Abstract
The Drosophila melanogaster P-transposable element is an example of mobile DNA transferred horizontally and known to have spread globally over the last 50-60 years. In Drosophila, the P-element causes a syndrome known as 'P-M hybrid dysgenesis' that obstructs normal ovary development in the female progeny of susceptible populations. Despite extensive research, the stability and global population dynamics of P-M dysgenic phenotypes remain poorly understood. Here, we report a recent and rapid transition in the P-M status of D. melanogaster populations from Ukraine. We demonstrate that these populations are currently dominated by the P'-cytotype characterized by active genomic P-elements and unknown from Ukraine just two decades ago. Our results suggest a recent invasion of the P-element in Ukraine, a pattern that matches recent discoveries from Turkey.