Developmental Morphological Analyses on the Preglottal Salivary Gland in Japanese Quails (Coturnix Japonica)

Abstract To understand the development of the mucous preglottal salivary gland in Coturnix japonica (Japanese quail), morphological and histochemical studies were performed on 20 healthy Japanese quail embryos (aging from 10 th to 17 th incubation days) and 25 healthy quail chicks (aging from 0 th to 60 th days). The primordia of preglottal salivary gland was observed as an epithelial bud at the early embryonic stage, which then elongated and differentiated into secretory units by the end of this stage. In Japanese quails, the preglottal salivary gland was a mucous polystomatic tubulo-alveolar unpaired gland composed of two lateral portions and a middle one embedded into submucosa of the lingual root. The gland openings accompanied taste pore (8.17 μm) of taste buds associated salivary glands type; some skeletal muscle fibers embedded among secretory lobules extended from muscle cricohyoideus at 14 th day old quail chick. Also, both herbts corpuscles and secretory motor plexus could be detected among secretory lobules. Based on our investigations, the development of preglottal salivary gland could clearly be distinguished in the embryonic stage into prebud and bud stages at 10 th day old, cord and branching stages ended by cavitation at 11 th day old, canalization stage at 13 th day old, lobulation and secretory stages by the 17 th day old. This mucous secretion showed different histochemical reactions ended with highly alcinophilic mucous indicated highly sialomucin (acidic) content. Myoepithelial cells could be demonstrated at 17-day old quail embryo and there after, surrounded the secretory endpieces of the preglottal salivary gland.