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Regenerative therapies aimed at replacing photoreceptors are a promising approach for the treatment of otherwise incurable causes of blindness. However, such therapies still face significant hurdles, including the need to improve subretinal delivery and long-term survival rate of transplanted cells, and promote sufficient integration into the host retina. Here, we successfully delivered in vitro-derived human photoreceptor precursor cells (PRPCs; also known as immature photoreceptors) to the subretinal space of seven normal and three rcd1/PDE6B mutant dogs with advanced inherited retinal degeneration. Notably, while these xenografts were rejected in dogs that were not immunosuppressed, transplants in most dogs receiving systemic immunosuppression survived up to 3-5 months postinjection. Moreover, differentiation of donor PRPCs into photoreceptors with synaptic pedicle-like structures that established contact with second-order neurons was enhanced in rcd1/PDE6B mutant dogs. Together, our findings set the stage for evaluating functional vision restoration following photoreceptor replacement in canine models of inherited retinal degeneration.

The morphology of the farmed African catfish distal intestines and rectum was investigated. The samples were dissected out and the tissue slices were passed through graded ethanol, cleared in xylene, embedded in paraffin wax, sectioned and stained for light microscopy. Grossly, the intestine was subdivided into proximal, middle, distal and rectal regions based on palpable thickness and diameter of the regions. No intestino-rectal valve was observed; hence the rectum was not well defined. The histology revealed the presence of tunica mucosa of simple columnar cells, lamina propria of collagen fibres and muscularis mucosae of smooth muscle fibres; submucosa of loose connective tissues and blood vessels; tunica muscularis of smooth muscles in an inner circular and outer longitudinal arrangement; and a serosa in all regions except the rectum and anus that presented tunica adventitia. The mucosal folds were fingerlike to orange leaf shaped ingrowths into the lumen on a transverse section. They decreased in complexity and height but increased in width towards the rectum. The lining epithelium of the intestinal tract was comprised of the absorptive simple columnar cells containing goblet cells and intraepithelial lymphocytes. Some rectal simple columnar epithelium contained supranuclear vacuoles while others contained non-vacuolated cytoplasm. The goblet cells contained neutral and acid mucins, and increased in number progressively towards the rectum. The anal tunica muscularis contained mostly skeletal muscles.

The parotid salivary gland microscopic morphology of the adult African Palm squirrel (Epixerus ebii) was investigated. This study was carried out to provide the basic histology of this organ in the palm squirrel, as there is dearth of information of its microscopic morphology from available literature. This becomes more important as the increasing use of this species of rodent as a pet and animal of importance in African game reserves for tourist attraction. The possibility of its domestication as a ready source of animal protein is also growing. Hence the need to understand the digestive biology to help animal nutritionist in feed formulation. The histology revealed the presence of only serous secretory acini cells. The serous cells were triangular to polyhedral shaped with a roundish basally located nucleus inside the mostly pinkish granulated cytoplasm. Myoepithelial cells were seen around the secretory cells and the intercalated ducts. The intralobular ducts of intercalated and striated ducts were lined by simple cuboidal and simple columnar cells, respectively. The excretory duct seen in the surrounding connective tissue was lined by stratified cuboidal cells. The granules in the cytoplasm of serous cells must be the digestive enzyme amylase that initiates carbohydrate digestion. This well developed serous parotid salivary gland reflects the need for efficient carbohydrate digestion since the animal forages on fruits and nuts that are rich in carbohydrates. The granules could also contain lysozymes which serve in local defense against pathogenic agents in the oral cavity. This study for the first time documents the normal histology of the parotid salivary gland in this species, hence filling the knowledge gap that will help biologists to investigative more profundly. It will also help wild life veterinarians in diagnosis disease. Se investigó la histología de la glándula parótida salival de la ardilla adulta de la palma Africana (Epixerus ebii). Este estudio se realizó para proporcionar la histología básica de este órgano en esta especie animal, ya que hay escasez de información relacionada con su morfología microscópica proveniente de la literatura disponible. Esto constituye un aspecto importante, por el incremento en el uso de esta especie de roedor como mascota y como animal de importancia en las reservas animales africanas de atracción turística. También está creciendo la posibilidad de su domesticación como una fuente rápida de proteína animal. De allí, la necesidad de entender la biología digestiva para ayudar al nutricionista en la formulación alimenticia. Los resultados de los estudios histológicos solamente revelaron la presencia de células acinares secretoras serosas. La forma de las células serosas varió de triangular a poliédrica, con un núcleo redondeado, localizado basalmente dentro de un citoplasma granulado predominantemente rosáceo. Se observaron células mioepiteliales alrededor de las células secretoras y de los ductos intercalados. Los ductos intralobulares de los ductos intercalados y estriados estaban alineados respectivamente en células cúbicas simples y en células columnares simples. El ducto excretor observado en el tejido conectivo circundante estaba alineado por células cúbicas estratificadas. Los gránulos en el citoplasma de las células serosas pudieran corresponderse con la enzima amilasa que inicia la digestión de carbohidratos. Esta glándula salival parótida bien desarrollada, refleja la necesidad de una eficiente digestión de carbohidratos, ya que el animal se alimenta de frutos y nueces ricos en estos principios inmediatos. Los gránulos también pudieran contener lisozimas que sirven para la defensa contra agentes patógenos presentes en la cavidad oral. Este estudio documenta por primera vez, la histología normal de la glándula parótida de esta especie, llenando por consiguiente, la brecha de conocimiento que ayudará a los biólogos a investigar más profundamente, y a los veterinarios que trabajan en fauna silvestre, en el diagnóstico de enfermedades.