Biologia celular e do desenvolvimento
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Histogenesis of the Camel Retina (Camelus dromedarius)

Abdel-Hamid Kamal Osman, Hussein Eidaroos and Elsayed Metwally

The histological and histochemical studies were carried out on 60 camel embryos and foetuses eye balls of different Crown Vertebral Rump Length (CVRL). Paraffin sections were prepared and subjected to different stains. The present study revealed that, the optic pit was detected at 0.8 cm CVRL, as shallow groove on either side of the neural folds. The optic vesicle was observed at 1.5 cm CVRL, comprising from neuroectodermal cells, which became modified into a crescentic cup-like structure representing the optic cup at 2 cm CVRL. The optic cup was comprised from outer pigmented epithelium and the inner neuroblastic layer. The ganglion cells were distinctly differentiated at 6 cm CVRL, which separated from neuroblastic cells by the inner plexiform layer. The inner nuclear layer was firstly observed at 30 cm CVRL, which exhibited its full differentiation at 35 cm CVRL and became separated from the outer nuclear layer by the outer plexiform layer. First appearance of the photoreceptor cells was observed at 55 cm CVRL, which differentiated into outer and inner segments at 74 cm CVRL. All the layers of the retina were completely differentiated at 98 cm CVRL, comprising ten retinal layers.