Protocol for Transplantation of Healthy Cells Between Adult Drosophila of Different Ages and Sexes

Drosophila melanogaster is utilized as an exceptionally powerful and versatile model organism for investigating tissue allotransplantation. This is largely attributable to its remarkably short life cycle, high degree of genetic manipulability, and the significant homology observed in many of its key signaling pathways when compared to those in mammals. The protocol described herein outlines the procedure for performing tissue transplants between adult individuals of differing ages and sexes. The procedure involves several critical steps: beginning with the meticulous dissection of the donor’s midgut tissue, followed by the precise microinjection of the dissected tissue into the recipient organism, and subsequently tracking the engraftment and integration of these transplanted tissues by exploiting the differences in the sex chromosomes between the donor and the recipient. The principal outcomes of this protocol reveal that the host organisms exhibit a high rate of short-term survival (exceeding 80%), and that the transplanted tissues undergo encapsulation by hemocytes. Moreover, there is a pronounced sexual dimorphism observed in the outcome of the transplantations: female hosts tend to mount a significantly stronger immune response through the activation of the Toll pathway, which in turn results in a more frequent rejection of the transplant, whereas male hosts display a higher level of tolerance towards foreign tissues. Additionally, it is noted that age-related changes in both the donor and the recipient have a significant impact on the overall success of the procedure. Older individuals often demonstrate a reduced regenerative capacity of their tissues, a phenomenon that is linked to the downregulation of crucial signaling pathways such as Hippo/DPP and an accumulation of oxidative stress. This methodology also permits the modeling of intestinal stem cell regeneration. Despite certain technical limitations – such as the very small size of the tissues involved and the lack of an adaptive immune system – the protocol affords researchers unique opportunities to analyze innate immune mechanisms, aging processes, and intercellular interactions. The data generated underscore the potential of Drosophila as an invaluable preclinical model, combining low costs, ethical acceptability, and the high standardization of experimental conditions. Ultimately, this work opens promising avenues for the study of evolutionarily conserved processes underlying both tissue regeneration and immune response within the context of allotransplantation. Keywords: аllotransplantation, дrosophila melanogaster, sexual dimorphism, pathway, aging, signaling