An inspiring overview Recent research into ploidy changes, gene and genome duplications encompasses and wide spectrum of fascinating topics. Like most fields of modern biology, polyploidy research experiences an ongoing transformation thanks to next and beyond-next generation sequencing technologies. More than 30 years ago, Lewis edited his comprehensive work on polyploid plants and animals. Although there have been efforts to bring together polyploidy researchers from botany and zoology in recent conferences, collaboration between them is still scarce. Therefore, the editors of this thematic issue have made a special attempt to mirror and contrast research on polyploid animals with that on plants. Featuring 15 articles on various hot topics in polyploidy research ranging from cytology to evolution, this publication provides an inspiring overview and will be useful reading to both animal and plant researchers.