EVIDENCES OF 2 DIFFERENT SETS OF HISTONE GENES ACTIVE DURING EMBRYOGENESIS OF THE SEA-URCHIN PARACENTROTUS-LIVIDUS

Histone mRNAs at different stages of development were purified by hybridization with the cloned homologous histonegenes. The electrophoretic patterns of oocytes, 2-4 blastomeres, 64 cells and morula histone mRNAs was found to be identical, whereas the electrophoretic pattern of mesenchyme blastula histone mRNA was different. The cloned histone DNA of P.lividus was hybridized with the RNA of each stage. The Tm was 74°C in all cases except for the raeaenchyme histone mRNAs whose Tm was 59°C, thus suggesting that at least two different clusters of histone genes are active in the course of the sea urchin development. © 1979 Information Retrieval Limited.