Comparative transcriptome, digital gene expression and proteome profiling analyses provide insights into the brachyurization from the megalopa to the first juvenile in Eriocheir sinensis

Eriocheir sinensis larva normally experiences 11 stages. The reduced abdomen folded beneath the thorax is the most prominent characteristic of morphological alteration from megalopa to juvenile crab. Up to date, the molecular mechanisms of brachyurization remain a mystery. Here, transcriptome library, digital gene expression (DGE) libraries and proteome libraries at two developmental stages [the megalopa stage of E. sinensis (stage M) and the first stage of juvenile crab (stage J1)] of the Chinese mitten crab larva were constructed for RNA sequencing and iTRAQ approaches followed by bioinformatics analysis, respectively. In total, 1106 genes and 871 proteins were differentially expressed between the stage M and stage J1. Moreover, several important pathways were identified, including biosynthesis of secondary metabolites, metabolic pathways, focal adhesion, and some disease pathways. Besides, muscle contraction, oxidative phosphorylation, calcium signaling, PI3K-Akt, DNA replication pathway, and integrin signaling pathway also had important functions in brachyurization process. Furthermore, the components, actin, actin-related protein, collagens, filamin-A/B, laminin, integrins, paxillin, and fibronectin had upregulated expression levels in M stage compared to J1 stage.

Automated summary

Eriocheir sinensis larvae undergo 11 stages, with the most notable change being the folding of the reduced abdomen under the thorax during the transformation from megalopa to juvenile crab. The molecular mechanisms behind this brachyurization process are still unknown. To shed light on this, researchers constructed transcriptome, digital gene expression (DGE), and proteome libraries for Chinese mitten crab larvae in two developmental stages (megalopa and first stage of juvenile crab) and performed RNA sequencing and iTRAQ analysis. They found that 1106 genes and 871 proteins showed differential expression between the two stages. Several important pathways, including biosynthesis of secondary metabolites, metabolic pathways, focal adhesion, and disease pathways, were identified. Muscle contraction, oxidative phosphorylation, calcium signaling, PI3K-Akt, DNA replication pathway, and integrin signaling pathway were also found to play important roles in brachyurization. Additionally, certain components, such as actin, actin-related protein, collagens, filamin-A/B, laminin, integrins, paxillin, and fibronectin, were upregulated in the megalopa stage compared to the first stage of juvenile crab.