Ultrastructure of the gastro intestinal tract of healthy Japanese quail (Coturnix japonica) using light and scanning electron microscopy

Effect of Replacing Inorganic Copper, Zinc, and Selenium with Chelated Minerals on Productive Performance, Nutrient Utilization, Tibia Morphology, and Intestinal Histology of Growing Japanese Quail (Coturnix japonica)

This study evaluated the impact of replacing inorganic mineral sources of Cu, Zn, and Se with chelated organic minerals (OM) on performance, nutrient and mineral utilization rates, and intestinal morphometry in growing Japanese quails (Coturnix japonica). A total of 150 nine-day-old quails were randomly assigned to receive one of the following diets over 4 weeks: CTRL (100% inorganic minerals), OM33 (replacement of 33% inorganic minerals), OM67 (replacement of 67% inorganic minerals), and OM100 (100% organic minerals). Quails fed the OM67 diet exhibited higher (P < 0.05) viability, daily weight gain, and live weight than the other groups, with no significant difference in feed intake or feed efficiency across treatments. The utilization rates of Cu and Fe were lower in the OM33 group. The CTRL group presented the lowest tibial weight (P < 0.05). Growing quails fed the OM67 diet contained the highest intestinal villi in the duodenum, jejunum, and ileum. In conclusion, the partial replacement (up to 67%) of inorganic mineral with OM in the diet of growing quails can enhance their productive performance and intestinal histological traits.

Developmental morpho-analysis of the caecum in Japanese quail embryos (Coturnix coturnix japonica)

In the current study, we are focusing on the microanatomical structure of quail caecum during the prehatching time to try to understand the function and the role of each cell-built quail caecum reaching how caecum plays an essential role in immunity and absorption. The morpho-developmental features of the quail caecum were described in detail daily from the third incubation day (ID) till hatching time, investigating the gross morphology, microscopic, and ultrastructure using light and scanning electron microscope. The embryonic caecum appeared grossly as two lateral outpocketings with blinded ends, emerging laterally at the junction between the small and large intestine (the ileocaecal junction). The primordia of two caeca, represented by two lateral swellings from the hindgut on the fourth ID, continued growing till the day of hatching, where the caecal wall consisted of three apparent layers: mucosa, musculosa, and serosa. At the time of hatching, the quail caecum was still not fully mature and will continue growing posthatching. The findings in this study can be applied in further studies intended to understand the physiological mechanisms of the caecum during prehatching and posthatching periods. RESEARCH HIGHLIGHTS: Caecum is one of the hindgut derivatives that started as two lateral swellings. The caecal wall consisted of three layers; mucosa, musculosa, and serosa. The caecum plays an essential role in immunity maintenance. Caecum continues to grow posthatching as it is not fully mature at hatching time.

Anatomical, histological, and scanning electron microscopic features of the esophagus and crop in young and adult domestic pigeons (Columba livia Domestica)

BACKGROUND

Pigeons (Columba livia) are mainly raised as a source of animal protein, racing, leisure and as an experimental animal. The present study investigated the morphology of the esophagus in the young and adult domestic pigeon, Columba livia domestica.

METHODS

Ten young and ten adult, normal, and healthy pigeons were collected from the local breeders. Samples from different parts of esophagus and crop were examined grossly, by stereomicroscopy, scanning and light microscopy.

RESULTS

The esophagus consisted of a long cervical part, a crop, and a short thoracic part. The crop was represented by a thin-walled outpouching with two lateral diverticula. The mucosa presented wavy fine folds in the cervical esophagus, irregular folds in the lateral diverticula giving it a corrugated appearance, and prominent longitudinal folds with several gland openings in the middle and lower parts of the crop, as well as in the thoracic esophagus. The density of gland openings was higher in adult pigeons than that in young pigeons. The mucosa of the esophagus was lined by non-keratinized stratified squamous epithelium. The shape, height, and branching of the mucosal folds differed between young and adult pigeons. Mucous-secreting alveoli were detected in the middle part of the crop as well as in the thoracic esophagus, but not in the cervical esophagus or lateral diverticula of the crop.

CONCLUSION

The variations between the young and adult pigeons suggest a functional adaptation of adult pigeons to their diet compared to young pigeons.

Atractylenolide I Alleviates Indomethacin-Induced Gastric Ulcers in Rats by Inhibiting NLRP3 Inflammasome Activation

Atractylodes macrocephala Koidz, a traditional Chinese medicine, contains atractylenolide I (ATR-I), which has potential anticancer, anti-inflammatory, and immune-modulating properties. This study evaluated the therapeutic potential of ATR-I for indomethacin (IND)-induced gastric mucosal lesions and its underlying mechanisms. Noticeable improvements were observed in the histological morphology and ultrastructures of the rat gastric mucosa after ATR-I treatment. There was improved blood flow, a significant decrease in the expression of tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), IL-1β, and IL-18, and a marked increase in prostaglandin E2 (PGE2) expression in ATR-I-treated rats. Furthermore, there was a significant decrease in the mRNA and protein expression levels of NOD-like receptor thermal protein domain associated protein 3 (NLRP3), apoptosis-associated speck-like protein (ASC), cysteinyl aspartate specific proteinase-1 (caspase-1), and nuclear factor-κB (NF-κB) in rats treated with ATR-I. The results show that ATR-I inhibits the NLRP3 inflammasome signaling pathway and effectively alleviates local inflammation, thereby improving the therapeutic outcomes against IND-induced gastric ulcers in rats.

Network and structural analysis of quail mucins with expression pattern of mucin 1 and mucin 4 in the intestines of the Iraqi common quail (Coturnix coturnix)

Background and Aim

In avian and other species, mucins (MUCs) play a crucial role in the gastrointestinal tract (GIT), and constitute a large group of O-glycosylated glycoproteins, are glycoconjugate proteins. MUCs present in two forms: (1) membrane-attached on cell surfaces to repel external threats and (2) detachable, gel-forming proteins in the soluble form. In quail GIT, the specific types of MUCs that are expressed remain largely unknown. We investigated the expression of MUC1 and MUC4 MUCs in the GIT of Iraqi common quails and conducted network and structural analyses of all known MUC types across quail breeds.

Materials and Methods

Histological and gene expression analyses of MUC1 and MUC4 were conducted using fresh small intestine and large intestine samples from 10 quails. Using the STRING Database, Chimera software, and PrankWeb-ligand binding site prediction tool, network and structural analyses of all reported types of quail MUCs were conducted.

Results

Most intestinal MUCs in quails were acidic, with few neutral MUCs detectable through Alcian blue and periodic acid-schiff stains. Acidic MUCs were more expressed in the duodenum, ileum, cecum, and colon, whereas neutral MUCs were more expressed in the jejunum. MUC1 and MUC4 messenger RNA expression was significantly higher in the jejunum and colon than in the duodenum and ileum. The analysis of the network revealed that MUC 1, 15, 16, and 24 formed homologous networks, while MUC 2, 4, 5, and 6 formed heterologous networks. Specific MUC combinations, including MUC5A-MUC6, MUC5A-MUC5B, and MUC5B-MUC6, show higher intermolecular hydrogen bond formation affinity. MUC15, MUC16, and MUC24 showed minimal interaction with other MUC types. Among the analyzed MUCs, MUC5B, and MUC6 had the highest probability for binding, while MUC2, MUC4, and MUC5A showed lower probabilities despite greater numbers of binding sites.

Conclusion

This study's results offer significant insights into quails' MUCs' composition, expression, network interactions, and binding sites, advancing knowledge of MUC-related processes in gastrointestinal physiology and their potential connection to gastrointestinal diseases.

The developmental architecture of the crop of quail embryos (Coturnix coturnix): Morphometric, light and scanning electron microscopy

The present study focused on the histogenesis of the crop in quail embryos. The developmental sequence was recorded from day 10 of incubation to the hatching day (17th day) by gross anatomy, morphometric analysis and by using light and scanning electron microscope (SEM). Grossly, the crop was distinguished as an enlarged pouch of the cervical oesophagus on the 12th day of incubation. Histologically, the development of the crop began on the 10th day of incubation. The muscularis mucosae was observed as a small, thin layer of myoblast cells on the 10th day, then it appeared as longitudinally arranged smooth muscle fibres with progression of the developmental age till hatching day. The submucosal layer was also observed on the 10th day, while the lamina propria, muscular layer (inner circular and outer longitudinal layers of smooth muscle fibre) and glandular primordia were detected on the 12th day. The epithelial cells of crop revealed affinity for PAS stain and AB-PAS on the 10th day of incubation till the 17th day, while the affinity for AB stain appeared on the 14th day of incubation. Additionally, the glandular cells showed the positive for AB, PAS and AB-PAS on the 12th day of incubation. SEM sections showed variable sizes of the openings of the oesophageal glands. In conclusion, the present study provided a detailed overview of the histogenesis of the crop in quail embryos.

Dietary macroalgae Chaetomorpha linum supplementation improves morphology of small intestine and pectoral muscle, growth performance, and meat quality of broilers

Background and Aim

Over the last decades, the poultry industry has experienced steady growth. Although the industry is gradually expanding in Indonesia, poultry feed production has always been expensive. There is a need to study alternative ingredients to obtain affordable feed from natural resources. Chaetomorpha linum (CL) is an abundant macroalgae available throughout the year in Indonesia. This study aimed to determine the effect of CL on the histological structure of the small intestine, pectoralis muscle, growth performance, and meat quality of broilers.

Materials and Methods

This study used 300-day-old chick (DOC) male broilers that were reared until they were 21 days old. This study used a completely randomized design with four treatment groups and five replications, and each replication group contained 15 DOC individuals. The treatment groups consisted of Control (CON), CON basal feed (BF), CL1 (0.75%/kg BF), CL2 (1.5%/kg BF), and CL3 (3%/kg BF) groups. The histological structure of the small intestine, pectoralis muscle, growth performance, and meat quality of the broiler was examined.

Results

Small intestine and pectoral muscle histomorphology, growth performance, and meat quality were significantly improved in the CL2 (1.5%) and CL3 (3%) groups compared with the CL1 (0.75%) and CON groups.

Conclusion

Dietary CL supplementation ameliorates small intestine and pectoral muscle histomorphology, growth performance, and meat quality of broilers.

Pre-gastric secretory epithelium: A light, scanning and transmission electron microscopic study of an epithelial modification of the esophagus in embryonic quails

The current study investigated epithelial modification of embryonic quail esophagus using gross examination, light microscopy, transmission and scanning electron microscopy. By semithin sections, the pre-gastric modified region had unfolded mucosa, formed epithelial flabs and pockets, and had reduced muscularis mucosae, thin muscular layer, less glandular tissue, and outer esophageal groove. Conversely, the normal esophageal mucosa was folded, had abundant glandular tissue and prominent muscularis mucosae, with two muscular layers; the outer and the inner. The modified epithelium resembled stratified squamous type that had a high affinity for PAS, methylene blue, and PAP stains. Ultra-structural features of the modified esophageal epithelium resembled stratified squamous epithelium and contained hypertrophic Keratinocytes; dark and light. Hypertrophic keratinocytes had RER organized, few ribosomes, and developed loose bundle of cytokeratin compared with squamous keratinocytes. Hypertrophic Keratinocytes synthesize two types of granules; peripherally located small electron-dense granules and large electron-lucent granules. Hypertrophic keratinocytes had peroxisomes that were identified by the crystalline core of the urate oxidase. In conclusion, epithelia modification may have secretory function. Further studies should be carried out to explain the exact function of this type of modified epithelium.

Tracking the developmental events in the duodenum of the quail embryo: Using light and electron microscope

The present study described the full morphology of the duodenum of the Japanese quail during the embryonic stage from 3rd day of incubation till hatching using the light and electron (scanning and transmission) microscope. The specimens were collected, analyzed and described anatomically, morphometrically and microscopically. The first recognition of the prospective duodenum was at the 4th day of incubation and developed continuously by age progression. The prospective duodenum consisted of a flat pseudostratified epithelium, mesenchyme and covering mesothelium. On day 8th of incubation, the epithelium developed three evaginations lead to formation three previllous ridges protruding inside the duodenal lumen, which later at the 9th day differentiated into numbers of projections; villi. On the 9th day, the epithelium lined the villi transformed into a simple columnar type, the duodenal villi appeared as pyramidal-shaped projections, had wide base and narrow apex and by age progression, the duodenal villi went through changes in number, size and shape. On hatching day, the duodenal epithelium consisted of enterocytes interspersed with secretory goblet cells, which stained positive for both Periodic Acid Schiff (PAS) and Alcian blue AB and represented filled with metachromatic granules. The muscular wall started as mesenchymal condensation on the 6th day then differentiated into the circular smooth muscle layer on the 9th day of incubation. Giving detailed information about the morphological development of the duodenum during the incubation period of quail embryo helps in reaching a satisfactory explanation about how the duodenum plays a vital role in digestion, absorption and immunity.

Mucosa-Like Conformal Hydrogel Coating for Aqueous Lubrication

Mucosa is a protective and lubricating barrier in biological tissue, which has a great clinical inspiration because of its slippery, soft, and hydrophilic surface. However, mimicking mucosal traits on complex surface remains an enormous challenge. Herein, a novel approach to create mucosa-like conformal hydrogel coating is developed. A thin conformal hydrogel layer mimicking the epithelial layer is obtained by first absorbing micelles, followed by forming covalent interlinks with the polymer substrate via interface-initiated hydrogel polymerization. The resulting coating exhibits uniform thickness (≈15 µm), mucosa-matched compliance (Young's modulus = 1.1 ± 0.1 kPa) and lubrication (coefficients of friction = 0.018 ± 0.003), robust interfacial bonding against peeling (peeling strength = 1218.0 ± 187.9 J m^-2 ), as well as high water absorption capacity. It effectively resists adhesion of proteins and bacteria without compromising biocompatibility. As demonstrated by an in vivo cynomolgus monkey model and clinical trial, applications of the mucosa-like conformal hydrogel coating on the endotracheal tube significantly reduce intubation-related complications, such as invasive stimuli, mucosal lesions, laryngeal edema, inflammation, and postoperative pain. This work offers a promising prototype for surface decoration of biomedical devices and holds great prospects for clinical translation to enable interventional operations with minimally invasive impacts.

Macro- and microstructures of the digestive tract in the Eurasian collared dove, Streptopelia decaocto (Frivaldszky 1838): Adaptive interplay between structure and dietary niche

We describe the functional morphology of the digestive tract of the Eurasian collared dove, Streptopelia decaocto using anatomical, morphometric, histological, histochemical, and ultrastructure techniques, and relate our findings to the species' dietary niche. Our results revealed that the esophagus is displaced on both sides of the neck and has highly folded tunica mucosa, which confer greater elasticity for efficient swallowing and passage of food to the crop. The proventriculus is delicate and its mucosal layer contains polymorphic glands with dense profound and superficial secretory units that open to the luminal surface by gastric pores. The ventriculus is biconvex and lined with a keratinized koilin membrane. The tubular glands within the mucosal lining include the isthmus, the neck, and the basal segment that comprise chief and basal cells with prominent nuclei. At the cuticle-mucosal interface, pyramidal vertical rodlets of the cuticle are secreted and superficially covered by a thin film of a horizontal matrix. The mucosa of the ileum form pyramidal villi that are oriented perpendicularly to the central lumen. Enterocytes infiltrated with goblet cells make up the epithelial lining of the villi. There are subtle differences in the thicknesses of corresponding tunics together with histochemical reactions of alcian blue (AB) and Masson-Goldner trichrome (MT) for their microstructures. Overall, our findings reveal remarkable convergence of both macro-and microstructures in S. decaocto to other granivorous species, and offer further evidence of the close association between functional morphology and feeding style relative to food swallowing, digestion, and absorption.

Cellular elements in the developing caecum of Japanese quail (Coturnix coturnix japonica): morphological, morphometrical, immunohistochemical and electron-microscopic studies

The present study aims to investigate the histological, histochemical and electron microscopic changes of the caecal proximal part of Japanese quail during both pre- and post-hatching periods starting from the 2nd embryonic day (ED) until four weeks post-hatching. On the 2nd and 3rd ED, the primordia of caeca appeared as bilateral swelling on the wall of the hindgut. On the 7th ED, the lamina propria/submucosa contained the primordia of glands. On the 8th ED, rodlet cells could be observed amongst the epithelial cells. On the 9th ED, the caeca began to divide into three parts with more developed layers. With age, the height and number of villi increased. On the 13th ED, immature microfold cells (M-cells) could be identified between the surface epithelium of the villi. The caecal tonsils (CTs) appeared in the form of aggregations of lymphocytes, macrophages, dendritic cells and different types of leukocytes. Telocytes and crypts of Lieberkuhn were observed at this age. On hatching day, the crypts of Lieberkuhn were well-defined and formed of low columnar epithelium, goblet cells, and enteroendocrine cells. Post-hatching, the lumen was filled with villi that exhibited two forms: (1) tongue-shaped villi with tonsils and (2) finger-shaped ones without tonsils. The villi lining epithelium contained simple columnar cells with microvilli that were dispersed with many goblet cells, in addition to the presence of a high number of intra-epithelial lymphocytes and basophils. Moreover, the submucosa was infiltrated by numerous immune cells. CD3 immunomarker was expressed in intraepithelial lymphocytes, while CD20 immunomarker showed focal positivity in CTs. In conclusion, the caecal immune structures of quails at post-hatching were more developed than those in pre-hatching life. The high frequency of immune cells suggests that this proximal part may be a site for immunological surveillance in the quail caecum. The cellular organisation of the caecum and its relation to the immunity was discussed.

Microscopic features of lamina muscularis mucosae of the goose gut

The aim of work was to determine the features of the microscopic structure of the lamina muscularis mucosae of the goose gut during the postnatal ontogenesis. According to the review of the literature, during the characterisation of the structure of the intestinal mucosa, researchers first pay attention to the condition of the villi, crypts, epithelial layer and their morphometric parameters, leaving the lamina muscularis mucosae aside. The intestinal lamina muscularis mucosae is an under-researched structure of the intestinal wall, the information on which is fragmentary and contradictory. The middle parts of the duodenum, jejunum, ileum, cecum and rectum of large grey geese of 13 age groups were investigated. The classic histological methods of staining by hematoxylin and eosin, aniline blue – orange (by Mallory), as well as azure II – eosin were used. It was established that the lamina muscularis mucosae of the goose’s small intestine is formed by two layers of unstriated muscle tissue: internal and external. In contradistinction to mammals, the thicker inner layer of the LMM has not a circular, but a longitudinal direction of cell location while by contrast the thinner outer layer is located in a circular direction. According to results of our research, the thickness of the lamina muscularis mucosae of the small intestine of the geese rapidly increased with age. The thickness of the duodenum corresponded to the value of adult geese at 60 days of age; jejunum, ileum, and rectum – at 21 days, cecum – at 7 days age. The lamina muscularis mucosae was thinnest in the duodenum, and it was thickest in the ileum. The lamina muscularis mucosa of the large intestine of geese is represented by only one longitudinal layer. By contrast, the thinner outer layer is located in a circular direction. Detailed information of the microscopic structure of the lamina muscularis mucosae of the intestine of geese can be useful for specialists, both morphologists and physiologists, for analyzing the histological preparations of the intestine of birds by the action of biotic and abiotic factors, as well as a basis of comparison with such structure in other species of animals. The description of the construction of this important microscopic structure of the intestine can serve a morphological basis for elucidating its function.