Project description:Female larvae of the honeybee (Apis mellifera) develop into either queens or workers depending on nutrition during larval development. This nutritional stimulus triggers different developmental trajectories, resulting in adults that differ in physiology, behaviour and life-span. To understand how these developmental trajectories are established we have undertaken a comprehensive analysis of differential gene expression throughout larval development. Gene expression of honeybee queen and worker larval samples was analysed at seven time points during larval development (6 hr, 12 hr, 36 hr, 60 hr, 84 hr, 108 hr and 132 hr)
Project description:Female larvae of the honeybee (Apis mellifera) develop into either queens or workers depending on nutrition during larval development. This nutritional stimulus triggers different developmental trajectories, resulting in adults that differ in physiology, behaviour and life-span. To understand how these developmental trajectories are established we have undertaken a comprehensive analysis of differential gene expression throughout larval development. Gene expression of honeybee queen and worker larval samples was analysed at 60 hours with high-throughout sequencing
Project description:Female larvae of the honeybee (Apis mellifera) develop into either queens or workers depending on nutrition during larval development. This nutritional stimulus triggers different developmental trajectories, resulting in adults that differ in physiology, behaviour and life-span. To understand how these developmental trajectories are established we have undertaken a comprehensive analysis of differential gene expression throughout larval development.
Project description:Female larvae of the honeybee (Apis mellifera) develop into either queens or workers depending on nutrition during larval development. This nutritional stimulus triggers different developmental trajectories, resulting in adults that differ in physiology, behaviour and life-span. To understand how these developmental trajectories are established we have undertaken a comprehensive analysis of differential gene expression throughout larval development.
Project description:The major environmental determinants of honeybee caste development come from larval nutrients: royal jelly stimulates the differentiation of larvae into queens, whereas beebread leads to worker bee fate. However, these determinants are not fully characterized. Here we report that plant RNAs, particularly miRNAs, which are more enriched in beebread than in royal jelly, delay development and decrease body and ovary size in honeybees, thereby preventing larval differentiation into queens and inducing development into worker bees. Mechanistic studies reveal that amTOR, a stimulatory gene in caste differentiation, is the direct target of miR162a. Interestingly, the same effect also exists in non-social Drosophila. When such plant RNAs and miRNAs are fed to Drosophila larvae, they cause extended developmental times and reductions in body weight and length, ovary size and fecundity. This study identifies an uncharacterized function of plant miRNAs that fine-tunes honeybee caste development, offering hints for understanding cross-kingdom interaction and coevolution.
Project description:BackgroundFemale larvae of the honeybee (Apis mellifera) develop into either queens or workers depending on nutrition. This nutritional stimulus triggers different developmental trajectories, resulting in adults that differ from each other in physiology, behaviour and life span.ResultsTo understand how these trajectories are established we have generated a comprehensive atlas of gene expression throughout larval development. We found substantial differences in gene expression between worker and queen-destined larvae at 6 hours after hatching. Some of these early changes in gene expression are maintained throughout larval development, indicating that caste-specific developmental trajectories are established much earlier than previously thought. Within our gene expression data we identified processes that potentially underlie caste differentiation. Queen-destined larvae have higher expression of genes involved in transcription, translation and protein folding early in development with a later switch to genes involved in energy generation. Using RNA interference, we were able to demonstrate that one of these genes, hexamerin 70b, has a role in caste differentiation. Both queen and worker developmental trajectories are associated with the expression of genes that have alternative splice variants, although only a single variant of a gene tends to be differentially expressed in a given caste.ConclusionsOur data, based on the biases in gene expression early in development together with published data, supports the idea that caste development in the honeybee consists of two phases; an initial biased phase of development, where larvae can still switch to the other caste by differential feeding, followed by commitment to a particular developmental trajectory.
Project description:Epigenetic modifications are known to profoundly affect the development and behavior of social insects. In the well-known caste differentiation process of honeybee (Apis mellifera), female larvae with identical genomes are fed royal jellydifferently and develop into either normal workers or into very large, long-lived, and extremely fecund queens, and the queen-worker asymmetry of honeybee is known to be result largely to differential genomic imprinting during larval development that involves DNA methylation-based regulation. The discovery of reversible N6-methyladenosine (m6A) RNA methylation modification has defined a new era for RNA-metabolism-related genetic regulation, yet much remains unknown about m6A-mediated post-transcriptional regulatory mechanisms. Here, we report the first honeybee RNA m6A methylome. Specifically, we used the m6A-seq technique to examine the RNA m6A methylomes of honeybee larvae, including queen and worker larvae at multiple instar stages. We identified multiple conserved features of m6A methylation machinery and transcriptome-wide m6A distribution trends among insect species, and observed that m6A marks exert functions in regulating caste differentiation, with apparently particularly strong functional impacts on fifth instar worker larvae. Functional annotation of differentially methylated candidate caste-differentiation-related transcripts revealed many known regulators of caste differentiation (e.g. ILP-2, p110, PI3K, and JHAMT etc.) as well as the widely-studied Vitellogenin gene, which has not previously been implicated in caste differentiation. As ever-more regulatory roles for m6A marks are discovered, honeybees may become an excellent model studying the biology of such epi-transcriptomic regulatory systems, from embryonic development through holometabolous caste-specific development and on towards behavior and the emergent social hierarchies underlying eusociality in animals.