TY - JOUR
AB - Tasting the bitterness of Antidesma bunius berries Page 463 The ability to perceive the bitterness of phenylthiocarbamide (PTC) and propylthiouracil or not is mediated by the bitter taste receptor gene TAS2R38, which occurs in two common variants of almost equal frequencies. The “taster” receptor variant is referred to as TAS2R38-PAV based on the presence of proline, alanine and valine amino acid residues in positions 49, 262 and 296 of the polypeptide whereas TAS2R38-AVI represents the “non-taster” variant containing alanine, valine and isoleucine residues in these positions. A hypothesis has been put forward to explain the paradoxical high frequency of the presumed inoperable non-taster allele by balancing natural selection as TAS2R38-AVI could be a receptor for an unidentified bitter compound. Risso et al now confirmed that the ability to perceive the bitterness of Antidesma bunius berries inversely correlates with the bitterness perception of PTC. Moreover, all subjects in their sample who perceived Antidesma as bitter carried at least one “non-taster” allele, whereas not all carriers of this allele reported Antidesma as bitter. No other bitter, sweet or umami taste receptor gene variant were associated with tasting the sweetness, sourness or bitterness of the Antidesma bunius fruits. The authors thus conclude that the allele encoding TAS2R38-AVI is necessary for tasting Antidesma’s bitterness but other factors are likely to contribute. The authors also emphasize that the data do not support the simple hypothesis that TAS2R38-AVI functions as a receptor for bitter compounds of Antidesma bunius. Please see also the commentary by Stephen Wooding on page 447. Chemoreception in hydrodermal and coastal shrimps Page 489 Alvinocaridid shrimp are endemic to deep sea hydrothermal vent regions and other areas on the sea floor characterized by hydrogen sulfide, methane and hydrocarbon containing fluids. These shrimps display various adaptations to their environment relating, for example to ectosymbiosis with bacteria, respiration in hypoxic conditions and thermal stress. By comparing the hydrothermal shrimp, Mirocaris fortunata, to the coastal relative, Palaemon elegans, Machon et al now investigated if the vent species has special chemosensory adaptations at its disposal. The authors found little difference in the ability of the two species to detect food odors and short- and long-distance stimuli. The hydrothermal shrimp did also not show special innervation of the aesthetasc sensilla by olfactory sensory neurons. The vent species, however, possesses pore-like structures and dense bacterial covering of the aesthetasc cuticle, yet the link of these specializations to chemoreception remains unknown. Ortho- and retronasal routes evoke different olfactory percepts Page 515 The Duality of Smell hypothesis proposes that odorants delivered retronasally elicit different sensations compared to their orthonasal delivery despite activating the same olfactory receptors in the sensory epithelium of the nose. Hannum et al now asked panelist to match familiar and unfamiliar aromas delivered orthonasally or retronasally with the same aroma from sets of four unknowns delivered by the same or different route. When familiar odors were used matches did not much differ suggesting stable perceptual constructs across routes. When unfamiliar odors were used, however, more samples were correctly matched in the same conditions compared with the opposite conditions. Across delivery routes correct matches decreased with similarity and decreasing flavor familiarity. Together the results suggest that odorant percepts depend on delivery route and support the Duality of Smell hypothesis. © The Author(s) 2018. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com This article is published and distributed under the terms of the Oxford University Press, Standard Journals Publication Model (https://academic.oup.com/journals/pages/open_access/funder_policies/chorus/standard_publication_model)
TI - Articles highlighted
JF - Chemical Senses
DO - 10.1093/chemse/bjy052
DA - 2018-09-01
UR - https://www.deepdyve.com/lp/oxford-university-press/articles-highlighted-35mlEXDser
SP - 445
EP - 445
VL - 43
IS - 7
DP - DeepDyve
ER -