Immunohistochemical localization of cyclic GMP in aggregating Polysphondylium violaceum

Using indirect immunofluorescence technique, it has been possible to localize cyclic GMP in Polysphondylium violaceum cells. The bound cyclic nucleotide is localized throughout the cell during early stages, however, this staining increases and there is marked localization of cyclic GMP in the nuclear areas of the cells when aggregation is in full swing. Over 90% of the cells exhibited intense nuclear staining by 6 h and this decreased to less than 10% by 10 h.