Polypterus Olfactory Organ RNA-seq Analysis

The olfactory organ of terrestrial tetrapods is divided into MOE, which is mainly receptive to odorants, and VNO, which is mainly receptive to pheromones. On the other hand, the olfactory organ of aquatic eukaryotic fishes lacks VNO, and only OE is receptive to both odorants and pheromones. The olfactory organ of the ancient fish Polypterus, which is phylogenetically intermediate between terrestrial and aquatic animals, is known to consist of two structures, MOO and AOO, but the presence or absence of VNO has not been confirmed. In this study, we hypothesized that MOO and AOO function as MOE and VNO, respectively, and tested this hypothesis by examining the difference in gene expression levels between the two structures.