Cyclic variation of the oviduct structure of Boulengerula taitana, an oviparous species of Gymnophiona: morphological changes, proliferation and apoptosis

• Published in: African journal of herpetology Vol. 66; no. 2; pp. 93 - 105
• Main Authors: Brun, C., Raquet, M.A., Measey, G.J., Exbrayat, J.M.
• Format: Journal Article
• Language: English
• Published: Taylor & Francis 03.07.2017
• Subjects: Apoptosis; Cell proliferation; Gymnophiona; Herpelidae; Histology; Immunohistochemistry; Oviduct
• ISSN: 2156-4574; 2153-3660
• DOI: 10.1080/21564574.2017.1365098

Functioning of the amphibian oviduct is the subject of many studies, but detailed understanding of caecilian reproduction exists for very few species. In this study, a description is made of morphological changes of the oviduct of the caecilian Boulengerula taitana throughout the year, using conventional histology and immunohistochemistry. The reproductive cycle of this little-known species, originating from the Taita Hills in southeast Kenya, is annual. During the reproductive period (November-February), both lamina propria and the epithelium of the oviduct exhibit a maximum degree of development. The epithelial mucosa is more secretory and the cilia cells are abundant. Histological analysis shows the distribution of the different type of cells according to a specific pattern in the pars recta, pars convoluta and pars utera. Evaluation of proliferative (Ki-67 positive cells) and apoptotic cells (TUNEL and Apostain assays) into the different tissues brings out cyclic modifications of the lamina propria and epithelial cells throughout a seasonal cycle. The results demonstrate that the balance between cell proliferation and apoptosis reflects the functionality of the oviduct during the sexual cycle.