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

The greater amberjack (<i>Seriola dumerili</i>) 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., <i>ccnd1</i>, <i>cdk1</i>, <i>cdc6</i>, <i>cdc25b</i>, <i>fbxo43</i>, <i>cdkn1a</i> and <i>cdkn1d</i>), the TGF-beta signaling pathway (e.g., <i>gdf6</i>, <i>bmpr1b</i>, <i>gsdf</i>, <i>amh</i>, <i>tgfb3</i>, and <i>smad6</i>), steroid hormone biosynthesis (e.g., <i>hsd3b1</i>, <i>hsd11b2</i>, <i>hsd17b12</i> and <i>hsd20b2</i>), and the endocrine system (e.g., <i>mapk8a</i>, <i>mapk11</i>, <i>mapk12a</i>, <i>mapk13</i> and <i>adcy9</i>). 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.