The research in the field of Drosophila melanogaster in the last century has led to many landmark discoveries including accounting for six Nobel prizes. Drosophila, being one of the topmost studied genetic model organism, has many genetic tools to address and solve biological puzzles. This requires different mutations in genes of interest and many other transgenes for over expression or loss of function for particular gene of interest in study. So this accounts for many stocks for one particular gene. Since Drosophila genome encodes more than 13000 genes, its not surprising that there are more than 160000 stocks are present in various stock centers and individual labs and number of stocks keep increasing with the day .
Maintaining of these huge numbers of stocks requires lot of time and effort . Currently stock transfer is done manually, where hatched adults flies needs to transferred into fresh food vials every 20 to 22 days when kept at 18 degrees centigrade. One of the biggest challenge in the field of Drosophila research is lack of any proper cryopreservation method to freeze embryos or adults.
Cryopreservation ( storing at -20 or -80 C) serves as an excellent option for storing bacteria or cells from different cell lines. This allows us to store reagents when not required in freezers and thawed back when in need for experiments. So that its not required to keep maintaining them on plates or culture media. However this it not possible with Drosophila as there is no proper method to freeze embryos or any other stage of Drosophila life cycle.
Recent work from the lab of Thomas Hays and John Bischof will go a long way in overcoming this hurdle of cryopreservation in the Drosophila research field. The work published in recent issue of Nature Communications demonstrate that more than 50% embryos hatch and >25% of the resulting larvae develop into adults after cryopreservation in 25 different Drosophila strains.
If this protocol turns out to be widely applicable in different labs around the world , this would provides many advantages. This decreases stock maintenance costs and reduce the risk of stock loss caused by contamination or accidental mixing of precious stocks. This long awaited tool will be a great addition to already available list of genetic tools and further strengthen this amazing model of biology.
Zhan, L., Li, Mg., Hays, T. et al. Cryopreservation method for Drosophila melanogaster embryos. Nat Commun 12, 2412 (2021). https://doi.org/10.1038/s41467-021-22694-z