Synthesis of DNA. RNA and protein during conjugation in Pseudourostyla cristata was studied by autoradiography. Before every nuclear division in the conjugants

exept the second maturation division

a new DNA synthesis occurs. During development of the macronuclear anlage DNA synthesis is divided into two phases. A low level of RNA synthesis in the old macronuclei of conjugants is a continuous process

but it abruptly stops when the conjugating partners separate. And a round of active transcription occurs de novo in the cells when the macronuclear anlage has divided into several new macronuclei after four days. After the beginning of conjugation there is a continuous but slow synthesis of protein

and the synthesis speeds up to the onset of the second conical reorganization. reorganization. experiment also showed that some RNAs synthesized in the conjugants and some proteins synthesized in the exconjugants actively participate in the development of the macronuclear anlagen.