The Experts below are selected from a list of 14175 Experts worldwide ranked by ideXlab platform
Alison R. Mercer - One of the best experts on this subject based on the ideXlab platform.
-
Changes in responsiveness to allatostatin treatment accompany shifts in stress reactivity in Young Worker honey bees
Journal of Comparative Physiology A, 2019Co-Authors: Elodie Urlacher, Jean-marc Devaud, Alison R. MercerAbstract:Exposing honey bees to isopentylacetate (IPA) can cause stress-related changes in learning performance. In bees of foraging age, IPA’s effects on learning are mimicked by C-type allatostatins (AstCC, AstCCC) injected into the brain. Here we ask whether allatostatins induce a similar response in Young (6-day-old) bees and if so, whether their effects on learning performance are modulated by queen mandibular pheromone (QMP). We found that Young bees exposed to IPA responded less to the conditioned stimulus during training than controls (Type 1-like stress response). AstCC treatment induced a similar response, but only in bees maintained without QMP. Bees exposed to QMP responded to AstCC with increased odour responsiveness and odour generalisation in the 1-h memory test (Type 2-like response). Type 2-like responses could be induced also by the A-type allatostatin, AstA. However, in bees exposed to QMP, AstA-induced odour generalisation was absent. Effects of AstCCC treatment in Young bees were weak, indicating that responsiveness to this peptide changes with age. Our findings are consistent with the hypothesis that honey bee allatostatins play a role in stress reactivity, but suggest in addition that allatostatin signalling is age dependent and susceptible to modulation by pheromone released by the queen bee.
-
social modulation of stress reactivity and learning in Young Worker honey bees
PLOS ONE, 2014Co-Authors: Elodie Urlacher, Ingrid Tarr, Alison R. MercerAbstract:Alarm pheromone and its major component isopentylacetate induce stress-like responses in forager honey bees, impairing their ability to associate odors with a food reward. We investigated whether isopentylacetate exposure decreases appetitive learning also in Young Worker bees. While isopentylacetate-induced learning deficits were observed in guards and foragers collected from a queen-right colony, learning impairments resulting from exposure to this pheromone could not be detected in bees cleaning cells. As cell cleaners are generally among the Youngest Workers in the colony, effects of isopentylacetate on learning behavior were examined further using bees of known age. Adult Workers were maintained under laboratory conditions from the time of adult emergence. Fifty percent of the bees were exposed to queen mandibular pheromone during this period, whereas control bees were not exposed to this pheromone. Isopentylacetate-induced learning impairments were apparent in Young (less than one week old) controls, but not in bees of the same age exposed to queen mandibular pheromone. This study reveals Young Worker bees can exhibit a stress-like response to alarm pheromone, but isopentylacetate-induced learning impairments in Young bees are suppressed by queen mandibular pheromone. While isopentylacetate exposure reduced responses during associative learning (acquisition), it did not affect one-hour memory retrieval.
-
Steroid hormone (20-hydroxyecdysone) modulates the acquisition of aversive olfactory memories in pollen forager honeybees
Learning & Memory, 2013Co-Authors: Lisa H. Geddes, Vanina Vergoz, H. James Mcquillan, Alastair Aiken, Alison R. MercerAbstract:Here, we examine effects of the steroid hormone, 20-hydroxyecdysone (20-E), on associative olfactory learning in the honeybee, Apis mellifera. 20-E impaired the bees’ ability to associate odors with punishment during aversive conditioning, but did not interfere with their ability to associate odors with a food reward (appetitive learning). The steroid had a significant impact also on the expression of amine-receptor genes in centers of the brain involved in the formation and recall of associative olfactory memories (mushroom bodies). 20-E increased expression of the dopamine receptor gene, Amdop2, and reduced the expression of the putative dopamine/ecdysone receptor gene, Amgpcr19. Interestingly, Amgpcr19 tended to be highly expressed in the brains of foragers that exhibited strong aversive learning, but expressed at lower levels in bees that performed well in appetitive learning assays. In 2-d-old bees, transcript levels of the same gene could be reduced by queen mandibular pheromone, a pheromone that blocks aversive learning in Young Worker bees. As ecdysteroid levels rise to a peak 2 d after adult emergence and then fall to low levels in foragers, we examined aversive learning also in Young Worker bees. Aversive learning performance in 2-d-old bees was consistently poor. The results of this study indicate that learning in honeybees can be modulated by ecdysteroids. They highlight, in addition, a potential involvement of the putative dopamine/ecdysone receptor, AmGPCR19, in hormonal regulation of associative olfactory learning in the honeybee.
-
Queen pheromone blocks aversive learning in Young Worker bees
Science, 2007Co-Authors: Vanina Vergoz, Haley A. Schreurs, Alison R. MercerAbstract:Queen mandibular pheromone (QMP) has profound effects on dopamine signaling in the brain of Young Worker honey bees. As dopamine in insects has been strongly implicated in aversive learning, we examined QMP's impact on associative olfactory learning in bees. We found that QMP blocks aversive learning in Young Workers, but leaves appetitive learning intact. We postulate that QMP's effects on aversive learning enhance the likelihood that Young Workers remain in close contact with their queen by preventing them from forming an aversion to their mother's pheromone bouquet. The results provide an interesting twist to a story of success and survival.
Elodie Urlacher - One of the best experts on this subject based on the ideXlab platform.
-
Changes in responsiveness to allatostatin treatment accompany shifts in stress reactivity in Young Worker honey bees
Journal of Comparative Physiology A, 2019Co-Authors: Elodie Urlacher, Jean-marc Devaud, Alison R. MercerAbstract:Exposing honey bees to isopentylacetate (IPA) can cause stress-related changes in learning performance. In bees of foraging age, IPA’s effects on learning are mimicked by C-type allatostatins (AstCC, AstCCC) injected into the brain. Here we ask whether allatostatins induce a similar response in Young (6-day-old) bees and if so, whether their effects on learning performance are modulated by queen mandibular pheromone (QMP). We found that Young bees exposed to IPA responded less to the conditioned stimulus during training than controls (Type 1-like stress response). AstCC treatment induced a similar response, but only in bees maintained without QMP. Bees exposed to QMP responded to AstCC with increased odour responsiveness and odour generalisation in the 1-h memory test (Type 2-like response). Type 2-like responses could be induced also by the A-type allatostatin, AstA. However, in bees exposed to QMP, AstA-induced odour generalisation was absent. Effects of AstCCC treatment in Young bees were weak, indicating that responsiveness to this peptide changes with age. Our findings are consistent with the hypothesis that honey bee allatostatins play a role in stress reactivity, but suggest in addition that allatostatin signalling is age dependent and susceptible to modulation by pheromone released by the queen bee.
-
social modulation of stress reactivity and learning in Young Worker honey bees
PLOS ONE, 2014Co-Authors: Elodie Urlacher, Ingrid Tarr, Alison R. MercerAbstract:Alarm pheromone and its major component isopentylacetate induce stress-like responses in forager honey bees, impairing their ability to associate odors with a food reward. We investigated whether isopentylacetate exposure decreases appetitive learning also in Young Worker bees. While isopentylacetate-induced learning deficits were observed in guards and foragers collected from a queen-right colony, learning impairments resulting from exposure to this pheromone could not be detected in bees cleaning cells. As cell cleaners are generally among the Youngest Workers in the colony, effects of isopentylacetate on learning behavior were examined further using bees of known age. Adult Workers were maintained under laboratory conditions from the time of adult emergence. Fifty percent of the bees were exposed to queen mandibular pheromone during this period, whereas control bees were not exposed to this pheromone. Isopentylacetate-induced learning impairments were apparent in Young (less than one week old) controls, but not in bees of the same age exposed to queen mandibular pheromone. This study reveals Young Worker bees can exhibit a stress-like response to alarm pheromone, but isopentylacetate-induced learning impairments in Young bees are suppressed by queen mandibular pheromone. While isopentylacetate exposure reduced responses during associative learning (acquisition), it did not affect one-hour memory retrieval.
Kirsten S. Traynor - One of the best experts on this subject based on the ideXlab platform.
-
Age matters: pheromone profiles of larvae differentially influence foraging behaviour in the honeybee, Apis mellifera
Animal Behaviour, 2015Co-Authors: Kirsten S. Traynor, Yves Le Conte, Robert E. Page Jr.Abstract:How a colony regulates the division of labour to forage for nutritional resources while accommodating for size and demographic composition is a fundamental question in the sociobiology of social insects. In honeybees, Apis mellifera, Young and old larvae produce pheromones that differ in composition. Nurses differentially regulate larval nutrition, feeding Young Worker larvae a surplus diet that parallels queen larvae in protein composition and food availability, while old larvae are restrictively fed a diet with similar sugar content as queens. The presence of larvae affects division of labour, but it is unknown whether foragers regulate resource collection based on larval age or pheromone production in the nest. We studied how larval age demography and the larval pheromone e-beta ocimene affect foraging activity and foraging load. Our results suggest that Workers recognize larval age, probably by detecting changes in the pheromones emitted by larvae as they mature, and adjust the foraging division of labour (pollen versus nectar) to meet the nutritional needs of the colony's brood. For Younger larvae, this results in a bias towards pollen collection.
-
Queen and Young larval pheromones impact nursing and reproductive physiology of honey bee (Apis mellifera) Workers
Behavioral Ecology and Sociobiology, 2014Co-Authors: Kirsten S. Traynor, Yves Le Conte, Robert E. PageAbstract:Several insect pheromones are multifunctional and have both releaser and primer effects. In honey bees (Apis mellifera), the queen mandibular pheromone (QMP) and ebeta- ocimene (eβ), emitted by Young Worker larvae, have such dual effects. There is increasing evidence that these multifunctional pheromones profoundly shape honey bee colony dynamics by influencing cooperative brood care, a fundamental aspect of eusocial insect behavior. Both QMP and eβ have been shown to affect Worker physiology and behavior, but it has not yet been determined if these two key pheromones have interactive effects on hypopharyngeal gland (HPG) development, actively used in caring of larvae, and ovary activation, a component of Worker reproductive physiology. Experimental results demonstrate that both QMP and eβ significantly suppress ovary activation compared to controls but that the larval pheromone is more effective than QMP. The underlying reproductive anatomy (total ovarioles) of Workers influenced HPG development and ovary activation, so that Worker bees with more ovarioles were less responsive to suppression of ovary activation by QMP. These bees were more likely to develop their HPG and have activated ovaries in the presence of eβ, providing additional links between nursing and reproductive physiology in support of the reproductive ground plan hypothesis.
Silvio Erle - One of the best experts on this subject based on the ideXlab platform.
-
origin and function of the major royal jelly proteins of the honeybee apis mellifera as members of the yellow gene family
Biological Reviews, 2014Co-Authors: Anja Uttsted, Robi F A Moritz, Silvio ErleAbstract:In the honeybee, Apis mellifera, the queen larvae are fed with a diet exclusively composed of royal jelly (RJ), a secretion of the hypopharyngeal gland of Young Worker bees that nurse the brood. Up to 15% of RJ is composed of proteins, the nine most abundant of which have been termed major royal jelly proteins (MRJPs). Although it is widely accepted that RJ somehow determines the fate of a female larva and in spite of considerable research efforts, there are surprisingly few studies that address the biochemical characterisation and functions of these MRJPs. Here we review the research on MRJPs not only in honeybees but in hymenopteran insects in general and provide metadata analyses on genome organisation of mrjp genes, corroborating previous reports that MRJPs have important functions for insect development and not just a nutritional value for developing honeybee larvae.
Solomon Zewdu Altaye - One of the best experts on this subject based on the ideXlab platform.
-
new insights into the biological and pharmaceutical properties of royal jelly
International Journal of Molecular Sciences, 2020Co-Authors: Saboo Ahmad, Filippo Fratini, Maria G Campos, Solomon Zewdu AltayeAbstract:Royal jelly (RJ) is a yellowish-white and acidic secretion of hypopharyngeal and mandibular glands of nurse bees used to feed Young Worker larvae during the first three days and the entire life of queen bees. RJ is one of the most appreciated and valued natural product which has been mainly used in traditional medicines, health foods, and cosmetics for a long time in different parts of the world. It is also the most studied bee product, aimed at unravelling its bioactivities, such as antimicrobial, antioxidant, anti-aging, immunomodulatory, and general tonic action against laboratory animals, microbial organisms, farm animals, and clinical trials. It is commonly used to supplement various diseases, including cancer, diabetes, cardiovascular, and Alzheimer’s disease. Here, we highlight the recent research advances on the main bioactive compounds of RJ, such as proteins, peptides, fatty acids, and phenolics, for a comprehensive understanding of the biochemistry, biological, and pharmaceutical responses to human health promotion and life benefits. This is potentially important to gain novel insight into the biological and pharmaceutical properties of RJ.
