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Poultry Science Nov 2010The objectives of this study were to compare the behaviors, postures, and heterophil-to-lymphocyte ratios (H:L) of laying hens housed in a cage system when offered a Ca...
The objectives of this study were to compare the behaviors, postures, and heterophil-to-lymphocyte ratios (H:L) of laying hens housed in a cage system when offered a Ca premolt treatment and low-energy molt diets vs. a traditional feed withdrawal (FW) treatment during and after molt. A total of 144 Hy-Line W-36 hens (85 wk of age), housed 3 hens/cage (413 cm(2)/hen), were used. Hens were allotted to treatments according to a randomized complete block design, with the cage location and initial BW as the blocking criteria. Six treatments were compared in a 2 × 3 factorial arrangement with 2 Ca premolt treatments (fine or coarse) and 3 low-energy molt diets (FW, soybean hulls, or wheat middlings). The 2 Ca premolt treatments differed only in Ca particle size (fine was 0.14 mm and coarse was 2.27 mm mean diameter). Two postures and 5 behaviors were recorded and H:L was measured. Data were analyzed using the MIXED procedure of SAS, with P < 0.05 considered significant. There were no differences in behaviors, postures, or H:L during the premolt baseline period. The Ca premolt treatment had no carryover effects during or after molt for behaviors or postures. During molt, hens in the FW treatment were more active, and they ate and drank less compared with hens fed soybean hulls or wheat middlings, but there were no differences in aggression, nonnutritive pecking, or sitting. Drinking and aggression during and after molt were not different, but hens postmolt engaged in more sitting and feeding and less activity, nonnutritive pecking, and preening compared with during molt. There were no differences in H:L during or after molt. In conclusion, a Ca premolt treatment did not affect the behavior of the laying hen. The low-energy molt diets did not adversely affect behavior compared with FW and did not increase H:L; therefore, they could be useful alternatives for inducing molt in laying hens.
Topics: Aggression; Animal Feed; Animal Husbandry; Animals; Antibodies, Heterophile; Behavior, Animal; Calcium; Chickens; Eating; Housing, Animal; Lymphocytes; Molting; Oviposition; Photoperiod; Posture; Random Allocation
PubMed: 20952693
DOI: 10.3382/ps.2010-00769 -
Oecologia Nov 2020Global reduction in snow cover duration is one of the most consistent and widespread climate change outcomes. Declining snow duration has severe negative consequences...
Global reduction in snow cover duration is one of the most consistent and widespread climate change outcomes. Declining snow duration has severe negative consequences for diverse taxa including seasonally color molting species, which rely on snow for camouflage. However, phenotypic plasticity may facilitate adaptation to reduced snow duration. Plastic responses could occur in the color molt phenology or through behavior that minimizes coat color mismatch or its consequences. We quantified molt phenology of 200 wild snowshoe hares (Lepus americanus), and measured microhabitat choice and local snow cover. Similar to other studies, we found that hares did not show behavioral plasticity to minimize coat color mismatch via background matching; instead they preferred colder, snow free areas regardless of their coat color. Furthermore, hares did not behaviorally mitigate the negative consequences of mismatch by choosing resting sites with denser vegetation cover when mismatched. Importantly, we demonstrated plasticity in the initiation and the rate of the molt and established the direct effect of snow on molt phenology; greater snow cover was associated with whiter hares and this association was not due to whiter hares preferring snowier areas. However, despite the observed snow-mediated plasticity in molt phenology, camouflage mismatch with white hares on brown snowless ground persisted and was more frequent during early snowmelt. Thus, we find no evidence that phenotypic plasticity in snowshoe hares is sufficient to facilitate adaptive rescue to camouflage mismatch under climate change.
Topics: Animals; Climate Change; Hares; Molting; Seasons; Snow
PubMed: 32583125
DOI: 10.1007/s00442-020-04680-2 -
Poultry Science Jun 2003There is an interaction between feed withdrawal induced-molting and foodborne Salmonella Enteritidis colonization and invasion in susceptible laying hens. Less is known... (Review)
Review
There is an interaction between feed withdrawal induced-molting and foodborne Salmonella Enteritidis colonization and invasion in susceptible laying hens. Less is known about the ecology of the indigenous microflora and their response to feed removal, the response of S. Enteritidis to feed removal (virulence expression), and the interaction between the gastrointestinal tract microenvironment and S. Enteritidis. Because the crop is the first host environment encountered by S. Enteritidis after ingestion, it can influence the survival and virulence of S. Enteritidis. Feed withdrawal alters the microenvironment of the crop by causing alterations in the indigenous microbial population along with lactate and short-chain fatty acids (SCFA) concentrations and an increase in pH. This altered crop environment is accompanied by increased S. Enteritidis colonization of the crop and ceca along with invasion of the spleen and liver. The observation that crop composition influences the virulence of S. Enteritidis has important implications for understanding the gastrointestinal factors necessary for protection against S. Enteritidis infection. Consequently, an important aspect for minimizing S. Enteritidis colonization during molting is to maintain the crop microflora and their fermentative activities as similar as possible to that of crop microflora and fermentation activities of birds with fully active gastrointestinal microbial populations.
Topics: Animal Feed; Animals; Chickens; Digestive System; Female; Fermentation; Food Deprivation; Hydrogen-Ion Concentration; Molting; Population Dynamics; Salmonella enteritidis; Virulence
PubMed: 12817456
DOI: 10.1093/ps/82.6.1003 -
BMC Genomics Oct 2015A complete understanding of barnacle adhesion remains elusive as the process occurs within and beneath the confines of a rigid calcified shell. Barnacle cement is mainly...
BACKGROUND
A complete understanding of barnacle adhesion remains elusive as the process occurs within and beneath the confines of a rigid calcified shell. Barnacle cement is mainly proteinaceous and several individual proteins have been identified in the hardened cement at the barnacle-substrate interface. Little is known about the molt- and tissue-specific expression of cement protein genes but could offer valuable insight into the complex multi-step processes of barnacle growth and adhesion.
METHODS
The main body and sub-mantle tissue of the barnacle Amphibalanus amphitrite (basionym Balanus amphitrite) were collected in pre- and post-molt stages. RNA-seq technology was used to analyze the transcriptome for differential gene expression at these two stages and liquid chromatography-mass spectrometry/mass spectrometry (LC-MS/MS) was used to analyze the protein content of barnacle secretions.
RESULTS
We report on the transcriptomic analysis of barnacle cement gland tissue in pre- and post-molt growth stages and proteomic investigation of barnacle secretions. While no significant difference was found in the expression of cement proteins genes at pre- and post-molting stages, expression levels were highly elevated in the sub-mantle tissue (where the cement glands are located) compared to the main barnacle body. We report the discovery of a novel 114kD cement protein, which is identified in material secreted onto various surfaces by adult barnacles and with the encoding gene highly expressed in the sub-mantle tissue. Further differential gene expression analysis of the sub-mantle tissue samples reveals a limited number of genes highly expressed in pre-molt samples with a range of functions including cuticular development, biominerialization, and proteolytic activity.
CONCLUSIONS
The expression of cement protein genes appears to remain constant through the molt cycle and is largely confined to the sub-mantle tissue. Our results reveal a novel and potentially prominent protein to the mix of cement-related components in A. amphitrite. Despite the lack of a complete genome, sample collection allowed for extended transcriptomic analysis of pre- and post-molt barnacle samples and identified a number of highly-expressed genes. Our results highlight the complexities of this sessile marine organism as it grows via molt cycles and increases the area over which it exhibits robust adhesion to its substrate.
Topics: Animals; Computational Biology; Gene Expression; Gene Expression Profiling; Gene Expression Regulation; High-Throughput Nucleotide Sequencing; Molecular Sequence Annotation; Molting; Proteins; Thoracica; Transcriptome
PubMed: 26496984
DOI: 10.1186/s12864-015-2076-1 -
Journal of Structural Biology Nov 2020One fundamental character common to pancrustaceans (Crustacea and Hexapoda) is a mineralized rigid exoskeleton whose principal organic components are chitin and...
One fundamental character common to pancrustaceans (Crustacea and Hexapoda) is a mineralized rigid exoskeleton whose principal organic components are chitin and proteins. In contrast to traditional research in the field that has been devoted to the structural and physicochemical aspects of biomineralization, the present study explores transcriptomic aspects of biomineralization as a first step towards adding a complementary molecular layer to this field. The rigidity of the exoskeleton in pancrustaceans dictates essential molt cycles enabling morphological changes and growth. Thus, formation and mineralization of the exoskeleton are concomitant to the timeline of the molt cycle. Skeletal proteinaceous toolkit elements have been discovered in previous studies using innovative molt-related binary gene expression patterns derived from transcriptomic libraries representing the major stages comprising the molt cycle of the decapod crustacean Cherax quadricarinatus. Here, we revisited some prominent exoskeleton-related structural proteins encoding and, using the above molt-related binary pattern methodology, enlarged the transcriptomic database of C. quadricarinatus. The latter was done by establishing a new transcriptomic library of the cuticle forming epithelium and molar tooth at four different molt stages (i.e., inter-molt, early pre-molt, late pre-molt and post-molt) and incorporating it to a previous transcriptome derived from the gastroliths and mandible. The wider multigenic approach facilitated by the newly expanded transcriptomic database not only revisited single genes of the molecular toolkit, but also provided both scattered and specific information that broaden the overview of proteins and gene clusters which are involved in the construction and biomineralization of the exoskeleton in decapod crustaceans.
Topics: Animal Shells; Animals; Biomineralization; Chitin; Crustacea; Epithelium; Gene Expression Profiling; Molar; Molting; Proteins; Transcriptome
PubMed: 32896659
DOI: 10.1016/j.jsb.2020.107612 -
ELife Jul 2019Ecdysis (moulting) is the defining character of Ecdysoza (arthropods, nematodes and related phyla). Despite superficial similarities, the signalling cascade underlying...
Ecdysis (moulting) is the defining character of Ecdysoza (arthropods, nematodes and related phyla). Despite superficial similarities, the signalling cascade underlying moulting differs between Panarthropoda and the remaining ecdysozoans. Here, we reconstruct the evolution of major components of the ecdysis pathway. Its key elements evolved much earlier than previously thought and are present in non-moulting lophotrochozoans and deuterostomes. Eclosion hormone (EH) and bursicon originated prior to the cnidarian-bilaterian split, whereas ecdysis-triggering hormone (ETH) and crustacean cardioactive peptide (CCAP) evolved in the bilaterian last common ancestor (LCA). Identification of EH, CCAP and bursicon in Onychophora and EH, ETH and CCAP in Tardigrada suggests that the pathway was present in the panarthropod LCA. Trunk, an ancient extracellular signalling molecule and a well-established paralog of the insect peptide prothoracicotropic hormone (PTTH), is present in the non-bilaterian ctenophore . This constitutes the first case of a ctenophore signalling peptide with homology to a neuropeptide.
Topics: Animals; Arthropods; Biological Evolution; Molting; Signal Transduction
PubMed: 31266593
DOI: 10.7554/eLife.46113 -
Poultry Science Feb 2012The objectives of this study were to evaluate and compare the effects of production, physiology, egg quality, and economics of laying hens housed in a cage system when...
The objectives of this study were to evaluate and compare the effects of production, physiology, egg quality, and economics of laying hens housed in a cage system when offered a calcium premolt treatment and low-energy molt diets versus a traditional feed withdrawal (FW) treatment during and after molt. In total, 981 Hy-Line W-36 laying hens (85 wk of age) housed 3 per cage were used. Six treatments were compared in a 2 × 3 factorial design with 2 calcium premolt treatments (fine and coarse) and 3 molt diets (FW, soybean hulls, and wheat middlings). The coarse Ca was a 50:50 mix of fine (0.14-mm mean diameter) and coarse (2.27-mm mean diameter) CaCO(3), whereas the fine Ca was an all-fine CaCO(3). Both diets were formulated to contain 4.6% Ca, such that only the particle size of the CaCO(3) differed. Production parameters in experiment 1 included egg production, egg weight and mass, specific gravity, Haugh units, egg components, feed consumption and utilization, and BW. Physiological parameters in experiment 2 included ovary and oviduct weights, femur- and humerus-ash percentages, heterophil to lymphocyte ratios, plasma Ca and inorganic P concentrations, and alkaline phosphatase activity. Data were analyzed by ANOVA and P < 0.05 was significant. The fine-Ca premolt treatment was more effective than the coarse-Ca treatment at decreasing egg production during molt and increasing it postmolt, regardless of the molt diet. The FW molt diet resulted in the greatest decrease in production, but the soybean hulls diet resulted in lower production and ovary and oviduct weights during molt compared with those of the wheat middlings molt diet. Therefore, a fine-Ca premolt treatment and a low-energy molt diet, particularly soybean hulls, can be useful alternatives to a FW molt.
Topics: Animal Feed; Animal Husbandry; Animal Nutritional Physiological Phenomena; Animals; Calcium; Calcium, Dietary; Chickens; Diet; Eggs; Female; Food Deprivation; Molting; Oviposition
PubMed: 22252340
DOI: 10.3382/ps.2011-01685 -
Nature Dec 2022Insect societies are tightly integrated, complex biological systems in which group-level properties arise from the interactions between individuals. However, these...
Insect societies are tightly integrated, complex biological systems in which group-level properties arise from the interactions between individuals. However, these interactions have not been studied systematically and therefore remain incompletely known. Here, using a reverse engineering approach, we reveal that unlike solitary insects, ant pupae extrude a secretion derived from the moulting fluid that is rich in nutrients, hormones and neuroactive substances. This secretion elicits parental care behaviour and is rapidly removed and consumed by the adults. This behaviour is crucial for pupal survival; if the secretion is not removed, pupae develop fungal infections and die. Analogous to mammalian milk, the secretion is also an important source of early larval nutrition, and young larvae exhibit stunted growth and decreased survival without access to the fluid. We show that this derived social function of the moulting fluid generalizes across the ants. This secretion thus forms the basis of a central and hitherto overlooked interaction network in ant societies, and constitutes a rare example of how a conserved developmental process can be co-opted to provide the mechanistic basis of social interactions. These results implicate moulting fluids in having a major role in the evolution of ant eusociality.
Topics: Animals; Ants; Larva; Molting; Pupa; Social Behavior; Body Fluids
PubMed: 36450990
DOI: 10.1038/s41586-022-05480-9 -
WormBook : the Online Review of C.... Jan 2006Nuclear receptors (NRs) are transcription factors typically regulated by lipophilic hormones, which coordinate metazoan metabolism, development and homeostasis. C.... (Review)
Review
Nuclear receptors (NRs) are transcription factors typically regulated by lipophilic hormones, which coordinate metazoan metabolism, development and homeostasis. C. elegans has undergone a remarkable expansion of the family, harboring 284 of these receptors in its genome. Approximately 20 of them have been analyzed genetically, most of which correspond to conserved homologs in other metazoans. These NRs variously affect broad life history traits such as sex determination, molting, developmental timing, diapause, and life span. They also impact neural development, axon outgrowth and neuronal identity. Finally, they influence lipid and xenobiotic metabolism. The study of C. elegans NRs holds great promise for dissecting nuclear receptor signaling pathways in vivo in the context of complex endocrine networks.
Topics: Animals; Caenorhabditis elegans; Humans; Molting; Nervous System; Receptors, Cytoplasmic and Nuclear; Sex Determination Processes; Species Specificity; Xenobiotics
PubMed: 18050471
DOI: 10.1895/wormbook.1.64.1 -
Poultry Science Sep 2007A study was conducted to evaluate the effects of alfalfa-based molt diets on molting performance and bone qualities. A total of 36 Single Comb White Leghorn hens were...
A study was conducted to evaluate the effects of alfalfa-based molt diets on molting performance and bone qualities. A total of 36 Single Comb White Leghorn hens were used for the study. There were 6 treatments: pretrial control (PC), fully fed (FF), feed withdrawal (FW), 90% alfalfa:10% layer ration (A90), 80% alfalfa:20% layer ration (A80), and 70% alfalfa:30% layer ration (A70). For the PC treatment, hens were euthanized by CO(2) gas, and bones were collected before molt was initiated. At the end of the 9-d molt period, hens were euthanized, and femurs and tibias were collected to evaluate bone qualities by peripheral quantitative computed tomography, mechanical testing, and conventional ash weights. The hens fed alfalfa-based molt diets and FW stopped laying eggs within 5 d after molt started, and all hens in these groups had reduced ovary weights compared with those of the FF hens. In the FW and A90 groups, total femur volumetric bone mineral densities (vBMD) at the midshaft were significantly lower, but those of the A80 and A70 groups were not significantly different from the values for the PC and FF hens. In cortical bone density, the midshaft tibial vBMD were significantly higher for FF and A70 hens than for PC hens. The medullary bone densities at the midshaft femur or tibia of the FW, A90, A80, and A70 hens were reduced compared with those of the PC hens. Femur cancellous densities at the distal femur for the FW and A90 hens were significantly reduced compared with those of the PC and FF hens. The FW, A80, and A70 hens yielded significantly higher elastic moduli, and the A80 hens had higher ultimate stress compared with the PC hens, suggesting that the mechanical integrity of the midshaft bone was maintained even though the medullary vBMD was reduced. These results suggest that alfalfa-based molt diets exhibit molt performance similar to FW, that medullary and cancellous bones are labile bone compartments during molting, and that alfalfa-based molt diets may be beneficial to maintain the mechanical properties of bones during molt.
Topics: Animal Feed; Animal Husbandry; Animal Nutritional Physiological Phenomena; Animals; Bone Density; Bone and Bones; Chickens; Diet; Female; Food Deprivation; Medicago sativa; Molting
PubMed: 17704367
DOI: 10.1093/ps/86.9.1821