Pss knockdown in the midgut causes growth retardation in Drosophila similar to that in human LMHD.

Background: Phosphatidylserine synthase (PSS), localized in the mitochondrial membrane, synthesizes phosphatidylserine. In humans, mutations in Pss lead to Lenz-Majewski hyperostotic dwarfism, a disorder affecting growth and development. The effects of Pss mutations on the growth of Drosophila melanogaster are not fully known. Hence, this study was conducted to investigate the effects of Pss knockdown on the growth and development of D. melanogaster.

Results: Enterocyte (EC)-specific Pss knockdown resulted in reduced cell size in the gut via reduced Akt signaling. EC-specific Pss knockdown was associated with a decrease in gut size, a change in gut pH, and reduced food intake. These abnormalities affected normal nutrient metabolism in larvae, leading to decreased secretion of Drosophila insulin-like peptides. Consequently, the reduced systemic Akt signaling at the organismal level resulted not only in impaired gut growth but also in abnormal organismal growth and development.

Conclusion: These findings highlight the significant role of the Pss gene in the growth and development of D. melanogaster.