Search Results (2)

Pubertal molting represents a pivotal transition in the life cycle of crustaceans, marking the shift from somatic growth to reproductive development. In mud crabs, mating is known to facilitate this process, yet the molecular mechanisms remain poorly understood. Here, we applied full-length transcriptome sequencing to characterize changes in gene expression and alternative splicing (AS) across post-mating ovarian development. AS analysis revealed extensive transcript diversity, predominantly alternative first exon (AF) and alternative 5′ splice site (A5) events, enriched in genes linked to chromatin remodeling, protein regulation, and metabolism, underscoring AS as a fine-tuning mechanism in ovarian development. Comparative analyses revealed profound molecular reprogramming after mating. In the UM vs. M1 comparison, pathways related to serotonin and catecholamine signaling were enriched, suggesting early neuroendocrine regulation. Serotonin likely promoted, while dopamine inhibited, oocyte maturation, indicating a potential “inhibition–activation” switch. In the UM vs. M3 comparison, pathways associated with oxidative phosphorylation, ATP biosynthesis, and lipid metabolism were upregulated, reflecting heightened energy demands during vitellogenesis. ECM-receptor interaction, HIF-1, and IL-17 signaling pathways further pointed to structural remodeling and tissue regulation. Enhanced antioxidant defenses, including upregulation of SOD2, CAT, GPX4, and GSTO1, highlighted the importance of redox homeostasis. Together, these findings provide the first comprehensive view of transcriptional and splicing dynamics underlying post-mating ovarian maturation in Scylla paramamosain, offering novel insights into the molecular basis of crustacean reproduction. Full article

Pubertal molt is a vital stage in the cultivation of mature female crabs in the aquacultural industry of Scylla paramamosain. Since fasting occurs during molting, which requires a large supply of energy, internal energy reserves are critical. However, the dynamics of energy supply during pubertal molt is not clear. This study focuses on the variations of carbohydrates and lipids in serum during the pubertal molt of S. paramamosain via a metabolomics approach. Eleven lipid or carbohydrate metabolic pathways were significantly influenced postmolt. A remarkable decrease in carbohydrates in serum suggested that free sugars were consumed for energy. A significant decrease in glucose and alpha-d-glucosamine 1-phosphate showed that chitin synthesis exhausted glycogen, resulting in insufficient glucose supply. An increase in l-carnitine and acetylcarnitine, and a significant decrease in 15 fatty acyls and 8 glycerophosphocholines in serum indicated that carnitine shuttle was stimulated, and β-oxidation was upregulated postmolt. In addition, astaxanthin, ponasterone A, and riboflavin in serum were significantly decreased postmolt. Eleven potential metabolite biomarkers were identified for pubertal molt. Taken together, carbohydrates and lipids were possibly major energy reserves in pubertal molt. This study suggests that an increase in carbohydrate and lipid levels in crab feed may alleviate the effects of fasting during molt and improve farm productivity in mature female crabs. Full article