Meeting Abstract

P2.106  Monday, Jan. 5  The Presence of Numerous Cilia and Goblet Cells in the Mouths of Snakes – a Derived Condition within Squamates FILORAMO, N.I.*; SCHWENK, K.; KLEY, N.; Clark University; University of Connecticut nfiloramo@clarku.edu

The presence of cilia and goblet cells in the esophagus of squamates (snakes + "lizards") is well established. These esophageal mucocytes presumably facilitate the process of swallowing and protect the esophagus from damage during swallowing. However, the presence and distribution of these cells in the oral cavity is poorly understood. We conducted a phylogenetically broad comparative study of oral morphology in squamate reptiles, and found that snakes have numerous goblet cells in their oral cavities. Furthermore, much of the oral epithelium in snakes is ciliated with the exception of the midline structures involved in stage I chemical delivery to the vomeronasal organs (VNOs). These midline structures include the sublingual plicae on the floor of the mouth, the lingual depressions in the palate, and the vomeronasal fenestrae. The lack of ciliated epithelium on these midline structures negates any involvement of cilia in chemical delivery to the VNOs. The possession of abundant cilia and goblet cells in the anterior regions of the oral cavities of snakes appears to be a unique condition within squamates. In lizards these types of cells, which are numerous in the esophagus, have a limited distribution in anterior portions of the digestive tract where they appear to be limited to the pharynx/posterior portion of the oral cavity. The presence of numerous mucocytes in the oral cavities of snakes may be a pleiotropic effect of the anteriorization of structures typically associated with the pharynx such as the opening of the trachea, whose anterior position is thought to allow for breathing during the ingestion and swallowing of whole prey items. The secretions from these goblet cells may also aid in the intraoral transport of large prey items.