Changes in the biochemical and gene expression profiles of Palaemon carinicauda during ovarian development.

Palaemon carinicauda is an economically important shrimp species in China. In this study, muscle, hepatopancreas and ovaries were collected to measure their biochemical composition during ovarian development. In addition, dynamic changes in the transcriptome of P. carinicauda ovaries were investigated. The results showed steady increases in glycogen, triglyceride (TG) and protein levels in the ovaries during maturation. The glycogen level increased consistently in the hepatopancreas, while in the muscle, glycogen showed a downward trend after reaching its highest value at Stage III. Similarly, TG concentration in the hepatopancreas decreased before subsequently increasing, while in the case of muscle, the TG level increased from Stage I to Stage IV prior to a significant decrease in Stage V. In hepatopancreas and muscle, the highest level of protein was observed at Stage III and Stage II respectively and at subsequent stages, the levels decreased, with the lowest value reached in Stage V. Results of RNA-seq revealed dynamic changes in the ovarian transcriptome during development, with extensive changes taking place from Stage I to Stage II and Stage IV to Stage V. KEGG pathway enrichment analysis of upregulated differentially expressed genes (DEGs) revealed that metabolic pathway, lysosome, protein processing in the endoplasmic reticulum, mitogen-activated protein kinase (MAPK) signaling pathway, extracellular matrix (ECM)-receptor interaction, purine metabolism and phagosome were the main enriched pathways. The above results provide a framework for understanding the biochemical and transcriptome dynamics during P. carinicauda ovarian development.