Ocular morphology of the fruit bat, Eidolon helvum, and the optical role of the choroidal papillae in the megachiropteran eye: a novel insight

BACKGROUND

This work was designed to provide a morphologic, morphometric and histochemical description of the eye of the African straw-coloured fruit bat (Eidolon helvum). An explanation of the optical role of the choroidal papillae in the vision of megachiropteran bats was provided.

MATERIALS AND METHODS

Enucleated eyes of captured fruit bats were measured and processed for light microscopy.

RESULTS

Typical gross features of the mammalian eye including an anterior transparent cornea, posterior whitish sclera and a golden-brown iris surrounding a round pupil were observed in the eye. Presence of undulating retina typically found in megachiropterans were also seen. The ratio of mean corneal diameter to mean axial eye diameter was 0.58 ± 0.08. The histochemical investigation of the eye indicated the presence of mucins, proteoglycans, hyaluronic acid, glycogen and/or glycoproteins in the corneal, scleral, choroidal and retinal tissues.

CONCLUSIONS

The presence of reflective materials of the tapetum lucidum on the undulating retina was shown to be a morphological adaptation for increased light sensitivity as each parabolic surface of the choroidal papillae served as a convex mirror, reflecting the light rays to the adjacent parabolic surface, thus sensitizing photoreceptors in affected regions. This phenomenon thus empowers megachiropteran bats with improved scotopic visual capability and could explain why most of them are reliant on their vison without the need for echolocation.

Ultrastructural features on the oral cavity floor (tongue, sublingual caruncle) of the Egyptian water buffalo (Bubalus bubalis): gross, histology and scanning electron microscope

The present work was focused on the morphological characters of the lingual caruncles, and tongue with its papillae of Egyptian water buffalo (Bubalus bubalis) using the gross, light, and scanning electron microscope. The ventral surface of the sublingual caruncle carried a small opening of the duct of both monostoamtic and mandibular salivary gland. The lingual mucosa of dorsal, lateral border, some extent to ventral surface of apex had lingual papillae (filiform, fungiform), while the lingual mucosa of body especially at torus linguae had conical papillae, but circumvallate papillae observed at the caudal part of body and root. The dorsal surface of apex and body carried numerous long thread-like with blunt apex caudally directed filiform papillae that covered with keratinized scales without secondary papillae. The degree of keratinization classified filiform papillae into rostral part of high keratinization and caudal less keratinization. Conical papillary surface carried exfoliated epithelium with longitudinal groove on its rostral surface and had CT core does not reach the level surface of epithelium and carried secondary papillae. Fungiform papillae scattered among filiform papillae on the dorsal and ventral surface of apex and its convex surface had exfoliated keratinized epithelium. Circumvallate papillae surrounded by circular deep groove that bordered by vallum that carried small secondary papillae that ended into the primary groove. Taste buds of circumvallate papillae opened in the lateral lining epithelium facing the groove. Von Ebner's glands were observed in CT under papillae especially toward the groove and their ducts open into the base of the groove.

Structural and Functional adaptation of the lingual papillae of the Egyptian fruit bat (Rousettus aegyptiacus): Specific Adaptive feeding Strategies

The current investigation was directed to clarify the correlations between the feeding strategy and lingual structure of the Egyptian fruit bat captured from the Egyptian east desert. The current work depends on twelve adult Egyptian fruit bats that observed grossly and with the help of the stereo, light, and scanning electron microscope. There were three types of the lingual papillae; one mechanical filiform and two gustatory (fungiform and circumvallate). There were seven subtypes of filiform papillae were recognized on the seven lingual regions. There were scanty numbers of fungiform papillae distributed among the filiform papillae on the lingual tip and two lateral parts of apex and body while fungiform papillae completely absent in the median part. There were three circumvallate papillae. The central bulb of circumvallate papillae surrounded by one layer of two segmented circular annular bad. The lingual tip had cornflower-like and diamond-shaped filiform papillae. Histochemical results revealed that the lingual glands were a stronger AB-positive reaction and gave dark blue color, while the reaction for the PAS-stain was negative. Also, the glands exhibited a blue color as an indication of positive AB reactivity with combined AB-PAS staining.

Morphology of the lips, cheeks, and the hard palate of the Egyptian water buffalo (Bubalus bubalis): a focus on histological, histochemical, and ultrastructural aspects

BACKGROUND

The available data is scanty about Egyptian water buffalo lips, cheeks, and palate.

AIMS

The current investigation was focused on describing the morphology of the lip, cheek, and palate.

METHODS

Our study included the gross, light, and electron microscopic examinations of ten heads of the Egyptian water buffalos.

RESULTS

The nasolabial plate surface carried numerous scales of keratinized epithelium. Internal labial surface and labial mucocutaneous junctions were covered with stratified squamous keratinized epithelium. Two types of hair follicles in the dermis included ordinary and cavernous types characterized by cavernous space. The conical papillae on the internal aspect of the oral commissure were projected from the mucous membrane. Seromucous glands were occasionally observed under the oral mucous membrane of the commissure and gave positive PAS and AB. Conical papillae density on the inner cheek surface had some variations: the rostral part had large papillae, while the dorsal part had numerous papillae than the ventral part, the caudal part had a smaller number of papillae, while the middle part was devoid of papillae. Parotid duct opening in the buccal vestibule was without papillae. Conical papillae had two surfaces; the rostral surface was highly keratinized than the caudal one. The buccal gland was a compound tubuloacinar mixed (mucoserous) gland and mucus acini only reacted to PAS and AB. The oral surface of palatine rugae was covered with highly keratinized epithelium than the aboral surface. Palatine glands showed PAS and AB positive.

CONCLUSION

The result describes the relationship between the available food particles, environmental conditions and the lip, cheek, and palate appearance, and structure.

Protein and lipid species in seminal plasma of fertile Holstein-Friesian bulls

Protein and lipid molecules in seminal plasma (SP) collected from fertile bulls were investigated. Semen was collected from 10 bulls (2 ejaculates each) and examined for standard semen analysis. Raw SP was recovered by centrifugation and total protein (TP) concentration was determined using a refractometer. Raw SP was desalted using a Sephadex G-25 desalting column then both raw and desalted SP was subjected to SDS-PAGE. Neutral lipids and phospholipids of raw and desalted SP were separated by thin-layer chromatography (TLC). The results revealed that, all bulls had normal semen characteristics and TP concentration in SP ranged from 7.0 to 10.4 g/dL except bull No. 6 had a relatively low concentration of 4.9 to 6.8 g/dL. Neither proteins nor lipids species were different between raw and desalted SP. Seventeen proteins were detected ranging from 8.5 to 185.8 kDa, and those of 12, 13.5, 15, 21, 23 and 38 kDa were predominant. Notably, proteins of 10, 17.5, 19, 21, 80 and 185.8 kDa might be new candidates of SP proteins (SPPs). The detected neutral lipid spots corresponded to cholesterol, 1,2-dimyristoyl glycerol, 1,2-dioleoyloglycerol, 1,3-dimyristoyl glycerol and 1,3-dioleoyloglycerol. The detected phospholipids spots corresponded to non-migrating phospholipids, sphingomyelin (SM), phosphatidylcholine (PC), phosphatidylserine (PS), phosphatidylinositol (PI), phosphatidylethanolamine (PE), cerebroside and polyglycerol phosphatide. Cholesterol represents the major molecule of neutral lipids, whereas SM, PC, PI and PE represent the major phospholipids. Noteworthy, there were 2 species of diacylglycerol (DAG) and 3 species of PI in bovine SP. In conclusion, this study gave a general picture of SP protein and lipid species in fertile bull semen, which might serve as fundamental knowledge for either semen analysis or prediction of male fertility.