Prof. Salwa ibrahim Abd El hady :: Publications:

The present study deals with the development of the vertebral column, ribs, pectoral and pelvic girdles of the commmon quail Coturnix coturnix japonica. The used specimen were examined dueing their developmental stages between 2 and 16 days old before hatching as well as 21 and 90 days after hatching. To study the skeletal system, the whole specimens were stained with Alcian blue and Alcian blue – Alzarin S. The distribution of the mucoid substances in the quail vertebrae were histochemically investigated in embryos on 6th , 10th , and 14th days of incubation. Polysaccharides were stained purple with PAS, while sulphated acidic mucins were stained blue with Alcian blue ( Ph 0.2 ). In 4 – days embryo, no evidence for the presence of vertebrae. In 5 – days embryo, the precartilaginous cells were accumulated under and upon the notochordal sheath forming the neural arch and the vertebral body. The neural arches were fused together forming the neural spine in the 6 – days embryo. The ossification began to appear on the 14th day of incubation in the neural arches of the cervical vertebrae. Both the sacral and caudal regions did not ossify until hatching. The cervical, caudal and thoracic vertebrae showed low content of sulphated acidic mucopolysaccharides in the neural arches, while the centrum displayed deep localization of this acidic polysaccharides. On the 10th day, the sulphated acidicmucopolysaccharides were mostly concentrated in the neural arches, neural spine and the centrum of both the cervical and thoracic vertebrae. The neural polysaccharides were greatly diminished in the outer boundries. The caudal vertebrae showed high contents of sulphated acidic mucopolysaccharides without any sign of the neural ones. On the 14th day embryo, the neutral polysaccharides were mostly observed in the intercellular matrix of the vertebrae especially at the neural spine. While mixed neutral and acidic mucopolysaccharides were detected in the neural arches. No indication was found for the presence of only acidic sulphated mucopolysaccharides. In this study, low polysaccharides content was observed in 6 – days embryo; these increased later on in 10t – days embryos with nearly similar pattern in all vertebrae. On the 14th day a high content of polysaccharide was observed at merges of the vertebrae and at the centrum where ossification occurred. Moreover, the content of neutral polysaccharides had the tendency to increase prior to the increase of acidic sulphated ones ( chondroitin sulphate ). In the examined embryos, the ribs appeared as short cartilaginous rods on the 5th day of incubation. The vertebral ribs were turned red by the end of 12th day. The first appearance of the pectoral rudiments occurred in 5 – days embryo as two small cartilaginous rods. They were represented as coracoid and scapula. No ossification was observed in the sternal rudiments in quail embryo on the 9th day. The sternal body was provided with two lateral cartilaginous processes. The sign of ossification was represented in the lateral ends of the processes in the 12 – days embryos and extended to the sternal body in 15 – 16 day embryos. The first sign of ossification occurred in the coracoid on the 8th day and in the middle part of the scapula in the 9 – days embryo, while the first appearance of the two bony clavicles was indicated on the 9th day of incubation. In the examined embryos, the cartilaginous ilia were observed on each side of the vertebral column in the 6 – days embryo. Both the ischium and pubis were indicated posterior to the end of the ilium on the 7th day of incubation, while the ossification was indicated in the ilium on the 9th day and in the pubis and the ischium on the 13th day.