COMMD family members exhibit immune-associated expression patterns following dietary selenomethionine supplementation and subsequent Bacillus cereus challenge in Pelodiscus sinensis.

The copper metabolism MURR1 domain-containing (COMMD) protein family participates in diverse cellular and immune-related processes, yet little is known about this family in reptiles. In this study, we performed a genome-wide characterization of the COMMD gene family in the Chinese soft-shelled turtle (Pelodiscus sinensis) and examined its tissue expression and transcriptional patterns following dietary selenomethionine (Se-Met) supplementation and subsequent Bacillus cereus challenge. Ten COMMD family members (COMMD1-COMMD10) were identified, all of which contained a conserved COMM domain and showed conserved evolutionary relationships with vertebrate orthologs. Most COMMD genes were highly expressed in the liver and spleen, although distinct tissue-specific patterns were observed among individual family members. After 45 days of dietary Se-Met supplementation, turtles were challenged with B. cereus, and COMMD genes exhibited heterogeneous, gene-, tissue-, and time-dependent transcriptional responses without a uniform concentration-dependent pattern. Pearson correlation analysis further revealed significant co-expression associations between several COMMD family members and representative immune-related genes, including TLR2, MyD88, TRAF6, NF-κB, TNF, and IL18. These transcriptional associations suggest potential links between COMMD family members and immune-related responses but do not establish direct regulatory relationships. This study provides a genomic and expression-level resource for future functional investigation of COMMD family members in reptilian immunity.