Genotype by Selenium Concentration Interactions for Selenium-Related Genes in Paramisgurnus dabryanus at Different Durations

To distinguish the direct regulatory effect of nano-selenium on selenoprotein pathways from its indirect induction of glutathione metabolism, we measured the expression of eight genes representing these two core pathways (selenoo1, trnau1apl, selenop, and gpx1 for selenoprotein synthesis; mgst1, cha2, hagh, and glo1 for glutathione metabolism) in Paramisgurnus dabryanus at 20, 40, and 60 days of feeding, enabling the characterisation of short-, medium- and long-term transcriptional responses. Additive main effects and multiplicative interaction (AMMI) and genotype environment interaction (GGE) biplots were used to analyse the genetic basis of expression of the two types of selenium-related genes. The AMMI analysis of the expression of two types of selenium-related genes in P. dabryanus showed that, for selenoprotein-synthesis-related genes, the effect of selenium concentration decreased slightly and then gradually increased over time. For glutathione metabolism-related genes, the effect of selenium concentration decreased linearly over time. For both gene types, as time progressed, a clear antagonistic relationship was observed between the genotype effect and the genotype × selenium concentration interaction. GGE biplot analysis indicated that, overall, for selenoprotein-synthesis-related genes, the top two based on comprehensive evaluation of both stability and high expression were gpx1 and selenop. gpx1 may serve as a potential candidate for assessing nano-selenium bioavailability, selenium nutritional status, and antioxidant responses, warranting further validation. Overall, the top two glutathione metabolism-related genes in terms of comprehensive evaluation were glo1 and hagh. glo1 may be a potential indicator of nano-selenium-induced oxidative stress or glutathione metabolic load.