Morphological Studies Of The Skin And Skin Sense Receptor Of Japalura Splendida Barbour And Dunn

The evolutionary relation of avian feathers and reptilian scales has been having long-playing attention. There have some different views. The one view is that avian feathers evolved from the reptile scales. The other view is that feathers are novel structures, while others emphasize that feathers and scales are homologous only at the placode stage, essentially all feather structures formed after the placode stage are evolutionary novelties that have no homologes within reptilian scales. The surface structure and microstructure of skin and skin sense receptors of Japalura splendida Barbour and Dunn were investigated using the scanning electron microscopy, iced section and immunofluresence. In this experiment, skin sense receptors are cap-like protubulances residing in the scale pits, the surface of which takes on disk structure and is covered with long, thick hairs. All the skin scales of Japalura splendida Barbour and Dunn have the skin sense receptors and usually one scale has only one receptor. However, we observed that some scales of head possessed 8 receptors, which indicated the important part of head in sensing outside stimuli. The skin structure of the skin sense receptor is markedly different from that of the normal skin. Theβ-layer of skin sense receptors clearly becomes thin, theα-layer is thicker thanβ-layer, and the germinal layer consists of some tall columnar cells. There is a specific dermal body under the skin sense receptor epiderm. In contrast, the oberhautchen together withβ-layer form the netted pits of scale surface,β-layer becomes thick, and theα-layer is thinner thanβ-layer. Such structure is in accordance with its function of protecting the skin from mechanical injury and hot radiation. The skin sense receptors is high proliferatived functionzlity structure, which has the important part in studying the evolutionary relation of feathers and scales.