Effects of sublethal methylmercury and food stress on songbird energetic performance: metabolic rates, molt and feather quality.

Organisms regularly adjust their physiology and energy balance in response to predictable seasonal environmental changes. Stressors and contaminants have the potential to disrupt these critical seasonal transitions. No studies have investigated how simultaneous exposure to the ubiquitous toxin methylmercury (MeHg) and food stress affects birds' physiological performance across seasons. We quantified several aspects of energetic performance in song sparrows, Melospiza melodia, exposed or not to unpredictable food stress and MeHg in a 2×2 experimental design, over 3 months during the breeding season, followed by 3 months post-exposure. Birds exposed to food stress had reduced basal metabolic rate and non-significant higher factorial metabolic scope during the exposure period, and had a greater increase in lean mass throughout most of the experimental period. Birds exposed to MeHg had increased molt duration, and increased mass:length ratio of some of their primary feathers. Birds exposed to the combined food stress and MeHg treatment often had responses similar to the stress-only or MeHg-only exposure groups, suggesting these treatments affected physiological performance through different mechanisms and resulted in compensatory or independent effects. Because the MeHg and stress variables were selected in candidate models with a ΔAICc lower than 2 but the 95% confidence interval of these variables overlapped zero, we found weak support for MeHg effects on all measures except basal metabolic rate, and for food stress effects on maximum metabolic rate, factorial metabolic scope and feather mass:length ratio. This suggests that MeHg and food stress effects on these measures are statistically identified but not simple and/or were too weak to be detected via linear regression. Overall, combined exposure to ecologically relevant MeHg and unpredictable food stress during the breeding season does not appear to induce extra energetic costs for songbirds in the post-exposure period. However, MeHg effects on molt duration could carry over across multiple annual cycle stages.

In ovo injection of AZD6244 suppresses feather follicle development by the inhibition of ERK and Wnt/ß-catenin pathways in goose embryos (Anser cygnoides).

1. Feathers are an important product from poultry, and the state of feather growth and development plays an important role in their economic value.2. In total, 120 eggs were selected for immunoblotting and immunolocalisation experiments of ERK and ß-catenin proteins in different developmental stages of goose embryos. The ERK protein was highly expressed in the early stage of goose embryo development, while ß-catenin protein was highly expressed in the middle stage of embryo development.3. The 120 eggs were divided into four treatment groups, including an uninjected group (BLANK), a group injected with 100 µl of cosolvent (CK), a group injected with 100 µl of AZD6244 containing cosolvent in a dose of 5 mg/kg AZD6244 containing cosolvent (AZD5) and a group injected with 100 µl of AZD6244 containing cosolvent in a dose of 15 mg/kg AZD6244 containing cosolvent (AZD15). The eggs were injected on the ninth day of embryonic development (E9). Samples were collected at E21.5 to observe feather width, feather follicle diameter, ERK and Wnt/ß-catenin pathway protein expression.4. The AZD5 and AZD15 doses were within the embryonic safety range compared to the BLANK and CK groups and had no significant effect on the survival rate and weight at the inflection point, but significantly reduced the feather width and feather follicle diameter (p < 0.05). The AZD6244 treatment inhibited ERK protein phosphorylation levels and blocked the Wnt/ß-catenin pathway, which in turn significantly down-regulated the expression levels of FZD4, ß-catenin, TCF4 and LEF1 (p < 0.05), with an inhibitory effect in the AZD15 group being more significant. The immunohistochemical results of ß-catenin and p-ERK were consistent with Western blot results.5. The small molecule inhibitor AZD6244 regulated the growth and development of feather follicles in goose embryos by the ERK and Wnt/ß-catenin pathways.

Antibiotic treatment increases yellowness of carotenoid feather coloration in male greenfinches (Chloris chloris).

Carotenoid plumage coloration is an important sexually selected trait in many bird species. However, the mechanisms ensuring the honesty of signals based on carotenoid pigments remain unclear. It has recently been suggested that intestinal integrity, which is affected by gut parasites and microbiota and influences nutrient absorption and acquisition, mediates the relationship between carotenoid ornamentation and individual quality. Here, we test whether carotenoid plumage coloration in greenfinches (Chloris chloris) is affected by the treatment of an antibiotic or an antiparasitic drug. We captured wild greenfinches (N = 71) and administered anticoccidial medication toltrazuril (TOLTRA) to one group, antibiotic metronidazole (METRO) to the second group to target trichomonosis, and the third group received no medication. In the METRO group, feathers grown during the experiment had significantly higher chroma of yellow parts, but there was no effect of TOLTRA on feather chroma. The results suggest that METRO increased the efficiency of carotenoid modification or deposition to the feathers rather than nutrient acquisition and/or freed energy resources that could be invested in coloration. Alternatively, though not measured, METRO might have affected microbial community and host physiology as microbial metabolites can modulate mitochondrial and immune function.

Dietary resistant potato starch improves growth performance and feather development in Pekin ducks fed a low phosphorus diet.

This study investigated whether dietary resistant potato starch (RPS) inclusion could ameliorate the negative impact of a low nonphytate phosphorus (nPP) diet on growth performance, feather growth, feather follicles (FF) development, and carcass traits by improving nutrient utilization and cecal microbiome fermentation capacity in Pekin ducks. The experiment was performed with a 2 × 2 randomized block design with 2 levels of RPS (0 or 12%) and 2 levels of nPP (low or normal, low: 0.22% at 1-14 d and 0.18% at 15-35 d of age; normal: 0.40% at 1-14 d and 0.35% at 15-35 d of age) for a total of 4 treatments, each with 8 replicate pens per treatment of 12 birds per pen. As regards growth performance and carcass traits, RPS inclusion markedly increased (P < 0.05) BW of 14 and 35 d, BWG and FI of 1-14 d, 15-35 d, and 1-35 d as well as abdominal fat and breast meat percentage of 35 d in ducks fed low nPP diets; moreover, RSP inclusion significantly reduced (P < 0.05) mortality in ducks fed low nPP diets. As regards feather growth and follicles development of 35 d, RPS inclusion significantly increased (P < 0.05) the fourth primary feather length, absolute feather weight, and the density of primary FF in the back skin in ducks fed low nPP diets. In regard to nutrition utilization, RPS supplementation significantly increased (P < 0.05) the availability of DM, CP, and energy, as well as dietary AME at 35 d of age in ducks fed low nPP diets. However, RPS supplementation had no effect (P > 0.05) on the concentration of cecal short-chain fatty acids and the activities of cecal phytase and cellulase in ducks fed low nPP diets. These results indicate that RPS can improve nutrient availability to ameliorate the negative effects on performance and feather development caused by a low nPP diet in Pekin ducks.

Estimated intestinal absorption of phosphorus and its deposition in chosen tissues, bones and feathers of chickens receiving chromium picolinate or chromium nanoparticles in diet.

The aim of the study was to determine whether the level and form of Cr in the diet of chickens influences its accumulation in tissues as well as intestinal absorption of P and its deposition in tissues. The experiment was carried out on 405 one-day-old male Ross 308 chickens that were randomly divided into five treatment groups. Control group was fed the diet without supplemental chromium; experimental groups were fed the diet with 3 or 6 mg/kg chromium picolinate (Cr-Pic) and with 3 or 6 mg/kg chromium nanoparticles (Cr-NP). Chromium was found to accumulate in the tissues of the ileum, liver, breast muscle, bones skin and in feathers of chickens. Chromium deposited in the ileum of chickens does not affect the ex vivo estimated intestinal absorption of P. The use of Cr in the diet of chickens carries the risk of lowering P levels in femur.

Local and systemic inflammatory responses to lipopolysaccharide in broilers: new insights using a two-window approach.

The inflammatory response involves a complex interplay of local tissue activities designed to recruit leukocytes and proteins from the blood to the infected tissue. For egg-type chickens, we established the growing feather (GF) as an accessible tissue test site to monitor tissue responses to injected test-material. For commercial broilers, whose health depends to a large extent on innate immune system functions, the GF test system offers an important novel window to directly assess their natural defenses. This study was conducted to adapt the GF test system for use in broilers, and use it to simultaneously examine local (GF) and systemic (blood) inflammatory responses initiated by GF pulp injection of lipopolysaccharide (LPS). Specifically, GF of 12 male and 12 female, 5-week-old broilers were injected with LPS (16 GF/chicken; 1 µg LPS/GF). Blood and GF were collected at 0 (before), 6, and 24 h after GF injection. GF pulp was used to determine leukocyte-infiltration and gene-expression profiles, reactive-oxygen-species generation, and superoxide dismutase (SOD) activity. Blood was used to determine blood cell profiles and SOD activity. A time effect (P ≤ 0.05) was observed for most aspects examined. In GF, LPS injection resulted in heterophil and monocyte infiltration reaching maximal levels at 6 and 24 h, respectively. Reactive-oxygen-species generation, SOD activity, and mRNA levels of IL-1ß, IL-8, IL-6, IL-10, and cathelicidin B1 were elevated, whereas those of TNF-α, LITAF, SOD1, and SOD2 decreased after LPS injection. In blood, levels of heterophils and monocytes were elevated at 6 h, lymphocytes and RBC decreased at 6 h, and thrombocytes and SOD activity increased at 24 h. Assessment of LPS-induced activities at the site of inflammation (GF) provided novel and more relevant insights into temporal, qualitative, and quantitative aspects of inflammatory responses than blood. Knowledge generated from this dual-window approach may find direct application in identification of individuals with robust, balanced innate defenses and provide a platform for studying the effects of exogenous treatments (e.g., nutrients, probiotics, immunomodulators, etc.) on inflammatory responses taking place in a complex tissue.

Alteration of dietary cysteine affects activities of genes of the transsulfuration and glutathione pathways, and development of skin tissues and feather follicles in chickens.

The dietary requirement for cysteine is not determined in poultry since it is not an essential amino acid. The cysteine need is expected to be met through the transsulfuration pathway where homocysteine, a precursor of methionine, is converted to cysteine. Cysteine is a major component of plumage, and the degree to which cysteine is involved in plumage and other keratized proteins are unknown. We randomly assigned chicks to control and treatment (deficient in cysteine) diets for 49 d. The thickness of the skin layers, feather follicle length, and thickness were measured at days 10, 24, 34, and 49. We also measured the hepatic mRNA expressions of cystathionine beta synthase (CBS), cystathionine γ-lyase (CTL), cysteine dioxygenase (CDO), and glutathione synthetase (GSS). Chickens fed the treatment diet had reduced epidermis thickness and shorter feather follicles compared with the controls. The chicken fed the treatment diet also had increased mRNA expression of CBS and CTL indicating a disruption of the transsulfuration pathway. The treatment chickens also had a decreased hepatic CDO and increased GSS mRNA expressions which are in concordance with the homeostatic regulation of cysteine. Compromised cysteine metabolism could affect thermoregulation and subsequently affect feed efficiency and welfare of the birds.

Do glucocorticoids or carotenoids mediate plumage coloration in parrots? An experiment in Platycercus elegans.

Conspicuous coloration can indicate phenotypic quality, and may reflect exposure or vulnerability to stress, or access to essential nutrients such as pigments. Although the production of pigmented colours is well understood, much less is known about how structural colours are affected by physiological state. In this study, we tested whether glucocorticoids (corticosterone) predicted expression of plumage coloration in an Australian parrot, the crimson rosella (Platycercus elegans). Parrots provide an interesting and unique test, as they possess conspicuous coloration produced by distinctive pigments known as psittacofulvins, in addition to structural coloration. We have previously documented that coloration in P. elegans is condition-dependent and responds to dietary manipulation. Here, n = 21 P. elegans underwent a dietary manipulation (including food restriction or carotenoid supplementation) during which they moulted, and the change in reflectance was measured for three structural and three pigmentary plumage patches. Stress-induced corticosterone (10 min after handling) measured at the start of the experiment predicted change in coloration in two pigmentary patches (crown and front). We also found that change in stress-induced corticosterone during the experiment was associated with the change in coloration of the crown and two structural patches (cheek and epaulette). Baseline corticosterone (<3 min after handling) was not associated with any measure of coloration. We found no effects of dietary manipulation on baseline or stress-induced corticosterone, but carotenoid supplementation was associated with an increase in a measure of chronic stress (heterophil/lymphocyte ratio), and the corticosterone response to handling decreased over the course of the study. Our results suggest that corticosterone may be linked to colour expression more broadly than previously recognised, including psittacofulvin and structural coloration in parrots, and they confirm the independence of plumage pigmentation in parrots from carotenoid accumulation. Moreover, our study provides new insight into the stress responses of Psittaciformes, one of the most highly threatened avian orders.

Leaves of Moringa, Rosemary and Olive as a Phytogenic Feed Additives in Muscovy Duck diets.

BACKGROUND AND OBJECTIVE: Alternative sources of natural ingredients such as herbs or phytogenic plants have beneficial effects which are used as feed supplements or medicines in poultry. The current research objective was to investigate the influence of using phytogenic plants as feed additives on Muscovy ducklings performance. MATERIALS AND METHODS: A total number of 315 of 14 days old Muscovy ducklings were divided randomly into 7 experimental groups, each group was allocated into three replicates. The experimental treatments were arranged in one way classification by using three sources of phytogenic plants being Moringa oleifera leaves meal (MLM), Rosmarinus officinalis leaves meal (RLM) and Olea europaea leaves meal (OLM) with two levels of plant addition (1 or 2%) compared to the commercial diet (control). The experimental diets were formulated to be iso-caloric and iso-nitrogenous. Feed and water were offered ad libitum from 14 up to 70 days old. RESULTS: Data showed that phytogenic plants did not affect negatively growth performance of ducklings but improved gain compared to the control group. The highest value of live body weights (4185 g) was recorded for diet that supplemented with 1% MLM at 70 days old while, the lowest weight recorded for diet supplemented with 2% OLM being 3507 g compared to the control. A significant decrease in FI (g/bird) was noticed for treatment groups during the interval and the whole experimental periods compared with control group. CONCLUSION: Ducklings fed diet supplemented with phytogenic plants recorded the highest values of feather, carcass, heart, liver and gizzard (%) compared to the control group.

The influence of petroleum oil films on the feather structure of tropical and temperate seabird species.

Feather fouling is a primary cause of seabird mortality during marine hydrocarbon oil spills. Understanding how oils interact with feathers is an important step in mitigating this threat. Seabird feathers from 12 taxa, representing most seabird families from the tropics and southern latitudes, were exposed to crude and condensate oil films under laboratory settings. Feathers were measured for changes in mass proportional to feather size, and for barbule clumping. Seabird feathers from six distinct families exposed to very thin oil sheens (<0.3 µm) showed no significant change in proportional mass relative to control treatments, and 10 of the 12 species exposed to these films revealed no significant difference in barbule clumping. By contrast, exposure to both crude and condensate oil films ≥3 µm resulted in significant increases in feather mass and clumping. Our findings highlight the importance of considering the influence of oil on feather structure when compiling threat assessments involving seabirds.

Inhibition of the Transsulfuration Pathway Affects Growth and Feather Follicle Development in Meat-Type Chickens.

Cysteine is a nonessential amino acid in poultry nutrition. Poultry diets are deficient in cysteine, but the bird's cysteine need is met through the transsulfuration pathway (TSP) where homocysteine is converted to cysteine: a process catalyzed by cystathionine ß-synthase (CBS) and cystathionine γ-lyase (CTH). Cysteine is also a major component of keratinized protein found in feathers, but the extent to which cysteine is involved in feather and skin development in poultry is unknown. We randomly assigned chicks to control and treatment (control diet plus 100 mg/kg body weight of propargylglycine which is an inhibitor of CTH) diets. The thickness of skin layers, primary feather follicle parameters, growth, and mRNA expression of CBS and CTH were measured. Inhibition of TSP corresponded with the upregulation of liver mRNA of both CBS and CTH and reduction in growth from 35 to 40 days of age. The epidermis thickness, feather follicle length, and diameter were reduced from 10 to 40 days of age. Incorporation of cysteine into keratinized protein may be more sensitive to the level of available cysteine than into nonkeratinized proteins. Thus, disruption of the TSP could affect the thermoregulatory ability of the bird.

How chemotherapy and radiotherapy damage the tissue: Comparative biology lessons from feather and hair models.

Chemotherapy and radiotherapy are common modalities for cancer treatment. While targeting rapidly growing cancer cells, they also damage normal tissues and cause adverse effects. From the initial insult such as DNA double-strand break, production of reactive oxygen species (ROS) and a general stress response, there are complex regulatory mechanisms that control the actual tissue damage process. Besides apoptosis, a range of outcomes for the damaged cells are possible including cell cycle arrest, senescence, mitotic catastrophe, and inflammatory responses and fibrosis at the tissue level. Feather and hair are among the most actively proliferating (mini-)organs and are highly susceptible to both chemotherapy and radiotherapy damage, thus provide excellent, experimentally tractable model systems for dissecting how normal tissues respond to such injuries. Taking a comparative biology approach to investigate this has turned out to be particularly productive. Started in chicken feather and then extended to murine hair follicles, it was revealed that in addition to p53-mediated apoptosis, several other previously overlooked mechanisms are involved. Specifically, Shh, Wnt, mTOR, cytokine signalling and ROS-mediated degradation of adherens junctions have been implicated in the damage and/or reparative regeneration process. Moreover, we show here that inflammatory responses, which can be prominent upon histological examination of chemo- or radiotherapy-damaged hair follicle, may not be essential for the hair loss phenotype. These studies point to fundamental, evolutionarily conserved mechanisms in controlling tissue responses in vivo, and suggest novel strategies for the prevention and management of adverse effects that arise from chemo- or radiotherapy.

Effect of dietary amino acid density on broiler breeder reproductive performance.

The effects of 3 dietary amino acid (AA) profiles during lay on reproductive performance of broiler breeders were investigated. A flock of 2,376 Ross 708 female broiler breeders were randomly divided into 3 treatments with 12 replicates of 66 females per replicate, and fed 2 breeder feed phases (breeder 1: 25 to 36 wk; breeder 2: 37 to 60 wk) which were formulated to 3 different AA densities (Aviagen advice = control; 10% increased AA in Aviagen advice = high-AA; and estimated AA needs for maintenance, growth, and egg mass = estimated-AA). No differences in total or hatching egg production due to dietary treatments were observed. Hens fed high-AA had a higher incidence of double-yolk eggs. During the second phase of lay, hens fed estimated-AA had lower livability compared to the other treatments. Hens fed estimated-AA also laid smaller eggs compared to control and high-AA fed birds. Back feather cover deteriorated as hens grew older, and hens fed the estimated-AA diets had poorer feather cover from 41 wk onward. Overall, these results suggest that feeding higher AA levels than Aviagen recommendations presented no benefit in reproductive performance or feather quality. The estimated-AA feeding approach supported laying performance similar as other treatments, although affected egg weight and back feather cover.

Efficacy of 2-hydroxy-4-methylthiobutanoic acid compared to DL-Methionine on growth performance, carcass traits, feather growth, and redox status of Cherry Valley ducks.

The objective of this study was to compare the bio-efficacy of 2-hydroxy-4-methylthiobutanoic acid (DL-HMTBA) with that of DL-methionine (DLM) as sources of methionine in terms of the growth performance, carcass traits, feather growth, and redox statuses of Cherry Valley ducks. Six hundred and thirty male ducks were randomly allotted to 9 dietary treatment groups with 7 replicates of 10 birds each. The first group received a basal diet (BD) without methionine addition that was deficient in the total number of sulfur amino acids. In Groups 2 to 5 and Groups 6 to 9, the BD was supplemented with 4 increasing doses of methionine as either DLM or DL-HMTBA. The trial was run from ages 1 to 42 d. Dietary supplementation with DLM and DL-HMTBA improved body weight gain and feed intake as well as weights of carcasses, breast meat, and feathers compared with the BD. No significant difference was observed between the 2 methionine sources on growth performance, carcass traits, and feather growth. Concentrations of some redox markers in the pectoralis major muscle were improved by addition of methionine to the BD. However, a significant difference was observed between DLM and DL-HMTBA in this respect, as the supplementation of DL-HMTBA significantly increased the total antioxidant capacity, the activities of glutathione peroxidase, and the concentration of reduced glutathione in the pectoralis major muscle, compared with DLM. No significant difference between methionine sources was found with regard to the concentrations of oxidized glutathione and malondialdehyde in the pectoralis major muscle. Both DLM and DL-HMTBA increased malondialdehyde concentrations in the pectoralis major muscle compared with the BD. In conclusion, these results indicated that DLM and DL-HMTBA have equal biological value for the growth performance, carcass traits, and feather growth of Cherry Valley duck. Moreover, the improved antioxidant capacity observed with DL-HMTBA makes this a better candidate than DLM for lowering the oxidation process in the meat during post-mortem storage and thereby contributes to a better duck meat quality.

Effects of an early-life paraquat exposure on adult resistance to oxidative stress, plumage colour and sperm performance in a wild bird.

Early-life stressful conditions can shape individual phenotypes and ultimately influence fitness. Oxidative stress is a pervasive threat that affects many fitness-related traits and can modulate life-history trade-offs. Yet, the extent to which exposure to oxidative stress during early life can have long-lasting effects on key fitness-related traits remains to be elucidated, particularly in natural populations of vertebrates. Using a wild population of great tits Parus major, we experimentally dosed 11-day-old birds with paraquat, a pro-oxidant molecule, aiming at increasing oxidative stress. One year later, we recaptured 39 of them as adult recruiting breeders and quantified effects of the paraquat exposure on their resistance to oxidative stress, carotenoid-based plumage coloration and male sperm performance. Despite the absence of a short-term effect of paraquat on oxidative stress measured two days later, the pre-fledging exposure to paraquat induced a reduction in individual oxidative damage measured at adulthood. Paraquat-dosed individuals also had brighter plumage, but no effect was observed on male sperm performance. For the first time in a natural population of vertebrates, we experimentally show that an early-life acute exposure to a pro-oxidant has long-lasting effects on individual resistance to oxidative stress at adulthood. Our results are in line with the environmental matching and the hormesis hypotheses but may also reflect selective disappearance of individuals with lower resistance to oxidative stress.

Spotlight on Ibrutinib in PCNSL: Adding Another Feather to Its Cap.

In this issue Grommes and colleagues elegantly show that the irreversible inhibitor of Bruton tyrosine kinase, ibrutinib, promotes a high proportion of durable responses in primary central nervous system lymphoma, a type of diffuse large B-cell lymphoma (DLBCL), and also in secondary DLBCL relapsing to the central nervous system. Mutations in the B-cell antigen receptor-associated protein CD79B with upregulation of the MTOR pathway were associated with diminished response, but preclinical combination of PIK3CA and PIK3CD inhibitors synergized with ibrutinib to overcome this resistance mechanism, providing opportunity for further targeted therapy of this difficult-to-treat disease. Cancer Discov; 7(9); 940-2. ©2017 AACRSee related article by Grommes et al., p. 1018.

Omega-3 polyunsaturated fatty acids provided during embryonic development improve the growth performance and welfare of Muscovy ducks (Cairina moschata).

The welfare of ducks can be affected by unwanted behaviors such as excessive reactivity and feather pecking. Providing long-chain n-3 polyunsaturated fatty acids (LC n-3 PUFA) during gestation and early life has been shown to improve the brain development and function of human and rodent offspring. The aim of this study was to test whether the pecking behavior of Muscovy ducks during rearing could be reduced by providing LC n-3 PUFA during embryonic and/or post-hatching development of ducklings. Enrichment of eggs, and consequently embryos, with LC n-3 PUFA was achieved by feeding female ducks (n-3F) a diet containing docosahexaenoic (DHA) and linolenic acids (microalgae and linseed oil). A control group of female ducks (CF) was fed a diet containing linoleic acid (soybean oil). Offspring from both groups were fed starter and grower diets enriched with DHA and linolenic acid or only linoleic acid, resulting in four treatment groups with 48 ducklings in each. Several behavioral tests were performed between 1 and 3 weeks of age to analyze the adaptation ability of ducklings. The growth performance, time budget, social interactions, feather growth, and pecking behavior of ducklings were recorded regularly during the rearing period. No significant interaction between maternal and duckling feeding was found. Ducklings from n-3F ducks had a higher body weight at day 0, 28, and 56, a lower feed conversion ratio during the growth period, and lower reactivity to stress than ducklings from CF ducks. Ducklings from n-3F ducks also exhibited a significantly reduced feather pecking frequency at 49 and 56 days of age and for the whole rearing period. Moreover, consumption of diets enriched with n-3 PUFA during the starter and grower post-hatching periods significantly improved the tibia mineralization of ducklings and the fatty acid composition of thigh muscles at 84 days of age by increasing the n-3 FA content.

The Feather Model for Chemo- and Radiation Therapy-Induced Tissue Damage.

Chemo- and radiation therapy are the main modalities for cancer treatment. A major limiting factor is their toxicity to normal tissue, thus reducing the dose and duration of the therapy. The hair follicle, gastrointestinal tract, and hematopoietic system are among the target organs that often show side effects in cancer therapy . Although these organs are highly mitotic in common, the molecular mechanism of the damage remains unclear. The feather follicle is a fast-growing mini-organ, which allows observation and manipulation on each follicle individually. As a model system, the feather follicle is advantageous because of the following reasons: (1) its complex structure is regulated by a set of evolutionarily conserved molecular pathways, thus facilitating the effort to dissect the specific signaling events involved; (2) its morphology allows the continuity of normal-perturbed-normal structure in a single feather, thus "recording" the damaging effect of chemo- and radiation therapy; (3) further histological and molecular analysis of the damage response can be performed on each plucked feather; thus, it is not necessary to sacrifice the experimental animal. Here, we describe methods of applying the feather model to study the molecular mechanism of chemo- and radiation therapy-induced tissue damage.

T lymphocytes dominate local leukocyte infiltration in response to intradermal injection of functionalized graphene-based nanomaterial.

Graphene-based nanomaterials (GBN) have many potential biomedical applications. However, information regarding their biological properties and interactions with cells and/or soluble factors within a complex tissue is limited. The objective of this study was to use the growing feather (GF) of chickens as a minimally invasive cutaneous test-site to assess and monitor leukocyte recruitment in response to intradermal GBN injection. Specifically, the dermis of 20 GFs per chicken was injected with 10 µl of phosphate-buffered saline (PBS)-vehicle or 10 µl of 300 µg ml-1 oxygen-functionalized (f) GBN (6 chickens/treatment). GFs were collected before- (0) and at 0.25, 1, 2, 3, 4, 5, and 7 days post-injection and used for leukocyte-population analysis of immunofluorescently stained pulp cell suspensions or histological examination. Based on flow-cytometric cell population analysis, lymphocytes and macrophages were the major leukocyte-populations infiltrating GFs in response to f-GBN presence. Compared with PBS-controls, levels of T cells (γδ-, αß-, CD4- and CD8-T cells) were greatly elevated in f-GBN-injected GFs within 6 h and remained elevated throughout the 7-day examination period. f-GBN's effects on local tissue leukocyte recruitment were not reflected in the blood, except for a higher percentage of lymphocytes on 7 days. These observations together with a visual examination of f-GBN-injected GF tissue-sections suggest a delayed-type hypersensitivity-like, inflammatory cell-mediated response to the non-biodegradable f-GBN. The GF 'in vivo test-tube'system together with blood sampling provided unique insight into the time-course, qualitative, and quantitative aspects of immune system activities initiated by the presence of f-GBN in a complex tissue of a living animal. Copyright © 2017 John Wiley & Sons, Ltd.

Trouble on takeoff: Crude oil on feathers reduces escape performance of shorebirds.

The ability to takeoff quickly and accelerate away from predators is crucial to bird survival. Crude oil can disrupt the fine structure and function of feathers, and here we tested for the first time how small amounts of oil on the trailing edges of the wings and tail of Western sandpipers (Calidris mauri) affected takeoff flight performance. In oiled birds, the distance travelled during the first 0.4s after takeoff was reduced by 29%, and takeoff angle was decreased by 10° compared to unoiled birds. Three-axis accelerometry indicated that oiled sandpipers produced less mechanical power output per wingbeat during the initial phase of flight. Slower and lower takeoff would make oiled birds more likely to be targeted and captured by predators, reducing survival and facilitating the exposure of predators to oil. Whereas the direct mortality of heavily-oiled birds is often obvious and can be quantified, our results show that there are significant sub-lethal effects of small amounts crude oil on feathers, which must be considered in natural resource injury assessments for birds.