Abstract: As a model organism, Drosophila has the advantages of short growth cycle, high reproductive capacity, and low research cost. Moreover, 65% of genes in Drosophila are homologous with those in human, especially the simple genetic background of Drosophila makes Drosophila play an important role in the study of biological growth and development, pathological mechanism and gene expression regulation. So far, eight insulins, Drosophila insulin-like peptides 1-8 (Dilp1-8), have been identified in Drosophila, and studies of the Drosophila insulin signaling pathway have focused on its regulation of growth and development and energy metabolism, which is mainly mediated through Dilp1-7. Little is known about the function of Dilp8 and the molecular mechanism of its action. In this article, we summarized the results of studies on Dilp8 since its discovery. Dilp8 was mainly expressed in imaginal discs and ovaries of adult female Drosophila. Dilp8 allows Drosophila to grow into individuals with a normal-sized and symmetrical body by regulating tissue growth and developmental timing. Dilp8 in damaged larvae mitigates abnormal growth by delaying developmental time. After being activated, Dilp8 enters the central nervous system and specifically binds to its receptor leucine-rich repeat-containing G protein-coupled receptor 3 (Lgr3), thereby inhibiting the synthesis of ecdysone to control the growth and development of Drosophila. It has been suggested that Lgr3 is associated with sex regulation in Drosophila. Dilp8 regulates the ovulatory capacity of adult female Drosophila. In addition, tumour-derived Dilp8 is associated with anorexia of Drosophila. Dilp8/Lgr3 is highly homologous with human INSL3/RXFP2. The molecular mechanism of action of Dilp8 needs further exploration.

Key words: Drosophila, Dilp8, Lgr3, growth and development, ovulatory capacity