Before revision: The phenomenon of genetic chiasmata (chiasmatypie) was discovered and described in 1909 by Frans Alfons Janssens, a Professor at the University of Leuven in Belgium.Elof Axel Carlson, Mendel's Legacy: The Origin of Classical Genetics, CSHL Press, 2004, , p.xviiIn pursuit of the gene: from Darwin to DNA By James Schwartz Harvard University Press (2008), p. 182 Retrieved 19 March 2010.
After revision: points of crossing over become visible as chiasma after the synaptonemal complex dissembles and the homologous chromosomes slightly apart from each otherThe phenomenon of genetic chiasmata (chiasmatypie) was discovered and described in 1909 by Frans Alfons Janssens, a Professor at the University of Leuven in Belgium.Elof Axel Carlson, Mendel's Legacy: The Origin of Classical Genetics, CSHL Press, 2004, , p.xviiIn pursuit of the gene: from Darwin to DNA By James Schwartz Harvard University Press (2008), p. 182 Retrieved 19 March 2010.