Ultrastructural observation of Infundibulum in Pre-laying and laying Japanese quail (Coturnix coturnix japonica)

Abstract

This study elucidates the histomorphological characteristics of the oviduct in Japanese quail (Coturnix coturnix japonica) across different reproductive phases, specifically pre-laying and laying periods, in an effort to address the knowledge gap regarding the avian reproductive tract. Utilizing transmission electron microscopy (TEM), fresh tissue samples were collected from the oviductal segments of quails and processed for detailed ultrastructural examination. Findings revealed that the infundibulum’s pseudostratified columnar epithelium primarily consists of ciliated, non-ciliated, and goblet cells, with ciliated cells being the most predominant. The study documented the morphology of ciliated cells, noting their oval to spherical euchromatic nuclei, which exhibited features consistent with active transcription. In contrast, non-ciliated cells displayed numerous cytoplasmic granules that increased in size and density during the 6th and 7th weeks of age, suggesting enhanced secretory activity. Glandular cuboidal cells in the ichnological layer revealed variable-sized cytoplasmic secretory granules, particularly enhanced in laying birds, aligning with previous findings in similar avian studies. These observations support the active role of both ciliated and non-ciliated epithelial cells in the physiological processes of the avian oviduct, particularly regarding secretion and egg formation, thereby contributing to a better understanding of quail reproductive biology.