A two-step method for permeabilization of Drosophila eggs

Area of Science:

• Developmental Biology
• Cryobiology
• Biophysics

Background:

• Cryopreservation of Drosophila melanogaster embryos is crucial for long-term storage and research.
• The waxy eggcase of D. melanogaster embryos impedes cryoprotectant permeation and water flux.
• A novel permeabilization method is needed to overcome these barriers.

Purpose of the Study:

• To develop a method for permeabilizing Drosophila melanogaster embryos for cryopreservation.
• To investigate the hydraulic conductivity of permeabilized embryos.
• To study the permeation of cryoprotective agents into permeabilized embryos.

Main Methods:

• A two-step organic solvent procedure (isopropanol and hexane) was used to remove the eggcase wax layer.
• Dechorionated embryos were assessed for permeabilization via osmotic contraction in sucrose.
• Hydraulic conductivity and cryoprotectant permeation were measured using microdiffusion chambers and video microscopy.

Main Results:

• The solvent procedure successfully permeabilized 80-95% of embryos, with 75-90% hatching survival.
• Permeabilized embryos exhibited ideal osmotic behavior (Boyle-van't Hoff function).
• The mean hydraulic conductivity coefficient (Lp) was determined to be 0.722 +/- 0.366 micron/(min.atm) at 20°C.

Conclusions:

• A robust method for permeabilizing Drosophila melanogaster embryos was established.
• The characterized hydraulic conductivity is vital for optimizing cryopreservation protocols.
• This research lays the foundation for successful cryopreservation of these embryos.