-
PloS One 2023Molting is an important process in which old and worn feathers are exchanged for new ones. Plumage color is determined by pigments such as carotenes, melanin and by the...
Molting is an important process in which old and worn feathers are exchanged for new ones. Plumage color is determined by pigments such as carotenes, melanin and by the ultrastructure of the feather. The importance of plumage coloration has been widely studied in different groups of birds, generally at a particular time of the year. However, plumage coloration is not static and few studies have addressed the change in plumage color over time and its relationship to reproductive tasks. The Eared Dove (Zenaida auriculata, Des Murs, 1847) has a melanistic coloration with sexual dichromatism in different body regions. The Eared Dove´s crown is the most exposed body region during the bowing display. Our objective was therefore to accurately determine the molting period of the crown feathers and study the seasonal variation in their coloration in females and males. Our findings indicate a molting period of 6 months (January to June). The new feathers are undergoing changes in their coloration from July to December. During that period we apply an avian vision model then enabled us to reveal a seasonal variation in the coloration of the crown feathers in both sexes, as given by a change in the chromatic distances. The highest values in the chromatic distances towards the reproductive period are given by a change in the UV-violet component of the spectrum, indicating changes in the microstructure of the feather. This change in crown coloration towards the breeding season could be linked to reproductive behaviors.
Topics: Animals; Male; Female; Seasons; Columbidae; Molting; Pigmentation; Melanins; Feathers; Color
PubMed: 36827341
DOI: 10.1371/journal.pone.0280819 -
Current Pharmaceutical Design 2020Chitin contributes to the rigidity of the insect cuticle and serves as an attachment matrix for other cuticular proteins. Deficiency of chitin results in abnormal...
Chitin contributes to the rigidity of the insect cuticle and serves as an attachment matrix for other cuticular proteins. Deficiency of chitin results in abnormal embryos, cuticular structural defects and growth arrest. When chitin is not turned over during molting, the developing insect is trapped inside the old cuticle. Partial deacetylation of cuticular chitin is also required for proper laminar organization of the cuticle and vertical pore canals, molting, and locomotion. Thus, chitin and its modifications strongly influence the structure of the exoskeleton as well as the physiological functions of the insect. Internal tendons and specialized epithelial cells called "tendon cells" that arise from the outer layer of epidermal cells provide attachment sites at both ends of adult limb muscles. Membrane processes emanating from both tendon and muscle cells interdigitate extensively to strengthen the attachment of muscles to the extracellular matrix (ECM). Protein ligands that bind to membrane-bound integrin complexes further enhance the adhesion between muscles and tendons. Tendon cells contain F-actin fiber arrays that contribute to their rigidity. In the cytoplasm of muscle cells, proteins such as talin and other proteins provide attachment sites for cytoskeletal actin, thereby increasing integrin binding and activation to mechanically couple the ECM with actin in muscle cells. Mutations in integrins and their ligands, as well as depletion of chitin deacetylases, result in defective locomotion and muscle detachment from the ECM. Thus, chitin in the cuticle and chitin deacetylases strongly influence the shape and functions of the exoskeleton as well as locomotion of insects.
Topics: Animals; Chitin; Humans; Insect Proteins; Insecta; Molting
PubMed: 32445445
DOI: 10.2174/1381612826666200523175409 -
Poultry Science Oct 2018More than 90% of the commercial egg production in the United States is pledged to be in cage-free systems by 2025. Management practices like induced molting and litter...
Effects of different litter substrates and induced molt on production performance and welfare quality parameters of white Leghorn hens housed in multi-tiered aviary system.
More than 90% of the commercial egg production in the United States is pledged to be in cage-free systems by 2025. Management practices like induced molting and litter area management have come under scrutiny because of the housing system change. The aim of this study was to determine the welfare and production implications of different litter substrates and also evaluate induced molting of hens in a cage-free system. Bovan White hens were housed in a multi-tier aviary system with daily access to open litter area of either Astroturf (AT), wood shavings (SH), or straw (ST) and bare concrete floor (CO) serving as control. At 68 wk of age, molt was induced in half of the hens whereas the other half continued without molting to 116 wk. Production and welfare parameters were measured periodically throughout first and second cycles. Litter substrate did not influence hen-day production and case-weight measurements. However, CO had the lowest total number of eggs produced during the first cycle (P < 0.05). Hen-day percentage was approximately 14% greater in molted hens during the second cycle with egg case weight being heavier in non-molt hens toward the end of second cycle (P < 0.05). The only welfare parameter influenced by litter substrate during the first cycle was a greater crop feather loss in AT than ST at mid-lay (P < 0.05). Keel deformations increased with age irrespective of the litter substrate with 91.5% of palpated hens having keel deformations at the end of first cycle (P < 0.05). Molting did not influence the keel palpation and footpad scores whereas frequency of moderate comb wound was greater in molt hens during molt (P < 0.05). Severe feather loss was seen in non-molt hens during the second cycle (P < 0.05). Litter substrate does not affect production and physical parameters of welfare of hens in a multi-tier aviary system. Additionally, induced molting can be successfully carried out in the multi-tier cage-free system.
Topics: Animal Husbandry; Animal Welfare; Animals; Chickens; Female; Floors and Floorcoverings; Housing, Animal; Molting; Random Allocation; Reproduction
PubMed: 29878244
DOI: 10.3382/ps/pey211 -
Frontiers in Cell and Developmental... 2020TILRR has been identified as an important modulator of inflammatory responses. It is associated with NF-κB activation, and inflammation. Our previous study showed that...
TILRR has been identified as an important modulator of inflammatory responses. It is associated with NF-κB activation, and inflammation. Our previous study showed that TILRR significantly increased the expression of many innate immune responsive genes and increased the production of several pro-inflammatory cytokines/chemokines by cervical epithelial cells. In this study, we evaluated the effect of TILRR-induced pro-inflammatory cytokines/chemokines on the migration of immune cells. The effect of culture supernatants of TILRR-overexpressed cervical epithelial cells on the migration of THP-1 monocytes and MOLT-4 T-lymphocytes was evaluated using Transwell assay and a novel microfluidic device. We showed that the culture supernatants of TILRR-overexpressed HeLa cells attracted significantly more THP-1 cells (11-40%, = 0.0004-0.0373) and MOLT-4 cells (14-17%, = 0.0010-0.0225) than that of controls. The microfluidic device-recorded image analysis showed that significantly higher amount with longer mean cell migration distance of THP-1 ( < 0.0001-0.0180) and MOLT-4 ( < 0.0001-0.0025) cells was observed toward the supernatants of TILRR-overexpressed cervical epithelial cells compared to that of the controls. Thus, the cytokines/chemokines secreted by the TILRR-overexpressed cervical epithelial cells attracted immune cells, such as monocytes and T cells, and may potentially influence immune cell infiltration in tissues.
PubMed: 32719797
DOI: 10.3389/fcell.2020.00563 -
Frontiers in Physiology 2022Chitinases are enzymes responsible for the hydrolysis of glycosidic linkages within chitin chains. In insects, chitinases are typically members of the multigenic...
Structure and expression of GH18 chitinases and chitinase-like proteins: Characterization of the physiological role of , a gene from subgroup VIII, in vector fitness and reproduction.
Chitinases are enzymes responsible for the hydrolysis of glycosidic linkages within chitin chains. In insects, chitinases are typically members of the multigenic glycoside hydrolase family 18 (GH18). They participate in the relocation of chitin during development and molt, and in digestion in detritivores and predatory insects, and they control the peritrophic membrane thickness. Chitin metabolism is a promising target for developing vector control strategies, and knowledge of the roles of chitinases may reveal new targets and illuminate unique aspects of their physiology and interaction with microorganisms. is an important vector of Chagas disease, which is caused by the parasite . In this study, we performed annotation and structural characterization of nine chitinase and chitinase-like protein genes in the genome. The roles of their corresponding transcripts were studied in more depth; their physiological roles were studied through RNAi silencing. Phylogenetic analysis of coding sequences showed that these genes belong to different subfamilies of GH18 chitinases already described in other insects. The expression patterns of these genes in different tissues and developmental stages were initially characterized using RT-PCR. RNAi screening showed silencing of the gene family members with very different efficiencies. Based on the knockdown results and the general lack of information about subgroup VIII of GH18, the gene was chosen for phenotype analysis. knockdown doubled the mortality in starving fifth-instar nymphs compared to dsGFP-injected controls. However, it did not alter blood intake, diuresis, digestion, molting rate, molting defects, sexual ratio, percentage of hatching, or average hatching time. Nevertheless, female oviposition was reduced by 53% in -silenced insects, and differences in oviposition occurred within 14-20 days after a saturating blood meal. These results suggest that may be involved in the reproductive physiology and vector fitness of .
PubMed: 36262251
DOI: 10.3389/fphys.2022.861620 -
Poultry Science Sep 2022This experiment was conducted to evaluate diets containing a high level of corn silage and alfalfa meal in inducing molt and reducing susceptibility to Salmonella...
This experiment was conducted to evaluate diets containing a high level of corn silage and alfalfa meal in inducing molt and reducing susceptibility to Salmonella Enteritidis (SE) colonization in laying hens. Thirty-two healthy hens were examined by cloacal swab samples to be free of Salmonella. Then they were weighed individually and distributed to 4 experimental groups containing 8 hens each, including Full-fed (control, FF); total feed withdrawal (positive control for molt induction, FW); 80% corn silage (CS) + 20% layer diet (CS80), and 80% alfalfa meal (AM) + 20% layer diet (AM80). The molting program was initiated at 71 wk of age. On d 4 of the experiment, all hens were inoculated with SE by oral gavage. All hens were first weighed at the ending molting period on d 10 and then euthanized by CO2 gas. The internal organs including the ovary, oviduct, liver, and spleen, were excised aseptically and weighed. Cloacal swab and feed samples at the beginning and organ samples (liver, ovary, spleen, and cecum) were collected from each hen at the end of the experiment and examined for SE colonies. Molted birds lost roughly 14 to 27%t of their body weight and had significantly lower organ weight and egg production compared to FF group (P < 0.05). No significant difference was observed in the number of days to zero egg production between molted treatments. The SE positive organs did not significantly differ between CS80 and AM80 with FF treatment. Treatment CS80 had the lowest crop pH and differed substantially from treatment FW. In conclusion, results indicate that using corn silage and alfalfa meal, can improve resistance to salmonella Enteritidis during molt inducing compared to traditional feed withdrawal.
Topics: Animal Feed; Animals; Chickens; Diet; Female; Medicago sativa; Molting; Salmonella enteritidis; Silage; Zea mays
PubMed: 35841630
DOI: 10.1016/j.psj.2022.101984 -
Developmental Cell Jan 2020Lysosomes degrade macromolecular cargos, recycle catabolites, and serve as signaling platforms to maintain cell homeostasis, but their role at the tissue level is...
Lysosomes degrade macromolecular cargos, recycle catabolites, and serve as signaling platforms to maintain cell homeostasis, but their role at the tissue level is unclear. Here, we investigate lysosome regulation and function during C. elegans molting, a specialized extracellular matrix (ECM) remodeling process essential for larval development. We found that lysosomes are specifically activated in the epidermis at molt when the apical ECM (cuticle) is being replaced. Impaired lysosome function affects endocytic cargo degradation, suppresses elevated protein synthesis at molt, and causes molting defects. Disturbance of ECM-epidermis attachments triggers lysosomal activation and induces expression of the vacuolar H-ATPase (V-ATPase), which is mediated by the GATA transcription factor ELT-3 and the STAT family protein STA-2. Our study reveals an ECM-to-nucleus signaling pathway that activates lysosomes to facilitate ECM remodeling essential for larval development.
Topics: Animals; Caenorhabditis elegans; Caenorhabditis elegans Proteins; Cell Nucleus; Epidermis; Extracellular Matrix; GATA Transcription Factors; Gene Expression Regulation, Developmental; Larva; Lysosomes; Molting; Vacuolar Proton-Translocating ATPases
PubMed: 31735670
DOI: 10.1016/j.devcel.2019.10.020 -
Frontiers in Microbiology 2023Induced molting enables laying hens to relax, restore energy and prolong the laying hen cycle, resolving problems such as poor egg quality and minimizing economic losses...
Induced molting enables laying hens to relax, restore energy and prolong the laying hen cycle, resolving problems such as poor egg quality and minimizing economic losses caused by rising global feeding costs. However, traditional molting methods may disrupt gut microflora and promote potential pathogens infections. This study used a customized additive with a mixture of probiotics and vitamins to induce molting and examine the cecal microbiota post molting. A total of two hundred 377 day-of-ISA Brown laying hens were randomly assigned to four groups: non-molt with basal diet (), 12-day feeding restriction (FR) in earlier-molting (), feed again to 27.12% egg production in middle-molting () and reach second peak of egg production over 81.36% in post-molting (). Sequencing 16S rRNA to analyze cecal microbial composition revealed that there is no significant change in bacterial community abundance post-molting. In contrast to group C, the number of potentially harmful bacteria such as and was not found to increase in groups B, A, or D. This additive keeps cecal microbiota diversity and community richness steady. In cecal contents, hens in group had lower (, , and ), no significant differences were found between post-molting and the non-molting. Furthermore, cecal microbiota and other chemicals (antibodies, hormones, and enzymes, etc.) strongly affect immunological function and health. Most biochemical indicators are significantly positively correlated with , and , while negatively with and . In conclusion, the additive of probiotics and vitamins improved the cecal microbiota composition, no increase in the associated pathogenic microbial community due to traditional molting methods, and enhances hepatic lipid metabolism and adaptive immunological function, supporting their application and induced molting technology in the poultry breeding industry.
PubMed: 37228378
DOI: 10.3389/fmicb.2023.1180838 -
Journal of Animal Science and Technology Jul 2022The study evaluated different molt-inducing methods to achieve the main goal of molting in commercial layers during molting and post-molting periods. A total of 400...
The study evaluated different molt-inducing methods to achieve the main goal of molting in commercial layers during molting and post-molting periods. A total of 400 60-week-old Lohmann Brown layers were randomly divided into five groups (eight replicates of 10 birds for each group). Laying hens in the fasting control group received no diet from day 1 to day 10. The second group received a molt-inducing diet recommended by the breeding company. The third group received a wheat bran-based diet. The fourth group received a commercial layer diet with 8,000 ppm zinc (as zinc oxide, ZnO). The fifth group received an induced molting diet given to the second group with 8,000 ppm zinc, respectively. Egg production in the fasting control group and groups fed a diet with ZnO were significantly lower ( < 0.001) than those in groups fed the molt-inducing and wheat bran-based diets without ZnO during molting. Egg laying in the fasting control group was rapidly reduced and stopped on the 5.9th day of molting. In both groups having molt treatment with ZnO, egg production was similarly reduced and ceased on the 6.9th day and 7.0th day of molting, respectively, none of them differed significantly from the control. Layers fed molt-inducing diet or wheat bran-based diet did not reach the cessation of laying even on the 28th d of molting period. Relative weights of the ovary and growing oocytes of layers subjected to fasting or fed diets with ZnO were significantly lower than those of other groups. During the first two weeks of post molting, layers fed molt-inducing diet with ZnO showed higher egg production than the other two groups ( < 0.01). The eggshell strength in the group fed the commercial diet with ZnO was significantly higher than those fed the molt-inducing diet or wheat bran-based diets at 6 weeks of post molting ( < 0.05). These results suggest that the non-feed withdrawal molting using ZnO is more effective in inducing molting and increasing post-molt egg production and egg quality than other methods using a molt-inducing diet alone or wheat bran-based diet without ZnO.
PubMed: 35969703
DOI: 10.5187/jast.2022.e41 -
Genes Aug 2018Various gene alterations related to acute leukemia are reported to be involved in drug resistance. We investigated idarubicin (IDR) resistance using exome nuclear DNA...
Various gene alterations related to acute leukemia are reported to be involved in drug resistance. We investigated idarubicin (IDR) resistance using exome nuclear DNA analyses of the human acute leukemia cell line MOLT-3 and the derived IDR-resistant cell line MOLT-3/IDR. We detected mutations in MOLT-3/IDR and MOLT-3 using both Genome Analysis Toolkit (GATK) and SnpEff program. We found 8839 genes with specific mutations in MOLT-3/IDR and 1162 genes with accompanying amino acid mutations. The 1162 genes were identified by exome analysis of polymerase-related genes using Kyoto Encyclopedia of Genes and Genomes (KEGG) and, among these, we identified genes with amino acid changes. In resistant strains, and helicase plurality genes showed amino-acid-related changes. An amino acid mutation was also confirmed in polymerase-associated genes. Gene ontology (GO) enrichment testing was performed, and lipid-related genes were selected from the results. Fluorescent activated cell sorting (FACS) was used to determine whether IDR permeability was significantly different in MOLT-3/IDR and MOLT-3. The results showed that an IDR concentration of 0.5 μg/mL resulted in slow permeability in MOLT-3/IDR. This slow IDR permeability may be due to the effects of amino acid changes in polymerase- and lipid-associated genes.
PubMed: 30071629
DOI: 10.3390/genes9080390