Comprehensive Analysis of the UGT Gene Superfamily in Spodoptera frugiperda

UDP-glycosyltransferases (UGTs) are widely distributed enzymes in living organisms that catalyze the transfer of glycosyl groups from donor molecules to acceptor molecules' glycoside ligands. These enzymes are pivotal for detoxifying and eliminating both endogenous and exogenous toxic substances in insects. In this study, bioinformatics methods were used to analyze the <i>UGT</i> gene superfamily in the fall armyworm (<i>Spodoptera frugiperda</i>), resulting in the identification of 48 <i>UGT</i> genes located across 10 chromosomes, including 23 tandem duplication pairs. The predicted SfUGT proteins mainly exhibit α-helical secondary structures. Intron numbers varied significantly, with high diversity observed in amino acid sequences. Phylogenetic analysis grouped <i>UGT</i> genes from three insect species into three distinct subfamilies, revealing a closer evolutionary relationship between <i>S. frugiperda</i> and <i>Spodoptera litura</i>, supported by a greater number of orthologous genes. Expression profiling showed that <i>SfUGT16</i> and <i>SfUGT21</i> are highly expressed in the first and fourth larval instars, respectively; <i>SfUGT16</i> is predominantly expressed in the Malpighian tubules and midgut, implying roles in digestion, metabolism, and detoxification. Meanwhile, <i>SfUGT21</i>, <i>SfUGT30</i>, and <i>SfUGT48</i> exhibited elevated expression in the hemolymph, suggesting functions in metabolism and transport, whereas <i>SfUGT40</i> showed high expression in both the midgut and hemolymph, indicating involvement in detoxification and metabolic processes. These findings provide a foundation for further exploration of the biological functions of the <i>UGT</i> gene family.