Project description:Social caste determination in the honey bee is assumed to be determined by the dietary status of the young larvae and translated into physiological and epigenetic changes through nutrient-sensing pathways. We have employed Illumina/Solexa sequencing to examine the small RNA content in the bee larval food source, and show that worker jelly is enriched in miRNA complexity and abundance relative to royal jelly. The miRNA levels in worker jelly were 7-215 fold higher than in royal jelly, and both jellies showed dynamic changes in miRNA content during the 4th to 6th day of larval development. Adding specific miRNAs to royal jelly elicited significant changes in queen larval mRNA expression and in morphological characters of the emerging adult queen bee. We propose that miRNAs in the nurse bee secretions constitute an additional element in the regulatory control of caste determination in the honey bee.
Project description:Background: Honey bee is a major insect used for pollination of a number of commercial crops worldwide. However, the number of managed honey bee colonies has recently declined in several countries, and a number of possible causes are proposed. Although the use of honey bees for pollination can be considered as disruption of the habitat, its effects on honey bees' physiology have never been addressed. In Japan, more than 100 thousands colonies are annually used for pollination, and intriguingly 80% of them are used in greenhouses. Recently, honey bee colonies have often collapsed when they are introduced into greenhouses. Thus, to suppress colony collapses and maintain the number of worker bees in the colonies are essential for successful long-term pollination in greenhouses and recycling honey bee colonies.
Project description:Social caste determination in the honey bee is assumed to be determined by the dietary status of the young larvae and translated into physiological and epigenetic changes through nutrient-sensing pathways. We have employed microRNA gene-microarray, and observed that both worker jelly and royal jelly showed dynamic changes in miRNA content during the 4th to 6th day of larval development . Adding specific miRNAs to royal jelly elicited significant changes in queen larval mRNA expression and in morphological characters of the emerging adult queen bee. We propose that miRNAs in the nurse bee secretions constitute an additional element in the regulatory control of caste determination in the honey bee.
Project description:Background: Honey bee is a major insect used for pollination of a number of commercial crops worldwide. However, the number of managed honey bee colonies has recently declined in several countries, and a number of possible causes are proposed. Although the use of honey bees for pollination can be considered as disruption of the habitat, its effects on honey bees' physiology have never been addressed. In Japan, more than 100 thousands colonies are annually used for pollination, and intriguingly 80% of them are used in greenhouses. Recently, honey bee colonies have often collapsed when they are introduced into greenhouses. Thus, to suppress colony collapses and maintain the number of worker bees in the colonies are essential for successful long-term pollination in greenhouses and recycling honey bee colonies. Honey bee hives were installed into strawberry and eggplant greenhouses, and then the gene expression profiles of the honey bees were examined at the different time periods. Total 16 samples with two replicates were analyzed.
Project description:Social caste determination in the honey bee is assumed to be determined by the dietary status of the young larvae and translated into physiological and epigenetic changes through nutrient-sensing pathways. We have employed Illumina/Solexa sequencing to examine the small RNA content in the bee larval food source, and show that worker jelly is enriched in miRNA complexity and abundance relative to royal jelly. The miRNA levels in worker jelly were 7-215 fold higher than in royal jelly, and both jellies showed dynamic changes in miRNA content during the 4th to 6th day of larval development. Adding specific miRNAs to royal jelly elicited significant changes in queen larval mRNA expression and in morphological characters of the emerging adult queen bee. We propose that miRNAs in the nurse bee secretions constitute an additional element in the regulatory control of caste determination in the honey bee. We collected worker and royal jelly of the Italian honeybee (ZND No.1, Apis mellifera ligustica) at 73~90 hours (4th-day larvae), 97~114 hours (5th-day larvae), and 121~138 hours (6th-day larvae) after hatching. After total RNA was extractedM-BM- and quantified , relative equal amounts of total RNAs from each of the three sampling days were pooled into respectively worker and royal jelly samples, and the fraction of small RNAs less than 30nt long was retained and sequenced on the Illumina/Solexa high-throughput platform (HTP).
Project description:Responses to social cues, such as pheromones, can be modified by genotype, physiology, or environmental context. Honey bee queens produce a pheromone (queen mandibular pheromone; QMP) which regulates many aspects of worker bee behavior and physiology. Forager honey bees are less responsive to QMP than young nurse bees engaged in brood care, suggesting that physiological changes associated with behavioral maturation may modulate response to this pheromone. Since cGMP is a major regulator of behavioral maturation in honey bee workers, we examined its role in modulating worker responses to QMP. Treatment with a cGMP analog, 8-Br-cGMP, resulted in significant reductions in both behavioral and physiological responses to QMP in young caged workers. Treatment significantly reduced attraction to QMP (the retinue response) and inhibited the QMP-mediated increase in vitellogenin levels in the fat bodies of worker bees. Genome-wide analysis of brain gene expression patterns demonstrated that cGMP has a larger effect on expression levels than QMP, and that QMP has specific effects in the presence of cGMP, suggesting that some responses to QMP may be dependent on an individual beesM-^R physiological state. Several functional gene categories were significantly differentially expressed, including genes involved in regulating GTPase activity, phototransduction, immunity, and carboxylic acid transmembrane transporter activity. Overall, our data suggest that cGMP-mediated processes play a large role in modulating responses to queen pheromone in honey bees, at the behavioral, physiological and molecular levels.
Project description:Social caste determination in the honey bee is assumed to be determined by the dietary status of the young larvae and translated into physiological and epigenetic changes through nutrient-sensing pathways. We have employed microRNA gene-microarray, and observed that both worker jelly and royal jelly showed dynamic changes in miRNA content during the 4th to 6th day of larval development . Adding specific miRNAs to royal jelly elicited significant changes in queen larval mRNA expression and in morphological characters of the emerging adult queen bee. We propose that miRNAs in the nurse bee secretions constitute an additional element in the regulatory control of caste determination in the honey bee. We collected worker and royal jelly of the Italian honeybee (ZND No.1, Apis mellifera ligustica) at 73~90 hours (4th-day larvae), 97~114 hours (5th-day larvae), and 121~138 hours (6th-day larvae) after hatching. After total RNA was extractedM-BM- and quantified , equal amounts of total RNAs from each of the three sampling days were analyzed on the LC Science miRNA-array to observe the expression variation of miRNAs between worker jelly and royal jelly along with the development time points (4th-day, 5th-day and 6th-day).