Preprint: Drosophila expressing AD-associated APOE4 variants show progressive behavioural and cognitive decline

A preprint posted to bioRxiv on 12 September 2026 describes the development and characterisation of a Drosophila melanogaster model carrying human APOE4 variants associated with Alzheimer's disease (AD). The authors report that flies expressing APOE4 showed progressive declines in behavioural and cognitive readouts compared with controls, providing phenotypic parallels to features of human AD.

APOE4 is the strongest and most common genetic risk factor for late-onset AD, present in approximately 75 per cent of AD patients according to the preprint's introduction, though APOE4 is neither necessary nor sufficient for disease. The authors note that because additional genetic and environmental factors modulate APOE4's effects, a tractable in vivo model that isolates APOE4 variant contributions would be valuable for pathway dissection and candidate therapeutic screening.

Drosophila models cannot recapitulate the full complexity of human neurodegeneration, and the specific APOE4 variants introduced, the behavioural assays used, and the research group responsible are not detailed in the available lede. As a preprint, this work has not yet undergone peer review. The study is primarily relevant to basic researchers working on AD genetics and model organisms, and to educators covering neurogenetics.