of the UV block treatment. Orientation of feathers toward the entrance hole was not related with their ultraviolet radiation. However, feathers placed within the nest-cup were more likely found with their reverse side oriented toward the entrance hole confirming our correlative findings. These results suggest a minor role of ultraviolet coloration on feather location by spotless starlings.

  13. 75 FR 30013 - South Feather Water and Power Agency; Notice of Availability of Environmental Assessment

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-05-28

    ... Energy Regulatory Commission South Feather Water and Power Agency; Notice of Availability of...), Commission staff has prepared an environmental assessment (EA) regarding South Feather Water and Power Agency... Creek development of the South Feather Power Project (FERC No. 2088). Sly Creek is located on Sly...

  14. 50 CFR 20.92 - Personal use of feathers or skins.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 50 Wildlife and Fisheries 9 2013-10-01 2013-10-01 false Personal use of feathers or skins. 20.92... WILDLIFE AND PLANTS (CONTINUED) MIGRATORY BIRD HUNTING Feathers or Skins § 20.92 Personal use of feathers or skins. Any person for his own use may possess, transport, ship, import, and export without...

  15. 50 CFR 20.92 - Personal use of feathers or skins.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 50 Wildlife and Fisheries 9 2012-10-01 2012-10-01 false Personal use of feathers or skins. 20.92... WILDLIFE AND PLANTS (CONTINUED) MIGRATORY BIRD HUNTING Feathers or Skins § 20.92 Personal use of feathers or skins. Any person for his own use may possess, transport, ship, import, and export without...

  16. 50 CFR 20.92 - Personal use of feathers or skins.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 50 Wildlife and Fisheries 9 2014-10-01 2014-10-01 false Personal use of feathers or skins. 20.92... WILDLIFE AND PLANTS (CONTINUED) MIGRATORY BIRD HUNTING Feathers or Skins § 20.92 Personal use of feathers or skins. Any person for his own use may possess, transport, ship, import, and export without...

  17. 50 CFR 20.92 - Personal use of feathers or skins.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 50 Wildlife and Fisheries 8 2011-10-01 2011-10-01 false Personal use of feathers or skins. 20.92... WILDLIFE AND PLANTS (CONTINUED) MIGRATORY BIRD HUNTING Feathers or Skins § 20.92 Personal use of feathers or skins. Any person for his own use may possess, transport, ship, import, and export without...

  18. Theoretical morphology and development of flight feather vane asymmetry with experimental tests in parrots.

    PubMed

    Feo, Teresa J; Prum, Richard O

    2014-06-01

    Asymmetry in flight feather vane width is a major functional innovation associated with the evolution of flight in the ancestors of birds. However, the developmental and morphological basis of feather shape is not simple, and the developmental processes involved in vane width asymmetry are poorly understood. We present a theoretical model of feather morphology and development that describes the possible ways to modify feather development and produce vane asymmetry. Our model finds that the theoretical morphospace of feather shape is redundant, and that many different combinations of parameters could be responsible for vane asymmetry in a given feather. Next, we empirically measured morphological and developmental model parameters in asymmetric and symmetric feathers from two species of parrots to identify which combinations of parameters create vane asymmetry in real feathers. We found that both longer barbs, and larger barb angles in the relatively wider trailing vane drove asymmetry in tail feathers. Developmentally, longer barbs were the result of an offset of the radial position of the new barb locus, whereas larger barb angles were produced by differential expansion of barbs as the feather unfurls from the tubular feather germ. In contrast, the helical angle of barb ridge development did not contribute to vane asymmetry and could be indicative of a constraint. This research provides the first comprehensive description of both the morphological and developmental modifications responsible for vane asymmetry within real feathers, and identifies key steps that must have occurred during the evolution of vane asymmetry.

  19. [Keratin 8 expression in mouth mucosa hyperkeratosis and squamous cell carcinoma ].

    PubMed

    Babichenko, I I; Grigor'ian, A S; Katushkina, A A

    2011-01-01

    The immunohistochemical study of proliferation and intermediate filament--keratin 8 expressions at oral hyperkeratosis and oral Squamous cell carcinoma (OSCC) has been carried out. It has been shown, that the specific character of keratin 8 expressions can be used in differential diagnosis between oral hyperkeratosis and OSCC. Different types of oral hyperkeratosis (without atypia, SIN1, SIN2 and SIN3) can be differentiated by Ki-67 and keratin 8. We have found the moderate positive correlation between proliferation and a keratin 8 expression in neoplastic epithelial cells.

  20. Ectopic production of hair keratin constitutes Rushton's hyaline bodies in association with hematogenous deposits.

    PubMed

    Sakamoto, Kei; Khanom, Rumana; Hamagaki, Miwako; Yamaguchi, Akira

    2012-09-01

    A Rushton's hyaline body (HB) is a concretion occasionally found in odontogenic cysts. Unspecified substances produced by the lining epithelium or derived from blood components have been suggested as possible causes of HB formation, but the origin of HBs is still elusive. This study aimed to clarify the origin of HBs. Ten specimens with HBs were obtained from 400 odontogenic cysts. HBs were stained by orcein and Congo red. Immunohistochemical examination revealed that HBs were positive for hair keratin and keratin 17. Hair keratin was concentrated in HBs, and cells with hair keratin expression were hardly seen, while cells with keratin 17 expression were observed near HBs. HBs were also positive for hemoglobin alpha chain. The presence of hair keratin in HBs was confirmed by Western blot analysis. The present study suggests that HBs are formed as a consequence of two independent events: unusual alteration of epithelial differentiation so as to provide hair keratin, and hemorrhage so as to provide erythrocytic substances. Although the ectopic production of hair keratin appears more essential, our results reconcile the long-standing debate between two theories, the keratin theory versus the hematogenous theory, concluding that both substances are required for the genesis of HBs, and also suggesting that they might be novel non-pathological amyloidogenic proteins.

  1. Empigen BB: a useful detergent for solubilization and biochemical analysis of keratins.

    PubMed

    Lowthert, L A; Ku, N O; Liao, J; Coulombe, P A; Omary, M B

    1995-01-05

    Intermediate filament (IF) proteins make up some of the most insoluble proteins known, and within the IF protein family, keratins are the least soluble. We compared the efficiency of nonionic, cationic, mixed nonionic and anionic, and zwitterionic detergents in solubilizing keratins from insect cells that express recombinant human keratins and from human colonic cell lines and normal keratinocytes. The cationic detergent cetyltrimethylammonium bromide was similar to the zwitterionic detergent Empigen BB in its ability to efficiently solubilize keratins, but the latter detergent was superior in that it maintained antibody reactivity and allowed for immunoprecipitation of the keratins. Although Nonidet-P40 partially solubilizes keratins, Empigen BB solubilizes a significant amount of keratins not solubilized by Nonidet-P40. In the case of vimentin, differences in solubilization efficiency among the detergents was not as dramatic as with keratins. Our results show that Empigen BB solubilizes a significant amount of epidermal and glandular keratins while preserving antigenicity. This detergent should prove useful for carrying out biochemical and molecular studies on these proteins and may be similarly beneficial for other IF proteins.

  2. Molecular composition and ultrastructure of Jurassic paravian feathers

    PubMed Central

    Lindgren, Johan; Sjövall, Peter; Carney, Ryan M.; Cincotta, Aude; Uvdal, Per; Hutcheson, Steven W.; Gustafsson, Ola; Lefèvre, Ulysse; Escuillié, François; Heimdal, Jimmy; Engdahl, Anders; Gren, Johan A.; Kear, Benjamin P.; Wakamatsu, Kazumasa; Yans, Johan; Godefroit, Pascal

    2015-01-01

    Feathers are amongst the most complex epidermal structures known, and they have a well-documented evolutionary trajectory across non-avian dinosaurs and basal birds. Moreover, melanosome-like microbodies preserved in association with fossil plumage have been used to reconstruct original colour, behaviour and physiology. However, these putative ancient melanosomes might alternatively represent microorganismal residues, a conflicting interpretation compounded by a lack of unambiguous chemical data. We therefore used sensitive molecular imaging, supported by multiple independent analytical tests, to demonstrate that the filamentous epidermal appendages in a new specimen of the Jurassic paravian Anchiornis comprise remnant eumelanosomes and fibril-like microstructures, preserved as endogenous eumelanin and authigenic calcium phosphate. These results provide novel insights into the early evolution of feathers at the sub-cellular level, and unequivocally determine that melanosomes can be preserved in fossil feathers. PMID:26311035

  3. Melanin Concentration Gradients in Modern and Fossil Feathers

    PubMed Central

    Field, Daniel J.; D’Alba, Liliana; Vinther, Jakob; Webb, Samuel M.; Gearty, William; Shawkey, Matthew D.

    2013-01-01

    In birds and feathered non-avian dinosaurs, within-feather pigmentation patterns range from discrete spots and stripes to more subtle patterns, but the latter remain largely unstudied. A ∼55 million year old fossil contour feather with a dark distal tip grading into a lighter base was recovered from the Fur Formation in Denmark. SEM and synchrotron-based trace metal mapping confirmed that this gradient was caused by differential concentration of melanin. To assess the potential ecological and phylogenetic prevalence of this pattern, we evaluated 321 modern samples from 18 orders within Aves. We observed that the pattern was found most frequently in distantly related groups that share aquatic ecologies (e.g. waterfowl Anseriformes, penguins Sphenisciformes), suggesting a potential adaptive function with ancient origins. PMID:23555675

  4. Melanin concentration gradients in modern and fossil feathers.

    PubMed

    Field, Daniel J; D'Alba, Liliana; Vinther, Jakob; Webb, Samuel M; Gearty, William; Shawkey, Matthew D

    2013-01-01

    In birds and feathered non-avian dinosaurs, within-feather pigmentation patterns range from discrete spots and stripes to more subtle patterns, but the latter remain largely unstudied. A ∼55 million year old fossil contour feather with a dark distal tip grading into a lighter base was recovered from the Fur Formation in Denmark. SEM and synchrotron-based trace metal mapping confirmed that this gradient was caused by differential concentration of melanin. To assess the potential ecological and phylogenetic prevalence of this pattern, we evaluated 321 modern samples from 18 orders within Aves. We observed that the pattern was found most frequently in distantly related groups that share aquatic ecologies (e.g. waterfowl Anseriformes, penguins Sphenisciformes), suggesting a potential adaptive function with ancient origins.

  5. Epidermolysis Bullosa Simplex-Type Mutations Alter the Dynamics of the Keratin Cytoskeleton and Reveal a Contribution of Actin to the Transport of Keratin SubunitsD⃞V⃞

    PubMed Central

    Werner, Nicola Susann; Windoffer, Reinhard; Strnad, Pavel; Grund, Christine; Leube, Rudolf Eberhard; Magin, Thomas Michael

    2004-01-01

    Dominant keratin mutations cause epidermolysis bullosa simplex by transforming keratin (K) filaments into aggregates. As a first step toward understanding the properties of mutant keratins in vivo, we stably transfected epithelial cells with an enhanced yellow fluorescent protein-tagged K14R125C mutant. K14R125C became localized as aggregates in the cell periphery and incorporated into perinuclear keratin filaments. Unexpectedly, keratin aggregates were in dynamic equilibrium with soluble subunits at a half-life time of <15 min, whereas filaments were extremely static. Therefore, this dominant-negative mutation acts by altering cytoskeletal dynamics and solubility. Unlike previously postulated, the dominance of mutations is limited and strictly depends on the ratio of mutant to wild-type protein. In support, K14R125C-specific RNA interference experiments resulted in a rapid disintegration of aggregates and restored normal filaments. Most importantly, live cell inhibitor studies revealed that the granules are transported from the cell periphery inwards in an actin-, but not microtubule-based manner. The peripheral granule zone may define a region in which keratin precursors are incorporated into existing filaments. Collectively, our data have uncovered the transient nature of keratin aggregates in cells and offer a rationale for the treatment of epidermolysis bullosa simplex by using short interfering RNAs. PMID:14668478

  6. Morphology of primary feathers in two falcon species

    NASA Astrophysics Data System (ADS)

    Honisch, B.; Bleckmann, H.; Schmitz, H.; Schmitz, A.

    2012-04-01

    Primary feathers allow birds to fly; however, morphology and material properties of theses feathers vary in different bird species. We therefore analysed both morphology and material properties of primary feathers in two raptor species, the peregrine falcon (Falco peregrinus) which is the fastest vertical flyer known, and the kestrel (Falco tinnunculus), using scanning electron microscopy (SEM) and nanoindentation. The program AutoCAD was used for the computation of the moments of inertia. The reduced E-modulus of the cortex of the rachis of the first, fifth, and tenth primary were measured at proximal (10% of total rachis length), central (50%) and distal (75%) cross-sections. In all cross sections the kestrel showed higher E-moduli than the peregrine falcon (values varied between 6.7 and 9.1 GPa). In the primaries, values increased from proximal to central but decreased distally. Looking at the hardness, the kestrel had higher values than the peregrine falcon yet again. The main differences occurred in the first primary. Values ranged between 0.17 and 0.4 GPa. SEM studies revealed that the tenth primary was more stable in the peregrine falcon, featuring more hamuli than the kestrel at all analysed positions and longer hamuli at the distal positions. The higher moments of inertia found in the peregrine falcon caused a much higher bending stiffness in this species. Values were 4.4 to 9.1 times larger in the peregrine falcon than in the kestrel. Because the given structures are responsible for the stability of the feather face it seems that the feathers of F. peregrinus are more robust than those of F. tinnunculus. Even when considering the higher body mass of the peregrine falcon compared to the kestrel (3.4 times), the determined stability of the feather compensates for this problem.

  7. FeatherSail - Design, Development and Future Impact

    NASA Technical Reports Server (NTRS)

    Alhorn, Dean C.; Scheierl, J. M.

    2010-01-01

    To the present day, the idea of using solar sails for space propulsion is still just a concept, but one that provides a great potential for future space exploration missions. Several notable solar propulsion missions and experiments have been performed and more are still in the development stage. Solar Sailing is a method of space flight propulsion, which utilizes the light photons to propel spacecrafts through the vacuum of space. This concept will be tested in the near future with the launch of the NanoSail-D satellite. NanoSail-D is a nano-class satellite, <10kg, which will deploy a thin lightweight sheet of reflective material used to propel the satellite in its low earth orbit. Using the features of the NanoSail-D architecture, a second-generation solar sail design concept, dubbed FeatherSail, has been developed. The goal of the FeatherSail project is to create a sail vehicle with the ability to provide steering from the sails and increase the areal density. The FeatherSail design will utilize the NanoSail-D based extendable boom technology with only one sail on each set of booms. This design also allows each of the four sails to feather as much as ninety degrees. The FeatherSail concept uses deployable solar arrays to generate the power necessary for deep space missions. In addition, recent developments in low power, low temperature Silicon-Germanium electronics provide the capability for long duration deep space missions. It is envisioned that the FeatherSail conceptual design will provide the impetus for future sail vehicles, which may someday visit distant places that mankind has only observed.

  8. Acidic and basic hair/nail ("hard") keratins: their colocalization in upper cortical and cuticle cells of the human hair follicle and their relationship to "soft" keratins

    PubMed Central

    1986-01-01

    Although numerous hair proteins have been studied biochemically and many have been sequenced, relatively little is known about their in situ distribution and differential expression in the hair follicle. To study this problem, we have prepared several mouse monoclonal antibodies that recognize different classes of human hair proteins. Our AE14 antibody recognizes a group of 10-25K hair proteins which most likely corresponds to the high sulfur proteins, our AE12 and AE13 antibodies define a doublet of 44K/46K proteins which are relatively acidic and correspond to the type I low sulfur keratins, and our previously described AE3 antibody recognizes a triplet of 56K/59K/60K proteins which are relatively basic and correspond to the type II low sulfur keratins. Using these and other immunological probes, we demonstrate the following. The acidic 44K/46K and basic 56-60K hair keratins appear coordinately in upper corticle and cuticle cells. The 10-25K, AE14-reactive antigens are expressed only later in more matured corticle cells that are in the upper elongation zone, but these antigens are absent from cuticle cells. The 10-nm filaments of the inner root sheath cells fail to react with any of our monoclonal antibodies and are therefore immunologically distinguishable from the cortex and cuticle filaments. Nail plate contains 10-20% soft keratins in addition to large amounts of hair keratins; these soft keratins have been identified as the 50K/58K and 48K/56K keratin pairs. Taken together, these results suggest that the precursor cells of hair cortex and nail plate share a major pathway of epithelial differentiation, and that the acidic 44K/46K and basic 56-60K hard keratins represent a co- expressed keratin pair which can serve as a marker for hair/nail-type epithelial differentiation. PMID:2432071

  9. Feather mites of Calidris fuscicollis (Aves: Scolopacidae) in Brazil.

    PubMed

    Gomes, S N; Pesenti, T C; Cirne, M P; Müller, G

    2015-11-01

    During the period 2010-2012, eighty individuals of Calidris fuscicollis (Vieillot, 1819) were collected on the southern coast of Rio Grande do Sul, Brazil, with the objective of determining the presence of feather mites. Of the 80 birds examined, 32.5% were infested by mites, identified as Avenzoaria calidridis (Oudemans, 1904) (Avenzoariidae) (31.25%), Montchadskiana securicata (Megnin & Trouessart 1884) (Pterolichidae) (22.5%) and Alloptes limosae (Dubinin, 1951) (Alloptidae) (6.25%). This is the first report of feather mites on Calidris fuscicollis in Brazil.

  10. From buds to follicles: matrix metalloproteinases in developmental tissue remodeling during feather morphogenesis.

    PubMed

    Jiang, Ting-Xin; Tuan, Tai Lan; Wu, Ping; Widelitz, Randall B; Chuong, Cheng-Ming

    2011-06-01

    Organogenesis involves a series of dynamic morphogenesis and remodeling processes. Since feathers exhibit complex forms, we have been using the feather as a model to analyze how molecular pathways and cellular events are used. While several major molecular pathways have been studied, the roles of matrix degrading proteases and inhibitors in feather morphogenesis are unknown. Here we addressed this knowledge gap by studying the temporal and spatial expression of proteases and inhibitors in developing feathers using mammalian antibodies that cross react with chicken proteins. We also investigated the effect of protease inhibitors on feather development employing an in vitro feather bud culture system. The results show that antibodies specific for mammalian MMP2 and TIMP2 stained positive in both feather epithelium and mesenchyme. The staining co-localized in structures of E10-E13 developing feathers. Interestingly, MMP2 and TIMP2 exhibited a complementary staining pattern in developing E15 and E20 feathers and in maturing feather filaments. Although they exhibited a slight delay in feather bud development, similar patterns of MMP2 and TIMP2 staining were observed in in vitro culture explants. The broad spectrum pharmacological inhibitors AG3340 and BB103 (MMP inhibitors) but not Aprotinin (a plasmin inhibitor) showed a reversible effect on epithelium invagination and feather bud elongation. TIMP2, a physiological inhibitor to MMPs, exhibited a similar effect. Markers of feather morphogenesis showed that MMP activity was required for both epithelium invagination and mesenchymal cell proliferation. Inhibition of MMP activity led to an overall delay in the expression of molecules that regulate either early feather bud growth and/or differentiation and thereby produced abnormal buds with incomplete follicle formation. This work demonstrates that MMPs and their inhibitors are not only important in injury repair, but also in development tissue remodeling as demonstrated

  11. Localisation of keratin K78 in the basal layer and first suprabasal layers of stratified epithelia completes expression catalogue of type II keratins and provides new insights into sequential keratin expression.

    PubMed

    Langbein, Lutz; Eckhart, Leopold; Fischer, Heinz; Rogers, Michael A; Praetzel-Wunder, Silke; Parry, David A D; Kittstein, Walter; Schweizer, Juergen

    2016-03-01

    Among the 26 human type II keratins, K78 is the only one that has not yet been explored with regard to its expression characteristics. Here, we show that, at both the transcriptional and translational levels, K78 is strongly expressed in the basal and parabasal cell layers with decreasing intensity in the lower suprabasal cells of keratinising and non-keratinising squamous epithelia and keratinocyte cultures. The same pattern has been detected at the transcriptional level in the corresponding mouse epithelia. Murine K78 protein, which contains an extraordinary large extension of its tail domain, which is unique among all known keratins, is not detectable by the antibody used. Concomitant studies in human epithelia have confirmed K78 co-expression with the classical basal keratins K5 and K14. Similarly, K78 co-expression with the differentiation-related type I keratins K10 (epidermis) and K13 (non-keratinising epithelia) occurs in the parabasal cell layer, whereas that of the corresponding type II keratins K1 (epidermis) and K4 (non-keratinising epithelia) unequivocally starts subsequent to the respective type I keratins. Our data concerning K78 expression modify the classical concept of keratin pair K5/K14 representing the basal compartment and keratin pairs K1/K10 or K4/K13 defining the differentiating compartment of stratified epithelia. Moreover, the K78 expression pattern and the decoupled K1/K10 and K4/K13 expression define the existence of a hitherto unperceived early differentiation stage in the parabasal layer characterized by K78/K10 or K78/K13 expression.

  12. Liposomes containing recombinant E protein vaccine against duck Tembusu virus in ducks.

    PubMed

    Ma, Tengfei; Liu, Yongxia; Cheng, Jia; Liu, Yanhan; Fan, Wentao; Cheng, Ziqiang; Niu, Xudong; Liu, Jianzhu

    2016-04-27

    To obtain an effective vaccine candidate against duck Tembusu viral (DTMUV) disease which causes egg-drop and great economical loss in the Chinese duck industry, liposome vaccines containing recombinant E protein were prepared and assessed in this study. The recombinant plasmid (PET28a-E) was constructed and transformed into BL21 (DE3) cells to produce E proteins. The recombinant E proteins were purified and entrapped by liposomes through reverse-phase evaporation. Eighty-four cherry valley ducks were randomly divided into seven groups and inoculated intramuscularly at one- or seven-day-old with liposomes-E protein or Freund's adjuvant-E protein vaccine. Blood samples were collected from the first week to the tenth week for serum antibody, plasma for viremia, as well as oropharyngeal and cloacal swabs for virus shedding analyses after being challenged with a 10(2.4) 50% tissue culture infective dose (TCID50) of duck Tembusu virus. Results showed that serum antibody level of the liposomes vaccine was higher than the Freund's adjuvant vaccine, and inoculating twice was superior to once; furthermore, the viremia and virus shedding tests also proved that the liposomes vaccine can provide complete protection against DTMUV challenge. These results demonstrated that the liposomes-E protein vaccine could be used as a potential candidate vaccine to prevent DTMUV infection in ducks.

  13. Pathogenicity and genetic characterization of a duck Tembusu virus associated with egg-dropping in Muscovy ducks.

    PubMed

    Shen, Han-Qin; Lin, Wen-Cheng; Wang, Zhan-Xin; Zhang, Kai; Yan, Zhuan-Qiang; Zhou, Qing-Feng; Qin, Jian-Ping; Xie, Qing-Mei; Bi, Ying-Zuo; Chen, Feng

    2016-09-02

    Duck Tembusu virus (DTMUV) has spread to the major duck-farming region in China, causing acute egg-production drop in Chinese duck population. In this study, we characterized a DTMUV strain (named GD2014) isolated from an egg-production drop duck farm in Guangdong province, South China. The virus was pathogenic to Muscovy duck embryos and caused severe egg production drop for laying Muscovy ducks. The genome sequence of GD2014 shared 97-99% homologies with other waterfowl-origin Tembusu viruses, and shared 89% identities with MM1775 strain isolated from mosquito. Phylogenetic analysis of entire open reading frame (ORF), E gene and NS5 gene indicated that GD2014 belonged to Ntaya group. These results have implications for understanding the orgin, emergence and pathogenicity of DTMUV as well as for the development of vaccines and diagnostics based on epidemiological data.

  14. Riemerella anatipestifer infection in domestic ducks in Japan, 2014

    PubMed Central

    CHIKUBA, Takumi; UEHARA, Haru; FUMIKURA, Shintaro; TAKAHASHI, Ken; SUZUKI, Yoshihisa; HOSHINOO, Kaori; YAMAMOTO, Yu

    2016-01-01

    The outbreak of Riemerella anatipestifer (RA) infection has been confirmed in meat-type domestic ducks (Anas platyrhynchos) for the first time in 27 years in Japan. In January 2014, increased mortality in a 14- to 21-day-old duck flock was reported to veterinary officials by the owner. The affected ducks exhibited reduced movement, ataxia and dorsal recumbency with leg paddling. Pathological findings were typical for an RA infection. Fibrinous and heterophilic pericarditis, airsacculitis, perihepatitis, ventriculitis and meningitis were observed. The bacterial isolate from duck organs was identified as RA by PCR-based 16S ribosomal RNA sequencing. PMID:27373315

  15. Diagnosis of duck plague in waterfowl by polymerase chain reaction

    USGS Publications Warehouse

    Hansen, W.R.; Nashold, S.W.; Docherty, D.E.; Brown, S.E.; Knudson, D.L.

    2000-01-01

    A recently developed polymerase chain reaction (PCR) assay was used for diagnosis of duck plague in waterfowl tissues from past and current cases of waterfowl mortality and to identify duck plague virus in combined cloacal/oral-pharyngeal swab samples from healthy mallards (Anas platyrhynchos) after a disease outbreak. The PCR was able to detect viral DNA from all the individual or pooled tissues assayed from 10 waterfowl, including liver and spleen samples from three Muscovy ducks (Cairina moschata domesticus) that did not yield virus isolates. The strong staining intensity of the PCR products from the waterfowl tissues indicated that large amounts of virus were present, even when virus was not isolated. Duck plague DNA was also detected in a cloacal swab sample from a wood duck (Aix sponsa) carcass submitted for diagnosis. The PCR assay identified duck plague DNA in 13 swab samples that produced virus isolates from carrier mallards sampled in 1981 after a duck plague die-off. The duck plague PCR clearly demonstrated the ability to quickly diagnose duck plague in suspect mortality cases and to detect virus shed by carrier waterfowl.

  16. Studies on the quality of duck meat sausages during refrigeration.

    PubMed

    Naveen, Z; Naik, B R; Subramanyam, B V; Reddy, P M

    2016-01-01

    Duck farming is on the raise in the current scenario, but processed products from duck meat are still uncommon to find. Investigating the duck meat qualities during storage will provide information to enhance duck meat utilization. Development of ready-to-eat and ready-to-cook duck meat products is expected to increase and improve non-chicken meat-based protein. The Study was aimed to evaluate the changes in quality characteristics of duck meat sausages preserved by refrigeration (7 ± 1 °C). Duck meat sausages were prepared by utilizing raw and partially cooked duck meat with addition of soy flour at 10% level as a binder. Different quality characteristics like physical and chemical characteristics, proximate composition, and organoleptic characteristics were evaluated. Cooking loss of partially cooked meat sausages was lower than raw duck meat sausages, whereas emulsion stability and 2-thiobarbituric acid (TBA) values of raw duck meat sausages were lesser than partially cooked meat sausages. Cooking loss and emulsion stability decreased in both types of meat sausages, while, 2-TBA values increased as refrigerated storage progressed for 14 days. Percent moisture content of raw duck meat sausages was higher than partially cooked meat sausages, which decreased in both types of meat sausages as refrigerated storage progressed for 14 days. Percent crude protein (CP) and percent ether extract (EE) content of partially cooked duck meat sausages were higher than raw duck meat sausages. Regardless of type of meat used, refrigerated storage of sausages increased CP and EE up to 10th day but decreased upon further storage up to 14th day. Organoleptic scores for raw duck meat sausages were higher than partially cooked duck meat sausages and all the scores decreased with an increase in the storage period. However the scores were within the acceptable limits. The findings prove that, duck meat can be effectively acclaimed as an alternative avenue to meet the escalating

  17. Effects of scalp dermatitis on chemical property of hair keratin

    NASA Astrophysics Data System (ADS)

    Kim, Kyung Sook; Shin, Min Kyung; Park, Hun-Kuk

    2013-05-01

    The effects of scalp dermatitis (seborrheic dermatitis (SD), psoriasis, and atopic dermatitis (AD)) on chemical properties of hair keratin were investigated by Fourier transform infrared (FT-IR) spectroscopy. Hairs were collected from lesional regions affected by SD, psoriasis, and AD and non-lesional regions separately. The hairs with SD were taken from patients with ages of 16-80 years. The ages of patients with psoriasis ranged from 8 to 67 years, and all patients exhibited moderate disease. Hairs with AD were taken from the patients with ages of 24-45 years and the average SCORing atopic dermatitis (SCORAD) was 48.75. Hairs from 20 normal adults were collected as a control. The FT-IR absorbance bands were analyzed by the Gaussian model to obtain the center frequency, half width, height, and area of each band. The height and area of all bands in the spectra were normalized to the amide I centered at 1652 cm-1 to quantitatively analyze the chemical composition of keratin. The spectra of hair with scalp dermatitis were different with that of control, the amide A components centered at 3278 cm-1 were smaller than those of the control. The psoriasis hair showed a large difference in the IR absorbance band between lesional and non-lesional hairs indicating good agreement with the morphological changes. The hairs with diseases did not show differences in the content of cystine, which was centered at 1054 cm-1, from the control. The chemical properties of keratin were not significantly different between the hairs affected by SD, psoriasis, and AD. However, the changes induced by scalp dermatitis were different with weathering. Therefore, FT-IR analysis could be used to screen differences between the physiological and pathological conditions of scalp hair.

  18. Identification of trichoplein, a novel keratin filament-binding protein.

    PubMed

    Nishizawa, Miwako; Izawa, Ichiro; Inoko, Akihito; Hayashi, Yuko; Nagata, Koh-ichi; Yokoyama, Tomoya; Usukura, Jiro; Inagaki, Masaki

    2005-03-01

    Keratins 8 and 18 (K8/18) are major components of the intermediate filaments (IFs) of simple epithelia. We report here the identification of a novel protein termed trichoplein. This protein shows a low degree of sequence similarity to trichohyalin, plectin and myosin heavy chain, and is a K8/18-binding protein. Among interactions between trichoplein and various IF proteins that we tested using two-hybrid methods, trichoplein interacted significantly with K16 and K18, and to some extent with K5, K6a, K8 and K14. In in vitro co-sedimentation assays, trichoplein directly binds to K8/18, but not with vimentin, desmin, actin filaments or microtubules. An antibody raised against trichoplein specifically recognized a polypeptide with a relative molecular mass of 61 kDa in cell lysates. Trichoplein was immunoprecipitated using this antibody in a complex with K8/18 and immunostaining revealed that trichoplein colocalized with K8/18 filaments in HeLa cells. In polarized Caco-2 cells, trichoplein colocalized not only with K8/18 filaments in the apical region but also with desmoplakin, a constituent of desmosomes. In the absorptive cells of the small intestine, trichoplein colocalized with K8/18 filaments at the apical cortical region, and was also concentrated at desmosomes. Taken together, these results suggest that trichoplein is a keratin-binding protein that may be involved in the organization of the apical network of keratin filaments and desmosomes in simple epithelial cells.

  19. PLA/chitosan/keratin composites for biomedical applications.

    PubMed

    Tanase, Constantin Edi; Spiridon, Iuliana

    2014-07-01

    Novel composites based on PLA, chitosan and keratin was obtained via blend preparation. The goal of this contribution was to evaluate mechanical and in vitro behavior of the composites. The results point out composites with improved Young modulus and decreased tensile strength, significant increase in hardness (compared to PLA) and a good uptake of the surface properties. Biological assessments using human osteosarcoma cell line on these composites indicate a good viability/proliferation outcome. Hence preliminary results regarding mechanical behavior and in vitro osteoblast response suggest that these composites might have prospective application in medical field.

  20. Size scaling and stiffness of avian primary feathers: implications for the flight of Mesozoic birds.

    PubMed

    Wang, X; Nudds, R L; Palmer, C; Dyke, G J

    2012-03-01

    The primary feathers of birds are subject to cyclical forces in flight causing their shafts (rachises) to bend. The amount the feathers deflect during flight is dependent upon the flexural stiffness of the rachises. By quantifying scaling relationships between body mass and feather linear dimensions in a large data set of living birds, we show that both feather length and feather diameter scale much closer to predictions for geometric similarity than they do to elastic similarity. Scaling allometry also indicates that the primary feathers of larger birds are relatively shorter and their rachises relatively narrower, compared to those of smaller birds. Two-point bending tests indicated that larger birds have more flexible feathers than smaller species. Discriminant functional analyses (DFA) showed that body mass, primary feather length and rachis diameter can be used to differentiate between different magnitudes of feather bending stiffness, with primary feather length explaining 63% of variance in rachis stiffness. Adding fossil measurement data to our DFA showed that Archaeopteryx and Confuciusornis do not overlap with extant birds. This strongly suggests that the bending stiffness of their primary feathers was different to extant birds and provides further evidence for distinctive flight styles and likely limited flight ability in Archaeopteryx and Confuciusornis.

  1. Developmental expression of chicken FOXN1 and putative target genes during feather development.

    PubMed

    Darnell, Diana K; Zhang, Li S; Hannenhalli, Sridhar; Yaklichkin, Sergey Y

    2014-01-01

    FOXN1 is a member of the forkhead box family of transcription factors. FOXN1 is crucial for hair outgrowth and thymus differentiation in mammals. Unlike the thymus, which is found in all amniotes, hair is an epidermal appendage that arose after the last shared common ancestor between mammals and birds, and hair and feathers differ markedly in their differentiation and gene expression. Here, we show that FOXN1 is expressed in embryonic chicken feathers, nails and thymus, demonstrating an evolutionary conservation that goes beyond obvious homology. At embryonic day (ED) 12, FOXN1 is expressed in some feather buds and at ED13 expression extends along the length of the feather filament. At ED14 FOXN1 mRNA is restricted to the proximal feather filament and is not detectable in distal feather shafts. At the base of the feather, FOXN1 is expressed in the epithelium of the feather sheath and distal barb and marginal plate, whereas in the midsection FOXN1 transcripts are mainly detected in the barb plates of the feather filament. FOXN1 is also expressed in claws; however, no expression was detected in skin or scales. Despite expression of FOXN1 in developing feathers, examination of chick homologs of five putative mammalian FOXN1 target genes shows that, while these genes are expressed in feathers, there is little similarity to the FOXN1 expression pattern, suggesting that some gene regulatory networks may have diverged during evolution of epidermal appendages.

  2. Feather corticosterone content in predatory birds in relation to body condition and hepatic metal concentration.

    PubMed

    Strong, Rebecca J; Pereira, M Glória; Shore, Richard F; Henrys, Peter A; Pottinger, Tom G

    2015-04-01

    This study investigated the feasibility of measuring corticosterone in feathers from cryo-archived raptor specimens, in order to provide a retrospective assessment of the activity of the stress axis in relation to contaminant burden. Feather samples were taken from sparrowhawk Accipiter nisus, kestrel Falco tinnunculus, buzzard Buteo buteo, barn owl Tyto alba, and tawny owl Strix aluco and the variation in feather CORT concentrations with respect to species, age, sex, feather position, and body condition was assessed. In sparrowhawks only, variation in feather CORT content was compared with hepatic metal concentrations. For individuals, CORT concentration (pgmm(-1)) in adjacent primary flight feathers (P5 and P6), and left and right wing primaries (P5), was statistically indistinguishable. The lowest concentrations of CORT were found in sparrowhawk feathers and CORT concentrations did not vary systematically with age or sex for any species. Significant relationships between feather CORT content and condition were observed in only tawny owl and kestrel. In sparrowhawks, feather CORT concentration was found to be positively related to the hepatic concentrations of five metals (Cd, Mn, Co, Cu, Mo) and the metalloid As. There was also a negative relationship between measures of condition and total hepatic metal concentration in males. The results suggest that some factors affecting CORT uptake by feathers remain to be resolved but feather CORT content from archived specimens has the potential to provide a simple effects biomarker for exposure to environmental contaminants.

  3. Indigenous Muscovy ducks in Congo-Brazzaville. 1. A survey of indigenous Muscovy duck management in households in Dolisie City.

    PubMed

    Banga-Mboko, H; Maes, D; Leroy, P L

    2007-02-01

    A cross-sectional study by means of a questionnaire with open-ended questions and multiple-choice questions was used to collect data on the profile of duck keepers, husbandry practices, and performances, opportunities and constraints of Muscovy duck breeding in households (n = 88) in Dolisie city (Congo-Brazzaville). The study confirmed the common observations on traditional poultry keeping such as scavenging during the day and housing overnight. The flock size (7.7 +/- 3 ducks per unit) showed no specialization of husbandry (100% of surveyed flocks were kept for simultaneous production of ducklings, meat and eggs) and a high drake-to-duck ratio (1:3). The hatchability was close to 80.5% +/- 13%, whereas the average number of eggs was 13.2 +/- 5 per clutch. In addition, a high mortality (80%) was observed in ducklings, which was due to poor feeding, lack of veterinary care and housing conditions. Eggs and live ducks were sold by duck farmers in response to the family needs rather than market price. The three most important findings were as follows: (1) duck keepers were mainly men (80% versus 20% of women); (2) there was no evidence of taboo; and (3) the duck as an exotic bird was not proscribed by cultural beliefs, and therefore development of the Muscovy duck in Congo Brazzaville should be unhindered.

  4. Injection of duck recombinant follistatin fusion protein into duck muscle tissues stimulates satellite cell proliferation and muscle fiber hypertrophy.

    PubMed

    Liu, He-he; Wang, Ji-wen; Yu, Hai-yue; Zhang, Rong-ping; Chen, Xi; Jin, Hai-bo; Dai, Fei; Li, Liang; Xu, Feng

    2012-06-01

    Follistatin (FST) can inhibit the expression of myostatin, which is a predominant inhibitor of muscle development. The potential application of myostatin-based technology has been prompted in different ways in agriculture. We previously constructed an expression vector of duck FST and isolated the FST fusion protein. After the protein was purified and refolded, it was added to the medium of duck myoblasts cultured in vitro. The results show that the 3-(4,5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide value of the myoblasts in the duck FST treatment group is higher than that in the control group, which indicates that the duck FST fusion protein exhibits the biological activities that can accelerate myoblast proliferation. To further investigate the roles of duck FST on muscle development, we injected the protein into the duck muscle tissues in vivo. The results show that both the duck muscle fiber cross-sectional area and the satellite cell activation frequency are influenced more in the FST treatment group than they are in the control group. In addition to these phenomena, expression of MyoD and Myf5 were increased, and the expression of myostatin was decreased. Together, these results suggest the potential for using duck FST fusion protein to inhibit myostatin activity and subsequently to enhance muscle growth in vivo. The mechanism by which FST regulates muscle development in the duck is similar to that in mammals and fishes.

  5. Evaluation of different contour feather types for biomonitoring lead exposure in Northern goshawk (Accipiter gentilis) and tawny owl (Strix aluco).

    PubMed

    Debén, Sofía; Angel Fernández, J; Aboal, Jesús R; Carballeira, Alejo

    2012-11-01

    The concentration of Pb was determined in feathers (contour feathers: mantle, pectoral, ventral, and primary- and secondary-coverts) of two sedentary species of raptors in Galicia (NW Spain): the tawny owl (Strix aluco) and the Northern goshawk (Accipiter gentilis). A high degree of intraindividual variability was observed in all types of feathers, with coefficients of variation exceeding 100 percent. The correlations between feather types were too low to enable use of a single type of body feather to predict the concentration of Pb in the other feathers. The number of body feathers required to differentiate individuals on the basis of the concentration of Pb was extremely high, in some cases higher than the number of the particular type of feather in the bird. All of this provides clear evidence that the contour and covert feathers of the raptor species considered cannot be used to biomonitor contamination by Pb, at least in this sample where the overall feather concentration were fairly uniform.

  6. A survey of North American migratory waterfowl for duck plague (duck virus enteritis) virus

    USGS Publications Warehouse

    Brand, Christopher J.; Docherty, Douglas E.

    1984-01-01

    A survey of migratory waterfowl for duck plague (DP) virus was conducted in the Mississippi and Central flyways during 1982 and in the Atlantic and Pacific flyways during 1983. Cloacal and pharyngeal swabs were collected from 3,169 migratory waterfowl in these four flyways, principally mallards (Anas platyrhynchos L.), black ducks (Anas rubripes Brewster), and pintails (Anas acuta L). In addition 1,033 birds were sampled from areas of recurrent DP outbreaks among nonmigratory and captive waterfowl, and 590 from Lake Andes National Wildlife Refuge, the site of the only known major DP outbreak in migratory waterfowl. Duck plague virus was not found in any of the samples. Results support the hypothesis that DP is not established in North American migratory waterfowl as an enzootic disease.

  7. Replication cycle of duck hepatitis A virus type 1 in duck embryonic hepatocytes.

    PubMed

    Yao, Fangke; Chen, Yun; Shi, Jintong; Ming, Ke; Liu, Jiaguo; Xiong, Wen; Song, Meiyun; Du, Hongxu; Wang, Yixuan; Zhang, Shuaibin; Wu, Yi; Wang, Deyun; Hu, Yuanliang

    2016-04-01

    Duck hepatitis A virus type 1 (DHAV-1) is an important agent of duck viral hepatitis. Until recently, the replication cycle of DHAV-1 is still unknown. Here duck embryonic hepatocytes infected with DHAV-1 were collected at different time points, and dynamic changes of the relative DHAV-1 gene expression during replication were detected by real-time PCR. And the morphology of hepatocytes infected with DHAV was evaluated by electron microscope. The result suggested that the adsorption of DHAV-1 saturated at 90 min post-infection, and the virus particles with size of about 50 nm including more than 20 nm of vacuum drying gold were observed on the infected cells surface. What's more, the replication lasted around 13 h after the early protein synthesis for about 5h, and the release of DHAV-1 was in steady state after 32 h. The replication cycle will enrich the data for DVH control and provide the foundation for future studies.

  8. Novel duck parvovirus identified in Cherry Valley ducks (Anas platyrhynchos domesticus), China.

    PubMed

    Li, Chuanfeng; Li, Qi; Chen, Zongyan; Liu, Guangqing

    2016-10-01

    An unknown infectious disease in Cherry Valley ducks (Anas platyrhynchos domesticus) characterized by short beak and strong growth retardation occurred in China during 2015. The causative agent of this disease, tentatively named duck short beak and dwarfism syndrome (DSBDS), as well as the evolutionary relationships between this causative agent and all currently known avian-origin parvoviruses were clarified by virus isolation, transmission electron microscope (TEM) observation, analysis of nuclear acid type, (RT-)PCR identification, whole genome sequencing, and NS1 protein sequences-based phylogenetic analyses. The results indicated that the causative agent of DSBDS is closely related with the goose parvovirus-like virus, which is divergent from all currently known avian-origin parvoviruses and should be a novel duck parvovirus (NDPV).

  9. Post-epizootic surveys of waterfowl for duck plague (duck virus enteritis)

    USGS Publications Warehouse

    Brand, C.J.; Docherty, D.E.

    1988-01-01

    Surviving birds from nine duck plague outbreaks in urban and confined waterfowl were sampled for duck plague (DP) virus and DP antibody during 1979-86. Duck plague virus was found in combined oral and cloacal swabs of birds from three outbreaks, and DP-neutralizing antibody was demonstrated in some birds from all nine outbreaks. Greater prevalence of DP antibody and higher titers were found in survivors from confined populations than from free-flying urban populations. Free-flying waterfowl from within 52 km of four DP outbreak sites were also sampled; virus was not found in any birds, but DP antibody was found in urban waterfowl in the vicinity of an outbreak in Potterville, Michigan. No evidence of exposure to or shedding of DP virus in migratory waterfowl was found in two regions where DP appears enzootic in urban and confined waterfowl (Eastern Shore of Maryland and the vicinity of Sacramento, California).

  10. A cis-Regulatory Mutation of PDSS2 Causes Silky-Feather in Chickens

    PubMed Central

    Feng, Chungang; Gao, Yu; Dorshorst, Ben; Song, Chi; Gu, Xiaorong; Li, Qingyuan; Li, Jinxiu; Liu, Tongxin; Rubin, Carl-Johan; Zhao, Yiqiang; Wang, Yanqiang; Fei, Jing; Li, Huifang; Chen, Kuanwei; Qu, Hao; Shu, Dingming; Ashwell, Chris; Da, Yang; Andersson, Leif; Hu, Xiaoxiang; Li, Ning

    2014-01-01

    Silky-feather has been selected and fixed in some breeds due to its unique appearance. This phenotype is caused by a single recessive gene (hookless, h). Here we map the silky-feather locus to chromosome 3 by linkage analysis and subsequently fine-map it to an 18.9 kb interval using the identical by descent (IBD) method. Further analysis reveals that a C to G transversion located upstream of the prenyl (decaprenyl) diphosphate synthase, subunit 2 (PDSS2) gene is causing silky-feather. All silky-feather birds are homozygous for the G allele. The silky-feather mutation significantly decreases the expression of PDSS2 during feather development in vivo. Consistent with the regulatory effect, the C to G transversion is shown to remarkably reduce PDSS2 promoter activity in vitro. We report a new example of feather structure variation associated with a spontaneous mutation and provide new insight into the PDSS2 function. PMID:25166907

  11. Boreal feather mosses secrete chemical signals to gain nitrogen.

    PubMed

    Bay, Guillaume; Nahar, Nurun; Oubre, Matthieu; Whitehouse, Martin J; Wardle, David A; Zackrisson, Olle; Nilsson, Marie-Charlotte; Rasmussen, Ulla

    2013-10-01

    The mechanistic basis of feather moss-cyanobacteria associations, a main driver of nitrogen (N) input into boreal forests, remains unknown. Here, we studied colonization by Nostoc sp. on two feather mosses that form these associations (Pleurozium schreberi and Hylocomium splendens) and two acrocarpous mosses that do not (Dicranum polysetum and Polytrichum commune). We also determined how N availability and moss reproductive stage affects colonization, and measured N transfer from cyanobacteria to mosses. The ability of mosses to induce differentiation of cyanobacterial hormogonia, and of hormogonia to then colonize mosses and re-establish a functional symbiosis was determined through microcosm experiments, microscopy and acetylene reduction assays. Nitrogen transfer between cyanobacteria and Pleurozium schreberi was monitored by secondary ion mass spectrometry (SIMS). All mosses induced hormogonia differentiation but only feather mosses were subsequently colonized. Colonization on Pleurozium schreberi was enhanced during the moss reproductive phase but impaired by elevated N. Transfer of N from cyanobacteria to their host moss was observed. Our results reveal that feather mosses likely secrete species-specific chemo-attractants when N-limited, which guide cyanobacteria towards them and from which they gain N. We conclude that this signalling is regulated by N demands of mosses, and serves as a control of N input into boreal forests.

  12. Feather and beak dystrophy and necrosis in cockatoos: clinicopathologic evaluations.

    PubMed

    Jacobson, E R; Clubb, S; Simpson, C; Walsh, M; Lothrop, C D; Gaskin, J; Bauer, J; Hines, S; Kollias, G V; Poulos, P

    1986-11-01

    Several species of imported and captive-bred southeast Asian cockatoos with feather and beak disease (FBD) were evaluated. In recently emerging stained feathers from affected birds, intracytoplasmic magenta to basophilic inclusions of various sizes were found in macrophages and basophil-like cells within the pulp and feather epidermis. Occasionally, amphophilic intranuclear inclusions were seen within degenerated feather epidermal cells. On the basis of electron microscopic findings, intracytoplasmic inclusions were not membrane bound and consisted of crystalline arrays of viral particles (17 to 22 nm in diameter). On the basis of size and conformation, viral particles most closely resembled those of parvovirus or picornavirus. Consistent hematologic or serum enzyme differences were not found among affected or healthy cockatoos. Compared with findings in healthy cockatoos, cockatoos with FBD had significantly lower serum protein concentrations, and results of serum protein electrophoresis indicated that birds with FBD had significantly lower concentrations of prealbumin and gamma-globulin fractions. Mean pre- and post-ACTH plasma corticosterone concentrations of cockatoos with FBD were not significantly different from those of healthy cockatoos. In 8 of 9 affected cockatoos evaluated, serum T4 concentrations before and after thyrotropin stimulation were considered normal.

  13. 50 CFR 20.91 - Commercial use of feathers.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... game authorities, except that: (a) No person shall purchase, sell, barter, or offer to purchase, sell, or barter for millinery or ornamental use the feathers of migratory game birds taken under authority... mounted specimens of migratory game birds taken under authority of this part....

  14. 50 CFR 20.91 - Commercial use of feathers.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... game authorities, except that: (a) No person shall purchase, sell, barter, or offer to purchase, sell, or barter for millinery or ornamental use the feathers of migratory game birds taken under authority... mounted specimens of migratory game birds taken under authority of this part....

  15. 50 CFR 20.91 - Commercial use of feathers.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... game authorities, except that: (a) No person shall purchase, sell, barter, or offer to purchase, sell, or barter for millinery or ornamental use the feathers of migratory game birds taken under authority... mounted specimens of migratory game birds taken under authority of this part....

  16. Harvest and dynamics of duck populations

    USGS Publications Warehouse

    Sedinger, James S.; Herzog, Mark P.

    2012-01-01

    The role of harvest in the dynamics of waterfowl populations continues to be debated among scientists and managers. Our perception is that interested members of the public and some managers believe that harvest influences North American duck populations based on calls for more conservative harvest regulations. A recent review of harvest and population dynamics of North American mallard (Anas platyrhynchos) populations (Pöysä et al. 2004) reached similar conclusions. Because of the importance of this issue, we reviewed the evidence for an impact of harvest on duck populations. Our understanding of the effects of harvest is limited because harvest effects are typically confounded with those of population density; regulations are typically most liberal when populations are greatest. This problem also exists in the current Adaptive Harvest Management Program (Conn and Kendall 2004). Consequently, even where harvest appears additive to other mortality, this may be an artifact of ignoring effects of population density. Overall, we found no compelling evidence for strong additive effects of harvest on survival in duck populations that could not be explained by other factors.

  17. Survival of postfledging female American black ducks

    USGS Publications Warehouse

    Longcore, J.R.; McAuley, D.G.; Frazer, C.

    1991-01-01

    We equipped 106 hatching-year (HY), female, black ducks (Anas rubripes) with transmitters during 1985-87 and monitored survival from late August to mid-December on a lightly hunted area on the Maine-New Brunswick border. The 1985-87 estimate of survival (hunting losses included) was 0.593, and when losses from hunting were censored it was 0.694. Survival in August-September was 0.987; by 31 October survival declined to 0.885, and by 30 November it was 0.718. Most nonhunting mortality was caused by predators (21/41, 53.2%); there were 14 deaths (34.1%) from mammals or unknown predators and 7 (17.1%) from raptors. Hunting caused 13 (31. 7%) deaths. Ducks with lowest mass had the lowest survival. The estimate of survival for postfledging female black ducks, when multiplied with interval survival rates for hunting, winter, and breeding periods, produced an annual survival estimate of 0.262, about 12% lower than that (0.38) based on analysis of banding data.

  18. Cysteine Prevents the Reduction in Keratin Synthesis Induced by Iron Deficiency in Human Keratinocytes.

    PubMed

    Miniaci, Maria Concetta; Irace, Carlo; Capuozzo, Antonella; Piccolo, Marialuisa; Di Pascale, Antonio; Russo, Annapina; Lippiello, Pellegrino; Lepre, Fabio; Russo, Giulia; Santamaria, Rita

    2016-02-01

    L-cysteine is currently recognized as a conditionally essential sulphur amino acid. Besides contributing to many biological pathways, cysteine is a key component of the keratin protein by its ability to form disulfide bridges that confer strength and rigidity to the protein. In addition to cysteine, iron represents another critical factor in regulating keratins expression in epidermal tissues, as well as in hair follicle growth and maturation. By focusing on human keratinocytes, the aim of this study was to evaluate the effect of cysteine supplementation as nutraceutical on keratin biosynthesis, as well as to get an insight on the interplay of cysteine availability and cellular iron status in regulating keratins expression in vitro. Herein we demonstrate that cysteine promotes a significant up-regulation of keratins expression as a result of de novo protein synthesis, while the lack of iron impairs keratin expression. Interestingly, cysteine supplementation counteracts the adverse effect of iron deficiency on cellular keratin expression. This effect was likely mediated by the up-regulation of transferrin receptor and ferritin, the main cellular proteins involved in iron homeostasis, at last affecting the labile iron pool. In this manner, cysteine may also enhance the metabolic iron availability for DNA synthesis without creating a detrimental condition of iron overload. To the best of our knowledge, this is one of the first study in an in vitro keratinocyte model providing evidence that cysteine and iron cooperate for keratins expression, indicative of their central role in maintaining healthy epithelia.

  19. Removal of Pb(II) from water using keratin colloidal solution obtained from wool.

    PubMed

    Sekimoto, Yuri; Okiharu, Tomoki; Nakajima, Haruka; Fujii, Toshihiro; Shirai, Koji; Moriwaki, Hiroshi

    2013-09-01

    The aim of this study is to investigate the use of keratin colloidal solution, which was obtained from wool, for the removal of Pb(II) from water. The addition of keratin colloidal solution (15 g L(-1), 0.30 mL) to a Pb(II) solution (1.0 mM, 0.90 mL, pH 5.0) resulted in the formation and precipitation of a Pb-keratin aggregate. Measurement of the Pb(II) and protein concentrations in the supernatant solution revealed that 88 and 99 % of the Pb(II) and keratin protein were removed from the solution, respectively. The maximum Pb(II) uptake capacity of keratin in the colloidal solution was 43.3 mg g(-1). In addition, the Pb-keratin aggregate was easily decomposed via the addition of nitric acid, which enabled the recovery of Pb(II). However, aggregation did not occur in solutions with Pb(II) concentrations below 0.10 mM. Therefore, we used a keratin colloidal solution encapsulated in a dialysis cellulose tube to remove Pb(II) from 0.10 mM solutions, which enabled the removal of 95 % of the Pb(II). From these results, we conclude that keratin colloidal solution is useful for the treatment of water polluted with Pb(II).

  20. Mammoth hair: stability of alpha-keratin structure and constituent proteins.

    PubMed

    Gillespie, J M

    1970-12-04

    Hair from a woolly mammoth (Mammuthus primigenius, age about 32,000 years) retains the ordered structure characteristic of alpha-keratins, but the proteins of this hair differ in composition from and are smaller than similar proteins isolated from other keratins, for example, elephant hair. It is suggested that these changes have been caused by limited proteolysis.

  1. The role of keratinized tissue and attached gingiva in maintaining periodontal/peri-implant health.

    PubMed

    Marquez, Ignacio Christian

    2004-01-01

    Although the band of keratinized tissue and attached gingiva is determined genetically, it may be affected by the presence of plaque-associated inflammation or by the action of certain mechanical interventions. This article reviews variations in the width of keratinized tissue and attached gingiva and their clinical significance regarding periodontal/peri-implant health.

  2. Skin fragility and impaired desmosomal adhesion in mice lacking all keratins.

    PubMed

    Bär, Janina; Kumar, Vinod; Roth, Wera; Schwarz, Nicole; Richter, Miriam; Leube, Rudolf E; Magin, Thomas M

    2014-04-01

    Keratins perform major structural and regulatory functions in epithelia. Owing to redundancy, their respective contribution to epidermal integrity, adhesion, and cell junction formation has not been addressed in full. Unexpectedly, the constitutive deletion of type II keratins in mice was embryonic lethal ∼ E9.5 without extensive tissue damage. This prompted us to analyze keratin functions in skin where keratins are best characterized. Here, we compare the mosaic and complete deletion of all type II keratins in mouse skin, with distinct consequences on epidermal integrity, adhesion, and organismal survival. Mosaic knockout (KO) mice survived ∼ 12 days while global KO mice died perinatally because of extensive epidermal damage. Coinciding with absence of keratins, epidermal fragility, inflammation, increased epidermal thickness, and increased proliferation were noted in both strains of mice, accompanied by significantly smaller desmosomes. Decreased desmosome size was due to accumulation of desmosomal proteins in the cytoplasm, causing intercellular adhesion defects resulting in intercellular splits. Mixing different ratios of wild-type and KO keratinocytes revealed that ∼ 60% of keratin-expressing cells were sufficient to maintain epithelial sheets under stress. Our data reveal a major contribution of keratins to the maintenance of desmosomal adhesion and epidermal integrity with relevance for the treatment of epidermolysis bullosa simplex and other keratinopathies.

  3. The width of clinically-defined keratinized gingiva in the mixed dentition.

    PubMed

    Bosnjak, Andrija; Jorgić-Srdjak, Ksenija; Maricević, Tomislav; Plancak, Darije

    2002-01-01

    Some authors have noticed a clear decrease of the width of keratinized gingiva when they compared the width over deciduous and newly erupted permanent teeth. The aim of this cross-sectional study was to assess the width of keratinized gingiva over permanent and deciduous teeth present in 6 to 11-year old children in an urban environment. The greatest width of keratinized gingiva was found over deciduous canines and permanent incisors. When comparing the width of keratinized gingiva over deciduous canines and molars and permanent first incisors and first molars, statistically significant differences were found only between 6- and 11-year-old groups. The findings do not seem to support previously published data, but do suggest that periodontal mucogingival surgery is not needed before the patient reaches the adult age, since there is a tendency of an increase of the width of keratinized gingiva.

  4. Click chemistry modification of natural keratin fibers for sustained shrink-resist performance.

    PubMed

    Yu, Dan; Cai, Jackie Y; Church, Jeffrey S; Wang, Lijing

    2015-01-01

    This paper introduces a novel chemical treatment for achieving sustained shrink-resist performance on natural keratin fibers. The new treatment involves the controlled reduction of keratin in the cuticle region of the fiber, and the application of a water soluble diacrylate, namely glycerol 1,3-diglycerolate diacrylate (GDA), on the reduced keratin substrate. The acrylate groups of the GDA react with cysteine residues in the reduced keratin through thiol-ene click reactions at room temperature, leading to GDA grafting and the formation of GDA crosslinks in the keratin structure. The modified substrates were characterized by infrared spectroscopy and scanning electron microscopy, and assessed for its shrink-resistance and wet burst strength. This chemical modification has shown to alter the fiber surface morphology and hydrophilicity, resulting in substantially improved shrink-resistance with good fiber strength retention. Possible shrink-resistance mechanisms were also discussed.

  5. Allometry of the Duration of Flight Feather Molt in Birds

    PubMed Central

    Rohwer, Sievert; Ricklefs, Robert E.; Rohwer, Vanya G.; Copple, Michelle M.

    2009-01-01

    We used allometric scaling to explain why the regular replacement of the primary flight feathers requires disproportionately more time for large birds. Primary growth rate scales to mass (M) as M 0.171, whereas the summed length of the primaries scales almost twice as fast (M 0.316). The ratio of length (mm) to rate (mm/day), which would be the time needed to replace all the primaries one by one, increases as the 0.14 power of mass (M 0.316/M 0.171 = M 0.145), illustrating why the time required to replace the primaries is so important to life history evolution in large birds. Smaller birds generally replace all their flight feathers annually, but larger birds that fly while renewing their primaries often extend the primary molt over two or more years. Most flying birds exhibit one of three fundamentally different modes of primary replacement, and the size distributions of birds associated with these replacement modes suggest that birds that replace their primaries in a single wave of molt cannot approach the size of the largest flying birds without first transitioning to a more complex mode of primary replacement. Finally, we propose two models that could account for the 1/6 power allometry between feather growth rate and body mass, both based on a length-to-surface relationship that transforms the linear, cylindrical growing region responsible for producing feather tissue into an essentially two-dimensional structure. These allometric relationships offer a general explanation for flight feather replacement requiring disproportionately more time for large birds. PMID:19529759

  6. Module Based Complexity Formation: Periodic Patterning in Feathers and Hairs

    PubMed Central

    Chuong, Cheng-Ming; Yeh, Chao-Yuan; Jiang, Ting-Xin; Widelitz, Randall

    2012-01-01

    Patterns describe order which emerges from homogeneity. Complex patterns on the integument are striking because of their visibility throughout an organism's lifespan. Periodic patterning is an effective design because the ensemble of hair or feather follicles (modules) allows the generation of complexity, including regional variations and cyclic regeneration, giving the skin appendages a new lease on life. Spatial patterns include the arrangements of feathers and hairs in specified number, size, and spacing. We explore how a field of equivalent progenitor cells can generate periodically arranged modules based on genetic information, physical-chemical rules and developmental timing. Reconstitution experiments suggest a competitive equilibrium regulated by activators / inhibitors involving Turing reaction-diffusion. Temporal patterns result from oscillating stem cell activities within each module (micro-environment regulation), reflected as growth (anagen) and resting (telogen) phases during the cycling of feather and hair follicles. Stimulating modules with activators initiates the spread of regenerative hair waves, while global inhibitors outside each module (macro-environment) prevent this. Different wave patterns can be simulated by Cellular Automata principles. Hormonal status and seasonal changes can modulate appendage phenotypes, leading to “organ metamorphosis”, with multiple ectodermal organ phenotypes generated from the same precursors. We discuss potential evolutionary novel steps using this module based complexity in several amniote integument organs, exemplified by the spectacular peacock feather pattern. We thus explore the application of the acquired knowledge of patterning in tissue engineering. New hair follicles can be generated after wounding. Hairs and feathers can be reconstituted through self-organization of dissociated progenitor cells. PMID:23539312

  7. 3D motion analysis of keratin filaments in living cells

    NASA Astrophysics Data System (ADS)

    Herberich, Gerlind; Windoffer, Reinhard; Leube, Rudolf; Aach, Til

    2010-03-01

    We present a novel and efficient approach for 3D motion estimation of keratin intermediate filaments in vitro. Keratin filaments are elastic cables forming a complex scaffolding within epithelial cells. To understand the mechanisms of filament formation and network organisation under physiological and pathological conditions, quantitative measurements of dynamic network alterations are essential. Therefore we acquired time-lapse series of 3D images using a confocal laser scanning microscope. Based on these image series, we show that a dense vector field can be computed such that the displacements from one frame to the next can be determined. Our method is based on a two-step registration process: First, a rigid pre-registration is applied in order to compensate for possible global cell movement. This step enables the subsequent nonrigid registration to capture only the sought local deformations of the filaments. As the transformation model of the deformable registration algorithm is based on Free Form Deformations, it is well suited for modeling filament network dynamics. The optimization is performed using efficient linear programming techniques such that the huge amount of image data of a time series can be efficiently processed. The evaluation of our results illustrates the potential of our approach.

  8. The clinical significance of keratinized gingiva around dental implants.

    PubMed

    Greenstein, Gary; Cavallaro, John

    2011-10-01

    Whether or not keratinized tissue is needed around dental implants to maintain peri-implant health is a controversial subject. To clarify this issue a search was conducted for clinical trials that appraised the significance ofkeratinized gingiva (KG) around teeth and dental implants. A critical assessment of the data revealed that the literature is replete with studies that contradict one another with respect to the need for KG as it relates to survivability of implants, gingival response to plaque, inflammation, probing depths, recession, and loss of bone. When groups of patients with and without KG were compared with respect to various clinical parameters, a statistically significant better result in the presence of KG could be interpreted to indicate that having KG is advantageous. However, quantitative differences between groups with and without KG were usually very small. Overall, the data was interpreted to indicate that some patients may need augmentation of keratinized tissue to maintain peri-implant health. Ultimately, the decision to augment KG is a judgment call that needs to be made by the treating clinician, because there are not enough data to facilitate development of definitive guidelines relevant to this subject. Apparently, the need for KG is patient specific, and at present there is no method to reliably predict who would benefit from tissue augmentation.

  9. Onset of re-epithelialization after skin injury correlates with a reorganization of keratin filaments in wound edge keratinocytes: defining a potential role for keratin 16

    PubMed Central

    1996-01-01

    Injury to stratified epithelia causes a strong induction of keratins 6 (K6) and 16 (K16) in post-mitotic keratinocytes located at the wound edge. We show that induction of K6 and K16 occurs within 6 h after injury to human epidermis. Their subsequent accumulation in keratinocytes correlates with the profound reorganization of keratin filaments from a pan-cytoplasmic distribution to one in which filaments are aggregated in a juxtanuclear location, opposite to the direction of cell migration. This filament reorganization coincides with additional cytoarchitectural changes and the onset of re-epithelialization after 18 h post-injury. By following the assembly of K6 and K16 in vitro and in cultured cells, we find that relative to K5 and K14, a well- characterized keratin pair that is constitutively expressed in epidermis, K6 and K16 polymerize into short 10-nm filaments that accumulate near the nucleus, a property arising from K16. Forced expression of human K16 in skin keratinocytes of transgenic mice causes a retraction of keratin filaments from the cell periphery, often in a polarized fashion. These results imply that K16 may not have a primary structural function akin to epidermal keratins. Rather, they suggest that in the context of epidermal wound healing, the function of K16 could be to promote a reorganization of the cytoplasmic array of keratin filaments, an event that precedes the onset of keratinocyte migration into the wound site. PMID:8636216

  10. Investigating the microstructure of keratin extracted from wool: peptide sequence (MALDI-TOF/TOF) and protein conformation (FTIR)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Keratin was extracted from wool by reduction with 2-mercaptoethanol. It was isolated as intact keratin and characterized by its similar molecular weight, protein composition, and secondary structure to native keratin. Gel electrophoresis patterns and MALDI-TOF/TOF peptide sequences provided the ide...

  11. Duck hunters' perceptions of risk for avian influenza, Georgia, USA.

    PubMed

    Dishman, Hope; Stallknecht, David; Cole, Dana

    2010-08-01

    To determine duck hunters'risk for highly pathogenic avian influenza, we surveyed duck hunters in Georgia, USA, during 2007-2008, about their knowledge, attitudes, and practices. We found they engage in several practices that could expose them to the virus. Exposures and awareness were highest for those who had hunted >10 years.

  12. Duck Hunters’ Perceptions of Risk for Avian Influenza, Georgia, USA

    PubMed Central

    Stallknecht, David; Cole, Dana

    2010-01-01

    To determine duck hunters’ risk for highly pathogenic avian influenza, we surveyed duck hunters in Georgia, USA, during 2007–2008, about their knowledge, attitudes, and practices. We found they engage in several practices that could expose them to the virus. Exposures and awareness were highest for those who had hunted >10 years. PMID:20678324

  13. Molecular cloning and characterization of duck interleukin-17

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Interleukin-17 (IL-17) belonging to the Th17 family is a proinflammatory cytokine produced by activated T cells. A 1034-bp cDNA encoding duck IL-17 (duIL-17) was cloned from ConA-activated splenic lymphocytes of ducks. The encoded protein, predicted to consisted of 169 amino acids, displayed a molec...

  14. Duck plague epizootics in the United States, 1967-1995

    USGS Publications Warehouse

    Converse, K.A.; Kidd, Gregory A.

    2001-01-01

    In 1967, the first confirmed diagnosis of duck plague (DP) in the USA was made from pekin ducks (Anas platyrhynchos domesticus) on commercial duck farms on Long Island, New York. Within 10 mo, DP was confirmed as the cause of death in migratory waterfowl on a Long Island bay. This paper reviews 120 DP epizootics reported from 1967 to 1995 that involved waterfowl species native to North America or were reported in areas with free-flying waterfowl at risk. Duck plague epizootics occurred in 21 states with the greatest number reported in Maryland (29), New York (18), California (16), and Pennsylvania (13). The greatest frequency of epizootics (86%) was detected during the months of March to June. At least 40 waterfowl species were affected with the highest frequency of epizootics reported in captive or captive-reared ducks including muscovy ducks (Cairina moschata) (68%), mallard ducks (A. platyrhynchos) (18%) and black ducks (A. rubripes) (14%). The greatest number of waterfowl died in three epizootics that involved primarily migratory birds in 1967 and 1994 in New York (USA) and 1973 in South Dakota (USA). The greatest number of DP epizootics reported since 1967 appear to have involved flocks of non-migratory rather than migratory waterfowl; therefore, in our opinion it remains unknown if DP is enzootic in either non-migratory or migratory waterfowl.

  15. Vaccination of domestic ducks against H5N1 HPAI

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Domestic ducks play an important role in the epidemiology of H5N1 and H5N8 highly pathogenic avian influenza (HPAI) viruses, and therefore, successful control of HPAI in ducks is vital for the eradication of the disease in poultry. Vaccination can be used as a tool for supporting eradication by inc...

  16. The effects of harvest regulations on behaviors of duck hunters

    USGS Publications Warehouse

    Haugen, Matthew T.; Powell, Larkin A.; Vrtiska, Mark P.; Pope, Kevin L.

    2015-01-01

    Uncertainty exists as to how duck harvest regulations influence waterfowl hunter behavior. We used the U.S. Fish and Wildlife Service’s Parts Collection Survey to examine how harvest regulations affected behaviors of Central Flyway duck hunters. We stratified hunters into ranked groups based on seasonal harvest and identified three periods (1975–1984, 1988–1993, 2002–2011) that represented different harvest regulations (moderate, restrictive, and liberal, respectively; season length and daily bag limits smallest in restrictive seasons and largest in liberal seasons). We examined variability of seven measures of duck hunter behaviors across the periods: days harvesting ducks, daily harvest, hunter mobility, mallard (Anas platyrhynchos) selectivity, gender selectivity, daily female mallard harvest, and timing of harvest. Hunters reported harvesting ducks on more days, at a higher efficiency, and in slightly more counties during liberal seasons relative to restrictive and moderate seasons. We provide evidence to suggest that future regulation change will affect hunter behaviors.

  17. Toward a Deuterium Feather Isoscape for Sub-Saharan Africa: Progress, Challenges and the Path Ahead

    PubMed Central

    Gutiérrez-Expósito, Carlos; Ramírez, Francisco; Afán, Isabel; Forero, Manuela G.; Hobson, Keith A.

    2015-01-01

    A key challenge to the application of continent-wide feather isoscapes for geographic assignment of migrant birds is the lack of ground-truthed samples. This is especially true for long-distance Palearctic-Afrotropical migrants. We used spatially-explicit information on the δ2H composition of archived feathers from Green-backed/Grey-backed Camaroptera, to create a feather δ2H isoscape for sub-Saharan Africa. We sampled from 34 out of 41 sub-Saharan countries, totaling 205 sampling localities. Feather samples were obtained from museum collections (n = 224, from 1950 to 2014) for δ2H assay. Region, altitude, annual rainfall and seasonal patterns in precipitation were revealed as relevant explanatory variables for spatial patterns in feather δ2H. Predicted feather δ2H values ranged from -4.0 ‰ to -63.3 ‰, with higher values observed in the Great Rift Valley and South Africa, and lower values in central Africa. Our feather isoscape differed from that modelled previously using a precipitation δ2H isoscape and an assumed feather-to-precipitation calibration, but the relatively low model goodness fit (F10,213 = 5.98, p<0.001, R2 = 0.18) suggests that other, non-controlled variables might be driving observed geographic patterns in feather δ2H values. Additional ground-truthing studies are therefore recommended to improve the accuracy of the African feather δ2H isoscape. PMID:26356677

  18. Mercury in wing and tail feathers of hatch-year and adult tidal marsh sparrows.

    PubMed

    Warner, Sarah E; Shriver, W Gregory; Olsen, Brian J; Greenberg, Russell G; Taylor, Robert J

    2012-11-01

    We estimated mercury exposure and bioaccumulation in sparrow feathers to determine variation among age groups, between sparrow species, and between feather types. Results of feather mercury studies in piscivorous birds indicate that mercury concentrations tend to increase with age and differ between feather types; however, data for insectivorous birds are lacking. We estimated mercury exposure of two insectivorous and sympatric tidal marsh sparrows: coastal plain swamp sparrow (Melospiza georgiana nigrescens), and seaside sparrow (Ammodramous maritimus). Tidal marshes have favorable conditions for mercury methlyation, thus it is likely that tidal marsh sparrows are exposed to methylmercury. We found no difference in mercury concentrations between males and female birds of both species. Adult swamp sparrow feather mercury concentrations did not differ among adult age groups; therefore, mercury was not found to increase with age in sparrows at the site. Hatch-year birds had significantly greater feather mercury concentrations compared with adult birds for both species. Mercury concentrations in adult seaside sparrows were twice as high as those in adult swamp sparrows suggesting species-specific variation, although concentrations in hatch-year sparrow species did not differ. Mercury concentrations differed between feather types in adults of both species. The first primary feather of both species had at least three times greater mercury concentrations than the outer tail feather possibly reflecting varying depuration rates with feather type.

  19. Bristles before down: a new perspective on the functional origin of feathers.

    PubMed

    Persons, Walter S; Currie, Philip J

    2015-04-01

    Over the course of the last two decades, the understanding of the early evolution of feathers in nonavian dinosaurs has been revolutionized. It is now recognized that early feathers had a simple form comparable in general structure to the hairs of mammals. Insight into the prevalence of simple feathers throughout the dinosaur family tree has gradually arisen in tandem with the growing evidence for endothermic dinosaur metabolisms. This has led to the generally accepted opinion that the early feather coats of dinosaurs functioned as thermo insulation. However, thermo insulation is often erroneously stated to be a likely functional explanation for the origin of feathers. The problem with this explanation is that, like mammalian hair, simple feathers could serve as insulation only when present in sufficiently high concentrations. The theory therefore necessitates the origination of feathers en masse. We advocate for a novel origin theory of feathers as bristles. Bristles are facial feathers common among modern birds that function like mammalian tactile whiskers, and are frequently simple and hair-like in form. Bristles serve their role in low concentrations, and therefore offer a feasible first stage in feather evolution.

  20. Toward a Deuterium Feather Isoscape for Sub-Saharan Africa: Progress, Challenges and the Path Ahead.

    PubMed

    Gutiérrez-Expósito, Carlos; Ramírez, Francisco; Afán, Isabel; Forero, Manuela G; Hobson, Keith A

    2015-01-01

    A key challenge to the application of continent-wide feather isoscapes for geographic assignment of migrant birds is the lack of ground-truthed samples. This is especially true for long-distance Palearctic-Afrotropical migrants. We used spatially-explicit information on the δ2H composition of archived feathers from Green-backed/Grey-backed Camaroptera, to create a feather δ2H isoscape for sub-Saharan Africa. We sampled from 34 out of 41 sub-Saharan countries, totaling 205 sampling localities. Feather samples were obtained from museum collections (n = 224, from 1950 to 2014) for δ2H assay. Region, altitude, annual rainfall and seasonal patterns in precipitation were revealed as relevant explanatory variables for spatial patterns in feather δ2H. Predicted feather δ2H values ranged from -4.0 ‰ to -63.3 ‰, with higher values observed in the Great Rift Valley and South Africa, and lower values in central Africa. Our feather isoscape differed from that modelled previously using a precipitation δ2H isoscape and an assumed feather-to-precipitation calibration, but the relatively low model goodness fit (F10,213 = 5.98, p<0.001, R2 = 0.18) suggests that other, non-controlled variables might be driving observed geographic patterns in feather δ2H values. Additional ground-truthing studies are therefore recommended to improve the accuracy of the African feather δ2H isoscape.

  1. The 50- and 58-kdalton keratin classes as molecular markers for stratified squamous epithelia: cell culture studies

    PubMed Central

    1983-01-01

    The keratins are a highly heterogeneous group of proteins that form intermediate filaments in a wide variety of epithelial cells. These proteins can be divided into at least seven major classes according to their molecular weight and their immunological reactivity with monoclonal antibodies. Tissue-distribution studies have revealed a correlation between the expression of specific keratin classes and different morphological features of in vivo epithelial differentiation (simple vs. stratified; keratinized vs. nonkeratinized). Specifically, a 50,000- and a 58,000-dalton keratin class were found in all stratified epithelia but not in simple epithelia, and a 56,500- and a 65-67,000-dalton keratin class were found only in keratinized epidermis. To determine whether these keratin classes can serve as markers for identifying epithelial cells in culture, we analyzed cytoskeletal proteins from various cultured human cells by the immunoblot technique using AE1 and AE3 monoclonal antikeratin antibodies. The 56,500- and 65-67,000-dalton keratins were not expressed in any cultured epithelial cells examined so far, reflecting the fact that none of them underwent morphological keratinization. The 50,000- and 58,000-dalton keratin classes were detected in all cultured cells that originated from stratified squamous epithelia, but not in cells that originated from simple epithelia. Furthermore, human epidermal cells growing as a monolayer in low calcium medium continued to express the 50,000- and 58,000-dalton keratin classes. These findings suggest that the 50,000- and 58,000-dalton keratin classes may be regarded as "permanent" markers for stratified squamous epithelial cells (keratinocytes), and that the expression of these keratin markers does not depend on the process of cellular stratification. The selective expression of the 50,000- and 58,000-dalton keratin classes, which are synthesized in large quantities on a per cell basis, may explain the high keratin content of

  2. Apoptosis induction in duck tissues during duck hepatitis A virus type 1 infection.

    PubMed

    Sheng, X D; Zhang, W P; Zhang, Q R; Gu, C Q; Hu, X Y; Cheng, G F

    2014-03-01

    To investigate the role of apoptosis in duck viral hepatitis pathogenesis, 4- and 21-d-old ducks were inoculated with duck hepatitis A virus serotype 1 and killed at 2, 6, 12, 24, and 48 h postinfection. TdT-mediated dUTP nick-end labeling was used to detect apoptosis cells. Expression profiles of apoptosis-related genes including caspase-3, -8, -9, and Bcl-2 in spleen, bursa of Fabricius, liver, and the quantity of virus in blood were examined using real-time PCR. The TdT-mediated dUTP nick-end labeling analysis indicated there was a significant difference of apoptotic cells between treatments and controls. The same difference also appeared in virus amount variation in blood during infection. Gene expression analysis revealed that the apoptosis-related gene expression profile was different in the 2 groups, and also different between various organs. This study suggested that apoptosis may play an important role in duck hepatitis A virus serotype 1 infection, and apoptosis suppression might facilitate virus multiplication, resulting in the highest virus concentration in the host.

  3. Epidemiology and molecular characterisation of duck hepatitis A virus from different duck breeds in Egypt.

    PubMed

    Erfan, Ahmed M; Selim, Abdullah A; Moursi, Mohamed K; Nasef, Soad A; Abdelwhab, E M

    2015-06-12

    Duck hepatitis virus (DHV) is an acute highly contagious disease of ducklings caused by three distinct serotypes of duck hepatitis A virus (DHAV), a member of the RNA family Picornaviridae, where serotype 1 is the most widespread serotype worldwide. To date, little if any is known about the prevalence and genetic characterisation of DHAV outside Asia. The current study describes surveillance on DHV in 46 commercial duck farms in Egypt with a history of high mortality in young ducklings from 3 to 15 day-old from 2012 to 2014. Clinical samples were examined by generic RT-PCR assays followed by partial sequence analysis of the 5'UTR, VP1 and 3D genes of the vaccine strain and 15 field viruses. The overall positive rate was 37% (n=17/46). All duck breeds (Pekin, Muscovy, Mallard and Green Winged) were susceptible to the disease with mortality ranged from 15% to 96.7%. Sequence and phylogenetic analyses indicated that the Egyptian strains cluster in the DHAV serotype 1 with Asian viruses and distinguishable from the vaccine strains. So far, this is the first report on the genetic characterisation of DHAV in Egypt. This study may be useful to better understand the epidemiology and evolution of DHAV.

  4. Expression and immunohistochemical distribution of duck plague virus glycoprotein gE in infected ducks.

    PubMed

    Chang, Hua; Cheng, Anchun; Wang, Mingshu; Xiang, Jun; Xie, Wei; Shen, Fuxiao; Jia, Renyong; Zhu, Dekang; Luo, Qihui; Zhou, Yi; Chen, Xiaoyue

    2011-03-01

    To determine the distribution of duck plague virus (DPV) gE protein in paraformaldehyde-fixed, paraffin-embedded tissues of experimentally DPV-infected ducks, an indirect immunoperoxidase assay was established to detect glycoprotein E (gE) protein for the first time. The rabbit anti-His-gE serum, raised against the recombinant His-gE fusion protein expressed in Escherichia coli BL21 (DE3), was prepared and purified. Western blotting and indirect immunofluorescence analysis showed that the anti-His-gE serum had a high level of reactivity and specificity and could be used as the first antibody for further experiments to study the distribution of DPV gE protein in DPV-infected tissues. A number of DPV gE proteins were distributed in the bursa of Fabricius, thymus, spleen, liver, esophagus, duodenum, jejunum, ileum, and kidney of DPV-infected ducks and a few DPV gE were distributed in the Harders glands, myocardium, cerebrum, and lung, whereas the gE was not seen in the skin, muscle, and pancreas. Moreover, DPV gE was expressed abundantly in the cytoplasm of lymphocytes, reticulum cells, macrophages, epithelial cells, and hepatocytes. The present study may be useful not only for describing the characteristics of gE expression and distribution in infected ducks but also for understanding the pathogenesis of DPV.

  5. An investigation of duck circovirus and co-infection in Cherry Valley ducks in Shandong Province, China.

    PubMed

    Zhang, Xingxiao; Jiang, Shijin; Wu, Jiaqiang; Zhao, Qin; Sun, Yani; Kong, Yibo; Li, Xiaoxia; Yao, Meiling; Chai, Tongjie

    2009-01-13

    The co-infection of duck circovirus (DuCV) with Riemerella anatipestifer (RA) or/and Escherichia coli (E. coli) or/and duck hepatitis virus I (DHV-I) in Cherry Valley ducks in China's Shandong Province was investigated by using polymerase-chain-reaction (PCR)-based methods. For this study, 742 ducks sampled at random from 70 duck farms during 2006-2007 were examined using PCR and dot-blot hybridisation (DBH) tests. Overall the DuCV infection rate was 33.29%. Compared with those at 2 weeks of age, the ducks at 3-4 weeks of age were more susceptible to DuCV infection. Compared with the DuCV-negative ones, the DuCV-positive ducks had a higher rate of infection by DHV-I (25.5% vs. 7.475%), RA (23.48% vs. 8.28%) and E. coli (16.19% vs. 4.85%). This investigation shows that DuCV infection is common in Cherry Valley ducks on some farms in Shandong Province.

  6. Evidence of possible vertical transmission of Tembusu virus in ducks.

    PubMed

    Zhang, Ying; Li, Xiuli; Chen, Hao; Ti, Jinfeng; Yang, Guoping; Zhang, Lu; Lu, Yunjian; Diao, Youxiang

    2015-09-30

    In 2013, Tembusu virus (TMUV) infection was successively observed on several breeding duck farms in Shandong province, China. Affected ducks showed consistently acute anorexia, diarrhea and egg production drop. 125 hatching eggs produced by TMUV infected breeding ducks from four duck farms were collected. Among them, 35 hatching eggs were selected randomly from all before incubation for vitelline membrane samples collection. The rest of 90 hatching eggs were incubated routinely. As a result, 16 hatching eggs were found non-embryonated, 28 duck embryos died during incubation and 46 newly hatched ducklings were obtained. Vitelline membranes of non-embryonated hatching eggs, vitelline membrane, brain or liver samples of dead embryos and brain samples of newly hatched ducklings were collected for virus detection. Samples collected from one egg, embryo or duckling were treated as one. Consequently, 18 of 35 (51.43%) hatching eggs, 2 of 16 (12.50%) non-embryonated duck eggs, 17 of 28 (60.71%) dead duck embryos and 5 of 46 (10.87%) newly hatched ducklings were detected positive for TMUV using NS3-based RT-PCR. Overall, 42 of 125 (33.6%) eggs were positive for TMUV. A virus strain, designated as TMUV-SDDE, was isolated from one of these dead duck embryos which were detected TMUV positive. The results of phylogenetic analysis showed that E gene of TMUV-SDDE virus was closely related to other TMUV strains isolated in China during 2010-2013. Pathogenicity studies showed that TMUV-SDDE strain was virulent to ducklings. This is the first report that TMUV is isolated from duck embryos. The findings provide evidence of possible vertical transmission of TMUV from breeding ducks to ducklings.

  7. Feather pecking in domestic fowl is genetically related to locomotor activity levels: implications for a hyperactivity disorder model of feather pecking.

    PubMed

    Kjaer, Joergen B

    2009-09-01

    Feather pecking is a major welfare problem in egg production. Genetic lines differing in the level of feather pecking have been developed by genetic selection. In two experiments correlated responses in locomotor activity were investigated. Firstly, general locomotor activity was estimated using electronic transponders. A total of 325 pullets from three lines: an unselected control line (CON), a line selected for low levels of feather pecking (LFP) and a line selected for high levels of feather pecking (HFP) during 6 generations, were reared in mixed line groups and activity was recorded from 13 to 17 weeks of age using antennas placed in the litter. Locomotor activity was significantly higher in the HFP and significantly lower in the LFP compared to the CON line (lsmeans 0.72 vs. 0.62 vs. 0.57 records per hen per h for HFP, CON and LFP respectively). In a second experiment locomotion was recorded in 40 chickens from the LFP and the HFP line at 5 weeks of age during day time from 09.00 to 16.00 h using a very precise computer facilitated tracking system. Distance travelled was found to be significantly higher in the high feather pecking line compared to the low feather pecking line (lsmeans 122 vs. 99 m per hour in HFP and LFP respectively). These results are discussed in relation to the ontogeny of feather pecking and a hyperactivity disorder model of feather pecking is suggested.

  8. Expression and distribution of the duck enteritis virus UL51 protein in experimentally infected ducks.

    PubMed

    Shen, Chanjuan; Cheng, Anchun; Wang, Mingshu; Xu, Chao; Jia, Renyong; Chen, Xiaoyue; Zhu, Dekang; Luo, Qihui; Cui, Hengmin; Zhou, Yi; Wang, Yin; Xu, Zhiwen; Chen, Zhengli; Wang, Xiaoyu

    2010-06-01

    To determine the expression and distribution of tegument proteins encoded by duck enteritis virus (DEV) UL51 gene in tissues of experimentally infected ducks, for the first time, an immunoperoxidase staining method to detect UL51 protein (UL51p) in paraffin-embedded tissues is reported. A rabbit anti-UL51 polyclonal serum, raised against a recombinant 6-His-UL51 fusion protein expressed in Escherichia coli, was prepared, purified, and used as primary antibodies. Fifty-eight 30-day-old DEV-free ducks were intramuscularly inoculated with the pathogenic DEV CHv strain as infection group, and two ducks were selected as preinfection group. The tissues were collected at sequential time points between 2 and 480 hr postinoculation (PI) and prepared for immunoperoxidase staining. DEV UL51p was first found in the spleen and liver at 8 hr PI; in the bursa of Fabricius and thymus at 12 hr PI; in the Harders glands, esophagus, small intestine (including the duodenum, jejunum, and ileum), and large intestine (including the caecum and rectum) at 24 hr PI; in the glandularis ventriculus at 48 hr PI; and in the pancreas, cerebrum, kidney, lung, and myocardium at 72 hr PI. Throughout the infection process, the UL51p was not seen in the muscle. Furthermore, the intensity of positive staining of DEV UL51p antigen in various tissues increased sharply from 8 to 96 hr PI, peaked during 120-144 hr PI, and then decreased steadily from 216 to 480 hr PI, suggesting that the expressional levels of DEV UL51p in systemic organs have a close correlation with the progression of duck virus enteritis (DVE) disease. A number of DEV UL51p was distributed in the bursa of Fabricius, thymus, spleen, liver, esophagus, small intestine, and large intestine of DEV-infected ducks, whereas less DEV UL51p was distributed in the Harders glands, glandularis ventriculus, cerebrum, kidney, lung, pancreas, and myocardium of DEV-infected ducks. Moreover, DEV UL51p can be expressed in the cytoplasm of various types

  9. Red fox predation on breeding ducks in midcontinent North America

    USGS Publications Warehouse

    Sargeant, Alan B.; Allen, Stephen H.; Eberhardt, Robert T.

    1984-01-01

    Red fox (Vulpes vulpes) predation on nesting ducks was assessed by examining 1,857 adult duck remains found at 1,432 fox rearing dens from 1968 to 1973. Dabbling ducks were much more vulnerable to foxes than diving ducks. Dabbling ducks (1,798) found at dens consisted of 27% blue-winged teals (Anas discors), 23% mallards (A. platyrhynchos), 20% northern pintails (A. acuta), 9% northern shovelers (Spatula clypeata), 8% gadwalls (A. strepera), 3% green-winged teals (A. crecca), 2% American wigeons (A. americana), and 10% unidentified. Relative abundance of individual species and nesting chronology were the most important factors affecting composition of ducks taken by foxes. Seventy-six percent of 1,376 adult dabbling ducks and 40% of 30 adult diving ducks for which sex was determined were hens. In western North Dakota and western South Dakota, 65% of mallard and northern pintail remains found at dens were hens compared with 76% in eastern North Dakota and eastern South Dakota (P < 0.05). Percentage hens varied among the 5 most common dabbling ducks found at dens. In eastern North Dakota and eastern South Dakota, where predation on ducks was greatest, an average of 64% of gadwall, 73% of northern pintail, 81% of blue-winged teal, 81% of mallard, and 90% of northern shoveler remains found at dens were hens. Percentage hens among duck remains found at dens increased as the duck nesting season progressed. Numbers of adult ducks found at individual dens ranged from 0 to 67. The average number of ducks found in and around den entrances was used as an index of fox predation rates on ducks. Predation rate indices ranged from 0.01 duck/den in Iowa to 1.80 ducks/den in eastern North Dakota. Average annual predation rate indices for dabbling ducks in a 3-county intensive study area in eastern North Dakota were closely correlated with May pond numbers (r = 0.874, P < 0.10) and duck population size (r = 0.930, P < 0.05), but all species were not affected in the same manner or to

  10. Complete genome sequence of a novel flavivirus, duck tembusu virus, isolated from ducks and geese in china.

    PubMed

    Yun, Tao; Zhang, Dabing; Ma, Xuejun; Cao, Zhenzhen; Chen, Liu; Ni, Zheng; Ye, Weicheng; Yu, Bin; Hua, Jionggang; Zhang, Yan; Zhang, Cun

    2012-03-01

    Duck tembusu virus (DTMUV) is an emerging agent that causes a severe disease in ducks. We report herein the first complete genome sequences of duck tembusu virus strains YY5, ZJ-407, and GH-2, isolated from Shaoxing ducks, breeder ducks, and geese, respectively, in China. The genomes of YY5, ZJ-407, and GH-2 are all 10,990 nucleotides (nt) in length and encode a putative polyprotein of 3,426 amino acids. It is flanked by a 5' and a 3' noncoding region (NCR) of 94 and 618 nt, respectively. Knowledge of the whole sequence of DTMUV will be useful for further studies of the mechanisms of virus replication and pathogenesis.

  11. Band reporting probablilities of mallards, American black ducks, and wood ducks in eastern North America

    USGS Publications Warehouse

    Garrettson, Pamela R.; Raftovich, Robert V.; Hines, James; Zimmerman, Guthrie S.

    2014-01-01

    Estimates of band reporting probabilities are used for managing North American waterfowl to convert band recovery probabilities into harvest probabilities, which are used to set harvest regulations. Band reporting probability is the probability that someone who has shot and retrieved a banded bird will report the band. This probability can vary relative to a number of factors, particularly the inscription on the band and the ease with which it can be reported. Other factors, such as geographic reporting region, and species and sex of the bird may also play a role. We tested whether reporting probabilities of wood ducks (Aix sponsa) and American black ducks (black ducks; Anas rubripes) differed from those of mallards (Anas platyrhynchos) and whether band reporting varied geographically or by the sex of the banded bird. In the analysis of spatially comparable wood duck and mallard data, a band reporting probability of 0.73 (95% CI = 0.67–0.78) was appropriate for use across species, sex, and reporting region within the United States. In the black duck–mallard comparison, the band reporting probability of black ducks in Eastern Canada (0.50, 95% CI = 0.44–0.57) was lower than in the Eastern United States (0.73, 95% CI = 0.62–0.83). These estimates reflected an increase in overall band reporting probability following the addition of a toll-free telephone number to band inscriptions. Lower reporting in Eastern Canada may be because of cultural, linguistic, or logistical barriers.

  12. Transient structures of keratins from hoof and horn influence their self association and supramolecular assemblies.

    PubMed

    Kakkar, Prachi; Balaraman, Madhan; Shanmugam, Ganesh

    2016-12-01

    Keratins as fibrous proteins, offer structural integrity to various tissues in providing the functional role of protection or load bearing. This work is a prelude to understand the structure - property correlation for a wide variety of keratins. The kinetics of aggregation of bovine hoof keratin (KF) and horn keratin (KR) were monitored by different biophysical methods. pH dependent studies indicated that initially both keratins existed in pre-aggregated form and the efficiency of aggregation decreased with increasing pH. The size of the aggregates was found to be larger in KF compared to KR. UV-vis and particle size analysis clearly revealed that the pre-aggregated forms of KF and KR dissociated to intermediate transient structures with smaller aggregate size, which acted as stronger nucleating agents for further self association of the keratins to form higher order supramolecular assemblies. Conformational analysis indicated that there was no significant conformational change during the aggregation of KF and KR. Morphology of the KF aggregates showed fractal arrangement while KR aggregates formed an ordered structure with no particular arrangement. To the best of our knowledge, this is the first report which shows an interesting and unique observation on changes in the structure during self-association of keratins.

  13. Collagen and keratin polypeptide models for assessing the natural and artificial protein decay of organic materials.

    PubMed

    Fotou, Evmorfia; Sakarellos-Daitsiotis, Maria; Ioakeimoglou, Eleni; Tziamourani, Eleni; Malea, Ekaterini; Panayiaris, George; Panou-Pomonis, Eugenia

    2016-11-01

    Among the materials constituting the natural and cultural heritage, organic materials of proteinaceous origin as bone (collagen), parchment and woolen textiles (keratin) are the most susceptible to damage and decay because of their exposure to air pollution, inappropriate values of ambient temperature, humidity and light. Aiming at contributing to the development of a reliable and reproducible immunoassay for the evaluation of collagen and keratin decay, three polypeptide models of these proteins were designed, synthesized and studied. Polypeptide [Pro-Ser(OBzl)-Gly]n incorporates the typical motif Pro-X-Gly of collagen; polypeptide [Pro-Cys(Acm)-Gly]n is a model of the C-terminal domain of type I keratin, corresponding to the repeating unit Pro-Cys-X of keratin, while polypeptide Ac-YRSGGGFGYRSGGGFGYRS-βAla-NH2 encloses the characteristic repeating sequence GGGFGYRS of the N-terminal part of Type II keratin. These polypeptides may be considered as simplified models that mimic fragments of collagen and keratin resulting from artificial and natural ageing or decay. It is concluded that high recognition of anti-polypeptide antibodies, produced after immunizations, by the bone, parchment and textile samples is indicative of high deterioration, while high anti-collagen or anti-keratin recognition is indicative of low deterioration. Copyright © 2016 European Peptide Society and John Wiley & Sons, Ltd.

  14. Tissue specificity of epithelial keratins: differential expression of mRNAs from two multigene families.

    PubMed Central

    Kim, K H; Rheinwald, J G; Fuchs, E V

    1983-01-01

    Human epithelial cells cultured from stratified and simple squamous tissues all produce keratins of 40,000 to 58,000 daltons, but within this range the number and sizes vary with different epithelial cells. We have shown that this tissue-specific variation in the keratins is not due to posttranslational modification or processing, but rather to the differential expression of a family of heterogeneous but closely related mRNAs. All of these epithelial keratin mRNAs can be further grouped into two distinct subfamilies by their ability to hybridize with either of two cloned epidermal keratin cDNAs. All of the keratin mRNAs hybridize to one or the other, but not both, of the two cloned cDNAs. However, the mRNAs within each group hybridize with varying degrees of stringency, indicating that they are of similar but not identical sequence. Both types of keratin mRNAs are always expressed in every epithelial cell line studied, suggesting that filament assembly is dependent on the presence of both types of keratins. Within each of these two groups, the slight sequence differences in each class may reflect subtle tissue-specific variations in the structural and functional requirements of the epithelial cytoskeleton. Images PMID:6190074

  15. Different Duck Species Infected Intramuscularly with Duck-Origin Genotype IX APMV-1 Show Discrepant Mortality and Indicate Another Fatal Genotype APMV-1 to Ducks.

    PubMed

    Fu, Guanghua; Cheng, Longfei; Fu, Qiuling; Qi, Baomin; Chen, Cuiteng; Shi, Shaohua; Chen, Hongmei; Wan, Chunhe; Liu, Rongchang; Huang, Yu

    2017-03-01

    Isolations of genotype IX (gIX) avian paramyxovirus type 1 (APMV-1) from various bird species have been more common recently, with isolates showing variable pathogenicity in different species of poultry. Here we sequenced the genome of a Muscovy duck origin gIX virus strain XBT14 and characterized the virulence and pathogenicity of this isolate in chickens and ducks. The genome sequence of strain XBT14 is 15,192 nt in length, containing multiple basic amino acids at the fusion protein cleavage site. The XBT14 strain shared 91.6%-91.9% nucleotide identities with early-genotype viruses (such as genotype III and IV) and shared 85.3%-85.9% nucleotide homologies with later genotype viruses (such as genotype VII). Pathogenicity tests showed that strain XBT14 could cause death in different duck breeds with a mortality rate of 44.4% in Muscovy duck, 25.9% in Sheldrake, and 11.1% in Cherry Valley duck, respectively. Similar mortality discrepancies were also observed in different ducks when infected with chicken-origin gIX virus strain F48E8. These results indicate that XBT14-like velogenic gIX APMV-1 (such as XBT14, F48E8, and GD09-2) could cause fatal infection in duck, and genotype IX is another genotype velogenic to duck as well as genotype VII. Accompanied by genetic differences in the vaccine strains or dominant strains prevailing in poultry, the virulent XBT14-like gIX viruses might become potentially endemic strains in poultry in the future.

  16. Determinants of breeding distributions of ducks

    USGS Publications Warehouse

    Johnson, D.H.; Grier, J.W.

    1988-01-01

    The settling of breeding habitat by migratory waterfowl is a topic of both theoretical and practical interest. We use the results of surveys conducted annually during 1955-81 in major breeding areas to examine the factors that affect the distributions of 10 common North American duck species. Three patterns of settling are described: homing, opportunistic, and flexible. Homing is generally more pronounced among species that use more stable (more predictable) wetlands, such as the redhead (Aythya americana), canvasback (A. valisineria), lesser scaup (A. affinis), mallard (Anas platyrhynchos), gadwall (Anas strepera), and northern shoveler (Anas clypeata). Opportunistic settling is more prevalent among species that use less stable (less predictable) wetlands, such as northern pintail (Anas acuta) and blue-winged teal (Anas discors). Flexible settling is exhibited to various degrees by most species.The 10 species are shown to fall along a natural ordination reflecting different life history characteristics. Average values of indices of r- and K-selection indicated that pintail, mallard, blue-winged teal, and shoveler have the most features associated with unstable or unpredictable environments. Gadwall, American wigeon (Anas americana), and green-winged teal (Anas crecca) were intermediate, and attributes of the diving ducks were associated with the use of stable or predictable environments.Some species--notably mallard, gadwall, blue-winged teal, redhead, and canvasback--tend to fill available breeding habitat first in the central portions of their range, and secondly in peripheral areas. Other species--American wigeon, green-winged teal, northern shoveler, northern pintail, and lesser scaup--fill their habitat in the order it is encountered during spring migration.Age and sex classes within species vary in their settling pattern. Some of this variation can be predicted from the mating systems of ducks in which breeding females, especially successful ones, have a

  17. New evidence on the colour and nature of the isolated Archaeopteryx feather.

    PubMed

    Carney, Ryan M; Vinther, Jakob; Shawkey, Matthew D; D'Alba, Liliana; Ackermann, Jörg

    2012-01-24

    Archaeopteryx has been regarded as an icon of evolution ever since its discovery from the Late Jurassic limestone deposits of Solnhofen, Germany in 1861. Here we report the first evidence of colour from Archaeopteryx based on fossilized colour-imparting melanosomes discovered in this isolated feather specimen. Using a phylogenetically diverse database of extant bird feathers, statistical analysis of melanosome morphology predicts that the original colour of this Archaeopteryx feather was black, with 95% probability. Furthermore, reexamination of the feather's morphology leads us to interpret it as an upper major primary covert, contrary to previous interpretations. Additional findings reveal that the specimen is preserved as an organosulphur residue, and that barbule microstructure identical to that of modern bird feathers had evolved as early as the Jurassic. As in extant birds, the extensive melanization would have provided structural advantages to the Archaeopteryx wing feather during this early evolutionary stage of dinosaur flight.

  18. A biotechnological process for treatment and recycling poultry feathers as a feed ingredient.

    PubMed

    Bertsch, A; Coello, N

    2005-10-01

    A strain of Kocuria rosea with keratinolytic capacity was cultured aerobically on submerged feathers to obtain a fermented feather meal (FFM). This FFM enriched with cells of K. rosea mainly contains crude protein (71%). The pepsin digestibility of the fermented product (88%) was similar to the value of the commercial feather meal and more than 70% greater that untreated feathers. The bacterial biomass improved the content of amino acids lysine (3.46%), histidine (0.94%) and methionine (0.69%). Additionally, the amino acid availability tested by in vivo assay was greater than commercial feather meal. The microbial cells also supplied carotenoid pigments to FFM (68 ppm). These results suggest that feather meal enriched with K. rosea may be useful in animal feeding as protein and pigment source.

  19. Effects of dietary vanadium in mallard ducks

    USGS Publications Warehouse

    White, D.H.; Dieter, M.P.

    1978-01-01

    Adult mallard ducks fed 0, 1, 10, or 100 ppm vanadyl sulfate in the diet were sacrificed after 12 wk on treatment; tissues were analyzed for vanadium. No birds died during the study and body weights did not change. Vanadium accumulated to higher concentrations in the bone and liver than in other tissues. Concentrations in bones of hens were five times those in bones of drakes, suggesting an interaction between vanadium and calcium mobilization in laying hens. Vanadium concentrations in most tissues were significantly correlated and increased with treatment level. Lipid metabolism was altered in laying hens fed 100 ppm vanadium. Very little vanadium accumulated in the eggs of laying hens.

  20. Efficiency of methionine retention in ducks.

    PubMed

    Adeola, Olayiwola

    2007-03-01

    The accretion of methionine and protein as a function of methionine intake was assessed in growing ducks between 22 and 42 d post-hatching. Four graded doses of dl-methionine at 0, 0 x 5, 1 x 0 or 1 x 5 g/kg diet were added to a methionine-limiting basal diet and fed to four replicate groups of four ducks each. The growth and efficiency of food use for growth increased linearly (P<0 x 05) as a function of methionine intake. The accretion of body protein increased (P<0 x 001) from 87 x 5 to 182 x 2 g, and that of methionine from 1616 to 3125 mg, over the 21 d period as dietary methionine increased. The accretion rate of methionine in the body (y, mg/d) as a function of methionine intake (x, mg/d) of ducks fed diets containing supplemental methionine at 0, 0 x 5, 1 x 0 or 1 x 5 g/kg diet from day 22 to day 42 post-hatching gave the regression equation: y=-148 x 86 (se 32 x 558)+0 x 312 (se 0 x 0384)X, r2=0 x 8253. For protein accretion rate in the body (y, mg/d) as a function of methionine intake (x, mg/d), the regression equation was: y= -9782 (se 2204)+19 x 505 (se 2 x 5994)x, r2=0 x 8009. There was a linear relationship between methionine (y, mg/d) and protein (x, mg/d) accretion in ducks that was described by the equation y=12 x 757 (se 7 x 4019)+0 x 01 525 (se 0 x 00 107)x, r2=0 x 9355. The results of these studies suggest a constant utilisation of methionine over the range 2 x 4-3 x 9 g digestible methionine/kg diet, with an efficiency of 31 %. Furthermore, the results suggest a quantitative relationship of 15 mg methionine for every gram of protein accretion.

  1. Ducks launch into flight at KSC

    NASA Technical Reports Server (NTRS)

    1999-01-01

    A flock of ducks launch into the morning sky in the Merritt Island National Wildlife Refuge at Kennedy Space Center. The open water of the refuge provides wintering areas for 23 species of migratory waterfowl, as well as a year-round home for great blue herons, great egrets, wood storks, cormorants, brown pelicans and other species of marsh and shore birds. The 92,000-acre refuge is also habitat for more than 310 species of birds, 25 mammals, 117 fishes and 65 amphibians and reptiles.

  2. Use of elevated nest baskets by ducks

    USGS Publications Warehouse

    Doty, H.A.; Lee, F.B.; Kruse, A.D.

    1975-01-01

    Open-top nest baskets were mounted on upright metal poles in various wetlands to assess the value of baskets as a potential technique for increasing duck nest success. Observations were made from 1966-1968 in North and South Dakota, Minnesota, and Wisconsin and were continued through 1973 in North Dakota. Baskets were used most readily in the prairie pothole region; of the 1,038 basket nest sites provided during 1966-68, 392 contained clutches of eggs (38 percent), and 324 (83 percent) hatched. Mallards (Anas platyrhynchos) initiated 98 percent of these nests. Factors affecting nest success included human disturbance, nesting material, egg freezing, and avian predation.

  3. Changes in enzymatic activity in composts containing chicken feathers.

    PubMed

    Bohacz, Justyna; Korniłłowicz-Kowalska, Teresa

    2009-07-01

    Enzymatic activity, i.e. respiratory activity, dehydrogenase activity, phosphatase activity, caseinian protease activity, BAA protease activity and urease activity, was determined to investigate the process of biochemical transformations and to select enzymatic indices of maturity of composts prepared from feathers and lignocellulose wastes (bark, straw). Composting was conducted for 7 months, with periodic determinations of activity of the enzymes. The study revealed significant differences in the enzymatic activity, related with the duration of composting and with the substrate composition of the composts. Generally, composts enriched with straw were characterised by higher enzymatic activity than composts without any addition of straw. It was found that the activity of such enzymes as cellulase and protease, towards the end of the period of composting decreased and stabilised. The enzymes enumerated can be taken into consideration in estimation of the maturity of composts prepared from feathers and lignocellulose wastes.

  4. Identification of protected avian species using a single feather barb.

    PubMed

    Boonseub, Sansook; Johnston, Greg; Linacre, Adrian

    2012-11-01

    We report on the unambiguous identification of protected avian species from as little as one barb of a feather. Many avian species are protected by international agreements and national legislation, yet they are traded illegally because of their high value. Two sections of the avian mitochondrial genome were chosen to identify bird species, being a 561-bp section of ND2 gene and a 921-bp section of the ND5 gene. Two different DNA extraction methods were compared for their ability to reliably isolate sufficient DNA to be detected in a subsequent PCR. Using a commercial kit supplied by QIAGEN, a complete sequence was obtained from one barb for the ND2 gene, whereas two barbs were required to reliably sequence the 921-bp section of the ND5 gene. The process worked on all species tested using feathers from archival museum specimens, resulted in minimal damage to the specimen and can readily be adopted by a forensic science laboratory.

  5. Keratin gene mutations in disorders of human skin and its appendages.

    PubMed

    Chamcheu, Jean Christopher; Siddiqui, Imtiaz A; Syed, Deeba N; Adhami, Vaqar M; Liovic, Mirjana; Mukhtar, Hasan

    2011-04-15

    Keratins, the major structural protein of all epithelia are a diverse group of cytoskeletal scaffolding proteins that form intermediate filament networks, providing structural support to keratinocytes that maintain the integrity of the skin. Expression of keratin genes is usually regulated by differentiation of the epidermal cells within the stratifying squamous epithelium. Amongst the 54 known functional keratin genes in humans, about 22 different genes including, the cornea, hair and hair follicle-specific keratins have been implicated in a wide range of hereditary diseases. The exact phenotype of each disease usually reflects the spatial expression level and the types of mutated keratin genes, the location of the mutations and their consequences at sub-cellular levels as well as other epigenetic and/or environmental factors. The identification of specific pathogenic mutations in keratin disorders formed the basis of our understanding that led to re-classification, improved diagnosis with prognostic implications, prenatal testing and genetic counseling in severe keratin genodermatoses. Molecular defects in cutaneous keratin genes encoding for keratin intermediate filaments (KIFs) causes keratinocytes and tissue-specific fragility, accounting for a large number of genetic disorders in human skin and its appendages. These diseases are characterized by keratinocytes fragility (cytolysis), intra-epidermal blistering, hyperkeratosis, and keratin filament aggregation in severely affected tissues. Examples include epidermolysis bullosa simplex (EBS; K5, K14), keratinopathic ichthyosis (KPI; K1, K2, K10) i.e. epidermolytic ichthyosis (EI; K1, K10) and ichthyosis bullosa of Siemens (IBS; K2), pachyonychia congenita (PC; K6a, K6b, K16, K17), epidermolytic palmo-plantar keratoderma (EPPK; K9, (K1)), monilethrix (K81, K83, K86), ectodermal dysplasia (ED; K85) and steatocystoma multiplex. These keratins also have been identified to have roles in apoptosis, cell proliferation

  6. Cytoskeleton in motion: the dynamics of keratin intermediate filaments in epithelia.

    PubMed

    Windoffer, Reinhard; Beil, Michael; Magin, Thomas M; Leube, Rudolf E

    2011-09-05

    Epithelia are exposed to multiple forms of stress. Keratin intermediate filaments are abundant in epithelia and form cytoskeletal networks that contribute to cell type-specific functions, such as adhesion, migration, and metabolism. A perpetual keratin filament turnover cycle supports these functions. This multistep process keeps the cytoskeleton in motion, facilitating rapid and protein biosynthesis-independent network remodeling while maintaining an intact network. The current challenge is to unravel the molecular mechanisms underlying the regulation of the keratin cycle in relation to actin and microtubule networks and in the context of epithelial tissue function.

  7. Repeatability of Feather Mite Prevalence and Intensity in Passerine Birds

    PubMed Central

    Diaz-Real, Javier; Serrano, David; Pérez-Tris, Javier; Fernández-González, Sofía; Bermejo, Ana; Calleja, Juan A.; De la Puente, Javier; De Palacio, Diana; Martínez, José L.; Moreno-Opo, Rubén; Ponce, Carlos; Frías, Óscar; Tella, José L.; Møller, Anders P.; Figuerola, Jordi; Pap, Péter L.; Kovács, István; Vágási, Csongor I.; Meléndez, Leandro; Blanco, Guillermo; Aguilera, Eduardo; Senar, Juan Carlos; Galván, Ismael; Atiénzar, Francisco; Barba, Emilio; Cantó, José L.; Cortés, Verónica; Monrós, Juan S.; Piculo, Rubén; Vögeli, Matthias; Borràs, Antoni; Navarro, Carlos; Mestre, Alexandre; Jovani, Roger

    2014-01-01

    Understanding why host species differ so much in symbiont loads and how this depends on ecological host and symbiont traits is a major issue in the ecology of symbiosis. A first step in this inquiry is to know whether observed differences among host species are species-specific traits or more related with host-symbiont environmental conditions. Here we analysed the repeatability (R) of the intensity and the prevalence of feather mites to partition within- and among-host species variance components. We compiled the largest dataset so far available: 119 Paleartic passerine bird species, 75,944 individual birds, ca. 1.8 million mites, seven countries, 23 study years. Several analyses and approaches were made to estimate R and adjusted repeatability (Radj) after controlling for potential confounding factors (breeding period, weather, habitat, spatial autocorrelation and researcher identity). The prevalence of feather mites was moderately repeatable (R = 0.26–0.53; Radj = 0.32–0.57); smaller values were found for intensity (R = 0.19–0.30; Radj = 0.18–0.30). These moderate repeatabilities show that prevalence and intensity of feather mites differ among species, but also that the high variation within species leads to considerable overlap among bird species. Differences in the prevalence and intensity of feather mites within bird species were small among habitats, suggesting that local factors are playing a secondary role. However, effects of local climatic conditions were partially observed for intensity. PMID:25216248

  8. Coevolution of caudal skeleton and tail feathers in birds.

    PubMed

    Felice, Ryan N

    2014-12-01

    Birds are capable of a wide range of aerial locomotor behaviors in part because of the derived structure and function of the avian tail. The tail apparatus consists of a several mobile (free) caudal vertebrae, a terminal skeletal element (the pygostyle), and an articulated fan of tail feathers that may be spread or folded, as well as muscular and fibroadipose structures that facilitate tail movements. Morphological variation in both the tail fan and the caudal skeleton that supports it are well documented. The structure of the tail feathers and the pygostyle each evolve in response to functional demands of differing locomotor behaviors. Here, I test whether the integument and skeleton coevolve in this important locomotor module. I quantified feather and skeletal morphology in a diverse sample of waterbirds and shorebirds using a combination of linear and geometric morphometrics. Covariation between tail fan shape and skeletal morphology was then tested using phylogenetic comparative methods. Pygostyle shape is found to be a good predictor of tail fan shape (e.g., forked, graduated), supporting the hypothesis that the tail fan and the tail skeleton have coevolved. This statistical relationship is used to reconstruct feather morphology in an exemplar fossil waterbird, Limnofregata azygosternon. Based on pygostyle morphology, this taxon is likely to have exhibited a forked tail fan similar to that of its extant sister clade Fregata, despite differing in inferred ecology and other aspects of skeletal anatomy. These methods may be useful in reconstructing rectricial morphology in other extinct birds and thus assist in characterizing the evolution of flight control surfaces in birds.

  9. Regulation of chick early B-cell factor-1 gene expression in feather development.

    PubMed

    El-Magd, Mohammed Abu; Sayed-Ahmed, Ahmed; Awad, Ashraf; Shukry, Mustafa

    2014-05-01

    The chick Ebf1 (early B-cell factor-1) gene is a member of a novel family of helix loop helix transcription factors. The expression profile, regulation and significance of this gene have been extensively studied in lymphatic, nervous, adipose and muscular tissues. However, cEbf1 expression, regulation and function in the feather of chick embryo have not yet been investigated. cEbf1 expression was first detected throughout the mesenchymal core of some few feather placodes (D7-D7.5). After feathers became mature and grew distally (D9 and D10), the mesenchymal expression of cEbf1 became confined to the caudal margin of the proximal half of all formed feather buds. Because this dynamic pattern of expression resembles that of Sonic Hedgehog (Shh) protein and bone morphogenetic protein (Bmp4) plus the crucial role of these two major signals in feather development, we hypothesized that cEbf1 expression in the feather may be regulated by Shh and Bmp4. In a feather explant culture system, Shh signals are necessary to initiate and maintain cEbf1 expression in the posterior half of the feather bud, while Bmp4 is crucial for the initial cEbf1 expression in the anterior half of the feather bud. Inhibition of Shh, not only down-regulates cEbf1, but also changes the morphology of feather buds, which become irregular and fused. This is the first study to demonstrate that cEbf1 expression in the feather bud is under the control of Shh and Bmp4 signals and that expression may play a role in the normal development of feathers.

  10. A nontetrameric species is the major soluble form of keratin in Xenopus oocytes and rabbit reticulocyte lysates

    PubMed Central

    1996-01-01

    Inside the interphase cell, approximately 5% of the total intermediate filament protein exists in a soluble form. Past studies using velocity gradient sedimentation (VGS) indicate that soluble intermediate filament protein exists as an approximately 7 S tetrameric species. While studying intermediate filament assembly dynamics in the Xenopus oocyte, we used both VGS and size-exclusion chromatography (SEC) to analyze the soluble form of keratin. Previous studies (Coulombe, P. A., and E. Fuchs. 1990. J. Cell Biol. 111:153) report that tetrameric keratins migrate on SEC with an apparent molecular weight of approximately 150,000; the major soluble form of keratin in the oocyte, in contrast, migrates with an apparent molecular weight of approximately 750,000. During oocyte maturation, the keratin system disassembles into a soluble form (Klymkowsky, M. W., L. A. Maynell, and C. Nislow. 1991. J. Cell Biol. 114:787) and the amount of the 750-kD keratin complex increases dramatically. Immunoprecipitation analysis of soluble keratin from matured oocytes revealed the presence of type I and type II keratins, but no other stoichiometrically associated polypeptides, suggesting that the 750-kD keratin complex is composed solely of keratin. To further study the formation of the 750-kD keratin complex, we used rabbit reticulocyte lysates (RRL). The 750-kD keratin complex was formed in RRLs contranslating type I and type II Xenopus keratins, but not when lysates translated type I or type II keratin RNAs alone. The 750-kD keratin complex could be formed posttranslationally in an ATP-independent manner when type I and type II keratin translation reactions were mixed. Under conditions of prolonged incubation, such as occur during VGS analysis, the 750-kD keratin complex disassembled into a 7 S (by VGS), 150-kD (by SEC) form. In urea denaturation studies, the 7 S/150-kD form could be further disassembled into an 80-kD species that consists of cofractionating dimeric and monomeric

  11. Genetic characterization of Duck Hepatitis A Viruses isolated in China.

    PubMed

    Li, Jing; Bi, Yuhai; Chen, Can; Yang, Limin; Ding, Chan; Liu, Wenjun

    2013-12-26

    In recent years, the spread of Duck Hepatitis A Viruses (DHAVs) has represented a serious threat and significant economic impact in duck industry of China. The sixteen reported DHAV isolates (15 DHAV-1 strains and one DHAV-3) were identified from infected ducks with clinical symptoms in China between 2009 and 2012. In the present study, the virulence of these viruses and complete sequences of the virion protein 1 (VP1) genes of the 16 DHAVs were characterized. The median embryonic lethal doses (ELD50) of the second generation duck embryo allantoic fluid of the 16 DHAV isolates were calculated on duck and chicken embryos. The results demonstrated that the various DHAV-1 strains have shown different pathogenic ability in embryos, and duck eggs were more susceptible to DHAV than chicken eggs. The histopathological examination revealed significant signs of virus infection, severe vacuolation, and hepatocyte necrosis. Phylogenetic analyses indicated that the 15 DHAV-1 viruses display significant correlation in their geographic distribution. The DHAV-1 strains isolated from Shandong Province were more evolutionarily divergent than the JX strains. There were two hypervariable regions in the VP1 protein, which may determine the virulence of DHAV-1 isolates in chicken eggs but not virulence in duck eggs. These results demonstrate the genetic and biological diversity of DHAVs in China and aid in understanding the epidemiology and evolution of DHAVs.

  12. Fall food habits of ducks near Santee Refuge, South Carolina

    USGS Publications Warehouse

    McGilvrey, F.B.

    1966-01-01

    During the 1961 waterfowl hunting season, 360 stomachs of 10 duck species were collected from hunters near the Santee National Wildlife Refuge, Lake Marion, South Carolina. Based on percentage of total volume, 20 of the most important foods are listed. The six most important duck species in the kill were: mallard (Anas platyrhynchos), wood duck (Aix sponsa), widgeon (Mareca americam), pintail (Anas acuta) , black duck ( Anas rubripes) , and green-winged teal (Anas carolinensis). Six plant species made up 5 percent or more of the total volume of food items found in the stomachs of all ducks. Only seeds of oaks (Quercus sp.), corn, sweet gum (Liquidambar Styraciflua), and buttonbush (Cephalanthus occidentalis) were consumed. Some seed, but mostly the vegetative portions of hydrochloa (Hydrochloa carolinensis) and only the vegetative portions of southern rice cutgrass (Leersia hexandra) were taken. The more important game ducks concentrated on the refuge farmlands when water levels were below 72 feet mean sea level (msl). When levels reached 75 feet msl, natural foods became available, ducks dispersed from refuge areas, and hunting success increased greatly.

  13. Evidence of possible vertical transmission of duck circovirus.

    PubMed

    Li, Zhiguo; Wang, Xin; Zhang, Ruihua; Chen, Junhao; Xia, Linlin; Lin, Shaoli; Xie, Zhijing; Jiang, Shijin

    2014-11-07

    To test the hypothesis that duck circovirus (DuCV) may be vertically transmitted from infected breeder ducks to their ducklings, we investigated 120 newly hatched ducklings, 30 dead duck embryos and 80 non-embryonated duck eggs with the duplex polymerase chain reaction (PCR). DuCV DNA was present in 15 newly hatched ducklings, 4 duck embryos and 3 non-embryonated eggs. Four ducklings from two flocks were co-infected by DuCV-1 and DuCV-2, three ducklings from three flocks were DuCV-1 single infection, and eight ducklings from six flocks were DuCV-2 single infection. One duck embryo and one non-embryonated egg were positive for both DuCV-1 and DuCV-2 DNAs, one embryo for DuCV-1 DNA, and two embryos and two non-embryonated eggs for DuCV-2 DNA. The findings provide evidence of possible vertical transmission of DuCV and simultaneous transmission of DuCV-1 and DuCV-2 from breeder ducks to ducklings.

  14. A full annual cycle modeling framework for American black ducks

    USGS Publications Warehouse

    Robinson, Orin J.; McGowan, Conor; Devers, Patrick K.; Brook, Rodney W.; Huang, Min; Jones, Malcom; McAuley, Daniel G.; Zimmerman, Guthrie S.

    2016-01-01

    American black ducks (Anas rubripes) are a harvested, international migratory waterfowl species in eastern North America. Despite an extended period of restrictive harvest regulations, the black duck population is still below the population goal identified in the North American Waterfowl Management Plan (NAWMP). It has been hypothesized that density-dependent factors restrict population growth in the black duck population and that habitat management (increases, improvements, etc.) may be a key component of growing black duck populations and reaching the prescribed NAWMP population goal. Using banding data from 1951 to 2011 and breeding population survey data from 1990 to 2014, we developed a full annual cycle population model for the American black duck. This model uses the seven management units as set by the Black Duck Joint Venture, allows movement into and out of each unit during each season, and models survival and fecundity for each region separately. We compare model population trajectories with observed population data and abundance estimates from the breeding season counts to show the accuracy of this full annual cycle model. With this model, we then show how to simulate the effects of habitat management on the continental black duck population.

  15. Melanosome evolution indicates a key physiological shift within feathered dinosaurs.

    PubMed

    Li, Quanguo; Clarke, Julia A; Gao, Ke-Qin; Zhou, Chang-Fu; Meng, Qingjin; Li, Daliang; D'Alba, Liliana; Shawkey, Matthew D

    2014-03-20

    Inference of colour patterning in extinct dinosaurs has been based on the relationship between the morphology of melanin-containing organelles (melanosomes) and colour in extant bird feathers. When this relationship evolved relative to the origin of feathers and other novel integumentary structures, such as hair and filamentous body covering in extinct archosaurs, has not been evaluated. Here we sample melanosomes from the integument of 181 extant amniote taxa and 13 lizard, turtle, dinosaur and pterosaur fossils from the Upper-Jurassic and Lower-Cretaceous of China. We find that in the lineage leading to birds, the observed increase in the diversity of melanosome morphologies appears abruptly, near the origin of pinnate feathers in maniraptoran dinosaurs. Similarly, mammals show an increased diversity of melanosome form compared to all ectothermic amniotes. In these two clades, mammals and maniraptoran dinosaurs including birds, melanosome form and colour are linked and colour reconstruction may be possible. By contrast, melanosomes in lizard, turtle and crocodilian skin, as well as the archosaurian filamentous body coverings (dinosaur 'protofeathers' and pterosaur 'pycnofibres'), show a limited diversity of form that is uncorrelated with colour in extant taxa. These patterns may be explained by convergent changes in the key melanocortin system of mammals and birds, which is known to affect pleiotropically both melanin-based colouration and energetic processes such as metabolic rate in vertebrates, and may therefore support a significant physiological shift in maniraptoran dinosaurs.

  16. Archaeopteryx feathers and bone chemistry fully revealed via synchrotron imaging

    PubMed Central

    Bergmann, U.; Morton, R. W.; Manning, P. L.; Sellers, W. I.; Farrar, S.; Huntley, K. G.; Wogelius, R. A.; Larson, P.

    2010-01-01

    Evolution of flight in maniraptoran dinosaurs is marked by the acquisition of distinct avian characters, such as feathers, as seen in Archaeopteryx from the Solnhofen limestone. These rare fossils were pivotal in confirming the dinosauria-avian lineage. One of the key derived avian characters is the possession of feathers, details of which were remarkably preserved in the Lagerstätte environment. These structures were previously simply assumed to be impressions; however, a detailed chemical analysis has, until now, never been completed on any Archaeopteryx specimen. Here we present chemical imaging via synchrotron rapid scanning X-ray fluorescence (SRS-XRF) of the Thermopolis Archaeopteryx, which shows that portions of the feathers are not impressions but are in fact remnant body fossil structures, maintaining elemental compositions that are completely different from the embedding geological matrix. Our results indicate phosphorous and sulfur retention in soft tissue as well as trace metal (Zn and Cu) retention in bone. Other previously unknown chemical details of Archaeopteryx are also revealed in this study including: bone chemistry, taphonomy (fossilization process), and curation artifacts. SRS-XRF represents a major advancement in the study of the life chemistry and fossilization processes of Archaeopteryx and other extinct organisms because it is now practical to image the chemistry of large specimens rapidly at concentration levels of parts per million. This technique has wider application to the archaeological, forensic, and biological sciences, enabling the mapping of “unseen” compounds critical to understanding biological structures, modes of preservation, and environmental context. PMID:20457935

  17. Archaeopteryx feathers and bone chemistry fully revealed via synchrotron imaging.

    PubMed

    Bergmann, U; Morton, R W; Manning, P L; Sellers, W I; Farrar, S; Huntley, K G; Wogelius, R A; Larson, P

    2010-05-18

    Evolution of flight in maniraptoran dinosaurs is marked by the acquisition of distinct avian characters, such as feathers, as seen in Archaeopteryx from the Solnhofen limestone. These rare fossils were pivotal in confirming the dinosauria-avian lineage. One of the key derived avian characters is the possession of feathers, details of which were remarkably preserved in the Lagerstätte environment. These structures were previously simply assumed to be impressions; however, a detailed chemical analysis has, until now, never been completed on any Archaeopteryx specimen. Here we present chemical imaging via synchrotron rapid scanning X-ray fluorescence (SRS-XRF) of the Thermopolis Archaeopteryx, which shows that portions of the feathers are not impressions but are in fact remnant body fossil structures, maintaining elemental compositions that are completely different from the embedding geological matrix. Our results indicate phosphorous and sulfur retention in soft tissue as well as trace metal (Zn and Cu) retention in bone. Other previously unknown chemical details of Archaeopteryx are also revealed in this study including: bone chemistry, taphonomy (fossilization process), and curation artifacts. SRS-XRF represents a major advancement in the study of the life chemistry and fossilization processes of Archaeopteryx and other extinct organisms because it is now practical to image the chemistry of large specimens rapidly at concentration levels of parts per million. This technique has wider application to the archaeological, forensic, and biological sciences, enabling the mapping of "unseen" compounds critical to understanding biological structures, modes of preservation, and environmental context.

  18. Habitat Suitability Index Models: American black duck (wintering)

    USGS Publications Warehouse

    Lewis, James C.; Garrison, Russell L.

    1984-01-01

    INTRODUCTION The American black duck, commonly known as the black duck, is migratory and has a wide geographic range. American black ducks breed from Cape Hatteras, North Carolina, west to the Mississippi River and north through the eastern Canadian boreal forest (Bellrose 1976). The winter range extends from the Rio Grande River on the Texas coast, northeast to Lake Michigan, east to Nova Scotia, south to Florida, and west to Texas (Wright 1954). American black ducks arrive on their wintering habitats between September and early December and remain there until February to April (Bellrose 1976). Their preferred habitat varies considerably through the wintering range. Habitat use appears related to food availability, freedom from disturbance, weather, and often upon the presence of large bodies of open water. These interrelated elements are essential for meeting the energy demands and other nutritional requirements of black ducks in response to the rigors of cold weather and migration. In the Atlantic Flyway, winter populations of American black ducks concentrate in marine and estuarine wetlands (U.S. Fish and Wildlife Service 1979). They use salt marshes and small tidal bays for feeding and loafing areas. In wintering areas north of Chesapeake Bay, American black ducks frequently feed on tidal flats and rest in emergent wetlands or on ice-free bays, rivers, and coastal reservoirs. In the Chesapeake bay area, migrant and wintering American black ducks occupy a wide variety of habitats (Stewart 1962). They strongly favor brackish bays with extensive adjacent agricultural lands. Estuarine bays, coastal salt marshes, tidal fresh marshes, and adjacent impoundments receive high usage. American black ducks also concentrate in forested wetlands in and adjacent to estuaries in the South Atlantic Flyway, especially in Virginia and North Carolina.

  19. Genetic characterization of a novel astrovirus in Pekin ducks.

    PubMed

    Liao, Qinfeng; Liu, Ning; Wang, Xiaoyan; Wang, Fumin; Zhang, Dabing

    2015-06-01

    Three divergent groups of duck astroviruses (DAstVs), namely DAstV-1, DAstV-2 (formerly duck hepatitis virus type 3) and DAstV-3 (isolate CPH), and other avastroviruses are known to infect domestic ducks. To provide more data regarding the molecular epidemiology of astroviruses in domestic ducks, we examined the prevalence of astroviruses in 136 domestic duck samples collected from four different provinces of China. Nineteen goose samples were also included. Using an astrovirus-specific reverse transcription-PCR assay, two groups of astroviruses were detected from our samples. A group of astroviruses detected from Pekin ducks, Shaoxing ducks and Landes geese were highly similar to the newly discovered DAstV-3. More interestingly, a novel group of avastroviruses, which we named DAstV-4, was detected in Pekin ducks. Following full-length sequencing and sequence analysis, the variation between DAstV-4 and other avastroviruses in terms of lengths of genome and internal component was highlighted. Sequence identity and phylogenetic analyses based on the amino acid sequences of the three open reading frames (ORFs) clearly demonstrated that DAstV-4 was highly divergent from all other avastroviruses. Further analyses showed that DAstV-4 shared low levels of genome identities (50-58%) and high levels of mean amino acid genetic distances in the ORF2 sequences (0.520-0.801) with other avastroviruses, suggesting DAstV-4 may represent an additional avastrovirus species although the taxonomic relationship of DAstV-4 to DAstV-3 remains to be resolved. The present works contribute to the understanding of epidemiology, ecology and taxonomy of astroviruses in ducks.

  20. Immunolocalization of specific keratin associated beta-proteins (beta-keratins) in the adhesive setae of Gekko gecko.

    PubMed

    Alibardi, Lorenzo

    2013-08-01

    The previous identification of 21 proteins in the digital setae transcriptome of Gekko gecko, 2 alpha-keratins of 52-53kDa and 19 beta-proteins (beta-keratins) of 10-21kDa, has indicated that most of setal corneous proteins are cysteine-rich. The production of specific antibodies for two of the main beta-protein subfamilies expressed in gecko setae has allowed the ultrastructural localization of two beta-proteins indicated as Ge-cprp-9 (cysteine-rich) and Ge-gprp-6 (glycine-rich). Only Ge-cprp-9, representing most of the 16 cysteine-rich beta-proteins, is present in the oberhautchen, setae and in the terminal spatula where adhesion takes place, supporting the previous expression study. Instead, the glycine-rich beta-proteins (Ge-gprp-6), representing the 3 glycine-rich beta-proteins of digital epidermis is only present in the stiff beta-layer of the digital scales and in the thin beta layer of the pad lamella sustaining the setae. Ge-cprp-9 is representative for most of the remaining 15 cys-rich proteins (Ge-cprp 1-16) and may have a structural and functional role in the process of adhesion. Most of the cysteine-rich setal proteins have a net positive charge and it is here hypothesized that these proteins may induce the formation of dipoles at the surface interface between the spatula and the substrate, enhancing the van der Waals forces and therefore adhesion to the substrate. The selection and improvement of these proteins during the evolution of geckos may have represented a successful factor for the survival and ecological adaptations of these climbing lizards.

  1. Long-term pair bonds in the Laysan Duck

    USGS Publications Warehouse

    Reynolds, M.H.; Breeden, J.H.; Vekasy, M.S.; Ellis, T.M.

    2009-01-01

    We describe long-term pair bonds in the endangered Laysan Duck (Anas laysanensis), a dabbling duck endemic to the Hawaiian Archipelago. Individually marked birds were identified on Laysan Island between 1998 and 2006 (n = 613 marked adults). We recorded pair bonds while observing marked birds, and documented within and between year mate switches and multi-year pair bonds. Twenty pairs banded before 2001 had stable pair bonds lasting ???5 years with a maximum enduring pair bond of nine breeding seasons. Understanding reproductive strategy, including mate retention, would aid conservation planning and management efforts for the Laysan Duck. Further study is needed to characterize the social system of this endangered species.

  2. Factors influencing depredation of artificial duck nests

    USGS Publications Warehouse

    Esler, Daniel N.; Grand, James B.

    1993-01-01

    Because artificial nests can facilitate controlled experiments of nest success, we used them to assess whether human visitation, nest density, vegetation structure, and proximity to habitat edge could affect depredation of duck nests on Yukon Flats National Wildlife Refuge, Alaska. More (P < 0.01) nests in a plot visited daily (100%) were depredated than those in plots visited at intervals of 7 (40%), 14 (35%), or 28 days (45%). More (P < 0.01) nests were depredated in a plot with 10 nests/ha (95%) than nests in a plot of a lower density (2/ha; 40%). Vegetation height, vegetation density, distance to a wetland, distance to forest edge, or distance to the nearest ecotone did not differ (P > 0.05) between depredated and undisturbed nests. We suggest that daily visitation of duck nests increases depredation, but longer intervals, typical of most nest studies, do not. High nesting densities, which could occur when flooding limits nesting habitat, may result in higher depredation rates.

  3. AFLP fingerprinting for paternity testing in ducks.

    PubMed

    Huang, C-W; Cheng, Y-S; Rouvier, R; Yang, K-T; Wu, C-P; Huang, M-C

    2007-06-01

    1. The accuracy and reproducibility of AFLP fingerprinting was investigated in the duck (Anas Platyrhynchos), using a multicolour fluorescent labeling technique. The fluorescent labelling fragments were separated on a capillary electrophoresis-base ABI PRISM 3100 Genetic Analyzer. 2. A total of 337 AFLP peaks with 103 of them being polymorphic markers were generated by 16 sets consisting of EcoRI/TaqI primer pair combinations. The number and size range of AFLP polymorphisms detected per primer pair varied from 3 to 11 and 58 to 290 bp, respectively. About 30.6% (103/337) of AFLP peaks were detected polymorphisms, with an average of 6.4 polymorphic markers per primer pair. 3. The clear polymorphic peaks were amplified with EcoR+AC/Taq+AC primer combinations. The AFLP peaks showed high reproducibility. From the family testing, we found that the fingerprints of all the offspring were derived from one or other parent. Therefore, we conclude that AFLP fingerprinting might be a suitable method for duck paternity testing.

  4. Homology and Potential Cellular and Molecular Mechanisms for the Development of Unique Feather Morphologies in Early Birds

    PubMed Central

    O’Connor, Jingmai K.; Chiappe, Luis M.; Chuong, Cheng-ming; Bottjer, David J.; You, Hailu

    2013-01-01

    At least two lineages of Mesozoic birds are known to have possessed a distinct feather morphotype for which there is no neornithine (modern) equivalent. The early stepwise evolution of apparently modern feathers occurred within Maniraptora, basal to the avian transition, with asymmetrical pennaceous feathers suited for flight present in the most basal recognized avian, Archaeopteryx lithographica. The number of extinct primitive feather morphotypes recognized among non-avian dinosaurs continues to increase with new discoveries; some of these resemble feathers present in basal birds. As a result, feathers between phylogenetically widely separated taxa have been described as homologous. Here we examine the extinct feather morphotypes recognized within Aves and compare these structures with those found in non-avian dinosaurs. We conclude that the “rachis dominated” tail feathers of Confuciusornis sanctus and some enantiornithines are not equivalent to the “proximally ribbon-like” pennaceous feathers of the juvenile oviraptorosaur Similicaudipteryx yixianensis. Close morphological analysis of these unusual rectrices in basal birds supports the interpretation that they are modified pennaceous feathers. Because this feather morphotype is not seen in living birds, we build on current understanding of modern feather molecular morphogenesis to suggest a hypothetical molecular developmental model for the formation of the rachis dominated feathers of extinct basal birds. PMID:24003379

  5. Homology and Potential Cellular and Molecular Mechanisms for the Development of Unique Feather Morphologies in Early Birds.

    PubMed

    O'Connor, Jingmai K; Chiappe, Luis M; Chuong, Cheng-Ming; Bottjer, David J; You, Hailu

    2012-09-14

    At least two lineages of Mesozoic birds are known to have possessed a distinct feather morphotype for which there is no neornithine (modern) equivalent. The early stepwise evolution of apparently modern feathers occurred within Maniraptora, basal to the avian transition, with asymmetrical pennaceous feathers suited for flight present in the most basal recognized avian, Archaeopteryx lithographica. The number of extinct primitive feather morphotypes recognized among non-avian dinosaurs continues to increase with new discoveries; some of these resemble feathers present in basal birds. As a result, feathers between phylogenetically widely separated taxa have been described as homologous. Here we examine the extinct feather morphotypes recognized within Aves and compare these structures with those found in non-avian dinosaurs. We conclude that the "rachis dominated" tail feathers of Confuciusornis sanctus and some enantiornithines are not equivalent to the "proximally ribbon-like" pennaceous feathers of the juvenile oviraptorosaur Similicaudipteryx yixianensis. Close morphological analysis of these unusual rectrices in basal birds supports the interpretation that they are modified pennaceous feathers. Because this feather morphotype is not seen in living birds, we build on current understanding of modern feather molecular morphogenesis to suggest a hypothetical molecular developmental model for the formation of the rachis dominated feathers of extinct basal birds.

  6. Effects of litter provision during early rearing and environmental enrichment during the production phase on feather pecking and feather damage in laying hens.

    PubMed

    Tahamtani, F M; Brantsæter, M; Nordgreen, J; Sandberg, E; Hansen, T B; Nødtvedt, A; Rodenburg, T B; Moe, R O; Janczak, A M

    2016-12-01

    Feather pecking is a multi-factorial behavioral disorder and a serious welfare issue in the poultry industry. Several studies report early life experience with litter to be a major determinant in the development of feather pecking. The current study aimed to test the large-scale on-farm efficiency of a simple and cheap husbandry procedure applied during the rearing period with the ultimate goal of reducing the incidence of feather pecking and plumage damage during the production stage in laying hens. Five laying hen-rearing farmers from across Norway participated in the study. These farmers were asked to create divisions within their hen rearing houses and to separate their chicks into 2 groups: one reared with access to a paper substrate from the first d of age, the other a control group without access to paper substrate during rearing. All flocks were visited at the production farms at 30 wk of age and observed for pecking behavior and f