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:Cytochrome P450 aromatase is an essential enzyme for vertebrates. It is responsible for the conversion of androgens to estrogens in the brain and gonadal tissues. Aromatase converts testosterone into estradiol and therefore participates in the regulation of many processes which are controlled by estrogens such as development and fertility. Teleosts have been characterized as having exceptionally high levels of brain estrogen biosynthesis when compared to the brains of the other vertebrates. Little is known about the effects of estrogens on brain function in teleosts. The main objective of this study was to assess the effects of fadrozole, a powerful aromatase inhibitor, on gene expression in the zebrafish brain. To achieve this, male zebrafish were exposed to fadrozole for 10 days. This exposure causes a decrease in estrogens along with an increase in androgens. Plasma testosterone levels showed a 3-fold increase in response to the exposure. In the telencephalon, 235 genes were identified by Affymetrix GeneChip analysis as being differentially regulated. Real-time RT-PCR was used to validate the data obtained from the microarrays. This technique was also used to evaluate the response in the hypothalamus, which appears to follow similar transcriptional regulation. Gene ontology analysis of the microarray data revealed common biological processes and molecular functions such as sensory perception and detection of light stimulus, homeobox and transcription factor complexes. This study has identified genes which are directly and/or indirectly controlled by estrogens and androgens which helped to demonstrate the pronounced effects of endocrine disrupting chemicals on gene expression in the brain of teleosts. Collectively, the results provide a better understanding of the effects of aromatase inhibitors on gene expression and also shed light on the underlying effects of sex hormone variation and their importance in the brain of teleosts. Adult male zebrafish were exposed to fadrozole (200 ug/L) for 10 days. Telencephalons were pooled; approximately 30 per array. 3 treated samples, 3 control samples
Project description:Purpose: Construction of 3D zebrafish spatial transcriptomics data for studying the establishment of AP axis. Methods: We performed serial bulk RNA-seq data of zebrafish embryo at three development points. Using the published spatial transcriptomics data as references, we implemented Palette to infer spatial gene expression from bulk RNA-seq data and constructed 3D embryonic spatial transcriptomics. The constructed 3D transcriptomics data was then projected on zebrafish embryo images with 3D coordinates, establishing a spatial gene expression atlas named Danio rerio Asymmetrical Maps (DreAM). Results: DreAM provides a powerful platform for visualizing gene expression patterns on zebrafish morphology and investigating spatial cell-cell interactions. Conclusions: Our work used DreAM to explore the establishment of anteroposterior (AP) axis, and identified multiple morphogen gradients that played essential roles in determining cell AP positions. Finally, we difined a hox score, and comprehensively demonstrated the spatial collinearity of Hox genes at single-cell resolution during development.