How do consumers deal with stoichiometric constraints?
Ontology highlight
ABSTRACT: Determine gene expression in daphnia exposed to biotic and abiotic stressors. Identify in Daphnia pulex unique gene regulatory patterns involved in the regulation of limited phosphorous.
Project description:Determine gene expression in daphnia exposed to biotic and abiotic stressors. Identify in Daphnia pulex unique gene regulatory patterns involved in the regulation of limited phosphorous. One-condition experiment: Exposed Daphnia pulex for 5 days to phosphorous-limited algae. Biological replicates: 4 exposures, 4 nonexposed controls, grown and harvested in groups of 20 daphnia. One replicate per array.
Project description:Despite a significant increase in genomic data, our knowledge of gene functions and their transcriptional responses to environmental stimuli remains limited. Here, we use the model keystone species Daphnia pulex to study environmental responses of genes in the context of their gene family history to better understand the relationship between genome structure and gene function in response to environmental stimuli. Daphnia were exposed to five different treatments, each consisting of a diet supplemented with one of five cyanobacterial species, and a control treatment consisting of a diet of only green algae. Differential gene expression profiles of Daphnia exposed to each of these five cyanobacterial species showed that genes with known functions are more likely to be shared by different expression profiles whereas genes specific to the lineage of Daphnia are more likely to be unique to a given expression profile. Furthermore, while only a small number of non-lineage specific genes was conserved across treatment type, there was a high degree of overlap in expression profiles at the functional level. The conservation of functional responses across the different cyanobacterial treatments can be attributed to the treatment specific expression of different paralogous genes within the same gene family. Comparison with available gene expression data in the literature suggests differences in nutritional composition in diets with cyanobacterial species compared to diets of green algae as a primary driver for cyanobacterial effects on Daphnia. We conclude that conserved functional responses in Daphnia across different cyanobacterial treatments are mediated through alternate regulation of paralogous gene families. Whole transcriptome dual color arrays were used to discover differentially expressed genes following sub-lethal exposure to five cyanobacteria in D. pulex. RNA was isolated from eight independent and concurrently replicated exposures of Daphnia to control and five cyanobacteria conditions. RNA was hybridized to microarrays using a standard, control vs. treated design that included dye swaps. Cyanobacteria were Anabaena (ANA), Aphanizomenon (Aph), Cylindrospermopsis (Cyl), Nodularia (Nod) and Oscillatoria (Osl).
Project description:We report the application of CAGE (Cap Analysis of Gene Expression) on collections of Daphnia pulex individuals representing three major developmental states. This submission comes from a project of Michael Lynch and was funded by a grant from the National Institutes of Health entitled 'Population Genomics of Daphnia pulex' (Project Number: 1R01GM101672-01A1).
Project description:Despite a significant increase in genomic data, our knowledge of gene functions and their transcriptional responses to environmental stimuli remains limited. Here, we use the model keystone species Daphnia pulex to study environmental responses of genes in the context of their gene family history to better understand the relationship between genome structure and gene function in response to environmental stimuli. Daphnia were exposed to five different treatments, each consisting of a diet supplemented with one of five cyanobacterial species, and a control treatment consisting of a diet of only green algae. Differential gene expression profiles of Daphnia exposed to each of these five cyanobacterial species showed that genes with known functions are more likely to be shared by different expression profiles whereas genes specific to the lineage of Daphnia are more likely to be unique to a given expression profile. Furthermore, while only a small number of non-lineage specific genes was conserved across treatment type, there was a high degree of overlap in expression profiles at the functional level. The conservation of functional responses across the different cyanobacterial treatments can be attributed to the treatment specific expression of different paralogous genes within the same gene family. Comparison with available gene expression data in the literature suggests differences in nutritional composition in diets with cyanobacterial species compared to diets of green algae as a primary driver for cyanobacterial effects on Daphnia. We conclude that conserved functional responses in Daphnia across different cyanobacterial treatments are mediated through alternate regulation of paralogous gene families.
Project description:This SuperSeries is composed of the following subset Series: GSE25841: Evolutionary Diversification of Duplicated Genes; Experiment A GSE25843: Evolutionary Diversification of Duplicated Genes; Experiments B-I, M-P GSE25845: Evolutionary Diversification of Duplicated Genes; Experiments B-I GSE25850: Evolutionary Diversification of Duplicated Genes; Experiment J GSE25851: Evolutionary Diversification of Duplicated Genes; Experiment L, K GSE25852: Empirical Annotation of the Daphnia pulex genome; Experiment B GSE25855: Empirical Annotation of the Daphnia pulex genome; Experiment A GSE25856: Empirical Annotation of the Daphnia pulex genome; Experiment C Refer to individual Series
Project description:Daphnia (Daphnia pulex) is a small planktonic crustacean and a key constituent of aquatic ecosystems. It is commonly used as a model organism for studying environmental toxic challenges. In the past decade, a Daphnia genomic information and proteomic dataset has been developed. This dataset has expanded the opportunity to relate toxicological effects with “Daphnia proteomics” as it integrates proteomic knowledge in Daphnia, those approach will provide greater insights for toxicological research. In order to exploit Daphnia for ecotoxicological research, information on the post-translational modification (PTM) of proteins is necessary as this is a critical regulator of biological processes. Acetylation of lysine (Kac) is a reversible and highly regulated PTM that is associated with diverse biological functions. However, a comprehensive description of Kac in Daphnia is not yet available. Here, to understand the cellular distribution of lysine acetylation in Daphnia, we identified 98 acetylation sites in 65 proteins by immunoprecipitation using an anti-acetyllysine antibody and an liquid chromatography system supported by mass spectroscopy. We identified 28 acetylated sites connected with metabolic proteins and 6 acetylated enzymes associated with the TCA cycle in Daphnia. From GO and KEGG enrichment analyses, we showed that Kac in D. pulex is highly enriched in proteins associated with metabolic processes. Our data provide the first global analysis of lysine acetylation in D. pulex. The expanded proteomic dataset will be an important resource for the functional analysis of Kac in D. pulex and it will be nice to have a first step done using a promising future model organism.
Project description:Stressors may have negative or positive effects in dependence of the dose (hormesis). We studied this phenomenon in Caenorhabditis elegans by applying weak or severe abiotic (cadmium, CdCl2) and/or biotic stress (different bacterial diets) during cultivation/breeding of the worms, and determining developmental speed or survival rates and performing transcriptome profiling and RT-qPCR analyses to explore the genetic basis of the detected phenotypic differences. This study showed that a bacterial diet resulting in higher levels of energy resources in the worms (E. coli OP50 feeding) or weak abiotic and biotic stress especially promote the resistance against severe abiotic or biotic stress and the age-specific survival rate of WT.
Project description:In this study we use nimblegen high-density arrays to examine gene expression regulation in a common-garden experiment varying thermal environments. We report genome-wide patterns of gene expression in two heat tolerant southern and two heat-sensitive northern clones of Daphnia pulex exposed to either optimal (18°C) or substressful (28°C) temperatures.
Project description:Investigation of gene expression level changes in Daphnia pulex MFP strain between in the presence or absence of Chaoborus kairomone.
Project description:We use a custom microarray for the crustacean Daphnia pulex to investigate gene expression in males, juvenile females and pregnant females. Keywords: sex-biased, developmental