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: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.
Project description:The exon junction complex (EJC) is composed of three core proteins Rbm8a, Magoh and Eif4a3 and is thought to play a role in several post-transcriptional processes. In this study we focus on understanding the role of EJC in zebrafish development. We identified transcriptome-wide binding sites of EJC in zebrafish via RNA:protein immunoprecipitation followed by deep sequencing (RIP-Seq). We find that, as in human cells, zebrafish EJC is deposited about 24 nts upstream of exon-exon junctions. We also identify transcripts regulated by Rbm8a and Magoh in zebrafish embryos using whole embryo RNA-seq from rbm8a mutant, magoh mutant and wild-type sibling embryos. This study shows that nonsense mediated mRNA decay is dysregulated in zebrafish EJC mutants.