Retraction: Shin, J.-H.; Jeong, C.-W. Zipper Is Necessary for Branching Morphogenesis of the Terminal Cells in the Drosophila melanogaster's Tracheal System. Biology 2021, 10, 729.

The published article [...].

The published article [1] has been retracted at the request of the authors. Following publication, the authors contacted the editorial office regarding errors in the data and methodology.

Although Figure 3 describes a validation experiment performed using an alternative stock of D. melanogaster—more specifically virgin female fruit flies with btl > gal4, UAS > cytoplasmic gfp and male stock with btl > gal4, UAS > zipper RNAi genes—following publication the authors realized that these were not independent stock from the initial one, but rather fruit flies stored in another container. Therefore, this was not a validation experiment and the entire dataset in Figure 3 is illegitimate. Furthermore, although Figure 4 is a rescue experiment demonstrating the sufficiency of Zipper in branching morphogenesis, the term ‘rescue experiment’ is inaccurate. A rescue experiment means that a gene-loss individual is able to reobtain a particular phenotype with the addition of such gene/protein. Yet, the methodology simply used an alternative stock that had the protein Zipper. Thus, there is no clear evidence of RNAi-induced fruit flies reobtaining the branching phenotype.

This retraction was approved by the Editor-in-Chief of the journal. The authors agreed to this retraction.