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At least 19 recordsLinked to original sources
PubMed1992

Trace element distribution in growing feathers: additional excretion in feather sheaths.

The use of feathers is a non-invasive and repeatable method for biomonitoring trace element levels in birds and their ecosystems. Trace element levels were examined in different parts of growing flight feathers from young common terns (Sterna hirundo) to determine distribution of heavy metals and selenium, potential bias from using partially grown feathers, and whether additional heavy metals and selenium are excreted in feather sheaths that are sloughed before feathers are usually sampled. Lead and mercury levels were significantly higher in the distal fully formed portion of the growing feather (with no residual blood supply) compared to the proximal, growing portion of the feather with a residual blood supply, but no significant differences were evident for cadmium and selenium. These results suggest that using partially grown feathers underestimates the amount of lead and mercury in fully formed feathers and that higher levels of lead and mercury are sequestered in feathers than are present in the blood at any one time. Significantly higher concentrations of lead and cadmium, and significantly lower levels of mercury were in the sheath compared to the whole feather blade. These data suggest that birds excrete more lead and cadmium during molt than previously thought.

Animals↗
PubMed1991

A novel DNA virus associated with feather inclusions in psittacine beak and feather disease.

The nature of feather inclusions was characterized in 32 psittacine birds (30 cockatoos, one peach-faced lovebird (Agapornis roseicollis), and one red-lored Amazon parrot (Amazona autumnalis autumnalis] with naturally-acquired psittacine beak and feather disease. Intranuclear inclusions within feather epithelial cells and intracytoplasmic inclusions within macrophages in the feather epithelium and pulp cavity contained psittacine beak and feather disease viral antigen when stained by the avidin-biotin complex immunoperoxidase technique. Ultrastructurally, inclusions were observed primarily within macrophages and to a lesser extent within epithelial cell nuclei. Macrophage inclusions appeared as paracrystalline arrays of viral particles. Intranuclear inclusions were less well defined, although scattered viral particles were present. Intracytoplasmic and intranuclear particles in ultrastructural preparations were identified by colloidal gold labeling as psittacine beak and feather disease virus. Feather epithelium was more frequently and severely involved in the disease process than was adjacent follicular epithelium. Plucked feathers with an intact epidermal collar and feather epithelium were preferred to follicular biopsies for histopathologic examination.

Animals↗
PubMed1975

The properties of bird feathers as converse piezoelectric transducers and as receptors of microwave radiation. II. Bird feathers as dielectric receptors of microwave radiation.

The characteristics of bird feathers as receptors of microwave fields were investigated in the 10- to 16-GHz region. Experiments were conducted coupling the specimen (feather) to a length of waveguide which served, together with other microwave components, as a primary detector. Microwave power radiation patterns were measured both in the presence and in the absence of the specimen. Results indicated a substantial increase in the microwave power collected in the forward direction and a decrease of the radiation pattern beam width when the feather was present. Fruthermore, some experiemental evidence indicated the possibility of inducing piezoelectric effects in the specimen by audiofrequency pulse-modulated microwave fields. These results are important in view of (i) the fundamental role that feathers play in the life of birds and (ii) the influence of environmental factors on bird behaviour.

Animals↗
PubMedDate not supplied

A feather-trap system for the removal of chicken feathers from laboratory sewage.

A simple feather-trap system is described for use on the drain lines of buildings housing poultry for research or other purposes where floors are frequently washed. The trap uses disposable plastic-mesh bags that can efficiently remove almost all feathers from the water, preventing sewer lines from being blocked by compacted feathers. Critical measurements and operational procedures are described.

Animals↗
PubMedDate not supplied

Inheritance of the henny feathering trait in the golden Campine chicken: evidence for allelism with the gene that causes henny feathering in the Sebright bantam.

The henny feathering mutation causes roosters to develop female feathering morphology as a result of increased conversion of androgen to estrogen (aromatase activity) in extraglandular tissues, including skin. This trait is maintained in two breeds of chickens: the Sebright Bantam and the Golden Campine. To characterize the inheritance of this trait further, we did breeding studies of the Golden Campine and identified the trait by measuring aromatase activity in biopsied skin. As previously established for the Sebright Bantam, the trait is transmitted in the Campine by an autosomal, incomplete dominant mechanism; heterozygous offspring express half the levels of extraglandular aromatase as do homozygous Campines on average. No reversions to wild-type levels were observed in 555 heterozygous offspring of crosses between homozygous Campines and normals. Compound heterozygotes for the trait were obtained by mating homozygous Sebrights and homozygous Campines. When these compound heterozygote birds were crossed to control birds, all 98 offspring had elevated aromatase activity in skin, suggesting that the traits in Sebright and Campine birds are allelic. Furthermore, the restriction fragment length polymorphism pattern performed on genomic DNA was the same in the Sebright and Campine birds. Thus, the phenotypic, endocrine, and genetic features suggest that the traits in Sebright and Campine birds are the same. The trait in the Campine probably was derived from the Sebright.

Alleles↗
PubMed1991

The influence of ev6 on the immune response to avian leukosis virus infection in rapid-feathering progeny of slow- and rapid-feathering dams.

Endogenous virus (EV) locus ev6 encodes only virus envelope glycoprotein. The influence of ev6 on the immune response to contact infection with hatchmates infected with avian leukosis virus (ALV) was compared in replicate hatches. The ALV Subgroup E-resistant, rapid-feathering (RF) female chickens produced by slow-feathering (SF) and RF dams with and without ev6 were exposed at hatch to hatchmates infected with ALV Subgroup A (Strain RPL-40). The RPL-40 viremia, shedding, and virus neutralizing antibodies were measured among pullets from two hatches at 22 wk of age. Although significant (P less than .05) differences between hatches in the immune response to contact infection were noted among ev6+ pullets, significantly fewer ev6+ pullets seroconverted than their ev6- hatchmates. At 22 wk of age, significantly more lymphomas were also found among ev6+ pullets than among ev6- hatchmates. In flocks wherein both parents and progeny were homozygous resistant to Subgroup E virus, there was no deterimental maternal effect on RF progeny from SF dams that carried ev21. These results also confirm that selection for genetic cellular resistance to Subgroup E ALV infection eliminates congenital transmission of EV21.

Animals↗
PubMed1975

The properties of bird feathers as converse piezoelectric transducers and as receptors of microwave radiation. I. Bird feathers as converse piezoelectric transducers.

An investigation was made of the properties of bird feathers as piezoelectric transducers in the audiofrequency range and as dielectric receptors of electromagnetic radiation in the microwave region. In the first case, cartridges of the ceramic and magnetic type and an electromagnetic transducer probe were used as detecting devices. Results show piezoelectric resonances in the 1 to 20-kHz region for the calami of feathers.

Animals↗
PubMed1991

Hydrolysis time as a factor affecting the nutritive value of feather meal and feather meal-blood meal combinations for growing calves.

The objectives of this research were to determine 1) the effects of hydrolysis time on feather meal (FTH) protein digestion and ruminal escape and 2) whether adding blood meal (BM) to FTH evoked a complementary response in animal performance. A lamb digestion trial was conducted to estimate true protein digestibility of soybean meal (SBM), BM, and FTH hydrolyzed for 10, 12, 15, or 18 min. Ruminal escape was estimated in situ. Two 94-d growth trials were conducted using 60 growing calves (226 kg) per trial to evaluate urea, FTH, BM, and 87.5:12.5, 75:25, and 50:50 combinations (CP percentage basis) of FTH:BM. There were small numerical differences in estimated escape of protein from the rumen and DM and protein digestibilities due to hydrolysis time. True protein digestibility of the 10- and 18-min samples was 5% higher (P less than .05) than for the 12- or 15-min FTH samples. In the growth trial, the slope-ratio technique showed that the most efficiently used protein supplement was 100% BM (protein efficiency = 2.45 +/- .19). No differences (P = .30) in protein efficiency were observed among supplements containing various combinations of FTH:BM. There was a quadratic (P less than .01) response to the level of BM, indicating a complementary effect. The largest complementary effect occurred at the 12.5% level of the BM addition. There were no nutritionally important effects of hydrolysis time between 10 and 18 min. Furthermore, supplements can be formulated more economically using small amounts of BM with FTH without compromising biological efficiency.

Animal Feed↗
PubMed1985

The spatial pattern and temporal sequence in which feather germs arise in the white Leghorn chick embryo.

Feather germs arise in a specific sequence and spatio-temporal pattern within each of 10 feather areas on the White Leghorn chick embryo. The time of feather germ initiation was determined by histological and gross macroscopic analyses. Protruding feather germs are sequentially visualized in the dorsal, thigh, breast, head, humoral, ventral, wing, eye, and external auditory meatus feather areas, respectively, from stage 31- to stage 39+ [V. Hamburger and H.L. Hamilton (1951) J. Morphol. 88, 49-92]. The rate at which successive feather tracts appear was found to differ for different feather areas and was not simply due to the size of a feather area. Feather germ histogenesis was examined in the dorsal, thigh, breast, ventral, wing, and tail feather areas. The stages of feather germ histogenesis, examined on the wing feather area, are similar to those previously described for the dorsal surface. Gross and histological analyses gave different times and temporal sequences of feather germ visualization. Some feather areas were readily visualized at the time of feather germ initiation, while others showed a lag between the histological appearance of feather germs and their macroscopic visualization. Thus, macroscopic observations do not accurately reflect the pattern of histogenesis.

Animals↗
PubMed1987

Identification of volatile sulfur derivatives released from feathers of chicks fed diets with various levels of sulfur-containing amino acids.

Physical changes are observed in the feathers of chickens fed diets with high levels of methionine or cysteine. Chicks were fed diets chemically analyzed to contain 21% crude protein, 0.35% methionine and 0.37% cystine (basal) supplemented with DL-methionine [0.063 (control), 0.25 or 1.45%] or L-cysteine (0.203%). At 3 wk of age, the birds were weighed and the feathers scored for softness. Feather strength (i.e., force-displacement curves) was determined on feathers from the pectoral tract. A significant (P less than 0.05) reduction in body weight and an increase in feather softness were seen when chicks fed the control diet and those fed the diet with 1.45% added methionine were compared. Chicks fed the diet supplemented with 0.203% L-cysteine produced the strongest feathers; those fed diets supplemented with 1.45% DL-methionine produced the weakest feathers. Volatile sulfur compounds released from the feathers were trapped as dinitrophenyl (DNP) thioethers and were analyzed by thin-layer chromatography, high pressure liquid chromatography and mass spectrometry. More bound sulfide (P less than 0.05) was recovered from feathers of chickens fed the diet supplemented with 1.45% methionine than from feathers of chickens fed the other diets. The feather softness score was correlated (r = 0.5; P less than 0.05) with bound sulfide. Thus, consumption of a diet with a level of methionine that is approximately three times the requirement resulted in decreased growth, elevated sulfide bound to the feathers and soft, weak feathers.

Amino Acids, Sulfur↗
PubMed1977

Abnormal morphogenesis of feather structures and pattern in the chick embryo integument. II. Histological description.

The development of skin and feathers in highly feathered scaleless mutants and normal Single Comb White Leghorn chick embryos was analyzed histologically. In addition, the growth of mutant feathers in chorioallantoic membrane culture is reported as a verification of several inferences made from observations of serially staged fixed specimens. The most striking feature of scaleless high line feather development is the widespread appearance of condensed or nearly condensed dermis. The discrete arrangement of normal placodes with underlying condensed dermis is replaced in the mutant by a heterogeneously shaped group of extremely large islands of columnar ("placodized") epithelium as long as 3,000 micron. The shape and extent of the condensed areas of dermis reflect the shape and extent of the overlying "placodized" epithelium. The polarity of the epidermis in normal feather germs, i.e., thicker epidermis on the posterior surface, is absent in mutant feather germs. This absence of epidermal polarity is reflected in the aberrant outgrowth of the mutant feather primordial. In the mutant, the basal cell layer of the epidermis invades the dermal core of the aberrant feather germs and may form barb vane ridges or feather sheaths. This process had no counterpart in the development of normal down feathers.

Animals↗
PubMed1985

Differentiation of embryonic chick feather-forming and scale-forming tissues in transfilter cultures.

The dermal-epidermal tissue interaction in the chick embryo, leading to the formation of feathers and scales, provides a good experimental system to study the transfer between tissues of signals which specify cell type. At certain times in development, the dermis controls whether the epidermis forms feathers or scales, each of which are characterized by the synthesis of specific beta-keratins. In our culture system, a dermal effect on epidermal differentiation can still be observed, even when the tissues are separated by a Nuclepore filter, although development is abnormal. Epidermal morphological and histological differentiation in transfilter cultures are distinct and recognizable, more closely resembling feather or scale development, depending on the regional origin of the dermis. Differentiation is more advanced when epidermis is cultured transfilter from scale dermis than from feather dermis, as assessed by morphology and histology, as well as the expression of the tissue-specific gene products, the beta-keratins. Two-dimensional polyacrylamide gel analysis of the beta-keratins reveals that scale dermis cultured transfilter from either presumptive scale or feather epidermis induces the production of 7 of the 9 scale-specific beta-keratins that we have identified. Feather dermis, although less effective in activating the feather gene program when cultured transfilter from either presumptive feather or scale epidermis, is able to turn on the synthesis of 3 to 6 of the 18 feather-specific beta-keratins that we have identified. However, scale epidermis in transfilter recombinants with feather dermis also continues to synthesize many of the scale-specific beta-keratins. Using transmission and scanning electron microscopy, we detect no cell contact between tissues separated by a 0.2-micron pore diameter Nuclepore filter, while 0.4-micron filters readily permit cell processes to traverse the filter. We find that epidermal differentiation is the same with either pore size filter. Furthermore, we do not detect a basement membrane in transfilter cultures, implying that neither direct cell contact between dermis and epidermis, nor a basement membrane between the tissues is required for the extent of epidermal differentiation that we observe.

Animals↗
PubMed1985

Analysis of morphogenesis and keratinization in transfilter recombinants of feather-forming skin.

The relationships between feather morphogenesis, histogenesis, and biochemical differentiation were examined by recombining backskin epidermis and dermis, from chick embryos (Hamburger-Hamilton stages 27-31), with an intervening Nucleopore filter (pore size of 0.4 micron). The filter inhibited normal feather morphogenesis and histogenesis of barb ridges, yet feather-like filaments, which were free of dermal cells, formed from the epidermal cells. Using indirect immunofluorescence, with antiserum against alpha- and beta-keratins, the biochemical differentiation of the feather-like filaments was compared to normal feathers. In the feather-like filaments resulting from tissues of stages 27-29, cells containing beta keratins were occasionally seen at the periphery of the filaments, yet cells containing alpha-keratins were inappropriately located throughout the filaments. In a few feather-like filaments on recombinants resulting from tissues of stages 29.5-31, cells positive for beta-keratins were found in the center of the filament, but again alpha-keratins were also found. Surrounding these cells there were several layers of cells, arranged circumferentially, resembling sheath cells. Some sheath-like cells contained beta-keratins. We conclude that although feather epidermal cells, which are separated from their dermis by a Nuclepore filter, can undergo limited morphogenesis and the production of alpha- and beta-keratins, normal feather morphogenesis, histogenesis, and biochemical differentiation require the intimate associations of epidermis and dermis.

Animals↗
PubMed1991

Adhesion molecules in skin development: morphogenesis of feather and hair.

Figure 9 summarizes the morphogenetic process of feather and hair. Hair of feathers are formed from a layer of homogeneously distributed mesenchymal cells. The mesenchymal cells start to condense to form foci in response to some unidentified induction signal (Fig. 9B). Several adhesion molecules, including L-CAM, N-CAM, integrin, tenascin, as well as proteoglycan, are involved. These adhesion molecules appear to have different roles in this process, because perturbation with specific antibodies leads to different aborted patterns. Hair or feather follicles then form following cell proliferation and epithelial invagination (Fig. 9C). The dermal papilla is enriched with N-CAM and tenascin, whereas the feather collar (equivalent of hair matrix) is enriched with L-CAM and PDGF receptor. Epithelial cells in the feather collar receive a signal from the dermal papilla and are able to continue to divide. Several growth factors, such as PDGF and EGF, may be involved. As epithelial cells are pushed upwards, they differentiate and keratinize in a cylindrical structure into hair. In feather, another morphogenetic event takes place to form the branched structure. The epithelial cylinder of the feather shaft invaginates to form rows of cells that die to become space and create the secondary branch or barbs (Fig. 9D). N-CAM is enriched in the cells destined to die and appears to form the border of cell groups within which the "death signal" is transmitted. In some, but not all, feathers the same process is repeated, in a way analogous to fractal formation, to form the tertiary branches or the barbules (Fig. 9E). Thus, in each step of the morphogenesis of feather and hair, different adhesion molecules are expressed and are involved in different functions: induction, mesenchymal condensation, epithelial folding, and cell death, depending on different scenarios. We have just begun to elucidate these molecular events.

Animals↗
PubMed1990

Gradients of homeoproteins in developing feather buds.

Homeoproteins are functionally involved in pattern formation. Recently, homeoproteins have been shown to be distributed in a graded fashion in developing limb buds. Here we examine the expression of homeoproteins in chicken feather development by immunocytochemical localization. We find that XlHbox 1 antigen is present in cell nuclei and is distributed in a gradient in the mesoderm of developing feather buds, with strongest expression in the anterior-proximal region. The gradient is most obvious in feather buds from the mid-trunk level. Feather buds from the scapular level express very high levels of XlHbox 1 and feather buds from the caudal region express no XlHbox 1, suggesting that a broad gradient along the body axis is superimposed on a smaller gradient within each individual feather bud. Feather ectoderm also expresses XlHbox 1 antigen but without an obvious graded pattern. Another homeoprotein, Hox 5.2, is also expressed in developing feather buds in a graded way, and its distribution pattern is partially complementary to that of XlHbox 1. These observations suggest that homeoproteins may be involved in setting up the anteroposterior polarity of cell fields at different levels, first for the body axis, then for the limb axis and finally for the feather axis.

Animals↗
PubMed1985

Possible control mechanisms of feather follicle movement in the pectoral tract of the chicken.

Feather follicle movement control was studied on feathers of the pectoral tract in the anaesthetized chicken. Dissection of nerves leading to the follicles showed that their origin was at least partially in the sympathetic ganglia. Reflectoric ruffling of feathers could be obtained after adequate stimulation. Intravenous injections of drugs in doses which influenced the circulation gave the following results: Adrenaline caused erection of feathers which was abolished by phentolamine. Noradrenaline caused up and down movements after injection only at high doses. Similar results were obtained by placing of skin pieces in saline containing the drugs. The reaction to drugs was typical always for a given group of feathers. Killing of birds and anaesthesia caused general erection of feathers which was not abolished by phentolamine. The findings suggest that adrenergic synapses are involved in feather follicle movement control, but at least another mechanism (CNS) regulates feather follicle movement.

Animals↗
PubMed1988

Altered proteoglycan synthesis disrupts feather pattern formation in chick embryonic skin.

We have tested the role of proteoglycans in the development of feather pattern by culturing 7-day-old embryonic chick skins on medium containing para-nitrophenyl-beta-D-xyloside (2 mM). Xylosides compete with core proteins of proteoglycans by acting as exogenous acceptors for the synthesis of glycosaminoglycans leading to the synthesis of under- or unglycosylated core proteins and free glycosaminoglycans. We have demonstrated that xyloside treatment alters the structure of the proteoglycans synthesized by embryonic skin and disrupts the feather pattern. The altered pattern is seen as the fusion of individual feather rudiments. Fusion can occur diagonally, and in an anteroposterior and mediolateral direction. The effect induced by the disruption of proteoglycan structure takes place during the first 24 hr of culture during which time all the rows of feather rudiments are being established. The effect is reversible if the skins are returned to control medium after 24 hr but not after 48 hr of treatment with xyloside. Once established during the first 24 hr the feather pattern can only be slightly distorted by the xyloside treatment. The results are interpreted to mean that proteoglycans play a developmental role in the establishment of the feather pattern but not in its maintenance, suggesting that the two processes are under different developmental control. The altered feather pattern obtained by disrupting proteoglycan structure is highly similar to that obtained when skins are cultured in the presence of antibodies to L-CAM (W.J. Gallin, C.-M., Chuong, L.H. Finkel, and G.M. Edelman (1986), Proc. Natl. Acad. Sci. USA 83, 8235-8239). This observation suggests that there may be a functional relationship between the extracellular matrix and cell adhesion molecules in the establishment of feather pattern.

Animals↗