Project description:We compare levels of gene expression in predator (Tigrosa helluo) exposed female Pardosa milvina compared to unexposed spiders and the offspring of predator exposed spiders to the offspring of control spiders.
Project description:Phenotypic plasticity, the ability of one genotype to express different phenotypes in response to changing environmental conditions, is one of the most common phenomena characterising the living world and is not only relevant for the ecology but also for the evolution of species. Daphnia, the waterflea, is a textbook example for predator induced phenotypic plastic defences including changes in life-history, behaviour and morphology. However, the analysis of molecular mechanisms underlying these inducible defences is still in its early stages.<br><br>We exposed Daphnia magna to chemical cues of the predator Triops cancriformis to identify key processes underlying plastic defensive trait formation. D. magna is known to develop an array of morphological changes in the presence of T. cancriformis including changes of carapace morphology and cuticle hardening. To get a more comprehensive idea of this phenomenon, we studied four different genotypes originating from habitats with different predation history, reaching from predator-free to temporary habitats containing T. cancriformis.<br><br>We analysed the morphologies as well as proteomes of predator-exposed and control animals. Three genotypes showed morphological changes when the predator was present. Using a high-throughput proteomics approach, we found 294 proteins which were significantly altered in their abundance after predator exposure in a general or genotype dependant manner. Proteins connected to genotype dependant responses were related to the cuticle, protein synthesis and calcium binding whereas the yolk protein vitellogenin increased in abundance in all genotypes, indicating their involvement in a more general response. Furthermore, genotype dependant responses at the proteome level correlated well with local adaptation to Triops predation.<br><br>Altogether, our study provides new insights concerning genotype dependant and general molecular processes involved in predator-induced phenotypic plasticity in D. magna.
Project description:It is unknown how the VMH regulates skeletal muscle metabolism and predator threat responses, or potential interactions between these. Because skeletal muscle has a great capacity for increasing energy expenditure and is rapidly activated by PO, understanding how the VMH regulates this process could uncover novel targets for obesity treatments. Due to lack of investigation, we sought to provide a foundation for mechanistic exploration. We report transcriptome-wide alterations of the VMH following PO exposure. Our results uncovered novel functional relationships among genes that can now be probed to better understand the dual processing role of the VMH in skeletal muscle metabolism and predator-threat responses.
Project description:Tadpoles of the anuran species Rana pirica can undergo predator-specific morphological responses. Exposure to a predation threat by larvae of the salamander Hynobius retardatus results in formation of a bulgy body (bulgy morph) with a higher tail. The tadpoles revert to a normal phenotype upon removal of the larval salamander threat. The objective of the present study was to use our own fabricated tadpole Rana pirica cDNA microarray to profile gene expression patterns during the predation threat. Experimental design used to produce control, bulgy morph and reversion type tadpoles for the microarray analysis was as follows. One group of tadpoles was placed with a larval salamander for 4 days to induce formation of the bulgy morph phenotype; the predator was then removed and the tadpoles were allowed to revert to the normal phenotype for 4 days. This group is termed “8 day out tadpoles”. A second group of tadpoles was placed with the predator for the full 8 days. The control group was not exposed to a predator. Tadpoles from the predator induced groups were sampled at 6 hours, 4 days and 8 days, those from the control group at 0 hour, 4 days, and 8 days. The comparative design of the microarray analysis was performed as (Exp 6 hours VS Cont 0 hours), (Exp 4 days VS Cont 4 days), (Exp 8 days VS Cont 8 days), and (Exp 8 days-Out VS Exp 8 days), respectively. These analyses were performed in triplicate with a dye swap experiment. Samples 0hr~8days were as follows. Sample plate (1~3A):Channel 1-Cy5 Experiment,Channel 2-Cy3 Control. Sample plate (1~3B):Channel 1-Cy5 Control, Channel 2-Cy3 Experiment. In case of 8day-out samples were as follows. Sample plate (1~3A):Channel 1-Cy5 8day-out,Channel 2-Cy3 full 8day. Sample plate (1~3B):Channel 1-Cy5 full 8day,Channel 2-Cy3 8day-out.
Project description:Tadpoles of the anuran species Rana pirica can undergo predator-specific morphological responses. Exposure to a predation threat by larvae of the salamander Hynobius retardatus results in formation of a bulgy body (bulgy morph) with a higher tail. The tadpoles revert to a normal phenotype upon removal of the larval salamander threat. The objective of the present study was to use our own fabricated tadpole Rana pirica cDNA microarray to profile gene expression patterns during the predation threat.
Project description:In this study, we used whole genome comparative oligonucleotide microarrays to investigate the brain transcriptomic response to predator cues using the threespine stickleback, Gasteroteus aculeatus. We showed that exposure to olfactory, visual and tactile cues of a predator (rainbow trout, Oncorhynchus mykiss) for six days resulted in subtle but significant transcriptomic changes in the brain of sticklebacks. Gene functional analysis and gene ontology (GO) enrichment revealed that the majority of the transcripts differentially expressed between the fish exposed to predator cues and the control group are primarily related to antigen processing and presentation (involving primarily the major histocompatibility complex (MHC)), transmission of synaptic signals, brain metabolic processes, gene regulation, or visual perception. Pathway analysis identified synaptic long-term depression, RAN signaling, relaxin signaling and phototransduction as the top four pathways that were over-represented.
Project description:In this study, we used whole genome comparative oligonucleotide microarrays to investigate the brain transcriptomic response to predator cues using the threespine stickleback, Gasteroteus aculeatus. We showed that exposure to olfactory, visual and tactile cues of a predator (rainbow trout, Oncorhynchus mykiss) for six days resulted in subtle but significant transcriptomic changes in the brain of sticklebacks. Gene functional analysis and gene ontology (GO) enrichment revealed that the majority of the transcripts differentially expressed between the fish exposed to predator cues and the control group are primarily related to antigen processing and presentation (involving primarily the major histocompatibility complex (MHC)), transmission of synaptic signals, brain metabolic processes, gene regulation, or visual perception. Pathway analysis identified synaptic long-term depression, RAN signaling, relaxin signaling and phototransduction as the top four pathways that were over-represented. Adult fish were placed in six different 26L tanks with three fish per tank in a partially recirculating flow-through system. Half of the tanks were assigned to the control group and the other half to the experimental group.10 samples were selected for microarray analysis. The ten samples comprised five biological replicates in the experimental group (fish exposed to predator cues) and five biological replicates in the control group (fish not exposed to predator cues), and were evenly distributed across tanks. The cDNA labeling (single color), hybridization, washing and scanning steps were performed in the NimbleGen microarray gene expression service department.