The Spemann-Mangold organiser and the dissemination of its discovery in interwar Finland.

Abstract

A century has passed since the publication of the discovery of the Spemann-Mangold organiser, most visibly celebrated by the Festschrift Spemann and Mangold centennial special issue in Cells & Development and the conference Self-Organization in Biology: Freiburg Spemann-Mangold Centennial Symposium in September 2024. In honour of the anniversary, the Festschrift commemorates and reviews the history of the Spemann school of embryology and the later developments in the quest to understand the mechanistic underpinnings of the organiser. Here, I share a few new and untold insights from the Finnish archives on how the discovery of the organiser was communicated to and within Finland in the 1920s and '30s. The Finnish zoologists Alexander Luther and Gunnar Ekman had been visiting scholars in Spemann's laboratory, brought the field of experimental embryology to their home country, and incorporated it into the curriculum. Especially Ekman taught embryology to a generation of students in both tertiary and secondary education, created the Finnish terminology of the field, and actively popularised the latest discoveries in various books and journals. Intriguingly, the archives reveal that Ekman published a synopsis of the organiser experiment in Finnish in the spring of 1924 prior to the publication of the original article in September, and invited Spemann to visit Finland in September 1925. These efforts consolidated the popularity of the Spemann school of experimental embryology in Finnish academia, and shed light on "how experimental embryology was transplanted to Finland".