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PubMed2004

Retrospective evidence that the MHC (B haplotype) of chickens influences genetic resistance to attenuated infectious bronchitis vaccine strains in chickens.

Infectious bronchitis is a respiratory disease of chickens that is caused by the coronavirus infectious bronchitis virus (IBV). Virtually all broiler and layer breeder flocks are routinely vaccinated against IBV. Two hatches of 1-day-old chicks from four lines were mistakenly vaccinated for infectious bronchitis using a moderately attenuated vaccine designed for chicks of an older age. The vaccination resulted in high mortality, and chicks from three of four lines died with signs typical of infectious bronchitis. The mortality that occurred using this less-attenuated vaccine was significantly influenced by the genetic line, and the MHC (B) haplotype in chickens of three B congenic lines. B congenic chickens possessing the B*15 haplotype were resistant in contrast to chickens possessing the B*13 or B*21 haplotypes. Chicks from two further hatches of the four lines were vaccinated appropriately with a more attenuated IBV vaccine, and only limited chick mortality was seen. These retrospective data from two repeated hatches confirm earlier data indicating chicken genes influence resistance to IBV, and indicate for the first time that genes tightly linked to the B haplotype are relevant in resistance to IBV. Due to extenuating circumstances it was not possible to verify results with chicks from F2 matings. Factors that may enhance definition of the role of the B haplotype in immune response to IBV, and the desirability for further analysis of a B haplotype-linked influence on immunity to IBV are discussed.

Animals↗
PubMed1993

Expression of myogenic factors in denervated chicken breast muscle: isolation of the chicken Myf5 gene.

In this study, we have isolated and characterized the chicken Myf5 gene, and cDNA clones encoding chicken MyoD1 and myogenin. The chicken Myf5 and MRF4 genes are tandemly located on a single genomic DNA fragment, and the chicken Myf5 gene is organized into at least three exons. Using genomic and cDNA probes, we further analyzed the mRNA levels of four myogenic factors during chicken breast muscle development. This analysis revealed that myogenin expression is restricted to in ovo stages in breast muscle, and is not detectable in neonatal and adult stages. On the other hand, Myf5 expression is detectable until day 7 post-hatching, and is not found in adult muscle, whereas high levels of MyoD1 and MRF4 are detectable at all stages. To further understand the roles of innervation on muscle maturation, we analyzed the expression of the four myogenic factors in denervated adult breast muscle. We found that MyoD1, myogenin, and MRF4 are induced at high levels in denervated muscle, whereas no change occurs in the level of Myf5. These studies suggest that innervation controls the relative abundance and type of myogenic factors that are expressed in adult muscle, and that when nerve control is removed, the muscle reverts to a neonatal phenotype, with the enhanced expression of three myogenic factors (MyoD1, myogenin, and MRF4).

Amino Acid Sequence↗
PubMed1982

Chicken antithrombin. Isolation, characterization, and comparison with mammalian antithrombins and chicken ovalbumin.

Chicken antithrombin was purified from fresh chicken plasma by affinity chromatography using heparin-agarose, and its amino acid and carbohydrate compositions, amino-terminal sequence, inhibition of human thrombin, and immunological properties were studied and compared with previously studied mammalian antithrombins (human, pig, rabbit, and rat), and also with chick ovalbumin. Chicken antithrombin is a single-chain glycoprotein with a total carbohydrate content of 17.5%, including 6.0% N-acetylglucosamine, 8.7% hexose, and 2.8% N-acetylneuraminic acid. The molecular weight estimated from sodium dodecyl sulfate(SDS)-polyacrylamide gel electrophoresis was 60,000. The amino-terminal sequence has been determined as Ala-Pro-Tyr-Ala-Val-Glu-Asp-Ile-Cys-Thr-Ala-Lys-Pro-Thr-Asp-Ile-Pro-Val-Asn, which is highly homologous to the terminal sequences of mammalian antithrombins, although the first 4 residues are quite different from those of mammalian species. Chicken antithrombin showed a stoichiometric inhibition against thrombin. The apparent dissociation constant (K1) for the complex was 6.4 X 10(-8) M. No immunological cross-reactivity was observed between chicken and mammalian antithrombins. Ovalbumin, which Hunt and Dayhoff (Biochem. Biophys. Res. Commun. 95, 864-871, 1980) proposed should be grouped in the same superfamily as antithrombin, showed neither immunological cross-reactivity with antithrombin or with its carboxymethylated derivative, nor any effect on the thrombin-antithrombin interaction. Ovalbumin showed no inhibitory effect on porcine elastase, either.

Amidohydrolases↗
PubMed2002

Glycerol-3-Phosphate dehydrogenase (E.C.1.1.1.8) is expressed in cultured chicken embryonic adipofibroblasts and upregulated by embryonic chicken serum.

Chicken embryonic adipofibroblasts (CEA) accumulate intracytoplasmic lipids when cultured in medium containing chicken serum (CS), but not in medium with fetal bovine serum (FBS). To characterize this process of lipid accumulation, we evaluated the expression of the enzyme glycerol-3-phosphate dehydrogenase (E.C.1.1.1.8) (GPDH), first in chicken tissues and then in CEA cultured under diverse conditions. GPDH activity in adipose depots from 4-wk-old broiler chickens was similar or higher than that shown by liver, the main organ for fatty acid synthesis in chickens, while skeletal muscle had the lowest levels of GPDH. In vitro, GPDH activity increased in CEA cultured in the presence of CS but not in medium with FBS, paralleling the lipid accumulation by these cells. Both lipid accumulation and GPDH activity were further increased in CEA cultured in the presence of embryonic CS. Our results show that GPDH is highly expressed in avian tissues related to lipid metabolism and therefore can be a reliable marker for avian adipogenesis, and suggest that ECS is an optimum source for the purification of avian adipogenic factors.

Adipose Tissue↗
PubMed2002

Increase of gamma-glutamyl-beta-alanyl-histidine isopeptide in the macromolecular fraction of model chicken extract during heating and distribution in commercial chicken extracts.

Changes in the amino acid composition and contents of gamma-glutamyl-beta-alanyl-histidine isopeptide in the macromolecular fraction were measured during heating of chicken extract. Increases of histidine, 1-methylhistidine, and beta-alanine were observed, suggesting that carnosine and anserine were incorporated into the macromolecular fraction. The increase of gamma-glutamyl-beta-alanylhistidine isopeptide in the macromolecular fraction of chicken extract was also observed during the heating process. Furthermore, measurement of gamma-glutamyl-beta-alanylhistidine isopeptide in commercial chicken extract showed that all kinds of chicken extract contained the above isopeptide (from 0.09 to 0.31 micromol/g DM in the macromolecular fraction). These results suggest that the formation of gamma-glutamyl-beta-alanyl-histidine and related isopeptides occur during heating of chicken extract.

Animals↗
PubMed2003

Cloning of cDNA encoding the nuclear form of chicken sterol response element binding protein-2 (SREBP-2), chromosomal localization, and tissue expression of chicken SREBP-1 and -2 genes.

Sterol regulatory element binding protein-1 and -2 (SREBP-1 and -2) are key transcription factors involved in the biosynthesis of cholesterol and fatty adds. The SREBP have mainly been studied in rodents in which lipogenesis is regulated in both liver and adipose tissue. There is, however, a paucity of information on birds, in which lipogenesis occurs essentially in the liver as in humans. As a prelude to the investigation of the role of SREBP in lipid metabolism regulation in chicken, we sequenced the cDNA, encoding the mature nuclear form of chicken SREBP-2 protein, mapped SREBP-1 and -2 genes and studied their tissue expressions. The predicted chicken SREBP-2 amino acid sequence shows a 77 to 79% identity with human, mouse, and hamster homologues, with a nearly perfect conservation in all the important functional motifs, basic, helix-loop-helix, and leucine zipper (bHLH-Zip) region as well as cleavage sites. As in the human genome, SREBP-1 and SREBP-2 chicken genes are located on two separate chromosomes, respectively microchromosome 14 and macrochromosome 1. Tissue expression data show that SREBP-1 and SREBP-2 are expressed in a wide variety of tissues in chicken. However, unlike SREBP-2, SREBP-1 is expressed preferentially in the liver and uropygial gland, suggesting an important role of SREBP-1 in the regulation of lipogenesis in avian species.

Amino Acid Sequence↗
PubMed2004

A plasmid DNA encoding chicken interleukin-6 and Escherichia coli K88 fimbrial protein FaeG stimulates the production of anti-K88 fimbrial antibodies in chickens.

Immunization using a plasmid to deliver an encoded protein for expression in situ as the antigen is a promising technology. A plasmid encoding the enterotoxigenic Escherichia coli K88 fimbrial protein FaeG when injected into chickens stimulates the production of antibodies against the fimbrial protein, similar to what has been observed in mice. The efficacy of a genetic adjuvant on fimbrial antibody production was tested by introducing the gene for chicken interleukin-6 in tandem with the faeG gene. Expression of both the fimbrial FaeG protein and chicken interleukin-6 protein was confirmed in COS-M6 cells. Slightly higher antiFaeG antibody titer in chickens was obtained compared with immunization with the plasmid encoding FaeG alone, especially at 10 (19%, P < 0.05) and 12 (27%, P < 0.05) wk, respectively, after the secondary immunization. Elevated antiFaeG antibody titer induced by chicken interleukin-6 and FaeG proteins expressed jointly persisted longer than when induced by FaeG protein alone. This is the first report of an avian cytokine enhancing an immune response, and confirms that coexpression of the antigen and adjuvant from a plasmid delivered by DNA immunization is an effective protocol.

Adhesins, Escherichia coli↗
PubMed2002

Expressed sequence tags for the chicken genome from a normalized 10-day-old white leghorn whole-embryo cDNA library. 3. DNA sequence analysis of genetic variation in commercial chicken populations.

Single nucleotide polymorphisms (SNPs) have emerged as a major class of DNA markers with the advantage of permitting the development of high-density genetic maps adequate for quantitative trait loci (QTL) identification by linkage-disequilibrium analysis. Here we describe results of a relatively high-depth survey of chicken broiler and layer populations for SNPs in targeted genomic regions of chicken expressed sequence tag (EST) sites. The sequences scanned, representing the composite sequence of 12 amplified fragments for a total of 6489 bp, were randomly distributed, occurring on six different chromosomes or linkage groups in the chicken genome. Although one of the genomic DNA sequences did not match the reference cDNA sequence, another contained an intron that separated two putative exons. The number of SNPs observed within each of the 12 EST-targeted genomic regions ranged from 0 to 10 for a total of 44 and a frequency of 0.7%. About 70% of the polymorphisms were shared between layer and broiler populations. The average heterozygosity within the populations ranged from 0.15 to 0.48, with the layer populations showing the higher heterozygosity. SNPs and oligonucleotides described will provide a resource for genetic analysis in commercial chicken populations. The data appear to indicate that the relative frequency of SNPs in the targeted regions scanned is higher than the frequency reported for any of the other regions scanned to date in other eukaryotic genomes. Additionally, the results suggest that the use of DNA pools may offer an efficient approach to SNP detection in chickens, as has been shown in other vertebrates.

Animals↗
PubMed1998

Allometric comparison of the brain and brain structures in the white crested polish chicken with uncrested domestic chicken breeds.

The feather crest on the head of the White Crested Polish Chicken covers a bony protuberance, a skull modification typical of crested chickens. The telencephalon is displaced into this protuberance, giving the brain the shape of an hour-glass. Allometric comparison (i.e., consideration of the influence of body weight on brain size) shows that the brain is relatively larger in crested chickens. This enlargement is partly due to enlarged ventricles, which are observed in some individuals. Among the brain structures measured, the tegmentum, cerebellum, tectum, paleostriatum, hippocampus, septum and olfactory bulb are not significantly larger in White Crested Polish chickens in comparison to those structures in seven uncrested chicken breeds; the optic tract, diencephalon, telencephalon, accessory hyperstriatum, dorsal and ventral hyperstriatum, and neostriatum, however, are significantly enlarged in this breed.

Animals↗
PubMed1986

Purified chicken growth hormone (GH) and a human pancreatic GH-releasing hormone increase body weight gain in chickens.

Purified chicken GH (cGH) and a synthetic human GH-releasing hormone (hpGRF) were tested for the ability to improve growth performance in chickens. Purified cGH was given to 4-week-old cockerels at 5, 10, and 50 micrograms/day for 14 days via daily iv injection. Body weights of chickens receiving 5 and 10 micrograms/day cGH were significantly increased at 6 days by 13.5% and 11.2%, respectively, relative to control values. At 14 days, body weights averaged 8.1% and 7.7% greater than controls, but these values were not statistically significant. There was a slight stimulation of body weight gain in chickens receiving 50 micrograms/day cGH. In general, cGH produces a transient stimulation of body weight gain in chickens. hpGRF was also given to 4-week-old cockerels for 14 days via daily iv injection at 0.1, 1.0, and 10.0 micrograms/day. hpGRF at 0.1 microgram/bird daily increased body weight on day 14 (9.1% over the control value). The stimulating effects of hpGRF on body weight are also transient. The effects of cGH on serum somatomedin-C (SM-C) were examined. Serum SM-C concentrations were significantly elevated 24 and 36 h after injection of cGH. In conclusion, purified cGH and hpGRF appear to have some growth-promoting activity. The stimulatory effect of hpGRF on weight gain may be mediated via GH, and the stimulatory effect of cGH could be mediated through SM-C.

Animals↗
PubMed2006

Campylobacter jejuni strains of human and chicken origin are invasive in chickens after oral challenge.

The aim of the study was to evaluate the colonizing ability and the invasive capacity of selected Campylobacter jejuni strains of importance for the epidemiology of C jejuni in Danish broiler chickens. Four C. jejuni strains were selected for experimental colonization studies in day-old and 14-day-old chickens hatched from specific pathogen free (SPF) eggs. Of the four C. jejuni strains tested, three were Penner heat-stable serotype 2, flaA type 1/1, the most common type found among broilers and human cases in Denmark. The fourth strain was Penner heat-stable serotype 19, which has been shown to be associated with the Guillain Barré Syndrome (GBS) in humans. The minimum dose for establishing colonization in the day-old chickens was approximately 2 cfu, whereas two- to threefold higher doses were required for establishing colonization in the 14-day-old chickens. Two of the C. jejuni strains were shown to be invasive in orally challenged chickens as well as in three different human epithelial cell lines.

Animals↗
PubMed2003

cDNA cloning of chicken orexin receptor and tissue distribution: sexually dimorphic expression in chicken gonads.

Orexin-A and -B are known to stimulate food intake in mammals. However, the critical roles of orexins in birds are not fully understood, since orexins have no stimulatory effect on food intake in the chicken. To understand the physiological role(s) of orexins in birds, we have cloned chicken orexin receptor (cOXR) cDNA by RT-PCR, and analysed the tIssue distribution of OXR mRNA in the chicken. The cOXR cDNA is 1869 bp long and encodes 501 amino acids. The cloned cDNA for cOXR corresponds to the type 2 OXR in mammals, and shows approximately 80% similarity to those of mammals at the amino acid level. Expression analysis by RNase protection assay revealed OXR mRNA was distributed widely in brain regions, and expression in the cerebrum, hypothalamus and optic tectum were abundant. In peripheral tIssues, OXR mRNA was expressed in the pituitary gland, adrenal gland and testis, but no mRNA expression was observed in other tIssues examined. Furthermore, we found that the amount of cOXR mRNA was different between testis and ovary, while prepro-orexin mRNA is equally expressed in the gonads of both sexes in the chicken. These data indicate that the orexins have neuroendocrine actions in chickens, which are mediated through hypothalamic receptors as has been observed in mammals. In addition, orexin may have specific role(s) in the regulation of gonadal function in which sex-dependent mechanisms could be involved.

Amino Acid Sequence↗
PubMed1984

Changes in turbidity during microtubule assembly in brain extracts from normal chickens and chickens with muscular dystrophy.

When extracts of brain from normal and dystrophic chickens were incubated at 30 degrees C under conditions that favored microtubule assembly, the increase in turbidity of the extract from the dystrophic animal was approximately 50% less than the increase in the turbidity of the extract from the normal animal. In developmental studies using age-matched normal and dystrophic chickens this difference in turbidity was observed only with chickens 65 days ex-ovo or older. The extent of microtubule assembly, as determined by a sedimentation methodology, was a linear function of the total protein concentration in the extract and was equal in extracts from normal and dystrophic chickens. In contrast, the total increase in turbidity was much larger than could be accounted for by sedimenting microtubules and varied in a non-linear manner with the total protein concentration. There was no increase in turbidity when brain extracts that were prepared by centrifugation at 100,000 g X 40 min were incubated at 30 degrees C. The condensation reaction of the tubulin in these high speed extracts with microtubules was equal in the extracts from normal and dystrophic animals. These studies indicate that a developmentally regulated difference in brain extracts from normal and dystrophic chickens can be demonstrated by turbidimetric methods but this difference is unrelated to the formation of microtubules in these extracts. These studies support the concept that muscular dystrophy is also accompanied by a change in the central nervous system.

Animals↗
PubMed1978

Fc receptor-bearing lymphoid cells in the chicken. II. Relative increase of Fc(IgG) receptor bearing cells in obese strain-chickens.

An EA rosette technique is used to study ontological development and organ distribution of Fc(IgG) receptor-bearing lymphoid cells in normal CS White Leghorn chickens, and in OS chickens with spontaneous autoimmune thyroiditis. During the embryonic period, no difference was seen between CS and OS in the tissue distribution of cells with Fc receptors. At the time of hatching and subsequently, the OS chickens possessed relatively more Fc receptor-bearing lymphoid cells than did CS chickens. The increase of Fc receptor-bearing lymphoid cells was most prominent among spleen cells. No difference in the affinity of Fc receptors between lymphocytes of the OS and CS chickens was demonstrated. The possible role of Fc receptor-carrying cells in the development of autoimmune thyroiditis is discussed.

Animals↗
PubMed1975

Horizontal transmission of turkey herpesvirus to chickens. 3. Transmission in three different lines of chickens.

Horizontal transmission of turkey herpesvirus (HVT) was studied in three separate trials using three different lines of chickens in each trial. There was no horizontal spread of HVT to contact cagemates through 8 weeks regardless of the line of donor chickens, when inoculated subcutaneously with 9.2 times 10-3 plaque-forming units (PFU) of HVT at 1 week of age. The virus spread poorly to a few cagemates from an experimental line of White Leghorns (W.S.U.-V.S.), but not from a commercial line of White Leghorns (C.-W.L.) or meat-type (C.-M.T.) chickens, when inoculated with 9.4 times 10-4 PFU of HVT at 1 week of age. The virus spread readily to contact cagemates from W.S.U.-V.S. but not at all from C.-W.L. or C.-M.T. chickens when inoculated with 2 times 10-4 PFU of HVT at 8 weeks of age. The incidence among cagemates of contact infection by HVT appeared similar regardless of genetic lines. This observation indicated a difference among different genetic lines of chickens in the development and/or shedding of infectious HVT following virus inoculation.

Animals↗
PubMed1976

Horizontal transmission of turkey herpesvirus to chickens. 5. Airborne transmission between chickens.

Airborne transmission of turkey herpesvirus (HVT) between chickens was studied in two trials using an experimental line of White Leghorns. HVT either did not spread or spread poorly to chickens that had been exposed for 8 weeks to the exhaust air from a cage containing donor chickens inoculated with HVT at 8 weeks of age. There was no airborne transmission of HVT to chickens that had been exposed for 4 weeks. This study indicated a possible by an infrequent spread of HVT between chickens via airborne route.

Air Microbiology↗
PubMed1991

Survival of Salmonella typhimurium ATCC 14028 on the surface of chicken legs or in mechanically deboned chicken meat gamma irradiated in air or vacuum at temperatures of -20 to +20 C.

Response-surface methodology was used to develop predictive equations for the response of Salmonella typhimurium ATCC 14028 on the surface of chicken legs or within mechanically deboned chicken meat (MDCM) to the effects of gamma radiation doses of 0 to 3.60 kGy (100 krad = 1 kGy) at temperatures of -20 to +20 C in air or vacuum. A streptomycin-resistant mutant was used in these studies to allow accurate estimations of the surviving salmonellae in the presence of residual normal flora. This strain has been demonstrated to have no significant shift in its biological properties nor in its resistance to ionizing radiation. The response of S. typhimurium to gamma radiation was similar on both chicken legs and MDCM. The radiation was significantly more lethal to the bacterial cells at temperatures above freezing. The response-surface equations developed from the studies predict that the number of viable cells per gram of MDCM or per square centimeter of the surface of chicken legs would be reduced approximately 2.8 to 5.1 log units at 0 C by radiation doses within the range of 1.5 to 3.0 kGy. The results of the present studies are similar to those obtained previously with sterile mechanically deboned chicken meat.

Analysis of Variance↗
PubMed1994

Development and characterization of chicken-chicken B cell hybridomas secreting monoclonal antibodies that detect sporozoite and merozoite antigens of Eimeria.

Chicken-chicken B cell hybridomas that secrete monoclonal antibodies (mAb) detecting antigens located at the anterior tip of the sporozoites of Eimeria acervulina have been produced. Peripheral blood lymphocytes (PBL) obtained from chickens infected with E. acervulina were fused with a thymidine-kinase deficient (TK-) chicken B cell line. Hybridomas secreting mAb binding to the sporozoite antigens of E. acervulina were selected using an ELISA. Two stable hybridomas, whose mAb were designated as P11 and P66, respectively, were obtained and their binding characteristics were assessed. The mAb P11 detects the sporozoite but not the merozoite antigens of E. acervulina and Eimeria tenella. The P66 mAb recognizes a cross-reactive antigen of sporozoite and merozoite of E. acervulina but not E. tenella. Flow cytometric analysis of the hybridomas secreting the P11 and P66 mAb showed expression of surface IgM and IgG, respectively. Western blot analysis under reducing conditions showed that mAb P11 recognized a sporozoite protein of 43 kDa. Both mAb recognized antigens located at the anterior end of the sporozoites by indirect immunofluorescence staining. This study shows the development of chicken B cell hybridomas that secrete coccidia-specific mAb.

Animals↗