Ultrastructural changes in the sublingual salivary gland of prenatal buffalo (Bubalus bubalis)

The present study was aimed to elucidate ultrastructural changes in the development of sublingual salivary gland of buffalo during prenatal life.

The study was carried out on sublingual salivary gland of 36 buffalo fetuses ranging from 13.2 cm curved crown-rump length (CVRL) (88(th) day) to full term. The fetuses were categorized into three groups based on their CVRL.

The cells lining the terminal tubules were undifferentiated with poorly developed cytoplasmic organelles but lacked secretory granules (SGs) at 13.2 cm CVRL (88(th) day). The SGs appeared first in the form of membrane-bound secretory vesicles with homogeneous electron-dense as well as electron-lucent contents at 21.2 cm CVRL (122(nd) day); however, mucous acinar cells contained electron-lucent granules, while serous secretory cells as well as serous demilunes showed electron-dense granules at 34 cm CVRL (150(th) day) of prenatal life. At 53.5 cm CVRL (194(th) day), both mucous and serous acini were differentiated by the density of SGs.

The cytoplasm of acinar cells was filled with mitochondria, rough endoplasmic reticulum, and Golgi profiles in mid and late fetal age groups. The SGs were increased in number during the late fetal age group. The myoepithelial cells (MECs) were located at the base of the acinar cells as well as intercalated and striated ducts and were stellate in shape. The ultrastructure of MEC revealed a parallel stream of myofilaments in the cytoplasm and its processes. The mucous cells were predominantly present in the sublingual salivary gland and were pyramidal in shape.