biostudies-literatureUnknown44(2)Hu XEicosanoids are crucial downstream signals in the insect immune responses. Phospholipase A2 (PLA2) catalyzes phospholipids, the initial step in eicosanoid biosynthesis. In mammals, the biological roles of <i>Ca²⁺-independent Phospholipase A2 (iPLA2)</i> have been extensively studied; however, only a few studies have attempted to explore <i>iPLA2</i> functions in insects. In this study, we identified two <i>iPLA2</i> genes (designated as <i>BmiPLA2A</i> and <i>BmiPLA2B</i>) in the silkworm, <i>Bombyx mori</i>. <i>BmiPLA2A</i> had a 2427 base pair (bp) open reading frame (ORF) that coded for a protein with 808 amino acids. In contrast, <i>BmiPLA2B</i> had a 1731 bp ORF that coded for a protein with 576 amino acids. Domain analysis revealed that BmiPLA2A had six ankyrin repeat domains, but BmiPLA2B lacks these domains. <i>BmiPLA2A</i> and <i>BmiPLA2B</i> were transcribed widely in various tissues and developmental stages with different expression patterns. The administration of 20-hydroxyecdysone increased their expression levels in the epidermis and hemocytes. Furthermore, challenged with virus, fungus, Gram-negative bacteria, and Gram-positive bacteria induced the expression of <i>BmiPLA2A</i> and <i>BmiPLA2B</i> with variable degrees along with different time points. Our findings imply that <i>BmiPLA2A</i> and <i>BmiPLA2B</i> may have important biological roles in the development and innate immunity of <i>B. mori</i>.Current issues in molecular biology777-790https://www.ebi.ac.uk/biostudies/studies/S-EPMC8929031biostudies-literatureMolecular Characterization of Two Genes Encoding Novel Ca²⁺-Independent Phospholipase A2s from the Silkworm, <i>Bombyx mori</i>.PMC8929031Zheng XJi HFeng KZhu YHu XGul ICui HAbbas MNZhang BfalseMolecular Characterization of Two Genes Encoding Novel Ca²⁺-Independent Phospholipase A2s from the Silkworm, <i>Bombyx mori</i>.Eicosanoids are crucial downstream signals in the insect immune responses. Phospholipase A2 (PLA2) catalyzes phospholipids, the initial step in eicosanoid biosynthesis. In mammals, the biological roles of <i>Ca²⁺-independent Phospholipase A2 (iPLA2)</i> have been extensively studied; however, only a few studies have attempted to explore <i>iPLA2</i> functions in insects. In this study, we identified two <i>iPLA2</i> genes (designated as <i>BmiPLA2A</i> and <i>BmiPLA2B</i>) in the silkworm, <i>Bombyx mori</i>. <i>BmiPLA2A</i> had a 2427 base pair (bp) open reading frame (ORF) that coded for a protein with 808 amino acids. In contrast, <i>BmiPLA2B</i> had a 1731 bp ORF that coded for a protein with 576 amino acids. Domain analysis revealed that BmiPLA2A had six ankyrin repeat domains, but BmiPLA2B lacks these domains. <i>BmiPLA2A</i> and <i>BmiPLA2B</i> were transcribed widely in various tissues and developmental stages with different expression patterns. The administration of 20-hydroxyecdysone increased their expression levels in the epidermis and hemocytes. Furthermore, challenged with virus, fungus, Gram-negative bacteria, and Gram-positive bacteria induced the expression of <i>BmiPLA2A</i> and <i>BmiPLA2B</i> with variable degrees along with different time points. Our findings imply that <i>BmiPLA2A</i> and <i>BmiPLA2B</i> may have important biological roles in the development and innate immunity of <i>B. mori</i>.2022-01-01T00:00:00Z2022 Feb2024-11-20T17:20:55.099Z2024-11-20T17:20:55.099ZS-EPMC89290313572333910.3390/cimb44020054