# Transcriptome Analysis of Different Stages in the Early Ovarian Development of the Greater Amberjack (Seriola dumerili)

## TL;DR

This study analyzes gene activity in early ovarian development of greater amberjack to identify key genes and pathways involved in this process.

## Contribution

The study provides new insights into the molecular mechanisms of early ovarian development in artificially bred greater amberjacks.

## Key findings

- Genes related to cell growth and death were identified as important in ovarian development.
- The TGF-beta signaling pathway and steroid hormone biosynthesis were found to be key in ovarian development.
- Endocrine-related genes were also found to play a role in the process.

## Abstract

The greater amberjack (Seriola dumerili) is a globally important aquaculture fish species. However, current research on the ovarian development and regulation of the greater amberjack is limited, particularly with regard to early ovarian development in artificially bred individuals. Therefore, this study aims to analyze the transcriptomes at the early stage of ovarian development to screen candidate genes and signaling pathways associated with ovarian development. This will provide a theoretical basis for exploring the underlying molecular mechanisms of early ovarian development in artificially bred greater amberjacks.

The greater amberjack (Seriola dumerili) is a globally important aquaculture fish species belonging to the family Carangidae. However, current research on the ovarian development and regulation of the greater amberjack is limited, particularly with regard to early ovarian development in artificially bred individuals. Therefore, this study aims to analyze the ovarian transcriptomes at the primary growth stage in one-year-old fish at the chromatin nucleolar stage and two-year-old fish at the perinucleolar stage to suggest how early ovarian development takes place in artificially bred greater amberjacks. To do this, the study constructed ovarian mRNA expression profiles of different stages of artificially bred fish and identified differentially expressed genes (DEGs), Gene Ontology terms, and Kyoto Encyclopedia of Genes and Genomes pathways important for various physiological processes. A functional analysis revealed that the DEGs closely related to ovarian development were involved in cell growth and death (e.g., ccnd1, cdk1, cdc6, cdc25b, fbxo43, cdkn1a and cdkn1d), the TGF-beta signaling pathway (e.g., gdf6, bmpr1b, gsdf, amh, tgfb3, and smad6), steroid hormone biosynthesis (e.g., hsd3b1, hsd11b2, hsd17b12 and hsd20b2), and the endocrine system (e.g., mapk8a, mapk11, mapk12a, mapk13 and adcy9). These findings suggest that ovarian development is the result of the coordinated regulation of various genes responsible for various functions. This study provides a theoretical basis for exploring the underlying molecular mechanisms of early ovarian development in artificially bred greater amberjacks.