We had previously reported a prostaglandin E synthase (bmPGES) in the silkworm Bombyx mori that catalyzes the isomerization of PGH(2) to PGE(2). The present study aimed to provide a genome-editing characterization of bmPGES in B. mori. Results showed bmPGES gene disruption to result in a reduced content of PGE(2). The change affected the expression of chorion genes and egg formation in silkworms. Collectively, the results indicated that bmPGES could be involved in reproduction of B. mori. Therefore, this study provides insights into the physiological role of bmPGES and PGE(2) in silkworms. (C) 2019 Elsevier Inc. All rights reserved.