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PubMed1993

Localization of sequences controlling the spatial, temporal, and sex-specific expression of the esterase 6 locus in Drosophila melanogaster adults.

The esterase 6 gene (Est-6) of Drosophila melanogaster is expressed in a variety of tissues that differ between larval and adult stages and among related species. Variability in the level of expression of this locus among different species and strains and its species- and tissue-specific patterns of expression make it a useful system for studying the evolution of gene regulation in Drosophila. We have begun to determine the location of the regulatory regions of Est-6 by constructing deletion mutants of the 5' regions of the gene and transforming them back into flies. Deletion mutants of the putative 5' promoter regions of Est-6 were fused to the bacterial beta-galactosidase gene (lacZ) and assayed for their ability to direct tissue-specific expression in transformed D. melanogaster adults. We have identified four independently acting Est-6 regulatory regions that direct the expression of lacZ in (i) the ejaculatory duct; (ii) the adult salivary glands; (iii) the respiratory system, prefrons, antennae, and maxillary palps; and (iv) the ejaculatory bulb and prefrons. We also found a region near the start of transcription that directed expression of Est-6 in the cardia or proventriculus in some transformed lines.

Animals↗
PubMed1995

Molecular cloning of a major cockroach (Blattella germanica) allergen, Bla g 2. Sequence homology to the aspartic proteases.

Inhalation of allergens produced by the German cockroach (Blattella germanica) elicits IgE antibody formation and the development of asthma in genetically predisposed individuals. We compared the allergenic importance of two cockroach (CR) allergens, Bla g 1 and Bla g 2, and determined the complete amino acid sequence of the major 36-kDa allergen, Bla g2. A survey of 106 sera from CR allergic patients showed the prevalence of IgE antibodies to Bla g 1 and Bla g 2 to be 30.2% and 57.6%, respectively. Immediate skin tests on 7 selected patients gave positive reactions using 10(-3) micrograms/ml either allergen, whereas controls showed no response to 10 micrograms/ml. Natural Bla g 2 was purified and the sequence of the NH2 terminus and tryptic peptides, comprising 36% of the molecule, was determined. The cDNA for Bla g 2 was cloned from a B. germanica expression library and encoded a 24-amino acid signal peptide and a 328-amino acid mature protein, which showed the highest degree of identity to mosquito (Aedes aegypti) lysosomal aspartic protease (30.8%), with similar identity to pepsin, cathepsins D and E, renin, and chymosin. Bla g 2 mRNA and protein were detected in B. germanica, but not in Periplaneta americana, the other principal domiciliary CR species in the U.S. High concentrations of Bla g 2 were found in CR digestive organs (esophagus, gut, and proventriculus). The results show that Bla g 2 is a major species-specific allergen of B. germanica and suggest that the allergen functions as a digestive enzyme in the cockroach.

Allergens↗
PubMed1998

Novel allergen structures with tandem amino acid repeats derived from German and American cockroach.

Cockroaches produce potent allergens that are an important cause of asthma. The two principal domiciliary cockroach species, Blattella germanica and Periplaneta americana, secrete major allergens, Bla g 1 and Per a 1. Here, we report the molecular cloning of three Bla g 1 cDNA clones, which showed 70% amino acid sequence identity with Per a 1. Plaque immunoassays with human IgE antibodies or murine monoclonal antibodies showed that these allergens were antigenically cross-reactive. The Bla g 1 sequences also showed homology to five previously undefined cockroach allergen sequences. An unusual feature of all these sequences was that they contained multiple tandem amino acid repeats of approximately 100 amino acid residues. Between one and seven repeat units were identified by dot-plot matrix analysis. The sequences also showed homology to a mosquito protein involved in digestion (ANG12 precursor) and to mitochondrial energy transfer proteins. High levels of Bla g 1 were found in cockroach hindgut and proventriculus. Amino acid sequencing of natural Bla g 1 and Per a 1 suggested that these allergens are cleaved by trypsin-like enzymes following secretion into the digestive tract. The repeat sequences appear to have evolved by duplication of an ancestral amino acid domain, which may have arisen from the mitochondrial energy transfer proteins.

Allergens↗
PubMed1978

Influence of overfeeding on growth, obesity and intestinal tract in young chicks of light and heavy breeds.

1. Heavy-breed (HB) chicks differed from light-breed (LB) ones in their propensity to be overfed. Whereas in the LB chicks the amount by which they could be overfed reached 70% more than the food consumed daily by the ad lib.-fed chicks, in the HB chicks the maximal excess was only 13%. 2. Overfeeding caused a slight but statistically significant increase in the linear growth rate (shank length) of the LB chicks, with an opposite effect in the HB chicks. 3. Overfeeding increased the weight of the crop, proventriculus, small intestine, pancreas, liver and adipose tissue but had no such effect on the heart, cerebrum or cerebellum. 4. Overfeeding had no effect on the specific activities of the pancreatic digestive enzymes, liver xanthine dehydrogenase, or tryptophan oxygenase (EC 1.13.1.12). The increase in the total activities was due entirely to organ hypertrophy. 5. Obesity induced in young chicks had no residual effects on the adult LB chicks, but reduced the linear growth of the adult HB chicks. 6. An explanation for the difference between breeds in response to overfeeding at an early age is discussed.

Adipose Tissue↗
PubMed1988

Some concepts of the interaction of Trypanosoma (Nannomonas) congolense and Glossina pallidipes.

Light and electron microscope investigations were carried out on the infection with Trypanosoma (Nannomonas) congolense of laboratory-reared tsetse flies Glossina pallidipes. Trypanosomes became entombed in the peritrophic membrane (PM) to form intraperitrophic cavities which were more electron-translucent than the amorphous layer of the PM. A hypothesis is suggested that after migration anteriorly in the ectoperitrophic space, the trypanosomes become enmeshed in the PM during its formation in the proventriculus, and that the trypanosomes are extricated in the midgut as the PM advances towards the posterior end of the gut.

Animals↗
PubMed2002

Gizzerosine-induced histopathological lesions in broiler chicks.

1. The aim of this study was to investigate pathomorphological changes in broiler chicks fed with different doses of gizzerosine, a substance produced during the heat treatments of fish meal. 2. The experiment was carried out in Ross broiler chicks which were divided into three groups: group A received 100% of non-medicated commercial mash for broiler chicks. During an experimental 5-d period, 50% of commercial mash was replaced with unheated fish meal (0.65 ppm gizzerosine) in group B and in group C with heated fish meal (1.15 ppm gizzerosine). Fourteen chicks from each group were killed every day. Samples of gastrointestinal and lymphoid organs, lung, pancreas, liver, brain and kidney tissue were sampled for histopathological analysis. Organs were embedded in paraffin and stained with hematoxylin-eosin stain and using periodic acid-Schiff reagent (PAS) and Sudan III (frozen sections). 3. Necropsy did not reveal notable differences between treated groups. There were no significant histopathological changes in immunocompetent organs nor in the lungs, the pancreas, the kidney or the brain. Sharply demarcated multiple vacuoles were observed in the myocardium in group C toward the end of the experiment. In group C, the prevalent changes in the gizzard and the proventriculus were slight to severe cuticle erosions and oedema of the lamina propria with or without multiple vacuoles, respectively, towards the end of the experiment. The most prominent changes toward the end of the experiment were dispersed cell vacuolisation in duodenal, jejunual, ileal and caecal lamina propria in group C. 4. In conclusion, it should be emphasised that extra-gizzard gizzerosine-induced lesions are probably not mediated by H2-receptor stimulation, but could be a consequence of cellular hypoxia.

Animal Feed↗
PubMed2002

Passage rate through the anterior digestive tract of broiler chickens fed on diets with ground and whole wheat.

1. Birds were fed diets containing ground or whole wheat and titanium dioxide for 10 min, followed by dissection of 4 birds per treatment after 30, 60, 90, 120, 150 and 180 min. 2. The crop, proventriculus and gizzard, duodenum, jejunum, and ileum from each bird were dried and combusted, and titanium content in each section was determined. 3. Significant amounts of titanium were found in the small intestine of the birds as soon as 30 min after being given feed containing titanium, and significant amounts had passed the small intestine after 120 to 150 min. 4. Titanium contents equivalent to approximately 5 g feed were eliminated from the gizzard per hour independently of whether ground or whole wheat was used. Thus, a hypothesis that the use of whole grain would slow down passage rate through the upper digestive tract was not supported by the current results.

Animal Feed↗
PubMed2002

Genetic and phenotypic relationships between and within support and demand tissues in a single line of broiler chicken.

1. With commercial selection for increased broiler performance there has been a correlated increase in the incidence of several metabolic disorders. A study was undertaken to investigate the balance between the unselected support tissues (including the heart, liver, spleen and the components of the gastrointestinal tract (GIT)) which drive growth in the selected demand tissues (eviscerated body mass) by assessing the genetic correlations between these traits. 2. Data were collected on 483 broiler birds taken from a commercial male broiler line with pedigree information. 3. Genetic parameters were estimated by restricted maximum likelihood with an individual animal model. Heritability estimates for the production traits ranged between h2 = 0.48 and 0.59 for leg and breast mass, respectively. The support tissues were generally associated with low to moderate heritabilities ranging between h2 = 0.19 for proventriculus to h2 = 0.38 for duodenum mass, although moderately high heritability estimates (h2 = 0.51 to 0.54) were associated with the spleen and gizzard. 4. The genetic correlations between production traits and support organs were generally low, however, heart mass was positively correlated with all carcase components of the lean tissue mass; the genetic correlations ranged between r(g) = 0.55 with breast mass to r(g) = 0.64 with eviscerated body mass. 5. In general, there were strong positive genetic correlations between the different components of the GIT. Organs that have been implicated in the development of metabolic disorders such as ascites (for example, the heart) could theoretically be used in commercial selection indices due to moderate heritabilities (heart: h2 = 0.30) and favourable correlations with commercially important traits.

Animals↗
PubMed2003

Quantitative feed restriction or meal-feeding of broiler chicks alter functional development of enzymes for protein digestion.

1. Two experiments were performed on broiler chicks to determine the effect of either quantitative feed restriction (QFR) from 5 to 11 d of age or meal-feeding (MF) from d 5 to 17 on development of activity of enzymes associated with protein digestion. 2. Proteolytic activity of the proventriculus was reduced by QFR but unaffected by MF. 3. General proteolytic and carboxypeptidase A activities of the pancreas were reduced by QFR and MF. 4. Amino- and dipeptidase activities of the small intestine were increased by QFR. Dipeptidase activity was unaffected by MF. 5. Nitrogen retention of QFR chicks was lower immediately following feed restriction but not in the 2 weeks following return to ad libitum access to feed. 6. Feeding regimen alters functional development of the enzymes of protein digestion and may therefore influence growth rate of broilers.

Aminopeptidases↗
PubMed2004

The incorporation of whole grain into pelleted broiler chicken diets. II. Gastrointestinal and digesta characteristics.

1. Pelleted diets, incorporating whole or ground wheat or barley in the pellets, were fed to broiler chickens and the performance, gastrointestinal development and digesta characteristics of those chickens recorded. 2. Body weight was similar with whole grain incorporation or enzyme application. Food conversion efficiency was improved by addition of enzyme to a full wheat diet. 3. Whole grain inclusion in pellets reduced proventriculus proportional mass and increased gizzard proportional mass with no apparent effects of exogenous feed enzyme addition. 4. Relative ileal mass was reduced by enzyme inclusion in a wheat diet and by inclusion of whole barley in the pellets. 5. Digesta viscosity was increased by whole wheat inclusion but reduced by enzyme inclusion irrespective of grain processing. Inclusion of 200 g/kg of barley did not alter viscosity of digesta beyond the duodenum. 6. Fresh excreta pH was higher with both cereals in the grower phase when whole grain was fed. On the barley diet, this was affected by enzyme addition, which created higher pH from a point earlier in the grower phase than when no enzyme was employed. 7. Evidence of a complex interaction between higher viscosity and pH being involved in differences in ileal relative mass was found through significant relationships being produced by enzyme use on the wheat diet alone.

Aging↗
PubMed1976

Ionic constituents and osmolality of the small intestinal fluids of the laying hen.

1. The osmotic pressure of the liquid phase of the contents of the small intestine is always hypertonic to plasma and not affected by egg formation. 2. Chloride concentration is higher during shell calcification, sodium and calcium concentrations increase at the end of shell deposition while calcium concentration shows a cyclic variation with a maximum 18 h after ovulation. 3. The relationships between the ions and water of the duodenum and upper jejunum are modified by egg formation: the apparent reduction of Na+ and W+ is compensated by an increase in Ca2+. 4. It is concluded that egg formation acts on the intestinal composition via the proventriculus and gizzard rather than through a direct effect on the intestine.

Animals↗
PubMed1976

Composition of crop and gizzard contents in the laying hen.

Crop and gizzard contents were analysed at six stages of egg formation. 2. The crop was empty during the day and full during the night while the gizzard contained a constant amount of dry matter. The water content of the crop did not change but that of the gizzard was at a minimum just after the ovulation and at a maximum 18 h later. 3. The osmotic pressure of the gizzard contents remained constant and close to that of the blood; that of the crop contents was almost isotonic at oviposition but hypertonic 18 h later. In both organs the pH of the liquid phase varied cyclicly with the egg formation and was lowest during egg shell deposition. 4. The Na+, K+ and Cl- contents of the crop liquid phase did not vary but Ca2+ increased with decreasing pH.Na+ and K+ were also constant in the gizzard liquid phase but Cl- and Ca2+ increased during shell formation. 5. It is concluded that the amount of HCl secreted by the proventiculus is related to egg shell deposition and that calcium solubilisation depends on microbial fermentation in crop and HCl secretion by proventriculus.

Animals↗
PubMed1984

Effect of the gut microflora on the size and weight of organs of chicks fed diets of different protein content.

Germ-free (GF) and conventional (CV) chicks were reared for 14 d on diets containing 50 (LD), 200 (AD) and 400 (HD) g protein/kg. Food and water were provided ad libitum. The size and weight of the proventriculus, gizzard, duodenum, jejunum, ileum, caeca, colon, liver, pancreas, heart, spleen, adrenal glands and kidneys were measured, and liver composition was examined. The absolute and relative (weight/kg body-weight) weights of the intestine of CV chicks fed AD and HD diets were greater than those of GF chicks. The LD diet did not affect the absolute and relative weights of the duodenum and jejunum. The absolute weight, relative weight and fat content of the liver of GF chicks given LD diet were greater than those of their CV counterparts. The size and weight of some organs are affected by the diet (dietary protein content)-microflora-host interaction.

Analysis of Variance↗
PubMed1987

Feeding responses to infusions of glucose solutions into the duodenum of cockerels and the influences of pre-fasting or vagotomy.

1. The duodenum of cockerels was chronically catheterised, to study the effects of 3 h infusions of glucose solutions on voluntary food intake. 2. Compared to water, solutions containing 30, 60 and 90 g glucose/l infused at 1 ml/min induced significant, dose-related depressions in intake after the first 30 min of infusion. 3. Fasting the birds for 3 h before the start of infusion resulted in higher intakes during the period of infusion than in unfasted birds. 4. Vagotomy at the level of the proventriculus prevented the inhibitory effects of glucose infusion into the duodenum, except at the highest concentration (120 g/l).

Animals↗
PubMed1994

Quantitative effects of pelleting on performance, gastrointestinal tract and behaviour of meat-type chickens.

1. In an attempt to quantify the effects of "degree" of pelleting, two experiments were conducted. Diets were prepared by mixing together a mash composed mainly of maize (experiment 1) or sorghum (experiment 2) with soft pellets, or soft pellets mixed with hard pellets. 2. The pelleting degrees (PDs) were as follows: 0 mash; 0.5 mixture of soft pellets and mash 1 to 1; 1 soft pellets pelleted once; 1.5 mixture of soft and hard pellets 1 to 1; 2 hard pellets pelleted twice. 3. In experiment 2, the weight and length of the digestive organs were determined as well as digestive enzyme activities. In both experiments, the behaviour recorded was eating, standing, sitting and drinking. 4. Food intake and body weight gain were related to the degree of pelleting in a curvilinear manner. PD had a positive effect up to a peak (1 to 1.5 PD), after which its effect decreased. Food efficiency was not related to PD. In experiment 1, food efficiency of PDs 1 to 2 were superior to PDs 0 to 0.5 and in experiment 2, PDs 1.5 to 2 were superior to PD 0. 5. The relative weight of the gizzard was reduced by pelleting, whereas pelleting increased the relative weight of abdominal fat. The content of the crop was not affected by PD, whereas that of the proventriculus was lowest in the PD 2 group. Gizzard content was inversely related to PD. Pelleting reduced the length of the jejunum and ileum: which were shortened by about 15% with PDs 1 to 2, as compared to PD 0. The weight/length ratio of the jejunum and ileum tended to increase with increasing PD to a peak at PD 1.5, and to decrease thereafter. 6. Trypsin activity in the pancreas and amylase activity in the intestinal content were reduced by pelleting. 7. Chicks fed pelleted diets were less active: they 'sat' more and spent less time eating than their mash-fed counterparts.

Adipose Tissue↗
PubMed1997

Disease outbreak in laying hens arising from the consumption of fumonisin-contaminated food.

1. During the last quarter of 1995 an unusual disease outbreak characterised by black sticky diarrhoea, severe reduction in food intake, egg production and body weight follow by lameness and death was observed in 2 layer farms in Andhra Pradesh. A total of 6700 hens of 64 weeks age and 3000 hens of 36 weeks age were affected. 2. Around 10% mortality and a 20% reduction in egg production was observed. Postmortem examinations showed pale yellow coloured livers with peripheral congestion, mild haemorrhage in the proventriculus and watery accumulations in the intestine. 3. The disease was traced to a new batch of food and its withdrawal improved the health status of the flocks. 4. Analysis of the diet indicated contamination with fumonisin B1 up to 8.5 mg/kg and aflatoxin B1 up to 0.1 mg/kg. 5. Diarrhoea was induced in day old cockerels by feeding the suspect diet containing 8.5 mg/kg fumonisin B1, and in laying hens by feeding a normal diet with fumonisin B1 additions of 8 and 16 mg/kg.

Animal Feed↗
PubMed1988

A study of the effects of Marek's disease in a broiler flock.

In a flock of 17000 broilers, characteristic Marek's disease (MD) paralysis, accompanied by increased mortality occurred during the fourth week of the flock's life. Cytolytic lesions and atrophy in the bursae of Fabricius, and the severity of lymphocytic infiltration of nerves, livers, proventriculus and brain are suggestive of the involvement of MD virus of greater pathogenicity than has been encountered previously in New Zealand.

Journal Article↗
PubMed1997

Megabacteriosis in a flock of budgerigars.

Megabacteriosis was diagnosed as the cause of depression and wasting in a flock of breeding budgerigars in the Manawatu. Large numbers of megabacteria were detected in direct smears from mucosal scrapings of the proventriculus of two birds and in the faeces of live birds. The diagnosis was confirmed by demonstrating a chronic proventriculitis histologically associated with megabacterial organisms. Treatment of seven individuals with amphotericin B resulted in clinically sustained weight gain over a 10-week period. Treatment of the whole flock resulted in the resumption of normal condition, behaviour and activity.

Journal Article↗