Figure 9 . Annotation and distribution of DEGs (|log2FC| > 2, p value < 0.05) in the pathway of protein processing in the endoplasmic reticulum ofM. rosenbergii . KEGG enrichment of DEGs in up-regulated expression in the brain (A) and up-regulated expression in the thoracic ganglion (B). The DEGs were separated into different principal components (C) the distribution is shown (D) according to tissues and sexes of M. rosenbergii . FB: female brain; FG: female thoracic ganglion; MB: male brain; MG: male thoracic ganglion; M: male; F: female.
The DEGs were involved in protein recognition by luminal chaperones (k09486, 3 genes), polypeptide folding, and correction (k1718, 3 genes). Most of the DEGs presented in the ER-associated degradation pathway (ERAD), a process which starts with misfolded protein recognition, followed by ubiquitination and retrotranslocation into the cytosol for degradation in proteasome (Figure 10). Protein disulfide- isomerases (PDIs, K09580, 10 genes) and Osteosarcoma-9 (OS-9, k10088, 1 gene) delivered misfolded polypeptide to the ubiquitin ligase complex, which is composed of ubiquitin-protein ligases such as Dao10 (k10661, 3 genes), Sel1L (k14026, 4 genes), and Hsp40 (k09502, 5 genes) in ERAD. A translocon-associated protein, TRAP (k13251, 3 genes), showed up-regulated expression in the male brain and thoracic ganglion, which plays a role in accelerating ER degradation of unfolded proteins (Figure 10).