FUNCTIONAL BERIFICATION OF GENES RELATED TO HELMET DEVELOPMENT IN DAPHNIA GALEATA: BASED ON RNA INTERGERENCE AND MOTPHOLOGICAL OBSERVATION ANALYSIS

In order to explore the molecular mechanism of helmet development in <italic>Daphnia galeata</italic>, this study investigated the expression of two genes related to helmet development (<italic>DgTrepsin</italic> and <italic>DgFerritin</italic>) and changes of helmet morphology in <italic>D. galeata</italic> under RNA interference. The results showed that at a 2% concentration of <italic>E. coli</italic>, compared with the <italic>EGFP</italic> group, the <italic>DgTrypsin</italic>-interference group exhibited significant reductions in helmet length, relative helmet length, and the ratio of helmet length to head width, accompanied by a 27.45% decrease in <italic>DgDrypsin</italic> expression. However, no significant morphological or gene expression changes were observed in the <italic>DgFerritin</italic>-interference group at this concentration. When the concentration concentration of <italic>E. coli</italic> was increased to 5%, both the <italic>DgTrypsin</italic> and <italic>DgFerritin</italic> groups showed significant decreases in all three helmet morphology metrics, along with respective gene expression reductions of 55.96% and 40.39%, respectively. These results indicate that higher levels of RNA interference have a stronger inhibitory effect on the morphological changes and expression levels of the target genes. The findings demonstrate that <italic>DgTrypsin</italic> and <italic>DgFerritin</italic> genes are involved in the development of <italic>D. galeata</italic> helmet providing a valuable reference for further exploration of molecular mechanisms underlying the morphogenesis in <italic>Daphnia</italic>.