TY - JOUR A1 - Değirmenci, Laura A1 - Rogé Ferreira, Fabio Luiz A1 - Vukosavljevic, Adrian A1 - Heindl, Cornelia A1 - Keller, Alexander A1 - Geiger, Dietmar A1 - Scheiner, Ricarda T1 - Sugar perception in honeybees JF - Frontiers in Physiology N2 - Honeybees (Apis mellifera) need their fine sense of taste to evaluate nectar and pollen sources. Gustatory receptors (Grs) translate taste signals into electrical responses. In vivo experiments have demonstrated collective responses of the whole Gr-set. We here disentangle the contributions of all three honeybee sugar receptors (AmGr1-3), combining CRISPR/Cas9 mediated genetic knock-out, electrophysiology and behaviour. We show an expanded sugar spectrum of the AmGr1 receptor. Mutants lacking AmGr1 have a reduced response to sucrose and glucose but not to fructose. AmGr2 solely acts as co-receptor of AmGr1 but not of AmGr3, as we show by electrophysiology and using bimolecular fluorescence complementation. Our results show for the first time that AmGr2 is indeed a functional receptor on its own. Intriguingly, AmGr2 mutants still display a wildtype-like sugar taste. AmGr3 is a specific fructose receptor and is not modulated by a co-receptor. Eliminating AmGr3 while preserving AmGr1 and AmGr2 abolishes the perception of fructose but not of sucrose. Our comprehensive study on the functions of AmGr1, AmGr2 and AmGr3 in honeybees is the first to combine investigations on sugar perception at the receptor level and simultaneously in vivo. We show that honeybees rely on two gustatory receptors to sense all relevant sugars. KW - AmGr1 KW - AmGr2 KW - AmGr3 KW - sugar responsiveness KW - proboscis extension response (PER) KW - gustatory receptors (Grs) KW - honeybee taste perception Y1 - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-302284 SN - 1664-042X VL - 13 ER - TY - JOUR A1 - Schilcher, Felix A1 - Hilsmann, Lioba A1 - Rauscher, Lisa A1 - Değirmenci, Laura A1 - Krischke, Markus A1 - Krischke, Beate A1 - Ankenbrand, Markus A1 - Rutschmann, Benjamin A1 - Mueller, Martin J. A1 - Steffan-Dewenter, Ingolf A1 - Scheiner, Ricarda T1 - In vitro rearing changes social task performance and physiology in honeybees JF - Insects N2 - In vitro rearing of honeybee larvae is an established method that enables exact control and monitoring of developmental factors and allows controlled application of pesticides or pathogens. However, only a few studies have investigated how the rearing method itself affects the behavior of the resulting adult honeybees. We raised honeybees in vitro according to a standardized protocol: marking the emerging honeybees individually and inserting them into established colonies. Subsequently, we investigated the behavioral performance of nurse bees and foragers and quantified the physiological factors underlying the social organization. Adult honeybees raised in vitro differed from naturally reared honeybees in their probability of performing social tasks. Further, in vitro-reared bees foraged for a shorter duration in their life and performed fewer foraging trips. Nursing behavior appeared to be unaffected by rearing condition. Weight was also unaffected by rearing condition. Interestingly, juvenile hormone titers, which normally increase strongly around the time when a honeybee becomes a forager, were significantly lower in three- and four-week-old in vitro bees. The effects of the rearing environment on individual sucrose responsiveness and lipid levels were rather minor. These data suggest that larval rearing conditions can affect the task performance and physiology of adult bees despite equal weight, pointing to an important role of the colony environment for these factors. Our observations of behavior and metabolic pathways offer important novel insight into how the rearing environment affects adult honeybees. KW - honeybee KW - artificial rearing KW - behavior KW - in vitro KW - juvenile hormone KW - triglycerides KW - PER KW - foraging KW - nursing Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-252305 SN - 2075-4450 VL - 13 IS - 1 ER -