Temporal Transcriptome Analysis Reveals Dynamic Expression Profiles of Gametes and Embryonic Development in Japanese Flounder (Paralichthys olivaceus)

Abstract

The maternal-to-zygotic transition (MZT) is a crucial event in embryo development. While the features of the MZT across species are shared, the stage of this transition is different among species. We characterized MZT in a flatfish species, Japanese flounder (Paralichthys olivaceus). In this study, we analyzed the 551.57 GB transcriptome data of two types of gametes (sperms and eggs) and 10 embryo developmental stages in Japanese flounder. We identified 2512 maternal factor-related genes and found that most of those maternal factor-related genes expression decreased at the low blastula (LB) stage and remained silent in the subsequent embryonic development period. Meanwhile, we verified that the zygotic genome transcription might occur at the 128-cell stage and large-scale transcription began at the LB stage, which indicates the LB stage is the major wave zygotic genome activation (ZGA) occurs. In addition, we indicated that the Wnt signaling pathway, playing a diverse role in embryonic development, was involved in the ZGA and the axis formation. The results reported the list of the maternal genes in Japanese flounder and defined the stage of MZT, contributing to the understanding of the details of MZT during Japanese flounder embryonic development.

Unveiling Gene Expression Dynamics during Early Embryogenesis in Cynoglossus semilaevis: A Transcriptomic Perspective

“…This study generated high-quality RNA-seq data for C. semilaevis gametes (sperm and oocyte) and early embryos at different developmental stages (from the four-cell to gastrula stages) to track the global gene expression changes during early embryogenesis. For the first time, we confirmed that large-scale ZGA occurs at the blastula stage in C. semilaevis, consistent with the findings for Japanese flounders [44], zebrafish, and frogs [4]. Accordingly, gene transcripts that were abundant in C. semilaevis oocytes were also abundant in four-cell to one thousand-cell embryos, which conferred functions that are vital for pre-ZGA cleavage (e.g., the enrichment of mitosis-related genes in the Maternal module).…”

Temporal transcriptome analysis reveals several key pathways involve in cadmium stress response in Nicotiana tabacum L.

“…This method could dynamically monitor plant responses to different stages of stimuli exposure at the gene expression level. For example, it has previously been used to reveal how wheat can coordinate the expression of homologous genes to cope with various environmental constraints at the genome-wide level ( Hao et al., 2021 ); how candidate genes regulate flower opening and closing in Iris, leading to an improved understanding of the regulatory network of flowering ( Liu et al., 2022 ).…”