IMMUNOFLUORESCENT STUDIES OF BASIC NUCLEAR PROTEINS

Abstract

Histone antibodies were obtained by injecting salt extracted calf thymus basic nuclear proteins into chickens. Fluorescent globulins were prepared from chicken antisera with precipitating antibodies against a single electrophoretic fraction of the nuclear protein extract. The fluorescent antiserum was specific for nuclei and chromosomes but was neither organ nor species specific. It reacted specifically with nuclei of cell imprints of bovine and human leucocytes, with polytene chromosomes from Chironomus salivary gland cells, and with nuclei from lily and onion root tip cells. It did not react with chicken blood smears. A decrease in the intensity of fluorescence roughly proportional to the phylogenetic divergence of the tested species was observed.These studies indicate that this basic nuclear protein fraction has acquired remarkably little variation over a long evolutionary period.