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At least 127 records · Page 7Linked to original sources
PubMed1990

Identification and characterization of a dimeric chicken fibronectin receptor. Subunit-specific monoclonal antibodies to the putative chicken alpha 5 beta 1 integrin.

A fibronectin receptor was isolated from chicken embryo fibroblasts using a cell-binding fragment of chicken fibronectin as an affinity matrix. The synthetic peptide GRGDSP specifically eluted the receptor, whereas the GRGESP control peptide was negative. The purified chicken receptor is a heterodimeric molecule as are all described mammalian integrins. It showed an RGD-dependent binding to fibronectin-coated wells after incorporation into liposomes. Monoclonal antibodies were raised against the two subunits of the receptor. Immunoprecipitations with the beta chain-specific monoclonal antibody U2 beta gave the same pattern of multiple bands as with the "avian integrin complex" specific monoclonal antibody JG22. In contrast, the alpha chain-specific monoclonal antibody U1 alpha only precipitated a dimeric fibronectin receptor. On immunoblots, U2 beta recognized the chicken gizzard integrin beta 1 chain, but U1 alpha did not cross-react with the alpha chain of gizzard integrin. Immunofluorescence labeling of cell cultures with U1 alpha revealed an exclusive colocalization with extracellular fibronectin fibrils, whereas U2 beta showed in addition, diffuse staining of the whole cell surfaces. The alpha chain-specific monoclonal antibody for the first time allowed us to exclusively detect the putative chicken alpha 5 beta 1 integrin among the many beta 1 integrin complexes present on chicken cells.

Amino Acid Sequence↗
PubMed2006

Viral load in 1-day-old and 6-week-old chickens infected with chicken anaemia virus by the intraocular route.

Although the effects of chicken anaemia virus (CAV) infection have frequently been investigated in young chickens, there have been few studies of the pathogenesis of CAV infection in older birds. The aim of the work reported here was to study viral loads in 6-week-old chickens and to compare these with those seen in younger birds. Specific pathogen free chickens were inoculated at 1 day or at 6 weeks of age with 10(4) median tissue culture infective doses of CAV by the intraocular route. Chicks infected when 1 day old were euthanized at day 14, 18 or 22 post inoculation (p.i.), and those infected when 6 weeks old at day 16, 18 or 20 p.i. Their body and thymus weights were determined and samples were collected from their spleen, liver and thymus. A quantitative polymerase chain reaction assay was developed and used to determine the number of viral genome copies in the tissue samples. In both age groups, viral genome concentrations increased in all organs up to day 18 p.i. and reached a peak in the spleen and liver at day 18 p.i. The peak viral concentrations in the thymus were detected at day 18 in the younger birds and at day 20 p.i. in older chickens. These studies have shown that exposure to CAV in older birds leads to similar levels of active viral replication to those seen in younger birds, and may result in subclinical infections in older birds with the potential to increase susceptibility to other infectious agents.

Aging↗
PubMed1986

Identification in chicken macrophages of a set of proteins related to, but distinct from, the chicken cellular c-ets-encoded protein p54c-ets.

Using an antiserum to a bacterially expressed polypeptide corresponding to 56 amino acids of v-ets, we previously identified in chicken tissues a protein of 54 kd (p54c-ets) which shares extensive sequence homology to the v-ets-encoded domain of the E26-transforming protein p135gag-myb-ets and is thus apparently encoded by the c-ets proto-oncogene. We report here that the anti-ets serum specifically identifies in chicken cells a second set of proteins of 60 kd (p60), 62 kd (p62) and 64 kd (p64) which appear to be highly related to each other but display only a limited domain of homology with p54c-ets and p135gag-myb-ets and are thus probably encoded by a gene(s) partially related to, but different from c-ets. In contrast to p54c-ets which is expressed at high levels in chicken lymphoid tissues, prominent syntheses of p62 and p64 were found in both normal and transformed chicken macrophages but not in avian cells corresponding to immature stages of the myeloid differentiation pathway. These observations together with the fact that differentiation of avian myeloblastosis virus-transformed myeloblasts into macrophage-like cells after treatment with 12-O-tetradecanoylphorbol-13-acetate is accompanied by the synthesis of p62 and p64 suggest a role for these proteins in chicken macrophage differentiation or function. Induction of differentiation of human leukemia cell lines HL60 and U937 into macrophages is also accompanied by the increased synthesis of c-ets-encoded 68 kd, 62 kd and 58 kd proteins.

Animals↗
PubMed1984

Molecular characterization of fetal antigens on red blood cells of chickens, Japanese quail, and quail-chicken hybrids.

The molecular nature of chicken fetal antigen (CFA) and quail fetal antigen (QFA) was studied on embryonic red blood cells (RBCs) of the chicken, the Japanese quail, and the quail-chicken hybrid. Specific immunoprecipitation of radiolabeled membrane proteins followed by electrophoretic separation and autoradiography were used to identify the protein molecules carrying these fetal antigens. CFA was found on molecules of 24, 50, 88, 99, 130, 170, and 220 kd (kilodaltons) in the chicken and hybrid and on molecules of 24, 50, 99, and 170 kd in the Japanese quail. Similarly, quail fetal antigen was associated with 24-, 50-, 99-, and 170-kd molecules in the quail and hybrid and was not detected in the chicken. Partial proteolytic digestion of the 50- and 170-kd molecules isolated from RBCs of all sources showed remarkably similar peptide patterns. Likewise, two-dimensional separation of the CFA-positive and QFA-positive 50-kd molecules from quail RBCs revealed a similar pattern of at least nine isomorphic variants. Sequential depletions of quail embryonic RBC extracts with either anti-CFA or anti-QFA followed by immune precipitation with the reciprocal antiserum suggested that most of the cell surface proteins carrying QFA also have CFA on the same molecules. It is suggested that specific glycosylations of a variety of distinct molecular weight proteins determines the antigenic phenotype characterized as "fetal antigens."

Animals↗
PubMed1976

A comparison of the structure of chicken erythrocyte and chicken liver chromatin.

The structure of chicken erythrocyte and chicken liver chromatin has been studied by enzymatic digestion with micrococcal nuclease and DNAase I. Comparison of the fragments produced by brief digestion with micrococcal nuclease indicates that chicken erythrocyte chromatin has a longer nucleosome repeat than chicken liver chromatin, 212 base pairs as opposed to 200 base pairs (bp). More extensive digestion with micrococcal nuclease demonstrates that both tissues have 140 bp mucleosome cores. The difference in the length of the nucleosome repeat must therefore result from a difference in the length of the DNA linker between cores. Chicken erythrocyte chromatin is known to contain a tissue-specific, H1-like histone, H5, and to be genetically dormant. A model is presented to explain how changes in histone H1 could cause changes in the nucleosome repeat length and thereby alter the genetic activity of chromatin.

Animals↗
PubMed1983

On the possible presence of beta 2-microglobulin-like protein in extracts of livers from normal chickens and chickens with erythroblastosis--II. Amino acid analysis of the protein.

1. Amino acid analyses are presented for a small molecular weight (mol. wt 11,000) protein (SMWP) obtained from the livers of normal chickens and chickens infected with erythroblastosis virus. It is resistant to acid denaturation and was isolated following acidification of liver homogenates and removal of haem and lipids. 2. Close homology exists between SMWP of fowl and human liver, and a protein of the same size obtained from chicken serum, (similar in size to human beta 2-microglobulin). 3. Human beta 2-microglobulin, virus core proteins and chicken prealbumin show a lower order relationship. 4. The amino acid residues of SMWP from healthy and erythroblastosis infected chicken livers are identical despite immunologic differences.

Alpharetrovirus↗
PubMed1983

On the possible presence of a beta 2-microglobulin-like protein in extracts of livers from normal chickens and chickens with erythroblastosis-IV. Homology of small molecular weight (mol.wt 11,000) protein with serum albumin based on the content of amino acid residues.

A small molecular weight (mol.wt 11,000) protein (SMWP) was obtained from the livers of normal chickens and chickens infected with erythroblastosis virus. SMWP, which had been shown to have no biochemical homology with beta 2-microglobulin, is homologous with chicken serum albumin. SMWP shows a similar order of homology with another small molecular weight protein isolated by others from chicken plasma. Like chicken albumin, SMWP is more closely homologous with bovine albumin than with human albumin.

Alpharetrovirus↗
PubMed2006

Identification of microRNAs from different tissues of chicken embryo and adult chicken.

We report for the first time the identification of 25 microRNAs from tissues originating from chicken embryo and adult chicken. Most of the cloned microRNAs are expressed in both adult chickens and chicken embryos. Fourteen were identified without any prior prediction. One microRNA, miR-757, is thought to be chicken-specific. Three of the microRNAs appear to be extremely tissue specific.

Animals↗
PubMed2006

Single nucleotide polymorphisms in the chicken Lmbr1 gene are associated with chicken polydactyly.

Polydactyly is a common malformation of vertebrate limbs. Preaxial polydactyly (PPD) has been mapped in human, mouse and chicken to the syntenic region of human 7q36. Lmbr1 was thought as the critical candidate gene for human and mouse PPD. To understand the molecular mechanism underlying chicken polydactyly, we have cloned the open reading frame (ORF) of chicken Lmbr1, which contains 1467 nucleotides. Within this ORF, we found one short and one long splice forms. The short splice form has a complete deletion of exon 4. Six cSNPs were found in the chicken ORF, and two of these cSNPs, G797A and G1255A, lead to amino acid substitutions. However, G797A substitution had no significant association with polydactyly and the G1255A substitution had very low frequency in the population. The T1254C polymorphism in exon 13 was found to be strongly associated with polydactyly. Radiation hybrid mapping of a DNA fragment containing intron 13 of the chicken Lmbr1 assigned the gene to chromosome 2 between MCW071 (a marker within the EN2 gene) and ADL0270, a syntenic region to human 7q36.

Alleles↗
PubMed2005

Biological activity of recombinant chicken interleukin-6 in chicken hybridoma cells.

Interleukin-6 (IL-6), a multipotential cytokine that plays roles in regulating immune responses, acute phase reactions and hematopoiesis, induces proliferation and antibody production in hybridoma cells. The biological activities of the recombinant chicken IL-6 (rchIL-6) were determined using murine and chicken hybridoma cells. Cell proliferation and tyrosine phosphorylation of signal transducer and activator of transcription-3 (STAT3) were induced by rchIL-6 in the IL-6-dependent murine hybridoma cell line MH60, whereas the recombinant protein exhibited no significant cell proliferation activity in chicken hybridoma cells but induced antibody production and tyrosine phosphorylation of STAT3. The lack of cell proliferation induced by rchIL-6 in HUC2-13 cells may have been because the cell line was not IL-6-dependent in contrast to MH60 cells. These results suggest that rchIL-6 may be useful for promoting antibody production of chicken hybridoma cells as well as for creating chicken hybridomas by cell fusion.

Animals↗
PubMed2002

Cold-induced mitochondrial uncoupling and expression of chicken UCP and ANT mRNA in chicken skeletal muscle.

Although bird species studied thus far have no distinct brown adipose tissue (BAT) or a related thermogenic tissue, there is now strong evidence that non-shivering mechanisms in birds may play an important role during cold exposure. Recently, increased expression of the duckling homolog of the avian uncoupling protein (avUCP) was demonstrated in cold-acclimated ducklings [Raimbault et al., Biochem. J. 353 (2001) 441-444]. Among the mitochondrial anion carriers, roles for the ATP/ADP antiporter (ANT) as well as UCP variants in thermogenesis are proposed. The present experiments were conducted (i) to examine the effects of cold acclimation on the fatty acid-induced uncoupling of oxidative phosphorylation in skeletal muscle mitochondria and (ii) to clone the cDNA of UCP and ANT homologs from chicken skeletal muscle and study differences compared to controls in expression levels of their mRNAs in the skeletal muscle of cold-acclimated chickens. The results obtained here show that suppression of palmitate-induced uncoupling by carboxyatractylate was greater in the subsarcolemmal skeletal muscle mitochondria from cold-acclimated chickens than that for control birds. An increase in mRNA levels of avANT and, to lesser degree, of avUCP in the skeletal muscle of cold-acclimated chickens was also found. Taken together, the present studies on cold-acclimated chickens suggest that the simultaneous increments in levels of avANT and avUCP mRNA expression may be involved in the regulation of thermogenesis in skeletal muscle.

Animals↗
PubMed1998

Nucleotide sequence of the chicken HMGI-C cDNA and expression of the HMGI-C and IGF1 genes in autosomal dwarf chicken embryos.

Mutations in the genes for high mobility group protein I-C (HMGI-C) and insulin-like growth factor 1 (IGF1) are known to be responsible for dwarf phenotypes in the mouse. Because the locus for autosomal dwarfism (adw) in the chicken maps to a region which is syntenic to a region in the human and mouse in which the HMGI-C and IGF1 genes are located, HMGI-C and IGF1 are likely candidate genes for adw in the chicken. In this study their possible role in the establishment of this phenotype has been investigated. We have cloned and sequenced the complete coding region of the chicken HMGI-C cDNA. Comparison with its human counterpart revealed a nucleotide sequence conservation of 84%. Only nine amino acids are present principally in the N-terminal segment before the first DNA-binding domain. Northern blot analysis showed no difference in the expression of the HMGI-C gene between adw and wild-type chicken embryos. Also no mutations in either the HMGI-C or the IGF1 RNA nucleotide sequence were detected in adw chicken embryos.

Amino Acid Sequence↗
PubMed1997

AMP-deaminases from chicken and rabbit muscle: partial primary sequences of homologous 17-kDa CNBr fragments: autorecognition by rabbit anti-[chicken AMPD].

The apparent size (87.5 kDa) of the major polypeptide in freshly isolated chicken muscle AMP deaminase (AMPD.M) was comparable with that predicted from the sequences of the genes for the major muscle isoforms from human and rat. The size of the subunit of AMP deaminase from chicken muscle is indistinguishable from that of the rabbit enzyme. The peptide profiles of cyanogen bromide digests of AMPD.M from chicken and rabbit share a 17-kDa fragment, representing approximately 20% of the intact subunits of these enzymes. The first 25 residues of these fragments are 88.5% identical; the rabbit and chicken segments are greater than 92% and 84% identical, respectively, to the sequences predicted for residues 310-335 for AMPD.M from human and rat. Polyclonal rabbit antisera directed against AMPD.M from chicken breast recognize the full-length AMPD.M polypeptides on immunoblots of extracts of both avian and rabbit muscle, including an antiserum from the rabbit in which the antibody was prepared. The 17-kDa fragments, derived by incomplete cleavage of highly conserved internal segments of the deaminase subunit, share epitopes involved in the autorecognition of rabbit AMPD.M by rabbit polyclonal antibodies directed against the avian AMPD.M.

AMP Deaminase↗
PubMed2003

A one-year study of campylobacter carriage by individual Danish broiler chickens as the basis for selection of Campylobacter spp. strains for a chicken infection model.

From February 1999 to February 2000, 1,250 individual broiler chickens representing 125 broiler flocks originating from 62 broiler farms in Denmark were screened for campylobacter carriage. Every month, 10 flocks were tested for campylobacter carriage. The swabs were tested individually and as a pooled sample representing the flocks. Campylobacter spp. carriage was detected from 512 (40.9%) broiler chickens originating from 63 (50.4%) positive flocks. Campylobacter carriage by both individual chickens and flocks showed seasonal variation. Campylobacter jejuni was the dominant species (95.5%). Campylobacter isolates were typed using Penner heat-stable serotyping and flaA-typing methods. Data of campylobacter carriage by individual chickens and data generated by the use of different typing methods contributed to a better understanding of the dynamics of campylobacter infection within the broiler flocks. C. jejuni Penner heat-stable serotype HS2, flaA-type 1 was the most common type found in Danish broiler chickens.

Animals↗
PubMed2000

Expression of cytokine genes in Marek's disease virus-infected chickens and chicken embryo fibroblast cultures.

The role of cytokines in the pathogenesis and immunity of Marek's disease (MD), a herpesvirus-induced T-cell lymphoma in chickens, is poorly understood. Two different experiments were used to examine the potential role of particular cytokines in the pathogenesis and immune responses of MD. First, chicken embryo fibroblasts (CEF) were stimulated with lipopolysaccharide (LPS) and/or recombinant chicken interferon-gamma (rChIFN-gamma) and used to develop techniques for examining transcription of IFN-alpha, IFN-gamma, inducible nitric oxide synthase (iNOS), interleukin (IL)-1beta, IL-2, IL-6 and IL-8 by reverse transcription-polymerase chain reaction (RT-PCR). Addition of LPS and/or rChIFN-gamma resulted in the up-regulation of mRNA for iNOS, IL-1beta and IL-6, while IFN-gamma was up-regulated by LPS alone. IL-2 was down-regulated by the treatments. Second, to determine the effects of Marek's disease herpesvirus (MDV) infection on cytokine transcription in vivo, chickens were infected with MDV at 21 days of age and examined at 7 days post-infection (p.i.) (exp. 1) or were infected with MDV at 1 day of age and examined from 3 to 15 days p.i. (exp. 2). In MDV-infected chickens, IFN-gamma transcription was up-regulated as early as 3 days p.i. until the termination of the experiment at 15 days p.i., while iNOS and IL-1beta were up-regulated between 6 and 15 days p.i. Infection of 1-day-old chicks increased levels of mRNA for IFN-gamma and iNOS between 16- and 64-fold at 9 days p.i. These results suggest that IFN-gamma and iNOS may play an important role in the pathogenesis of MD.

Animals↗
PubMed2000

Development and use of monoclonal antibodies to chicken fibronectin to show that the chicken hepatocellular carcinoma cell line, LMH, constitutively expresses fibronectin.

Fibronectin (Fn) is a high molecular weight glycoprotein and acute phase reactant that contributes to a variety of cellular activities including proliferation and wound healing. Production of Fn is influenced by cytokines such as IL-1alpha, IL-6 and TNF -alpha, and in serum Fn levels can function as an indicator of sepsis and reticulo-endothelial function. Here we describe the production of a panel of mAb to chicken Fn and give evidence that a chicken hepatocellular carcinoma cell line, LMH, constitutively expresses Fn. A capture ELISA to measure chicken Fn was developed using an IgG1 mAb (AV62) as the capture Ab, and biotinylated AV63 (IgG2b) as the detecting Ab. This study identified a single commercially available mAb directed against human Fn that also recognised chicken Fn. By contrast, the anti-chicken Fn mAbs did not cross-react with either human or bovine Fn.

Animals↗
PubMed1981

Reactivation of chicken erythrocyte nuclei in heterokaryons results in expression of adult chicken globin genes.

Activation of chicken globin gene transcription has been demonstrated in chicken erythrocyte--rat L6 myoblast heterokaryons. The globin mRNA is polyadenylylated and is translated into adult chicken alpha A-, alpha D-, and beta-globin polypeptides. No fetal globin mRNA or globin polypeptides were detected. Heterokaryons between chicken erythrocytes and mouse neuroblastoma cells or hamster BHK cells also synthesized adult chicken globins.

Animals↗
PubMed2006

Are happy chickens safer chickens? Poultry welfare and disease susceptibility.

1. Contaminated chicken meat remains an internationally important vehicle for human infection with Salmonella and Campylobacter spp. In addition, the last 20 years has seen an international pandemic of human salmonellosis caused by the contamination of eggs with Salmonella Enteritidis. 2. It has been a long held scientific view that Campylobacter spp. and most, if not all of the common zoonotic salmonella, are essentially commensal in chickens. They usually form part of the gut flora and contaminate chicken carcases, for example, by faecal spillage at slaughter. Even when certain salmonella serovars like S. Enteritidis are invasive in laying hens overt evidence of clinical disease is rare and the birds appear to behave normally. 3. Are these bacteria just 'passing through' the avian host and only transient members of the bacterial flora or is there a more dynamic perspective to this infection/colonisation process? Chickens mount antibody responses to both pathogens, which indicate something other than commensalism. Such immune responses, however, do not always result in the clearance of the pathogen. 4. Not all animals in a group will carry salmonella or campylobacter, even under experimental conditions, and will vary, especially those that are outbred, in their responses to pathogen challenge. Identifying the reasons behind this could have important implications for disease control. 5. Both salmonella and campylobacter are more likely to be found in animals, which are compromised and this may explain at least part of the variations seen. Animals are more susceptible to infection when they are in a poor environment, fed a poor diet and/or under physical or psychological stress. 6. Work in this area has naturally focused on pathogens of medical significance and has shown that neurotransmitters such as noradrenaline can markedly alter pathogen behaviour. Other host responses like Interferon gamma can also affect host tissues in a way, which facilitates invasion by pathogens and may also interact directly with certain bacteria. 7. From a food safety perspective, there is evidence that egg contents contamination in ovo may be linked to transient stress in the hen. Current work at the University of Bristol on the epidemiology of campylobacter in broiler production is also showing a potential link between gut health and campylobacter colonisation and challenging the concept that these bacteria are common commensals. 8. The poor economic returns received by the egg and poultry industries mean that intensive production methods are common. Is it possible to rear chickens under these conditions in such a way as to exclude zoonotic pathogens like salmonella and campylobacter? Data from the UK strongly suggest that this is possible with the former pathogen. Can similar advances be achieved with campylobacter?

Animal Welfare↗