Ears Bone Development And Its Integration With The Inner Ear,

This research explored the role of pharyngeal pouch endoderm (PPE) to development (induction and patterning ) of chick ossicle and integration of the ossicle and inner ear by quail-chick chimera. First, we observed the normal morphology of chick ossicle, columella, during development in the whole mount, and established a criterion for normal columella. Then, investigated the induction and patterning of R4 PPE to columella, R4R5 to the integration of columella and inner ear by isotopic transplantation, and R4 to cartilages originating from R3 to Midbrain (MB) by ectopic transplantation. And proved PPE can induce development of columella and integration of columella and inner ear, and located the sites of the PPE, which elucidate partly mechanism of normal development and defect formation of the middle and inner ear.The 1st part: Normal morphology of chick columella during development. Objective master normal morphology and establish a criterion of chick columella during its development, and find a method which can show the configuration of deep located columella in the whole mount. Method Collected E5- E19 chick embryos' heads, fixed specimen with 4%PFA, stained cartilages with Alcian Blue, cleared tissue with methyl salicylate, and observed columella and other cartilages around, such as quadrate, articular, squamosum, Meckel' s cartilage, inner...