Project description:The microsporidia Nosema ceranae are intracellular parasites that proliferate in the midgut epithelial cells of honey bees (Apis mellifera). To analyze the pathological effects of those microsporidia, we orally infected honey bee workers 7 days after their emergence. Bees were flash frozen 15 days after the infection. Then, the effects on the gut ventriculi were analyzed and compared to non-infected (control) bees.
Project description:Honey bee queens undergo dramatic behavioral (e.g., reduced sexual receptivity), physiological (e.g., ovary activation, ovulation, and modulation of pheromone production) and molecular changes after they complete mating. To elucidate how queen post-mating changes are influenced by seminal fluid, a non-spermatozoa-containing component of semen, we injected queens with semen or seminal fluid alone. We assessed queen sexual receptivity, ovary development, worker retinue response (which is influenced by queen pheromone production), and transcriptional changes in queen abdominal fat body and brain tissues. Injection with either seminal fluid or semen resulted in decreased sexual receptivity, increased attractiveness of queens to workers, and altered expression of several genes that are also regulated in naturally mated queens. The post-mating and transcriptional changes of queens receiving seminal fluid were not significantly different from queens treated with seminal fluid, suggesting that components in seminal fluid, such as seminal fluid proteins, are largely responsible for stimulating post-mating changes in queens.
Project description:The present study is the first study to identify the involvement of mRNA, lncRNAs, circRNAs and miRNA in the ovary of honey-bee workers.We predicted 10271 mRNAs, 7235 lncRNAs, 11794 circRNAs and 164 miRNAs in the ovary of honey bee workers.
Project description:The microsporidia Nosema ceranae are intracellular parasites that proliferate in the midgut epithelial cells of honey bees (Apis mellifera). To analyze the pathological effects of those microsporidia, we orally infected honey bee workers 7 days after their emergence. Bees were flash frozen 15 days after the infection. Then, the effects on the gut ventriculi were analyzed and compared to non-infected (control) bees. Comparisons of control vs Nosema ceranae bees
Project description:Adult honey bee queens and workers drastically differ in ovary size. This adult ovary phenotype difference becomes established during the last two larval instars, when massive programmed cell death in the ovaries of worker larvae leads to the degeneration and removal of 95-99% of the ovariole anlagen. The higher juvenile hormone (JH) levels in queen larvae protect their ovaries against such degeneration. To gain insights into the molecular architecture underlying this divergence critical for adult caste fate we performed a microarray analysis contrasting RNA extracts from fourth and early fifth instar queen and worker ovaries. While for the fourth instar we found differential expression (log2FC > 1.0) for only nine genes, the number of differentially represented transcripts (DRTs) increased to 56 in early fifth instar ovaries. From these, 18 had their expression levels further analyzed by real-time PCR (RT-qPCR). For 13 of these the expression differed significantly between queen and worker ovaries at least one time point in development, and interestingly, genes with enzyme functions were overexpressed in workers, while genes related to transcription and signaling were so in queens. For the RT-qPCR confirmed genes we further analyzed their response to JH, revealing a significant up-regulation for two genes, one encoding a short chain dehydrogenase (SDR) and the other heat shock protein 90 (Hsp90). Five other genes, including Hsp60 and hexamerin 70b, were significantly down-regulated by JH. As SDR genes have previously come up as differentially expressed in different transcriptome assays in honey bee larvae, and heat shock proteins are involved in hormone responses, these are interesting candidates for further functional assays.
Project description:Here we present the first characterisation of small RNAs in honey bee reproductive tissues. We conclude that small RNAs are likely to play an integral role in honey bee gametogenesis and reproduction and provide a plausible mechanism for parent-of origin-effects on gene expression and reproductive physiology. present in honey bee reproductive tissues: ovaries, spermatheca, semen, fertilised and unfertilised eggs, and testes.
Project description:Experimental infection of (2 days old) adult honey bee workers (30 bees per replicates, 3 replicates per treatments, from 3 different colonies (one colony per cage for each treatment)) with 10^9 genome equivalent of Black Queen Cell Virus (BQCV) in 10µl of sugar solution and/or 10^5 fresh Nosema ceranae spores (control bees were given a similar bee extract in PBS, without pathogen). Bees were kept in cages of 30 bees in incubator (30°C/50%RH). At day 13 p.i., bees were flash frozen, and stored at -80°C.
Project description:Sexual reproduction brings genes from two parents – matrigenes and patrigenes – into one individual. These genes, despite being unrelated, should show nearly perfect cooperation because each gains equally through production of offspring. However, an individual’s matrigenes and patrigenes can have different probabilities of being present in other relatives, so that kin selection could act on them differently. Such intragenomic conflict could be implemented by partial or complete silencing (imprinting) of an allele by one of the parents. Evidence supporting this theory is seen in offspring-mother interactions, with patrigenes favoring acquisition of more of the mother's resources if some of the costs fall on half siblings who do not share the patrigene. The kinship theory of intragenomic conflict is little tested in other contexts, but it predicts that matrigene-patrigene conflict may be rife in social insects. We tested the hypothesis that honey bee worker reproduction is promoted more by patrigenes than matrigenes by comparing across 9 reciprocal crosses of two distinct genetic stocks. As predicted, hybrid workers show reproductive trait characteristics of their paternal stock, indicating enhanced activity of the patrigenes on these traits, greater patrigenic than matrigenic expression, and significantly increased patrigenic biased expression in reproductive workers. These results support both the general prediction that matrigene-patrigene conflict occurs in social insects and the specific prediction that honey bee worker reproduction is driven more by patrigenes. The success of these predictions suggests that intragenomic conflict may occur in many contexts where matrigenes and patrigenes have different relatednesses to affected kin.