| Abstract |
Insects taste nonvolatile chemicals through gustatory receptors (Grs) and make choices for feeding, mating, and oviposition. To date, genome projects have identified 69 Gr genes in the silkworm, Bombyx mori; however, the expression sites of these Grs remain to be explored. In this study, we used reverse transcription (RT)-PCR to investigate expression of the B. mori Gr-6 (BmGr6) gene, a member of the putative sugar clade gene family in various tissues. BmGr6 is expressed in the midgut, central nervous system (CNS), and oral sensory organs. Moreover, immunohistochemistry using an anti-BmGr6 antiserum demonstrated that BmGr6 is expressed in cells by oral sensory organs, midgut and nervous system. Furthermore, double-immunohistochemistry indicated that BmGr6 is expressed in midgut enteroendocrine cells, also in CNS neurosecretory cells. In particular, a portion of BmGr6-expressing cells, in both midgut and CNS, secretes FMRFamide-related peptides (FaRPs). These results suggest that BmGr6 functions not only as a taste receptor, but also as a chemical sensor such as for the regulation of gut movement, physiological conditions, and feeding behavior of larvae.
|
