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PubMedDate not supplied

Characterization of three infectious bronchitis virus isolates from China associated with proventriculus in vaccinated chickens.

Outbreaks of an avian disease in infectious bronchitis-vaccinated chickens in China have led to the characterization of coronaviral isolates Q1, J2, and T3, which were isolated from proventricular tissues of the affected young layer flocks. Serologic analysis revealed that they could induce high titers of infectious bronchitis virus (IBV) antibodies in inoculated specific-pathogen-free (SPF) chickens in indirect enzyme-linked immunosorbent assay but were not neutralized by antisera specific to the IBV serotype M41 and the Australian T strain. In a pathogenicity experiment, the clinical signs and related gross lesions resembling those of field outbreaks were reproduced in SPF chickens, and viruses were reisolated from the damaged tissues, including trachea, proventriculus, duodenum, and cecal tonsil. Sequence data demonstrated the complete S1 amino acid sequences of these isolates were almost identical despite recovery from geographically different areas in China and had 47.3%-82.3% similarity in comparison with the 47 published S1 sequences. On the basis of genotyping and limited serology, the three isolates, which were responsible for field outbreaks of the disease, might be a new IBV variant.

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PubMed1975

The occurrence of lipid in the oxyntico-peptic cells of the proventriculus of the fasting domestic fowl.

A histological study has shown that considerable amounts of lipid accumulate in the oxyntico-peptic cells of the proventriculus of domestic fowls deprived of food. Lipid droplets were first seen in the cells 6 hours after commencing the fast and they reached a maximum in 24 hours; a decrease was detected histologically 2 hours after re-feeding and all lipid had disappeared 8 hours after access to food. Lipid was observed in fasted chickens aged from 1 to 27 weeks, in four different breeds, and in certain naturally occurring diseases. Small amounts of lipid were also seen in the proximal convoluted tubules of the kidneys of chickens which had been fasted. The relationship of the lipid to the metabolism of the oxyntico-peptic cells and to certain disease states is discussed.

Animals↗
PubMedDate not supplied

Characterization of a gram-positive bacterium from the proventriculus of budgerigars (Melopsittacus undulatus).

The cellular, cultural, and biochemical characteristics of eight isolates of a large gram-positive bacillus that are commonly observed as apparently normal flora in the proventriculus of budgerigars (Melopsittacus undulatus) were determined. The bacterium was highly pleomorphic and changed markedly in both diameter and length when subcultured on agar media. The bacterium was facultative anaerobic and capnophilic, hemolytic on blood agar, and formed flat colonies with irregular edges after incubation for several days. All isolates grew on sodium azide agar but did not grow on MacConkey agar. The isolates were catalase-negative and oxidase-negative and did not reduce nitrate. All isolates failed to utilize arginine, lysine, ornithine or tryptophane but produced acid from glucose, galactose, levulose, maltose, melibiose, starch, and sucrose. All isolates produced acetoin from glucose and hydrolyzed esculin. The eight isolates could not be identified to either genus or species level based on the descriptions of currently classified organisms in the division Firmicutes as described in Bergey's Manual of Systematic Bacteriology.

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PubMed1990

Use of lectins for detection of glycoconjugate changes in mucous epithelium of the chicken proventriculus.

The lectin binding pattern in the mucous epithelium of the chicken proventriculus was studied by using a peroxidase labeling method and correlated procedure. The nature of glycoconjugates in the mucous epithelium was found to change during the upward cell migration from deep to superficial parts. The superficial mucous epithelium (plica) was found to contain predominantly neutral glycoconjugates with N-acetyl-D-glucosamine residues and terminal galactose-N-acetylgalactosamine disaccharides whereas the deep epithelium (sulcus) contained acidic sulfated glycoconjugates with terminal sialic acid-galactose dimer. A continuous intraluminal mucous layer over the surface epithelium was found to contain a mixture of glycoconjugates secreted from both the plica and sulcus mucous cells. The data suggests that the changes in glycoconjugates of epithelial cells were closely correlated with cellular maturation.

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PubMed1983

The endocrine cells of the chicken proventriculus.

The endocrine cells of the chicken proventriculus were investigated by selective staining techniques, immunohistochemistry and electron microscopy. The following endocrine cell types were identified: 1) Argyrophilic ECL-cells, of unknown function, were very numerous in the 21-day-old chick, but less numerous in the newborn chick; 2) somatostatin-producing D-cells; 3) GLI-cells producing glucagon-related peptides; 4) X-cells of unknown function; 5) BN-cells producing bombesin; and 6) relatively few 5-hydroxytryptamine-producing EC-cells. Each of these cell types show a distinct morphology, distribution and histochemical reactivity. With the exception of BN-cells, they resemble rather closely the corresponding endocrine cell types previously described in the oxyntic mucosa (EGL, D, X and EC cells) or in the intestinal mucosa (L-cells) of the mammalian gut.

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PubMed1984

Ontogenesis of bombesin-like immunoreactive cells in the chicken proventriculus.

The distribution and morphological behaviour of bombesin like immunoreactive cells in the proventriculus of chick embryos, newborns and adults were investigated by indirect immunoperoxidase procedure. The first immunoreactive cells appear around the 11th day of incubation. Initially few, they increase progressively to reach a peak around the 18th day. Throughout the embryonic period almost all immunoreactive cells are column-shaped, display a typical "open" behaviour, and are situated among other superficial lining epithelial cells. Around hatching time, these "open" cells suddenly decrease in number while another immunoreactive "closed" cell type becomes more evident in a deeper location. In newborns and adults, the majority of immunoreactive cells are oval shaped and are characteristically situated near the neck of lobular glands; they seem to display a "closed" behaviour. The results demonstrate two different kinds of peptide-containing cells which probably exert different functions. During the embryonic period, in fact, they resemble a chemioreceptor, but in postnatal life they appear as a paracrine/endocrine elements.

Animals↗
PubMed1984

Tetrameres columbicola (Nematoda: Spiruridae) infection of pigeons: ultrastructure of the gravid female in glands of the proventriculus.

The light and electron microscopies of Tetrameres columbicola gravid females in sections of the parasitized proventriculus of pigeons were studied. By light microscopy, the most conspicuous structures in the sectioned parasite were the intestine, ovary, and especially the uterus that contained numerous eggs. By electron microscopy, there was a thick mat of pigment-coated microvilli on the surfaces of the intestinal epithelial cells. The germinal zone of the ovary contained nonmembrane-bound oocytes, but oocytes were confined by a membrane in the growth zone of the ovary. The core of the spermatheca contained oocytes and the periphery harbored sperm. In this location, the unfertilized oocyte had pseudopods; sperm had invaginations of the plasma membrane. After fertilization, there was proliferation of ribosomes within the oocyte. Embryonating eggs in the uterus had thick shells and were partially enveloped by elongations of the uterine epithelial cells. Surfaces of the epithelial cells were pleated and they had electron opaque areas at the points of the pleats. Larvae in eggs had a well developed annulated cuticle and muscular layer. Somatic muscle cells had tailed appendages that protruded into the pseudocoelom. The single layer of cells beneath the hypodermis had lateral processes at the base of the cells that interdigitated with similarly elongated processes of adjacent muscle cells. Striated fibers were present in the central portion of the cells.

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PubMedDate not supplied

Histochemical characterization of the mucins of the epithelial cells in the chick embryo proventriculus.

The histochemical characteristics of the epithelial mucins, which are produced by the lining epithelium, the superficial glands and the compound glands of the proventriculus were investigated in the chick embryo from the 7th day of incubation to hatching. Results showed that the time of appearance of the carboxylated, sulphated and neutral mucosubstances differed at the three investigated sites. From the 13th to the 19th day of incubation, intense production of the various mucins was detected at the three sites. However, the modality of intracytoplasmatic storage and the production of mucins in both the cells of the lining epithelium and the superficial glands appeared to differ from those observed in the cells of the compound glands. At the 20th and 21st day, the mucins were primarily produced by the lining epithelium and the superficial glands, whereas production diminished in the compound glands. Furthermore, from the 7th to the 17th day of incubation, the cells of the principal ducts of the compound glands showed the same histochemical characteristics and modality of production as those of the glandular cells of the compound glands. On the other hand, from the 18th day to hatching, these cells assumed the same characteristics as those of the lining epithelium and of the superficial glands.

Alcian Blue↗
PubMed2001

Neurotransmitters regulating acid secretion in the proventriculus of the Houbara bustard (Chlamydotis undulata): a morphological viewpoint.

Endocrine cells containing somatostatin (Som), gastrin-releasing peptide (GRP), and neuronal nitric oxide synthase (nNOS) and nerve fibers containing choline acetyl transferase (ChAT), tyrosine hydroxylase (TH), galanin (Gal), substance P (SP), and vasoactive intestinal polypeptide (VIP) were immunolocalized in the proventriculus of the Houbara bustard, Chlamydotis undulata. While GRP-immunoreactive (GRP-IR) cells occur in the inner zone, somatostatin (Som-IR) and polyclonal nNOS (nNOS-IR) immunoreactive cells were localized mainly in the peripheral zone of submucosal glands. GRP-IR, Som-IR, and nNOS-IR cells were occasionally observed in the walls of the gastric glands. Endocrine cells are of the closed variety and usually possess apical processes extending along the basal surfaces of adjacent nonreactive cells. Ultrastructural features of these cells are typical. ChAT, Gal, SP, VIP, and TH were immunolocalized in nerve fibers and terminals in the walls of arterioles and capillaries at the periphery of submucosal glands. Immunoreactivity to monoclonal nNOS occurred mainly in neuronal cell bodies in ganglia located around the submucosal glands. ChAT and TH immunoreactive cell bodies were also occasionally seen around the submucosal glands in the peripheral region. Immunoreactivity to Gal, SP, and VIP, but not ChAT or TH, was discernible around the walls of gastric glands. It was concluded that the distribution of neurotransmitters in neuronal structures is similar, but that of the endocrine cells varies from that of some avian species. The roles of these neurotransmitters in the regulation of acid secretion are discussed.

Animals↗
PubMed1992

Ca2+-ATPase in mucous and oxyntico-peptic cells of the fowl proventriculus.

Calcium adenosine triphosphatase (Ca(2+)-ATPase) was localized by means of histo-and ultracytochemistry in the secretory cells of the proventriculus of the domestic fowl. The mucous cells exhibited plasmalemmal-associated enzyme activity on the external aspect of the basolateral cell membrane. Intracellularly, the luminal aspect of Golgi-membranes and of secretory vesicle membranes reacted positively for Ca(2+)-ATPase activity, as did the apical cytosol and the matrix of lysosomes. Oxyntico-peptic cells were characterized by apical and apico-lateral plasmalemmal activity and by an organelle-associated distributional pattern similar to that in the mucous cells. In addition, Ca(2+)-ATPase was associated either with the matrix of mitochondria or with tubuli of the rough-surfaced endoplasmic reticulum. The results are discussed with respect to messenger and effector functions of calcium in the process of proventricular mucus secretion. In addition, Ca(2+)-ATPase distributional patterns in the oxyntico-peptic cell are related to the unique structure and function of these cells.

Animals↗
PubMed1985

Dilated cisternae of nuclear envelope and rough endoplasmic reticulum in the proventriculus of Drosophila auraria larvae.

In the cells of the middle layer of the proventriculus of Drosophila auraria larvae, the nuclear envelope and the rough endoplasmic reticulum are always found in the form of dilated cisternae. The length of these cisternae can reach 10 mu. There are indications that materials from the outer membrane of the nuclear envelope are directly transported to the Golgi complex of the examined cells.

Animals↗
PubMed2003

Differential requirement of EGFR signaling for the expression of defective proventriculus gene in the Drosophila endoderm and ectoderm.

A homeobox gene, defective proventriculus (dve), is expressed in various tissues including the ventral ectoderm and midgut. Here, we show the expression pattern of dve in the ventral ectoderm, in which dve expression is induced by Spitz, a ligand for Drosophila epidermal growth factor receptor (EGFR). In spitz mutants, dve expression is only lost in the ventral ectoderm and overexpression of Spitz induces ectopic dve activation in the ventral ectoderm. Dve expression in the middle midgut depends on Decapentaplegic (Dpp) signaling, while expression of a dominant-negative form of Drosophila EGFR (DER(DN)) also causes a marked decrease in dve expression in the middle midgut. Furthermore, heterozygous mutation of thick veins (tkv), a Dpp receptor, strongly enhances the effect of DER(DN). These results indicate that EGFR signaling is crucial for dve expression in the ventral ectoderm and is required in the middle midgut where it cooperates with Dpp signaling.

Animals↗
PubMed1972

Proventriculus of a marine annelid: muscle preparation with the longest recorded sarcomere.

EACH MUSCLE OF THE SYLLID (ANNELIDA: Polychaeta) proventriculus, the region of the gut posterior to the pharynx, contains a single zigzagging Z band, flanked on each side by a sequence of I-A-H-A-I bands defined by thick (60-90 nm) and thin (5 nm) filaments. The thick filaments show a 14-nm periodicity similar to paramyosin. The muscle cell terminates at the level of the outer I bands. The muscle does not include a complete sarcomere in the strict sense, as defined by a pair of Z bands, but the equivalent H-H distance reaches about 40 mum. Electrophysiological evidence suggests that contraction and relaxation of the cell are, respectively, associated with depolarizing and hyperpolarizing potentials.

Animals↗
PubMed2003

Defective proventriculus is required for pattern formation along the proximodistal axis, cell proliferation and formation of veins in the Drosophila wing.

Many genes have been identified that are required for the establishment of the dorsoventral (DV) and anteroposterior (AP) axes of the Drosophila wing. By contrast, little is known about the genes and mechanisms that pattern the proximodistal (PD) axis. Vestigial (Vg) is instrumental in patterning this axis, but the genes that mediate its effects and the mechanisms that operate during PD patterning are not known. We show that the gene defective proventriculus (dve) is required for a region of the PD axis encompassing the distal region of the proximal wing (PW) and a small part of the adjacent wing pouch. Loss-of-function of dve results in the deletion of this region and, consequently, shortening of the PD axis. dve expression is activated by Vg in a non-autonomous manner, and is repressed at the DV boundary through the combined activity of Nubbin and Wg. Besides its role in the establishment of the distal part of the PW, dve is also required for the formation of the wing veins 2 and 5, and the proliferation of wing pouch cells, especially in regions anterior to wing vein 3 and posterior to wing vein 4. The study of the regulation of dve expression provides information about the strategies employed to subdivide and pattern the PD axis, and reveals the importance of vg during this process.

Animals↗
PubMed1986

Ontogenesis of 5-hydroxytryptamine-like immunoreactive cells and their relationship with bombesin in chicken proventriculus.

By using a double-stain immunohistochemical procedure, the Aa. studied the onset, the behaviour and the possible interrelationship between the 5-HT-like and bombesin-like immunoreactive cells during the ontogenesis of chicken proventriculus and in adult animals. The 5-HT-like immunoreactive cells become evident from the 8th day of incubation and they reach their peak around the 16th day, then markedly decrease at hatching. In adult animal these cells are always present, but are not so numerous. Between the 14th and the 18th day many double-stained cells scattered among other only 5-HT or bombesin-like immunoreactive cells are present. They can also be observed in adults, but only occasionally.

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