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. HIGHLIGHTS: Studying the quail duodenum can be used as a model for understanding the mammalian duodenum. Understanding the duodenal structure and its function is the best way to maximize the efficiency of the production of the livestock through giving the best type of diet. Duodenum plays a vital role in digestion through the digestible secretions, absorption of nutrients, and immunity against invaders. Duodenum is the spot where the food digestion mostly occurs.

Morphological and ultrasonographic characterization of the three zones of supratesticular region of testicular artery in Assaf rams.

To fully understand the histological, morphometrical and heamodynamic variations of different supratesticular artery regions, 20 mature and healthy Assaf rams were examined through ultrasound and morphological studies. The testicular artery images of the spermatic cord as shown by B-mode analysis indicated a tortuous pattern along its course toward the testis, although it tends to be less tortuous close to the inguinal ring. Doppler velocimetric values showed a progressive decline in flow velocity, in addition to pulsatility and vessel resistivity when entering the testis, where there were significant differences in the Doppler indices and velocities among the different regions. The peak systolic velocity, pulsatility index and resistive index were higher in the proximal supratesticular artery region, followed by middle and distal ones, while the end diastolic velocity was higher in the distal supratesticular region. The total arterial blood flow and total arterial blood flow rate reported a progressive and significant increase along the testicular cord until entering the testis. Histological examination revealed presence of vasa vasorum in the tunica adventitia, with their diameter is higher in the proximal supratesticular zone than middle and distal ones. Morphometrically, the thickness of the supratesticular artery wall showed a significant decline downward toward the testis; meanwhile, the outer arterial diameter and inner luminal diameter displayed a significant increase distally. The expression of alpha smooth muscle actin and vimentin was higher in the tunica media of the proximal supratesticular artery zone than in middle and distal ones.

Performance scanning electron microscopic investigations and elemental analysis of hair of the different animal species for forensic identification.

Veterinary forensics have attracted less attention compared with human forensics. Animal hair morphological examination using scanning electron microscopy (SEM) and hair mineral analysis using energy-dispersive X-ray fluorescence (ED-XRF) provide reference databases for animal hair identification used in forensic investigations. This study was performed on four different animal species: large ruminants (buffalo and cattle), small ruminants (goat and sheep), carnivores (cat and dog), and equines (donkey and horse). The hair scale pattern, scale margin type, and distance between scales were identified. The hair scale pattern was imbricate in large ruminants, goat, and horse; coronal (crown-like) in carnivores and donkey; and spinous in sheep. The morphometric measurements, including cuticle layer thickness, cuticle scale height, cortex diameter, and hair shaft width were recorded. The highest cuticle thickness was found in horse, and the highest cuticle hair scale was detected in cattle. Moreover, the largest cortex diameter was measured in buffalo, whereas the smallest one was in cat. With regard the content of hair elements, some elements were specific for the hair of certain tested animals, such as bromine in sheep and magnesium and phosphorus in buffalo. In addition, vanadium and titanium were found only in cattle and dog, and the latter element was also detected in sheep. In conclusion, this study provides two techniques for animal hair identification that can be used in forensic investigations. RESEARCH HIGHLIGHTS: Hair scale pattern was imbricate in (large ruminants, goat, and horse); coronal in (carnivores and donkey); and spinous in (sheep) with different scale margins type. Hair shaft width in all tested animal species ranged from 23.78 ± 1.24 µm to 85.51 ± 1.14 µm.

Morphological and ultrastructural features of the laryngeal mound of Egyptian Cattle Egret (Bubulcus ibis, Linnaeus, 1758).

BACKGROUND: According to our acknowledgment this is the first full anatomical description of the studied laryngeal mound of the Egyptian Cattle Egret (Bubulcus ibis, Linnaeus, 1758). This study was obtained with the aid of scanning electron microscopy (SEM) and histological techniques. Heads of ten healthy adult male Egyptian cattle egrets were used in this study. RESULTS: The laryngeal mound (Mons laryngealis) was a pear-shaped musculoskeletal elevation. It represented 20.55 and 67.87% of the total length of the oropharyngeal floor and the pharyngeal floor, respectively. By SEM view, the lateral aspect of the caudal third of the laryngeal mound had a serrated mucosal appearance, forming of 6-7 finger-like projections. Furthermore, the terminal part of the laryngeal mound (except the middle part) was bordered a transverse row of pyramidal-shaped papillae, which demarcated from the esophagus. Histologically, laryngeal salivary glands termed (cricoarytenoid salivary glands) of the laryngeal mound were simple tubular type and were arranged in one row within the lamina propria connective tissue close to the lamina epithelialis. Those glands were surrounded by abundant aggregation of lymphocytes, extended overlying the surface lining epithelium. The glottis within the laryngeal mound was supported by hyaline cartilages; dorsally by paired arytenoid cartilages, ventrolaterally by cricoid cartilage, and caudodorsally by procricoid cartilage. Two groups of intrinsic laryngeal skeletal muscles have connected the cartilages. The glandular epithelium of the laryngeal salivary glands and chondrocytes of the laryngeal cartilages showed strongly positive alcian blue reaction. CONCLUSIONS: The laryngeal mound shows certain features that are unique as an adaptation to lifestyles and bird's habitat.

Scanning electron microscopy of the nasal skin in different animal species as a method for forensic identification.

The current study aims to provide a new method for the identification of animal species by using the scanning electron microscopic study on the nasal skin around the nostril. The reference databases for animal identification using traditional ways (i.e., hair and bone analyses) were somewhat available. This study was conducted on the nasal skin of seven different animal species: large ruminants (Saidi buffalo and frozen Angus cattle); small ruminants (Egyptian goat and Rahmani sheep); camels (one-hump dromedary camel); equines (African domestic donkey and Arabian horse); carnivores (farm domestic cat, Egyptian Baladi dog, and red fox); swine (Danish Landrace pig); and rodents (albino rat and New Zealand white rabbit). The nasal skin was divided by grooves into different shaped raised areas in some examined animals, the mean diameter of these areas and width of the grooves of each animal species were recorded. The characteristic differential features of the nasal skin of each animal species have been documented. Few openings of the nasolabial glands were demonstrated in large ruminants and swine, which were H letter-shaped in buffaloes, oval-shaped in cattle, and whirlpool-shaped with several layers of folds on their margin in pig. Moreover, the openings of the lateral nasal glands were whirlpool, ovoid, and oval shaped in goats, sheep, and camels, respectively. In conclusion, the present study proved that the skin around the nostrils plays an important role as means of identification in forensic investigations and improves the field of veterinary forensic medicine in general, which is not well-developed in comparison with human forensics.

Morphometrical, histological, and scanning electron microscopic investigations on the hard palate of Rahmani sheep (Ovis aries).

The present study investigated the hard palate of Rahmani sheep (Ovis aries). Samples from nine healthy adult male sheep were investigated using morphometrical, histological and scanning electron microscopic examination. Morphologically, the hard palate was elongated, narrow rostrally, and wide caudally. The incisive papilla was heart-shaped, flanked on both sides by a groove on which the nasopalatine duct opened. The palatine raphe was in the form of a groove that contained a ridge caudally. On both sides of the raphe, 13-15 pairs of palatine ridges were present and mainly occupying the narrow part. The wide part had a rough part that contains few ridges rostrally and a smooth part caudally. Histologically, the incisive papilla and palatine ridges were lined by a keratinized stratified squamous epithelium resting on a dense layer of lamina propria. The incisive papilla characterized by the presence of seromucoid salivary glands and hyaline cartilage fragments in the lamina propria. The salivary glands became abundant and well-developed in the wide part till the end of hard palate. All palatine salivary glands were Alcian blue-periodic acid-Schiff positive. By scanning electron microscopy, numerous gland openings were scattered on the surface of the palatine ridges. In conclusion, the hard palate of Rahmani sheep presented characteristic features, which may be related to the species differences, feeding behavior, and possible functional adaptations. This is the first study to report the presence of cartilaginous segments and salivary glands in the incisive papilla and provide detailed descriptions of the Rahmani sheep hard palate.

Histogenesis of the stomach of the pre-hatching quail: a light microscopic study.

The current study conducted a careful description of the histological events during the embryonic development of quail stomach. Daily histological specimens from the quail stomach from day 4 to day 17 post incubation were examined by light microscopy. The primitive gut tube of the embryonic quail appeared at day 4 post incubation. The gut tube consisted of an endodermal epithelium of pseudostratified type, surrounded by splanchnic mesenchyme. The prospective glandular epithelium invaginated at day 5 in the proventriculus and gradually developed to prospective proventricular glands. The muscular coat became distinguished at day 7 and day 8 in the proventriculus and gizzard, respectively. Transformation into simple columnar epithelium occurred in both proventriculus and the gizzard at day 12. The gizzard epithelium gave rise to tubular invaginations also at day 12. Canalization of the gizzard tubular glands was recognized at day 14. By day 15, the proventricular surface epithelium invaginated in a concentric manner around a central cavity to form immature secretory units that contained inactive oxyntico-peptic cells. The mucosal folding in the gizzard appeared at day 15 to form plicae and sulci. The wall of the proventriculus and gizzard at day 17 acquired histological features of post-hatching birds.

Wnt11 is required for oriented migration of dermogenic progenitor cells from the dorsomedial lip of the avian dermomyotome.

The embryonic origin of the dermis in vertebrates can be traced back to the dermomyotome of the somites, the lateral plate mesoderm and the neural crest. The dermal precursors directly overlying the neural tube display a unique dense arrangement and are the first to induce skin appendage formation in vertebrate embryos. These dermal precursor cells have been shown to derive from the dorsomedial lip of the dermomyotome (DML). Based on its expression pattern in the DML, Wnt11 is a candidate regulator of dorsal dermis formation. Using EGFP-based cell labelling and time-lapse imaging, we show that the Wnt11 expressing DML is the source of the dense dorsal dermis. Loss-of-function studies in chicken embryos show that Wnt11 is indeed essential for the formation of dense dermis competent to support cutaneous appendage formation. Our findings show that dermogenic progenitors cannot leave the DML to form dense dorsal dermis following Wnt11 silencing. No alterations were noticeable in the patterning or in the epithelial state of the dermomyotome including the DML. Furthermore, we show that Wnt11 expression is regulated in a manner similar to the previously described early dermal marker cDermo-1. The analysis of Wnt11 mutant mice exhibits an underdeveloped dorsal dermis and strongly supports our gene silencing data in chicken embryos. We conclude that Wnt11 is required for dense dermis and subsequent cutaneous appendage formation, by influencing the cell fate decision of the cells in the DML.