UDP-glycosyltransferase gene family expansion and functional perspectives in five tenebrionid beetles

UDP-glycosyltransferases (UGTs) are widely distributed biotransformation enzymes crucial for various physiological processes. Through genomic analysis, 216 UGT genes were identified in five tenebrionoid beetles: Tebebrio molitor (46), Tribolium castaneum (43), Asbolus verrucosus (30), Hycleus cichorii (60), and Hycleus phaleratus (37), classified into 14 families, with 13 being coleopteran-specific. Lineage-specific expansion of the UGT321, UGT323, UGT324, and UGT347 families was observed, with evidence of gene duplications within these families. Notably, phytophagous blister beetles showed higher UGT321 gene counts compared to omnivorous darkling beetles, while UGT324 family expansion was noted in the latter. Investigation of temporal and tissue-specific UGT gene expression in T. molitor revealed over 60% of TmUGTs were highly expressed in the salivary gland, fat body, midgut, and Malpighian tubule, indicating roles in metabolism and detoxification. Particularly, UGT321 family members exhibited high expression across various tissues, suggesting diverse functions, including potential involvement in olfaction and detoxification. These findings emphasize the multifunctionality of UGTs and provide a basis for further research, utilizing T. molitor as a model organism.