On March 19, Michael R. Botchan, Richard and Rhoda Goldman Distinguished Professor of Biology and Biochemistry of University of California Berkeley, guested at the “Inspiring Wisdom” Distinguished Lectures. He delivered a wonderful speech under the title "initial stage of the S phase of cells." This report was invited by Zhijun Wang and Jingdan Liang research associate.

Professor Botchan, mainly concentrated in the field of initiation of DNA replication in eukaryotic cells and molecular mechanisms of cell cycle control. A key molecular event of the initiation of DNA replication in Eukaryotic cells is the loading of Mcm2-7 complex to double strand DNA by ORC complex (origin recognition complex), with the help of Cdc6 and Ctd1. The Mcm2-7 complex is latent, does not have helicase activity, and can slide on ds DNA. Then Gins and Cdc45 proteins are recruited. The formation of the CMG complex (Cdc45, Mcm2-7, and Gins) activates Mcm2-7 helicase, leading to the separation of double strand DNA, and then DNA replication starts. Professor Botchan depicted a series of vivid scientific stories in cell G1 to S phase mitosis transition: from the finding of the involvement of Cdc45 in the helicase activity to the isolation of the CMG complex using traditional biochemical technique, and then the elucidation of the underlying helicase mechanism using Electron Microscope.

After the meeting, Professor Botchan discussed many interesting topics with students, such as the molecular events of cell cycle, the electron microscopy technology, the structure of protein, and the development of drugs.