Magnum Mucosa Research Articles

Supplementation of serine in low-gossypol cottonseed meal-based diet improved egg white gelling and rheological properties by regulating ovomucin synthesis and magnum physiological function in laying hens1

This study examined the effect of dietary serine (Ser) on egg white quality, ovomucin content of laying hens fed low-gossypol cottonseed meal (LCSM)-based diet and sought to explore the regulatory mechanism underlying the effects. A total of 288 Hy-Line Brown layers were randomly assigned into 3 treatments and respectively offered soybean meal (SBM)-based diet, LCSM-based diet, and LCSM-based diet supplemented with 0.435% L-Ser. Dietary Ser supplementation reversed the decrease in quality indices of albumen, including the proportion of thick albumen (P<0.05), thick-to-thin ratio (P<0.05), albumen height (P<0.05), Haugh unit (P<0.05), and apparent viscosity that were caused by LCSM intake. Also, dietary Ser supplementation mitigated the LCSM-induced reduction in ovomucin content of the albumen (P<0.05). FT-IR analysis of ovomucin revealed differences in second derivative spectra at 1200-800 cm-1 between birds received SBM- and LCSM-based diets, meanwhile, the α-helix of ovomucin was decreased by LCSM but increased by Ser addition (P<0.05). Furthermore, Ser addition up-regulated the mRNA expression of β-ovomucin in magnum mucosa at 2 h and 7.5 h post-oviposition (P<0.05). Ser mitigated the LCSM-induced impairment of magnum epithelium, increased goblet cell counts (P<0.05), and up-regulated the expression of occludin, mucin 2, and the relevant glycosyltransferases for O-glycosylation in magnum mucosa (P<0.05). Conclusively, the alleviating effect of Ser on declining albumen quality due to dietary LCSM, could be explained by the efficacy of Ser in regulating ovomucin synthesis. This regulation occurred at the levels of transcription and post-transcriptional O-glycosylation modification of β-ovomucin, while positive effect on magnum morphology and barrier function could also in part account for the ovomucin content. This would provide a promising research direction on the adoption of nutritional interventions for manipulation of egg white quality from perspectives of albumen protein synthesis.

Immunohistochemical localization of progesterone receptor isoforms and estrogen receptor alpha in the chicken oviduct magnum during development

In this work, the immunohistochemical expression of progesterone receptor (PR) isoforms and estrogen receptor alpha (ER-α), as well as the histomorphometric changes of the magnum region of the left oviduct from 8-day-old chicken embryos to one-month-old chickens were evaluated. Results indicate evident histological changes in the oviduct magnum during development mainly in the magnum's mucosa. Immunohistochemical analysis showed that the oviduct magnum from 8-day-old chicken embryos to one-day-old chickens did not present any PR isoform, but the oviduct magnum of one-week and one-month-old chickens expressed PR in the nuclei of all cell types. In epithelial cells, PR-B was the only isoform expressed; in muscle and serosa cells, PR-A isoform was the only isoform expressed; and stromal cells expressed both isoforms. The results also demonstrate positive ER-α immunostaining in the nuclei of different cells from embryonic life to later developmental stages of the oviduct magnum. Data indicate that the variations of ER-α or PR expression or dominance of either PR expression is differentially regulated depending on the cell type, the development of the oviduct, and in an age-specific manner. These variations in sex steroids hormone receptors are related with histological changes of the oviduct magnum through development.

Histomorphometrical and ultrastructural study of the effects of carbendazim on the magnum of the Japanese quail (&lt;i&gt;Coturnix coturnix japonica&lt;/i&gt;)

The study investigated the effect of various doses of carbendazim on the morphology of the magnum of the Japanese quail. No morphological changes were observed in the magnum in birds treated with carbendazim at doses of 25 mg/kg and 100 mg/kg bodyweight. A carbendazim dose of 400 mg/kg bodyweight was the lowest dose which caused morphological changes in the magnum. Histologically, carbendazim caused pyknosis and glandular atrophy in the magnum mucosa. Carbendazim also caused significant decreases in the height of the mucosal folds, epithelial height, glandular width and glandular luminal diameter at 400 mg/kg and 800 mg/kg (p < 0.05). At ultrastructural level, dose-dependent deciliation was observed. Pyknotic nuclei, dilated cisternae of rough endoplasmic reticulum, swollen mitochondria, numerous vacuoles and lysosomes in the luminal and glandular epithelia were identified. The observed degenerative changes could be due to cytoskeletal disruption caused by carbendazim toxicity. Degeneration of the luminal and glandular cells in the magnum pose a potential threat to the egg production and reproduction of exposed birds.

The Presence of Arcobacter Species in Breeding Hens and Eggs from These Hens

The presence of Arcobacter spp. in 2 breeding hen flocks was determined by examination of the intestinal tract, oviduct magnum mucosa, and ovarian follicles of slaughtered chicken. The bacteria were detected by PCR and cultural isolation in 34 out of 40 intestinal tracts from one flock (A) and 6 out of 30 from the other (B). The strains were Arcobacter butzleri, Arcobacter cryaerophilus, and Arcobacter skirrowii. From flock A, arcobacters were recovered from 6 out of 40 oviduct magnum mucosa samples. The majority of isolated strains were A. butzleri. Arcobacter spp. could not be detected, by either PCR or isolation, from 20 eggs collected on the farm of flock A and from 20 eggs still remaining in the vagina of hens in flock B. Furthermore, none of the ovarian follicles from each flock were positive. The results indicate that breeding hens can be infected with Arcobacter spp. in the intestinal tract and oviduct. No evidence was obtained for transmission of Arcobacter spp. from hens to eggs.

Changes in the presence of progesterone receptor isoforms in the oviduct magnum of newly-hatched chicks after gonadotropins treatment

The effects of Follicle-stimulating hormone (FSH) and Luteinizing hormone (LH) on progesterone receptor (PR) isoforms presence in different cell populations from the oviduct magnum of newly-hatched chicks treated in vivo on days 13, 15 and 17 of embryonic development, were analyzed by immunohistochemistry. We found that FSH promoted cytodifferentiation of the magnum's mucosa and increased PR immunoreactivity in all cell types of the oviduct magnum, whereas LH-treatment did not exert cytodifferentiation of magnum's mucosa, and PR immunoreactivity was only induced in some epithelial and stromal cells of the oviduct magnum. In all treatments the number of PR immunopositive cells incubated with the antibody PgR Ab-8 that recognizes both PR isoforms were significantly higher than the number of immunopositive cells incubated with antibody PgR Ab-6 that only recognizes PR-B. This suggests that PR-A should be the predominant isoform in the oviduct magnum of newly-hatched chicks treated with gonadotropins during embryonic development. We conclude that gonadotropins differentially regulate PR-A isoform presence in the oviduct magnum of newly-hatched chicks.

Human Alkaline Phosphatase Expression and Secretion into Chicken Eggs after in Vivo Gene Electroporation in the Oviduct of Laying Hens

In vivo gene electroporation was used to examine whether or not a recombinant protein is synthesized in the chicken oviduct and subsequently secreted into eggs. A plasmid DNA containing a secretion form of the human alkaline phosphatase gene was injected into mucosa of the chicken magnum. Immediately, in vivo gene electroporation was conducted. The human alkaline phosphatase activity in the oviduct mucosa increased and reached its peak at 2 days posttransfection, followed by a sharp decrease to a negligible level at 4 days posttransfection. In the egg white, the alkaline phosphatase activity showed a similar change to that in the magnum mucosa except for a delay of 4 days. The present results imply that in vivo gene electroporation method in the oviduct may serve as a rapid production system of recombinant proteins into chicken eggs.

Histomorphometric and progesterone receptor immunohistochemical analysis in the oviduct of newly hatched chicks treated with follicle-stimulating hormone during embryonic development.

In this study we evaluated the histomorphology and ultrastructure of the oviduct of newly hatched chicks, as well as the immunohistochemical expression of progesterone receptor (PR) in this tissue after follicle-stimulating hormone (FSH) treatment on days 13, 15 and 17 of embryonic development. Results indicated a marked difference in the histology of the oviduct of newly hatched chicks treated with FSH. Magnum mucosa from these animals presented a pseudostratified epithelium with evaginations from the lumen into the epithelium and from the latter into the stroma beneath where tubular glands are formed. In contrast magnum mucosa from control animals presented columnar epithelium with no evaginations. In magnum epithelium FSH also induced the formation of cilia and microvilli projections into the lumen as well as an increase in the wall and lumen areas and in the density of nuclei per unitarea. PR immunoreactivity was only observed in the oviduct of FSH treated animals. PR was located in the nucleus of epithelial luminal cells, mucosal stromal cells and smooth muscle cells. These findings suggest that FSH induces an adequate hormonal milieu for the cytodifferentiation and PR gene expression in the chick oviduct.

Avidin and ovalbumin induction by progesterone in chicken oviduct detected by sensitive immunoenzymometric assays

This study describes sensitive immunoenzymometric assays (IEMAs) for chicken avidin and ovalbumin, markers of cytodifferentiation and action of progesterone and oestrogen in the oviduct magnum mucosa. The determination range was 0.5-100 ng/ml and the detection limit 0.1 ng/ml in both IEMAs. The intra- and interassay coefficients of variation, measured from chicken tissue supernatants, averaged below 6 and 10% respectively. IEMAs correlated well with the radioimmunoassays for avidin and ovalbumin previously developed in our laboratory, and with the widely used [14C]biotin-binding method for avidin. Using an IEMA, we found avidin induction with low concentrations of progesterone in the differentiated oviduct of oestrogen-pretreated chicks. The induction has not been detected previously by less sensitive methods. Avidin was induced by all given doses of progesterone (0.2-200 mg/kg in vivo for 24 h after a short oestrogen treatment), the response being dose-dependent at doses of 0.2-20 mg progesterone/kg body weight, the maximum avidin production being about 70 micrograms/g tissue. Ovalbumin was induced at doses of 2-200 mg progesterone/kg body weight without variations in the responses, being about 35 mg/g. The mean content of avidin in the oviduct of laying hens was 58.1 micrograms/g, and of ovalbumin 74.9 mg/g. Minimal traces of avidin and ovalbumin were found in the oviduct after hatching (0.3 and 5 micrograms/g respectively); however, progesterone did not have an effect on this expression. Sensitivity, rapidity and practicability, together with non-radioactivity, are the main advantages of the present IEMAs for chicken avidin and ovalbumin.

Immunoelectron microscopical demonstration of endogenous avidin in secretory granules of the hen oviduct mucosa: a preliminary study.

The localization of avidin in the oviduct of the laying hen was investigated using ultrastructural immunoperoxidase techniques. Endogenous avidin was localized in secretory granules of both tubular gland cells and non-ciliated single epithelial cells in the magnum mucosa. These immunospecific granules were electron-dense and heterogeneous with a patchy core and dense peripheral region, especially in acinar cells. The size varied from small to large in the gland cells (500-2200 nm in diameter) and remained small in the epithelial cells (180-720 nm). Columnar epithelial cells containing avidin granules strongly resembled the protodifferentiated tubular gland cells appearing in the magnum mucosa of chicks artificially pretreated with ovarian hormones. On the other hand, no avidin was observed in either epithelial goblet cells or ciliated cells in adult hens, although both cell types were shown to produce avidin in young chicks when synchronized by the administration of progesterone. The present results parallel those obtained with biotinylated enzyme affinity methods in our previous cytochemical study. Therefore, avidin is one of the proteins produced and stored in the secretory granules of the tubular gland cells and protodifferentiated acinar cells present in the epithelial layer of the laying hen oviduct. It is not present in goblet cells. Although the initiation of a synthesis may be triggered by progesterone, it is still not clear whether different hormone dependent proteins are localized in the same granules in both the adult hen and the immature chick.

Immunoelectron microscopic localization of a progesterone-inducible protein (avidin) in the chick oviduct mucosa.

Avidin, a specific progesterone inducible protein, was localized in the oviduct magnum mucosa of chicks treated with diethylstilbestrol (DES) or DES plus progesterone, using ultrastructural immunoperoxidase techniques. Diffusion technique and the double or triple layer peroxidase staining method were applied. The results obtained by immunoelectron microscopic peroxidase techniques with high resolution power indicated that progesterone stimulation in the DES-treated chicks resulted in avidin production in the goblet cells of the oviduct epithelium. The sensitive-antiperoxidase staining method revealed a slight avidin production in many goblet cells of chicks treated with only DES. This method also showed some avidin-positive ciliated epithelial cells in chicks treated with progesterone. This results suggest that some ciliated epithelial cells may have functional or metabolic properties characteristic of secretory goblet cells.

The effect of hypophysectomy on the quail's oviduct response to low and high doses of estradiol benzoate.

The response of the quail's (Coturnix coturnix Japonica) oviduct to different doses of estradiol benzoate (EB) was explored in ovariectomized and ovariectomized-hypophysectomized animals. Doses of EB ranged from 10 microgram to 1 mg/animal daily for 6 consecutive days; animals were sacrificed 24 h after the last injection. Controls were injected with olive oil. Parameters thought to reflect stimulation of the oviduct were 1) wet and dry weight, 2) DNA, 3) RNA, 4) soluble proteins, 5) ovalbumin, and 6) morphological changes at the level of magnum's mucosa. A statistical significant difference in several of the parameters listed was found between the effect of different doses of EB and whether the injection was done in ovariectomized or in ovariectomized-hypophysectomized animals. The dose response with EB for cell proliferation and induced proteins accumulation (ovalbumin) show that it takes considerably more EB to maximally stimulate ovalbumin accumulation when compared with cell proliferation. Hypophysectomy decreases the oviduct responses to high EB doses. Ultrastructural studies of the magnum mucosa confirm these biochemical results. The evidence presented suggesting an EB dose-dependent difference induction of specific cellular responses in the presence and absence of the pituitary in quails are the basis to postulate the contributing role of the pituitary in the parameters measured.

Influence of the EGG formation cycle on α-aminoisobutyric acid (AIB) transport by magnum mucosa and liver slices in Japanese quails ( coturnix coturnix japonica)

1. The uptake of α-aminoisobutyric acid (AIB) by magnum mucosa and liver slices as affected by the egg formation cycle was studied in Japanese quails. 2. Much higher distribution ratios of AIB between the intracellular fluid and the incubation medium were obtained for magnum mucosa slices as compared to liver slices. 3. The presence of an egg in the magnum was associated with an increased uptake of AIB into the cells of the magnum mucosa. 4. Compared to quails with an egg in the oviduct (magnum or uterus) in quails without an egg in the oviduct lower AIB distribution ratios between the intracellular fluid and the incubation medium were obtained for liver slices. 5. The results indicate that in the Japanese quail amino acid uptake by both the magnum mucosa and liver cells is influenced by egg formation.

Fine structural observations on magnum mucosa in quail and hen oviducts.

Previous investigators have reported that albuminous material in the albumin-secreting (tubular gland) cells of the magnum of hen oviduct accumulates in the ergastoplasmic cisternae and is released directly into the glandular lumen without being first concentrated into secretory granules in the Golgi region (Zeigel and Dalton, 1962). Present fine structural studies on the tubular gland cells in oviducts from actively laying wild-type Japanese quail and in an oviduct from an actively laying hen indicate that the Golgi apparatus is directly involved in the formation of secretory granules. At least three types of granules can be observed in the tubular gland cells at various times, and all types seem to be associated initially with the Golgi apparatus.