Project description:Increasing evidence suggests microRNAs (miRNAs) control levels of mRNA expression during development of the nervous system and during sensory elicited remodelling of the brain. We used an associative olfactory learning paradigm (proboscis extension response) in the honeybee Apis mellifera to detect gene expression changes in the brain. Transcriptome analysis of bees trained to associate an odor with a reward and control bees exposed to air without reward, helped us abstract mRNA-miRNA interactions for empirical testing. Functional studies, feeding cholesterol-conjugated antisense RNA to bees resulted in the inhibition of miR-210 and of miR-932 that is embedded within the neuroligin 2 (Nlg2) gene involved in synapse development. Loss of miR-932 prevents long-term memory formation but not learning. We validated 3M-bM-^@M-^YUTR target site interactions of miR-932 and show miR-932 dysregulates actin, a key cytoskeletal molecule involved in neuronal development and activity-dependent plasticity of the brain. The analysis used Air group (no odor learning) as control sample for comparison to two groups of odor-conditioned bees: linalool and floral mix.
Project description:Increasing evidence suggests microRNAs (miRNAs) control levels of mRNA expression during development of the nervous system and during sensory elicited remodelling of the brain. We used an associative olfactory learning paradigm (proboscis extension response) in the honeybee Apis mellifera to detect gene expression changes in the brain. Transcriptome analysis of bees trained to associate an odor with a reward and control bees exposed to air without reward, helped us abstract mRNA-miRNA interactions for empirical testing. Functional studies, feeding cholesterol-conjugated antisense RNA to bees resulted in the inhibition of miR-210 and of miR-932 that is embedded within the neuroligin 2 (Nlg2) gene involved in synapse development. Loss of miR-932 prevents long-term memory formation but not learning. We validated 3’UTR target site interactions of miR-932 and show miR-932 dysregulates actin, a key cytoskeletal molecule involved in neuronal development and activity-dependent plasticity of the brain.
Project description:In honey bees, Vitellogenin (Vg) is hypothesized to be a major factor affecting hormone signaling, food-related behavior, immunity, stress resistance and lifespan. Likewise microRNAs play important roles in posttranscriptional gene regulation and affect many biological processes thereby showing many parallels to Vg functions. The molecular basis of Vg and microRNA interactions is largely unknown. Here, we exploited the well-established RNA interference (RNAi) protocol for Vg knockdown to investigate its effects on microRNA population in honey bee forager’s brain and fat body tissue. To identify microRNAs that are differentially expressed between tissues in control and knockdown foragers, we used µParaflo® microfluidic oligonucleotide microRNA microarrays. Our results show 76 and 74 miRNAs were expressed in the brain of control and knockdown foragers whereas 66 and 69 miRNAs were expressed in the fat body of control and knockdown foragers respectively. Target prediction identified potential seed matches for differentially expressed subset of microRNAs affected by Vg knockdown. These candidate genes are involved in a broad range of biological processes including insulin signaling, juvenile hormone (JH) and ecdysteroid signaling previously shown to affect foraging behavior. Thus, here we demonstrate a causal link between Vg expression-variation and variation in the abundance of microRNAs in different tissues with possible consequences for regulation of foraging behavior.
Project description:In honey bees, Vitellogenin (Vg) is hypothesized to be a major factor affecting hormone signaling, food-related behavior, immunity, stress resistance and lifespan. Likewise microRNAs play important roles in posttranscriptional gene regulation and affect many biological processes thereby showing many parallels to Vg functions. The molecular basis of Vg and microRNA interactions is largely unknown. Here, we exploited the well-established RNA interference (RNAi) protocol for Vg knockdown to investigate its effects on microRNA population in honey bee forager’s brain and fat body tissue. To identify microRNAs that are differentially expressed between tissues in control and knockdown foragers, we used µParaflo® microfluidic oligonucleotide microRNA microarrays. Our results show 76 and 74 miRNAs were expressed in the brain of control and knockdown foragers whereas 66 and 69 miRNAs were expressed in the fat body of control and knockdown foragers respectively. Target prediction identified potential seed matches for differentially expressed subset of microRNAs affected by Vg knockdown. These candidate genes are involved in a broad range of biological processes including insulin signaling, juvenile hormone (JH) and ecdysteroid signaling previously shown to affect foraging behavior. Thus, here we demonstrate a causal link between Vg expression-variation and variation in the abundance of microRNAs in different tissues with possible consequences for regulation of foraging behavior.
Project description:We analyzed the changes in the brain tissue of Apis mellifera ligustica at the molecular level by sequencing after using fluvalinate. We found that the differentially expressed miRNAs (DEM) may be involved in hippocampal cell apoptosis and damage to memory functions. This result may be related to behaviors observed after the administration of this medication, such as a lack of homing at night and behavioral disturbances. Overall, our results provide new information about the molecular mechanisms and pathways of fluvalinate action in the brain tissue of Apis mellifera ligustica.