| Abstract: | In turtles, the epithelia lining the upper and lower chambers of the nasal cavity project axons to the
ventral and dorsal parts of the olfactory bulbs, respectively. In a semi-aquatic soft-shelled turtle,
Pelodiscus sinensis, more than 1,000 odorant receptor genes have been found, but it is not
known where they are expressed. In this study, we aimed to clarify the distribution of cells expressing these
genes in the olfactory organs of soft-shelled turtles. Immunoreactions for the Gαolf, the α subunit of G
protein coupled to the odorant receptors, were detected on the surface of epithelia lining both the upper and
lower chambers of the nasal cavity. The receptor cells in the epithelium of both chambers possessed cilia on
the tip of their dendrites, whereas microvillous, non-ciliated, receptor cells were not found. These data
suggest that the odorant receptor genes are expressed by the ciliated receptor cells in the upper and lower
chamber epithelia. Precise location of the vomeronasal epithelium is not known at present. |
