The location of the genes for the major storage protein, phaseolin, was determined in the polytene chromosomes of the embryo-suspensor of
Phaseolus coccineus, cv. Hammond''s Dwarf Scarlett, by
in situ hybridization with a
35S-labelled cloned probe. The genes were adjoined to chromosome pair no. 3. The distribution of the label indicates a puffed state of the sites during embryogenesis of the legume studied. The location of the phaseolin genes was certified by hybridization of a ribosomal DNA probe to the polytene chromosomes, because their position is well known.