ABSTRACT: As part of the EcoToxChip project, 49 distinct exposure studies were conducted on three lab model species (Japanese quail, fathead minnow, African clawed frog) and three ecologically relevant species (double crested cormorant, rainbow trout, northern leopard frog), at multiple life stages (embryo, adult), exposed to eight chemicals of environmental concern (ethinyl estradiol-EE2, hexabromocyclododecane-HBCD, lead-Pb, selenomethionine-SeMe, 17β trenbolone-TB, chlorpyrifos-CPF, fluoxetine-FLX, and benzo [a] pyrene-BaP. Whole transcriptome analyses were conducted on these samples resulting in a rich RNA seq dataset covering various species, life stages and chemicals, which is one of the largest purposeful complications of RNA seq data within ecotoxicology. Recently, a unified bioinformatics platform of relevance to ecotoxicology, EcoOmicsAnalyst and ExpressAnalyst, was developed to facilitate RNA Seq analysis of non-model species lacking a reference transcriptome. The platform uses the Seq2Fun algorithm to map RNA-seq reads from eukaryotic species to an ortholog database comprised of protein sequences from >600 eukaryotic species (EcoOmicsDB) with a translated search. The availability of these tools presents a unique opportunity to examine the EcoToxChip RNA Seq dataset for cross species comparisons. This work shows the potential of the EcoOmicsAnalyst and Seq2Fun platform to facilitate fast and simple analysis of RNA Seq datasets from non-model organisms with unannotated genomes and conduct comparative transcriptomic analysis across various species and life stages for cross-species extrapolation.
Project description:The protozoan Ichthyophthirius multifiliis (Ich) is a eukaryotic ciliate parasite of freshwater fish. Ich causes ichthyophthiriosis or ‘white spot disease’ characterized by white cysts covering the host skin and gills. The parasite is responsible for high mortalities and severe economic losses to farmed species as well as to ornamental species of fish. Despite the global importance of Ich, little is known about the genetic processes underlying its infectivity. Ich has three main life-stages, an infective theront, a parasitic trophont, and a reproductive tomont. Further, Ich has been demonstrated previously to display a loss of infectivity as the number of lab-passages on a fish increase, presumably relating to senescence of the organism. To compare gene expression among two of the three Ich life-stages (the tomont and trophont life-stages) at different passages, oligonucleotide microarrays were utilized. Gene expression was analyzed in samples taken from two of the three Ich life-stages (the tomont and trophont life-stages) at the first serial passage on channel catfish in the lab (P1), and at serial passage 100 (P100). The results of this study will add in the understanding of protozoan global gene regulation and biology and should aid in the development of strategies aimed at the control of this important fish parasite. Submitted is a 12 chip oligo array design using 385 K Nimblegen arrays. A total of 12 microarrays were used for the experiment: three replicates from two of the three Ich life-stages (tomont and trophont life-stages) at serial passage #1 (P1) and serial passage #100 (P100). Probes were designed using 9,129 unique Ich ESTs (clustered contigs and singletons) as well as 26,273 Tetrahymena thermophila and 5,184 Plasmodium falciparum coding sequences. The probe design strategy was to create 12 60-mer oligonucleotide probes per I. multifiliis sequence, and 10 60-mer oligonucleotide probes for both T. thermophila and P. falciparum sequences. Total RNA was isolated in triplicate from the three life-stages of I. multifiliis and submitted to Nimblegen for labeling, hybridization, and scaning. This microarray study is based on the GPL9449 platform built for the developmental stages of the parasite.
Project description:African trypanosomes are dixenous eukaryotic parasites that impose a significant human and veterinary disease burden on sub-Saharan Africa. Diversity between species and life-cycle stages is concomitant with distinct host and tissue tropisms within this group. Here, the spatial proteomes of two African trypanosome species, Trypanosoma brucei and Trypanosoma congolense, have been mapped, each in mammalian and insect life-stages represented by bloodstream form (BSF) and procyclic form (PCF) respectively. Using the hyperLOPIT (hyperplexed localisation of organelle proteins by isotope tagging) methodology, this work has provided four highly comprehensive spatial proteomes.
Project description:Tritium is an ubiquist radionuclide which can be found in the environment due to natural and anthropogenic activities, particularly in aquatic ecosystems. In this context, tritium effects on aquatic species such as fish have to be characterized. HTO (tritiated water) effects were therefore investigated in zebrafish, Danio rerio, a common model in toxicology and ecotoxicology with a fully sequenced genome. Experiments were conducted on early life stages. Larvae were exposed to 0.4 and 4 mGy/h of HTO until 10 days post fertilization. Tritium internalization was quantified and effects were investigated using a proteomic analysis. The global analysis of the proteome was performed after protein extraction at 7 and 10 dpf on zebrafish eggs exposed from 3 hpf to 10 dpf.
Project description:The protozoan Ichthyophthirius multifiliis (Ich) is a eukaryotic ciliate parasite of freshwater fish. Ich causes ichthyophthiriosis or ‘white spot disease’ characterized by white cysts covering the host skin and gills. The parasite is responsible for high mortalities and severe economic losses to farmed species as well as to ornamental species of fish. Despite the global importance of Ich, little is known about the genetic processes underlying its infectivity. Ich has three main life-stages, an infective theront, a parasitic trophont, and a reproductive tomont. Further, Ich has been demonstrated previously to display a loss of infectivity as the number of lab-passages on a fish increase, presumably relating to senescence of the organism. To compare gene expression among two of the three Ich life-stages (the tomont and trophont life-stages) at different passages, oligonucleotide microarrays were utilized. Gene expression was analyzed in samples taken from two of the three Ich life-stages (the tomont and trophont life-stages) at the first serial passage on channel catfish in the lab (P1), and at serial passage 100 (P100). The results of this study will add in the understanding of protozoan global gene regulation and biology and should aid in the development of strategies aimed at the control of this important fish parasite.
Project description:Poly(A) tails enhance the stability and translation of most eukaryotic messenger RNAs, but difficulties in globally measuring poly(A)-tail lengths have impeded greater understanding of poly(A)-tail function. Here we describe poly(A)-tail length profiling by sequencing (PAL-seq) and apply it to measure tail lengths of millions of individual RNAs isolated from yeasts, cell lines, Arabidopsis thaliana leaves, mouse liver, and zebrafish and frog embryos. Poly(A)-tail lengths were conserved between orthologous mRNAs, with mRNAs encoding ribosomal proteins and other 'housekeeping' proteins tending to have shorter tails. As expected, tail lengths were coupled to translational efficiencies in early zebrafish and frog embryos. However, this strong coupling diminished at gastrulation and was absent in non-embryonic samples, indicating a rapid developmental switch in the nature of translational control. This switch complements an earlier switch to zygotic transcriptional control and explains why the predominant effect of microRNA mediated deadenylation concurrently shifts from translational repression to mRNA destabilization. 64 samples from a variety of species
Project description:RNA-seq technology was used to identify differentially localized transcripts from Xenopus laevis and Xenopus tropicalis stage VI oocytes. Besides the discovery of a group of novel animally enriched RNAs, this study revealed a surprisingly low conservation of vegetal RNA localization between the two frog species.
Project description:The protozoan Ichthyophthirius multifiliis (Ich) is a eukaryotic ciliate parasite of freshwater fish. Ich causes ichthyophthiriosis or ‘white spot disease’ characterized by white cysts covering the host skin and gills. The parasite is responsible for high mortalities and severe economic losses to farmed species as well as to ornamental species of fish. Despite the global importance of Ich, little is known about the genetic processes underlying its development and infectivity. Ich has three main life-stages, an infective theront, a parasitic trophont, and a reproductive tomont. To compare gene expression among Ich life-stages, oligonucleotide microarrays were constructed and utilized. All publicly-available Ich ESTs (~35K) were clustered to generate 9,129 unique consensus sequences represented as probes on custom microarrays produced in coordination with Roche NimbleGen. To facilitate comparative genomic analysis and to potentially increase gene content through cross-hybridization, gene coding sequences of related protozoans Tetrahymena thermophila and Plasmodium falciparum were also added to the microarrays. Gene expression was analyzed in samples taken from each of the three Ich life-stages. The results of this study will add in the understanding of protozoan global gene regulation and biology and should aid in the development of strategies aimed at the control of this important fish parasite. Submitted is a nine chip oligo array design using 385 K Nimblegen arrays. A total of nine microarrays were used for the experiment: three replicates from each of the three Ich life-stages (tomont, trophont, and theront life-stages). Probes were designed using 9,129 unique Ich ESTs (clustered contigs and singletons) as well as 26,273 Tetrahymena thermophila and 5,184 Plasmodium falciparum coding sequences. The probe design strategy was to create 12 60-mer oligonucleotide probes per I. multifiliis sequence, and 10 60-mer oligonucleotide probes for both T. thermophila and P. falciparum sequences. Total RNA was isolated in triplicate from the three life-stages of I. multifiliis and submitted to Nimblegen for labeling, hybridization, and scaning.
Project description:Human oocyte cDNA library was hybridized on a multi-species oocyte array (Bovine, Mouse, Frog) Temperature stringency criteria was used to evaluate the conservation degree of oocyte genes among vertebrates (Bovine, Mouse, Frog)