The concept of chemical sensing by organisms describes the detection of different types of compounds belonging to the external environment. In this process, multiple mechanisms based on the binomial compound-receptor interaction are involved in complex interconnections: from the opening of ligand-gated ion channels to triggering molecular interactions on the plasma membrane and the cytoplasm.
Among invertebrates, it is still common to distinguish taste from olfaction; however, in reality, it is more appropriate to break this distinction considering various lines of evidence for adaptation of the receptors involved in these "two senses" from more-primitive chemical sensors. Olfaction, indeed, is normally associated with distance from the source of the semiochemical, while taste is normally associated with contact with the source of the semiochemical. However, this is an anthropomorphic bias that may overshadow the nature of the receptors involved for taste and olfaction. Apart from this distinction, several findings in invertebrates suggest alternative roles for chemosensory receptors that do not fit with the concepts of “taste” and “olfaction”. Indeed, many reports have demonstrated expression of several chemosensory receptors among organs renowned for different functions than taste and olfaction, such as heat, gas, and moisture detection as well as sensing of mechanical stimulations, or organs involved in more complex biological functions, such as digestion and assimilation of nutrients, mating or oviposition.
We invite researchers in “viewing invertebrates, big and small, as complex chemosensory entities”, to investigate in sensu latu the various possible functional mechanisms involving subunits of chemoreceptors, independently from their classification as odorant or taste receptors.
We claim to challenge the binomial distinction of “taste” and “olfaction” by proposing a broader "vision" of the chemosensory modalities of the invertebrates. In particular, we want to take advantage of this target to improve knowledge of the molecular mechanisms behind the existence of primitive chemical sensors, such as the primitive ORs of insects (including Orco), the IR25a subfamily of IRs, or GR-like proteins.
In the same "vision", we seek to explore cytological and physiological mechanisms associated with the expression of chemoreceptors independent of their interaction with the external environment. For instance, recent evidence has demonstrated expression of insect ORs in the brain, gut, and reproductive organs. Unveiling the functionality of the receptors in these contexts may add knowledge to their possible involvement in endogenous sensing of chemicals.
We welcome studies on molecular aspects at the base of invertebrate chemosensory receptors at different levels, including evolutionary, functional, electrophysiological, and any aspect of receptor/ligand interactions. We give particular emphasis to investigations on primitive chemosensory receptor subunits, which may augment an understanding of the current evolutionary status of invertebrate chemosensory mechanisms. We encourage studies also on chemosensory receptors that have gotten little attention as chemosensory receptors per se, such as TRP channel and pickpocket receptors. For insects, aware about recent evidence of broad overlapping expression of ORs, IRs and GRs in sensory neurons, we would give particular interest also to functional evidence of chimeric receptors or neurophysiological cross-talk. We also accept studies exploring the role of odorant/tastant binding proteins or any accessory soluble or transmembrane protein actor involved in chemical sensing when these studies advance knowledge for the chemosensory receptor subunits associated with the accessory proteins.
The concept of chemical sensing by organisms describes the detection of different types of compounds belonging to the external environment. In this process, multiple mechanisms based on the binomial compound-receptor interaction are involved in complex interconnections: from the opening of ligand-gated ion channels to triggering molecular interactions on the plasma membrane and the cytoplasm.
Among invertebrates, it is still common to distinguish taste from olfaction; however, in reality, it is more appropriate to break this distinction considering various lines of evidence for adaptation of the receptors involved in these "two senses" from more-primitive chemical sensors. Olfaction, indeed, is normally associated with distance from the source of the semiochemical, while taste is normally associated with contact with the source of the semiochemical. However, this is an anthropomorphic bias that may overshadow the nature of the receptors involved for taste and olfaction. Apart from this distinction, several findings in invertebrates suggest alternative roles for chemosensory receptors that do not fit with the concepts of “taste” and “olfaction”. Indeed, many reports have demonstrated expression of several chemosensory receptors among organs renowned for different functions than taste and olfaction, such as heat, gas, and moisture detection as well as sensing of mechanical stimulations, or organs involved in more complex biological functions, such as digestion and assimilation of nutrients, mating or oviposition.
We invite researchers in “viewing invertebrates, big and small, as complex chemosensory entities”, to investigate in sensu latu the various possible functional mechanisms involving subunits of chemoreceptors, independently from their classification as odorant or taste receptors.
We claim to challenge the binomial distinction of “taste” and “olfaction” by proposing a broader "vision" of the chemosensory modalities of the invertebrates. In particular, we want to take advantage of this target to improve knowledge of the molecular mechanisms behind the existence of primitive chemical sensors, such as the primitive ORs of insects (including Orco), the IR25a subfamily of IRs, or GR-like proteins.
In the same "vision", we seek to explore cytological and physiological mechanisms associated with the expression of chemoreceptors independent of their interaction with the external environment. For instance, recent evidence has demonstrated expression of insect ORs in the brain, gut, and reproductive organs. Unveiling the functionality of the receptors in these contexts may add knowledge to their possible involvement in endogenous sensing of chemicals.
We welcome studies on molecular aspects at the base of invertebrate chemosensory receptors at different levels, including evolutionary, functional, electrophysiological, and any aspect of receptor/ligand interactions. We give particular emphasis to investigations on primitive chemosensory receptor subunits, which may augment an understanding of the current evolutionary status of invertebrate chemosensory mechanisms. We encourage studies also on chemosensory receptors that have gotten little attention as chemosensory receptors per se, such as TRP channel and pickpocket receptors. For insects, aware about recent evidence of broad overlapping expression of ORs, IRs and GRs in sensory neurons, we would give particular interest also to functional evidence of chimeric receptors or neurophysiological cross-talk. We also accept studies exploring the role of odorant/tastant binding proteins or any accessory soluble or transmembrane protein actor involved in chemical sensing when these studies advance knowledge for the chemosensory receptor subunits associated with the accessory proteins.