Project description:Zebrafish populations recently collected from the wild differ from domesticated populations in anxiety-related behaviors. We measured anxiety-related behaviors in wild and domesticated zebrafish populations and performed a multi-brain region transcriptional comparison using microarrays to try to understand the genetic changes that accompany behavioral adaptation to domestication. We performed a microarray analysis comparing the midbrain and telencephalon brain regions of male and female adult zebrafish from four populations varying in domestication history (Wild: Nadia (N) and Pargana (P), and Domesticated: Scientific Hatchery (S) and Transgenic Mosaic 1 (T)). We collected 16 samples per brain region (4 samples per zebrafish population, with 1 telencephalon sample missing for the S population). We attempted to maintain equal sex ratios within each zebrafish population, but this was not always possible due to sex biases within some populations.
Project description:We tested the hypothesis that the behavioral response to selenium (Se) follows a hormetic dose response pattern, manifested through the functions of selenoproteins within the brain. We measured anxiety-related behaviors in zebrafish (Danio rerio) at deficient, control and supplemented levels of dietary Se, and measured the transcriptional response of selenoprotein genes important for neuroprotection. We also used a microarray approach to assess the transcriptomic response of the midbrain to Se. The behavioral response to Se was characterized by hormesis, and the direction, magnitude, and shape of the hormetic responses were dependent on both sex and zebrafish population. Transcription of selenoproteins within the midbrain also responded to Se in a similar hormetic dose-dependent manner, with sex and population influencing the trajectory of the responses. The hormetic behavioral response to Se may therefore be manifested through selenoproteins in the brain, but the influence is not direct.
Project description:We tested the hypothesis that the behavioral response to selenium (Se) follows a hormetic dose response pattern, manifested through the functions of selenoproteins within the brain. We measured anxiety-related behaviors in zebrafish (Danio rerio) at deficient, control and supplemented levels of dietary Se, and measured the transcriptional response of selenoprotein genes important for neuroprotection. We also used a microarray approach to assess the transcriptomic response of the midbrain to Se. The behavioral response to Se was characterized by hormesis, and the direction, magnitude, and shape of the hormetic responses were dependent on both sex and zebrafish population. Transcription of selenoproteins within the midbrain also responded to Se in a similar hormetic dose-dependent manner, with sex and population influencing the trajectory of the responses. The hormetic behavioral response to Se may therefore be manifested through selenoproteins in the brain, but the influence is not direct. We performed a microarray analysis comparing the midbrain-specific transcriptome between male zebrafish from two populations (Pargana: P and Transgenic Mosaic 1: T) fed either a control, Se deficient, or Se supplemented diet (17 total samples: 9 fish per population, 3 fish per diet: missing 1 P control sample).
Project description:Humans and animals have problems producing eggs with high embryo developmental competence, but the causes of poor egg quality are usually unknown. This study delivered the first proteomic portraits of egg quality in zebrafish, a leading model for vertebrate development. Egg batches of good and poor quality, evidenced by embryo survival for 24 h, were used to create pooled or replicated sample sets subjected to different levels of fractionation before LC-MS/MS. Obtained spectra were searched against a custom zebrafish proteome database and detected proteins were annotated, categorized and quantified based on their normalized spectral counts. Manual and automated enrichment analyses were highly confirmative, showing that good and poor quality eggs have disparate proteomes. Proteins involved in protein synthesis, energy metabolism, and lipid metabolism, and certain vitellogenin products were strikingly underrepresented in poor quality eggs. Poor quality eggs also had significantly higher representation of proteins related to immune system and endosome/lysosome functioning, oncogenes, and apoptosis, as well as lectins and egg envelope proteins. Quantitative comparisons of highly abundant proteins revealed 9 candidate egg quality markers warranting further study. In conclusion, the zebrafish egg proteome appears to be linked to embryo developmental potential, a phenomenon that begs further investigation.
Project description:Humans and animals have problems producing eggs with high embryo developmental competence, but the causes of poor egg quality are usually unknown. This study delivered the first proteomic portraits of egg quality in zebrafish, a leading model for vertebrate development. Egg batches of good and poor quality, evidenced by embryo survival for 24 h, were used to create pooled or replicated sample sets subjected to different levels of fractionation before LC-MS/MS. Obtained spectra were searched against a custom zebrafish proteome database and detected proteins were annotated, categorized and quantified based on their normalized spectral counts. Manual and automated enrichment analyses were highly confirmative, showing that good and poor quality eggs have disparate proteomes. Proteins involved in protein synthesis, energy metabolism, and lipid metabolism, and certain vitellogenin products were strikingly underrepresented in poor quality eggs. Poor quality eggs also had significantly higher representation of proteins related to immune system and endosome/lysosome functioning, oncogenes, and apoptosis, as well as lectins and egg envelope proteins. Quantitative comparisons of highly abundant proteins revealed 9 candidate egg quality markers warranting further study. In conclusion, the zebrafish egg proteome appears to be linked to embryo developmental potential, a phenomenon that begs further investigation.
Project description:Domesticated animal populations often show profound reductions in predator avoidance and fear-related behavior compared to wild populations. These reductions are remarkably consistent and have been observed in a diverse array of taxa including fish, birds, and mammals. Experiments conducted in common environments indicate that these behavioral differences have a genetic basis. In this study, we quantified differences in fear-related behavior between wild and domesticated zebrafish strains and used microarray analysis to identify genes that may be associated with this variation. Compared to wild zebrafish, domesticated zebrafish spent more time near the water surface and were more likely to occupy the front of the aquarium nearest a human observer. Microarray analysis of the brain transcriptome identified high levels of population variation in gene expression, with 1,749 genes significantly differentially expressed among populations. Genes that varied among populations belonged to functional categories that included DNA repair, DNA photolyase activity, response to light stimulus, neuron development and axon guidance, cell death, iron-binding, chromatin reorganization, and homeobox genes. Comparatively fewer genes (112) differed between domesticated and wild strains with notable genes including gpr177 (wntless), selenoprotein P1a, synaptophysin and synaptoporin, and acyl-CoA binding domain containing proteins (acbd3 and acbd4). Microarray analysis identified a large number of genes that differed among zebrafish populations and may underlie behavioral domestication. Comparisons with similar microarray studies of domestication in rainbow trout and canids identified sixteen evolutionarily or functionally related genes that may represent components of shared molecular mechanisms underlying convergent behavioral evolution during vertebrate domestication. However, this conclusion must be tempered by limitations associated with comparisons among microarray studies and the low level of population-level replication inherent to these studies. RNA was extracted from the brains of fish from four behaviorally distinct strains of zebrafish and hybridized on Affymetrix microarrays. Brains from 2-5 individual fish of the same sex were pooled and homogenized together, for a total of two biological replicate pools per sex per strain (16 microarrays total).
Project description:Restriction site Associated DNA (RAD) tags are a genome-wide representation of every site of a particular restriction enzyme by short DNA tags. Most organisms segregate large numbers of DNA sequence polymorphisms that disrupt restriction sites, which allow RAD tags to serve as genetic markers spread at a high-density throughout the genome. Here, we demonstrate the applicability of RAD markers for both individual and bulk-segregant genotyping. First, we show that these markers can be identified and typed on pre-existing microarray formats. Second, we present a method that uses RAD marker DNA to rapidly produce a low-cost microarray genotyping resource that can be used to efficiently identify and type thousands of RAD markers. We demonstrate the utility of the former approach by using a tiling path array for the fruit fly to map a recombination breakpoint, and the latter approach by creating and utilizing an enriched RAD marker array for the threespine stickleback. The high number of RAD markers enabled localization of a previously identified region, as well as a second novel region also associated with the lateral plate phenotype. Taken together, our results demonstrate that RAD markers, and the method to develop a RAD marker microarray resource, allow high-throughput, high-resolution genotyping in both model and non-model systems. Keywords: microarray genotyping