Insect hemocytes play important biological roles at developmental stages,metamorphosis,and innate immunity.As one of the most abundant cell types,plasma-tocytes can participate in various innate immune responses,especially in encapsulation and node formation.Here,2 molecular markers of plasmatocytes,consisting of integrinβ2 and β3,were identified and used to understand the development of plasmatocytes.Plasmatocytes are widely distributed in the hematopoietic system,including circulating hemolymph and hematopoietic organs(HPOs).HPOs constantly release plasmatocytes with high proliferative activity in vitro;removal of HPOs leads to a dramatic reduction in the circulating plasmatocytes,and the remaining plasmatocytes gradually lose their abil-ity to proliferate in vivo.Our results demonstrated that the release of plasmatocytes from HPOs is regulated by insulin-mediated signals and their downstream pathways,including PI3K/Akt and MAPK/Erk signals.The insulin/PI3K/Akt signaling pathway can signifi-cantly irritate the hematopoiesis,and its inhibitor LY294002 could inhibit the hemocytes discharged from HPOs.While the insulin/MAPK/Erk signaling pathway plays a negative regulatory role,inhibiting its activity with U0126 can markedly promote the discharge of plasmatocytes from HPOs.Our results indicate that the circulating plasmatocytes are mainly generated and discharged by HPOs.This process is co-regulated by the PI3K/Akt and MAPK/Erk signals in an antagonistic manner to adjust the dynamic balance of the hemocytes.These findings can enhance our understanding of insect hematopoiesis.

Kui Zhang;Jingjing Su;Xin Hu;Xiaomin Yan;Siyuan Chen;Chongyang Li;Guangzhao Pan;Hongbo Chang;Wenli Tian;Muhammad Nadeem Abbas;Hongjuan Cui

State Key Laboratory of Silkworm Genome Biology,College of Sericulture,Textile and Biomass Sciences,Southwest University,Chongqing,China;Chongqing iCELL Biotechnology Co.Ltd,Chongqing,China;Department of Gastroenterology,The Second Affiliated Hospital of Chongqing Medical University,Chongqing,China;Institute of Apicultural Research,Chinese Academy of Agricultural Sci-ences,Beijing,China;Cancer Center,Reproductive Medicine Center,Medical Research Institute,Southwest University,Chongqing,China

中国昆虫科学（英文版）

[1]Kui Zhang;Jingjing Su;Xin Hu;Xiaomin Yan;Siyuan Chen;Chongyang Li;Guangzhao Pan;Hongbo Chang;Wenli Tian;Muhammad Nadeem Abbas;Hongjuan Cui-.Integrin β2 and β3:Two plasmatocyte markers deepen our understanding of the development of plasmatocytes in the silkworm Bombyx mori)[J].中国昆虫科学（英文版）,2022(06):1659-1671

plasmatocyte,plasmatocytes,hemocytes,tocytes,Plasmatocytes,HPOs,irritate

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