Frans Alfons Janssens

Frans Alfons Ignace Maria Janssens (Sint-Niklaas 23 July 1863 – Wichelen, 8 October 1924)[1] was Catholic priest and the discoverer of crossing-over of genes during meiosis, which he called "chiasmatypie".

His work was continued by the Nobel Prize winner Thomas Hunt Morgan to develop the theory of genetic linkage.

He was ordained as a priest on 18 September 1886, and obtained a PhD in Natural Science in 1890, with the highest honors and a scholarship to attend many prestigious foreign laboratories.

[1] He was sent by his bishop to the brewery school in Munich, then to the Carlsberg Laboratory in Copenhagen, where he worked with Johan Kjeldahl and Emil Christian Hansen.

[1] In 1896, he joined the Faculty of Sciences for the Catholic University of Leuven, as a professor in microscopy, and from 1899 in cytology, succeeding Jean-Baptiste Carnoy in the chair.