Immunohistochemical localization of a calcium pump and calbindin-D28k in the oviduct of the laying hen.

The localization of a plasma membrane calcium pump in the oviduct of the laying hen was investigated by immunohistochemical techniques, utilizing a monoclonal antibody (5F10) produced against the human erythrocyte calcium pump. This antibody was shown to react with an epitope of the pump in oviductal tissue, and prominent staining was observed on the microvilli of the tubular gland cells of the hen shell gland (uterus) and the isthmus. The Ca2+ pump was not detectable in the infundibulum or the magnum. Calbindin-D28k, also localized by immunohistochemical means, was observed to be present in the tubular gland cells of the shell gland and the distal isthmus (adjacent to shell gland) but not in either the proximal isthmus (adjacent to the magnum), the magnum or the infundibulum. The localization of the Ca2+ pump in the oviduct corresponds to known sites of mineral deposition during egg shell formation. The distribution of calbindin-D28k differed, co-localizing with the Ca2+ pump in the shell gland and distal isthmus but not in the proximal isthmus. This might reflect a greater rate of active Ca2+ secretion in the distal isthmus and shell gland as compared to the proximal isthmus.     

Immunohistochemical localization of a calcium pump and calbindin-D28k in the oviduct of the laying hen

Summary The localization of a plasma membrane calcium pump in the oviduct of the laying hen was investigated by immunohistochemical techniques, utilizing a monoclonal antibody (5F10) produced against the human erythrocyte calcium pump. This antibody was shown to react with an epitope of the pump in oviductal tissue, and prominent staining was observed on the microvilli of the tubular gland cells of the hen shell gland (uterus) and the isthmus. The Ca²⁺ pump was not detectable in the infundibulum or the magnum. Calbindin-D_28k, also localized by immunohistochemical means, was observed to be present in the tubular gland cells of the shell gland and the distal isthmus (adjacent to shell gland) but not in either the proximal isthmus (adjacent to the magnum), the magnum or the infundibulum. The localization of the Ca²⁺ pump in the oviduct corresponds to known sites of mineral deposition during egg shell formation. The distribution of calbindin-D_28k differed, co-localizing with the Ca²⁺ pump in the shell gland and distal isthmus but not in the proximal isthmus. This might reflect a greater rate of active Ca²⁺ secretion in the distal isthmus and shell gland as compared to the proximal isthmus.     

北京鸭产卵期输卵管管状腺细胞超微结构研究

用电子显徽镜对北京鸭输卵管管状腺细胞进行观察。鸭输卵管由五部分组成:漏斗、蛋白分泌部、峡部、壳腺和阴道。蛋白分泌部的管状腺细胞有四种类型。A型细胞有电子密度深色颗粒;B型细胞充满了无定型低电子密度物质;C型细胞具有非常明显的粗面内质网和高尔基复合体;D型细胞是由致密的颗粒和低电子密度的颗粒所组成,腔内充满分泌颗粒。我们在这篇文章中分析了蛋白分泌周期的四个不同阶段。     

Histochemical demonstration of the presence of serotonin in the hen (Gallus domesticus) reproductive tract

The purpose of the present study was to demonstrate visually and localize the presence of serotonin (5-HT) in the ovary and oviduct of the domestic hen using a histochemical Falck-Hillarp method. Experiments were carried out on White Leghorn laying hens with no egg in the shell gland. The specific yellow fluorescence, indicating the presence of 5-HT, was found both in the ovary and all examined oviductal parts. The strongest fluorescence was present in the ovarian stroma containing small follicles with a diameter under 4 mm. In the wall of the largest preovulatory follicle a very strong fluorescence was located mainly in the theca layer. In the oviductal parts, the intensity of 5-HT fluorescence in the infundibulum and magnum was fairly strong, whereas in the isthmus and shell gland it was weak. Fluorescence seen in the infundibulum, magnum, and isthmus was primarily localized along the luminal borders of the fold surface epithelium. In the shell gland 5-HT fluorescence was found within the uterine folds, especially in the tubular glands. Moreover, the presence of an egg in the definite oviductal segment (infundibulum or isthmus) increased the intensity of yellow fluorescence in this part.     

Cell-specific and temporal aspects of gene expression in the chicken oviduct at different stages of the laying cycle

Egg formation and embryonic development occur as the yolk passes through the magnum, isthmus, and shell gland of the oviduct before oviposition in hens. The present study identified candidate genes associated with secretory function of the chicken oviduct after ovulation and contributing to egg formation and oviposition. Hens (n = 5 per time point) were euthanized to recover the reproductive tract when the egg was in the magnum (3 h after ovulation) and the shell gland (20 h after ovulation). Total RNA was extracted from each segment of the oviducts and subjected to Affymetrix chicken GeneChip analysis. Quantitative PCR and in situ hybridization analyses of selected genes confirmed the validity of the gene expression patterns detected using microarray analysis. In particular, ACP1, CALB1, CYP26A1, PENK, RCAN1 and SPP1 expression increased significantly in the shell gland between 3 h and 20 h postovulation, whereas only RCNA1 expression increased significantly in the magnum between 3 h and 20 h postovulation. Results of the high-throughput analysis revealed cell-specific and temporal changes in gene expression in the oviduct at 3 h and 20 h postovulation in laying hens provide novel insight into changes at the molecular and cellular levels of candidate genes related to formation of the egg and oviposition.     

Morphometric and ultrastructural features of the mare oviduct epithelium during oestrus

Morphometric, scanning electron microscopy (SEM) and transmission electron microscopy (TEM) investigations have displayed regional differences in the mare oviductal epithelium. The entire mucosa of the oviduct was lined with a pseudostratified epithelium, which consisted of two distinct cell types, ciliated and non-ciliated. Ciliated cells were predominant in the three different segments of the oviduct and their percentage increased from fimbriae to ampulla and significantly decreased in the isthmus. SEM revealed in the infundibulum finger-like mucosal folds, some of them interconnected, in the ampulla numerous and elaborated branched folds of the mucosa, whereas the isthmus displayed a narrow lumen, short and non-branched mucosal folds. In the ampulla and isthmus the majority of non-ciliated cells showed apical blebs provided or not of short microvilli. TEM displayed different ultrastructural features of ciliated and non-ciliated cells along the oviduct. Isthmus ciliated cells presented a more electron-dense cytoplasm than in infundibulum and ampulla cells and its cilia were enclosed in an amorphous matrix. The non-ciliated cells of infundibulum did not contain secretory granules but some apical endocytic vesicles and microvilli coated by a well developed glycocalyx. Non-ciliated cells of ampulla and isthmus contained secretory granules. Apical protrusions of ampulla displayed two types of secretory granules as well as occasional electron-lucent vesicles. Isthmus non-ciliated cells showed either electron-lucent or electron-dense cytoplasm and not all contained apical protrusions. The electron-dense non-ciliated cells displayed microvilli coated with a well developed glycocalyx. Three types of granules were observed in the isthmus non-ciliated cells. The regional differences observed along the epithelium lining the mare oviduct suggest that the epithelium of the each segment is involved in the production of a distinctive microenvironment with a unique biochemical milieu related to its functional role.     

Localization of osteopontin in oviduct tissue and eggshell during different stages of the avian egg laying cycle

The avian eggshell is an acellular bioceramic containing organic and inorganic phases that are sequentially assembled during the time the egg moves along the oviduct. As it has been demonstrated in other mineralized tissues, mineralization of the eggshell is regulated by extracellular matrix proteins especially the anionic side chains of proteoglycans. Among them, osteopontin has been found in the avian eggshell and oviduct. However, its precise localization in the eggshell or in different oviduct regions during eggshell formation, nor its function have been established. By using anti-osteopontin antibody (OPN 1), we studied its immunolocalization in the isthmus, red isthmus and shell gland of the oviduct, and in the eggshell during formation. In the eggshell, osteopontin was localized in the core of the non-mineralized shell membrane fibers, in the base of the mammillae and in the outermost part of the palisade. In the oviduct, OPN 1 was localized in the ciliated epithelial but not in the tubular gland cells of the isthmus, in the ciliated epithelial cells of the red isthmus, and in the non-ciliated epithelial cells of the shell gland. The occurrence of osteopontin in each of the oviduct regions, coincided with the concomitant presence of the egg in such region. Considering the reported inhibitory function of osteopontin in other mineralized systems, together with its main occurrence in the non-mineralized parts of the eggshell and at the outermost part of the shell, suggests that this molecule could be part of the mechanism regulating the eggshell calcification.     

Histomorphological changes in the oviduct of the mallard (Aves: Anatidae)

Studies on histomorphometrical changes in different segments (infundibulum, magnum, isthmus, shell gland and vagina) of oviduct of mallard, Anas platyrhynchos during active and quiescent phases of the reproductive cycle have been made. The absolute and per cent length and width of each segment showed a marked change. The magnum showed an increase of 280 per cent. Of all the histological parameters studied the number and height of mucosal folds and mucosal epithelium showed more marked increase in all segments of oviduct. The size of tubular glands and frequency of ciliated and secretory cells were studied in relation to oviductal activity.     

Involvement of osteopontin in egg shell formation in the laying chicken

Expression of the osteopontin (OPN) gene in the oviduct of the laying hen was studied. It was detected only in the egg shell gland (ESG), where massive calcification occurs. No OPN gene expression was detected in any other part of the oviduct, such as the magnum and isthmus. The OPN gene was expressed in a circadian fashion during the daily egg cycle only during the period of egg shell calcification. No OPN gene expression was detected in the ESG of a pre-laying hen before the onset of reproduction, or after forced removal of the egg close to its entrance into the ESG. OPN was found to be synthesized by the epithelial cells of the ESG lining the lumen. Upon synthesis, OPN is immediately secreted out of cells and accumulates in the egg shell. These findings demonstrate for the first time temporal and spatial association of OPN with egg shell calcification. OPN, which was found to be part of the organic matrix of the egg shell, may play an important role in egg shell calcification.     

Presence of histamine and mast cells in chicken oviduct

The purpose of the present study was: (1) to demonstrate immunocytochemically the localization of histamine in the wall of four chicken oviductal parts, i.e. infundibulum, magnum, isthmus, and shell gland, (2) to identify the presence of mast cells in chicken oviduct, and (3) to determine histamine concentration in oviductal tissue by the spectrofluorometric method. Experiments were carried out on Isa Brown laying hens decapitated just after oviposition. The specific immuno-reactivity for histamine and the presence of mast cells were found in the wall of all the examined oviductal parts. The immuno-reactive histamine was localized in epithelium, tubular glands, connective tissue layer, circular and longitudinal muscles, and endothelium and muscles of blood vessels. The intensity of immuno-positive reaction was as follows: infundibulum > shell gland > magnum = isthmus and correlated with quantitatively determined histamine level and tissue density of mast cells. It is suggested that mast cells are the main source of histamine in the chicken oviduct.     

Zinc Secretion in the Oviduct of the Coturnix Quail

The oviduct from laying quail were used to investigate mechanisms of trace mineral secretion and the possible role of metallothionein in this process. Secretion of zinc occurred maximally at pH 5.4, which is close to the normal pH of the oviduct. Secretion occurred to a much greater extent in the isthmus and shell gland than in the magnum, the major protein-secretory section of the oviduct. Intraperitoneal administration of cadmium resulted in a marked reduction in Zn secretion from the oviduct of laying quail. This effect could not be correlated with metallothionein since metallothionein could not be detected in any section of the oviduct in control or Cd-induced quail. Small-molecular-weight metal-binding ligands were present in the isthmus and shell gland, which may play a role in trace mineral mobilization. Histological evaluation by light and elelctron microscopy show that Zn is transported from the smooth muscle cells through the connective tissue matrix in the extracellular space to the epithelial goblet cells. Presumably, Zn and other trace minerals are secreted from the secretory goblet cells into the egg.     

Comparative distribution of glycosaminoglycans and proteoglycans in the reproductive tissues of the female fowl

The objective of this work was to survey and compare the composition of the parts of the reproductive system of the female fowl in glycosaminoglycans and proteoglycans. Those parts analyzed were ovary, infundibulum, magnum, isthmus, shell gland and vagina. Methods of analysis included cellulose acetate electrophoresis, infrared spectroscopy, colorimetry, amino acid determination and scanning electron microscopy. Concentrations of glycosaminoglycans were higher in vagina, ovary, infundibulum and isthmus than in shell gland and magnum. Glycosaminoglycans may be important in those parts of the reproductive tract which contribute membraneous and mucosal material to the descending egg, and where fertilization of the egg occurs.     

[Ciliogenesis in the mucous cells of the quail oviduct. I. Ultrastructural study in the laying quail]

The luminal epithelium of the oviduct (magnum) of laying quails is composed of ciliated cells and mucous cells. Ciliogenesis was observed in some of the mucous cells. Both centrioles of the diplosome migrate to the top of the cell, and one of them induces the formation of a rudimentary cilium. In some of the other cells, that are filled with mucous granules, the formation of basal bodies by an acentriolar pathway was observed. In these cells, numerous, dense fibrous masses are associated with the forming face of the Golgi apparatus. In the Golgi zone, generative complexes composed of a deuterosome and some forming procentrioles were found. Cilia develop from completed basal bodies. During ciliogenesis, the Golgi apparatus is disorganized, and generally the production of mucous granules is arrested. The nucleus is also modified: it becomes larger and the chromatin is dispersed. It is assumed that mucous cells are able to be transformed into ciliated cells in the oviduct of laying quails.     

The fine structure of the secretory cells of the uterus (shell gland) of the chicken

The secretory processes in the shell gland of laying chickens were the subject of this study. Three cell types contribute secretory material to the forming egg: ciliated and non-ciliated columnar cells of the uterine surface epithelium, and cells of tubular glands in the mucosa. The ciliated cells as well as the non-ciliated cells have microvilli, which undergo changes in form and extent during the secretory cycle. At the final stages of shell formation they resemble stereocilia. It is postulated that the microvilli of both cells are active in the production of the cuticle of the shell. The ciliated cell which has both cilia and microvilli manufactures secretory granules which arise from the Golgi complex in varying amounts throughout the egg laying cycle. Granule production reaches its greatest intensity during the early stages of shell deposition. The ciliated cell probably supplies proteinaceous material to the matrix of the forming egg shell. The non-ciliated cell has only microvilli. Secretory granules, containing an acid mucopolysaccharide, arise from the Golgi complex. Some granules are extruded into the uterine lumen where they supply the egg shell with organic matrix. Others migrate towards the supranuclear zone. Here a number of them disintegrate. This is accompanied by the formation of a large membraneless space, which is termed “vacuoloid.” Subsequently the vacuoloid regresses and during regression an extensive rough endoplasmic reticulum with numerous polyribosomes of spiral configuration appears. It is suggested that material in the vacuoloid originating from the disintegrating granules is resynthesized and utilized for the formation of secretory product. The uterine tubular gland cells have irregular, frondlike microvilli. During egg shell deposition, these microvilli form large blebs and are probably related to the elaboration of a watery, calcium-containing fluid.     

Fine structural observations on magnum mucosa in quail and hen oviducts

Summary 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.In actively laying quail, the distribution of electron opaque, intermediate, and light granules within the superficial and deep regions of the glandular epithelium varies, depending on the presence of an egg in a particular region of the oviduct. Secretion of the product is merocrine, involving fusion of granule membranes with the plasmalemma of the cell surface.Granules first appear in the tubular gland cells of quail oviducts at about 4 1/2 weeks of age. The granules are of the electron opaque type and probably represent secretion in concentrated storage form. At this age, a few of the tubular gland cells exhibit distended ergastoplasmic cisternae containing material of low electron density. The appearance of these light cells, which occur with greater frequency in oviducts from older quail, probably reflects an increased level of secretory activity initiated by changes in hormonal levels. From 5 weeks of age on, intermediate and light (less concentrated) granules, as well as dark granules, are present.Supported by the National and Medical Research Councils of Canada.     

Histology and functional morphology of the female reproductive tract of the tortoise Gopherus polyphemus

The oviducts of 25 tortoises (Gopherus polyphemus) were examined by using histology and scanning electron microscopy to determine oviductal functional morphology. Oviductal formation of albumen and eggshell was of particular interest. The oviduct is composed of 5 morphologically distinct regions; infundibulum, uterine tube, isthmus, uterus, and vagina. The epithelium consists of ciliated cells and microvillous secretory cells throughout the oviduct, whereas bleb secretory cells are unique to the infundibulum. The epithelium and endometrial glands of the uterine tube histologically resemble those of the avian magnum which produce egg albumen and may be functionally homologous. The isthmus is a short, nonglandular region of the oviduct and appears to contribute little to either albumen or eggshell formation. The uterus retains the eggs until oviposition and may form both the fibrous and calcareous eggshell. The endometrial glands are histologically similar to the endometrial glands of the isthmus of birds, which are known to secrete the fibers of the eggshell. These glands hypertrophy during vitellogenesis but become depleted during gravidity. The uterine epithelium may supply "plumping water" to the egg albumen as well as transport calcium ions for eggshell formation. The vagina is extremely muscular and serves as a sphincter to retain the eggs until oviposition. Sperm are found within the oviductal lumen and endometrial glands from the posterior tube to the anterior uterus throughout the reproductive cycle. This indicates sperm storage within the female tract, although the viability and reproductive significance of these sperm are unknown.     

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

Summary 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.     

Changes in ovalbumin and protein synthesis in vivo in the magnum of laying hens during the egg formation cycle.

1. The present study was carried out to investigate whether or not the rate of synthesis of total protein in various oviducal segments and ovalbumin, a major egg white protein, in the magnum fluctuated during the egg formation cycle in laying hens. 2. Synthesis of total protein and ovalbumin was measured in vivo by the incorporation of [15N]methionine after a primed continuous infusion of tracer for 3 hr. 3. Protein and ovalbumin contents in the magnum and the entire oviduct decreased sharply when an ovum moved down from the magnum to the isthmus, probably due to the secretion of egg white proteins. 4. In contrast, total protein and ovalbumin synthesis in the magnum was significantly higher when an ovum was in there than when it was in any other segments. Fluctuations of ovalbumin synthesis and total protein synthesis in the magnum were roughly parallel to those of total protein synthesis in the entire oviduct. 5. It was concluded, therefore, that the changes seen in total protein synthesis in the whole oviduct during the egg formation cycle were mainly attributable to those in magnum protein synthesis, of which a significant portion was accounted for by the synthesis of ovalbumin.     

Acid glycosidases in the isthmus of the hen oviduct and egg shell membranes

Specific activities of seven acid glycosidases: beta-hexosaminidase, alpha- and beta-galactosidase, alpha- and beta-mannosidase, alpha-glucosidase and alpha-fucosidase were determined in various parts of the domestic hen oviduct (infundibulum, isthmus, shell gland and vagina). The activity of most enzymes was the highest in the isthmus. Multiple forms of all acid glycosidases from the isthmus were separated by strong anion exchange chromatography at pH 6.0. The isoelectric points of the isthmus forms of beta-hexosaminidase, beta-galactosidase and alpha- and beta-mannosidase were determined by chromatofocusing. For the first time the high beta-galactosidase activity was found in hen egg shell membranes.