New findings on Developmental Studies of the oropharyngeal Salivary Glands in Japanese Quails (Coutrinx coutrinx japonica)

Abstract The oropharyngeal floor of the lower beak in Japanese quails (Coutrinx coutrinx japonica) contains the sublingual and mandibular salivary glands. Although few literatures spoke about the oropharyngeal glands, our study demonstrated the best for full morphological and cytochemical illustration. The morphological and cytochemical analysis were done on 20 healthy Japanese quail embryos with ages of the 6th, 10th, 11th, and 13th days of incubation, and 25 healthy quail chicks at ages zero (hatching day old), 7th, 14th, 30th, and 60th days old. The primordia of the sublingual and mandibular salivary glands were noticed at the 6th and 10th days of the prehatching old respectively as an epithelial bud. After hatching, both primordia were elongated and differentiated into secretory units. These glands are mucous polystomatic tubulo-alveolar paired glands which were situated in the submucosa. The sublingual glands consisted of 3-5 lobes extended from two ceratobranchial caudally by their wide ends beyond the median sulcus of the prefrenular part of sublingual space rostrally; where they opened by their constricted part. The taste buds are variable in size and position; the associated salivary glands type was the largest, which all taste pores varied from 8.2-12 um. The mandibular glands lay on the paralingual groove which arose at 10 days old embryo. Furthermore, the mandibular glands were located dorsomedial to the sublingual glands and extended longitudinally from the rostral border of the frenulum linguae to the caudal tips of sublingual glands. Notably, the taste buds decreased in the volume and number with advancing age. Both gland secretions showed various histochemical reactions that ended with highly alcinophilic (acidic) materials in advanced ages.