Screening of key genes during early embryonic development of Nile tilapia (Oreochromis niloticus)

Abstract

The discovery of key genes for the early embryonic development of Nile tiapia (Oreochromis niloticus) is essential for the growth and development of Nile tilapia. However, mass mining of key genes during embryonic development using bioinformatics at once has not yet been performed. In this paper, a series of bioinformatics tools together with published tilapia microarray data were used to perform differential gene expression, GO and KEGG analysis, and string network construction. A total of 187 up-regulated genes and 276 down-regulated genes were obtained. The differentially expressed genes (DEGs) were enriched in focal adhesion, salmonella infection, adhersion junction, cytosolic DNA-sensing, regulation of actin cytoskeleton, C-type lectin receptor, mTOR, insulin, Toll-like receptor, progesterone-mediated oocyte and FoxO signaling pathway. Notably, Mapk3 and Pik3ca were associated with almost all enriched signaling pathways. Based on the string network, 10 key genes during early embryonic development of tilapia were identified. Among them, the Wasf, Yes and Cul5 genes were closely related to mitochondrial morphological defects and embryonic movement disorders. Hdac8, Rps14, Trrap, and Mrps6, were pathogenic genes for human diseases. As an important key gene in the string network, Mapk3 was selected for furthermore functional assays. The subcellular localization results showed that Mapk3 and Fgf12 co-localized and interacted only in the cytoplasm, while Mapk3 and Fgf24 were distributed in the nucleus and cytoplasm. The BiFC results showed that Mapk3 interacted with Fgf12 or Fgf24 and played a role in different spaces. In conclusion, this study might provide clues to further explore the key genes in the embryonic development of tilapia to reveal its embryonic development mechanism.