Design of recombinase and terminator-based genetic switches for cell state control / 生物工程学报

Various genetic switches have been developed to let engineered cells perform designed functions. However, a sustained input is often needed to maintain the on/off state, which is energy-consuming and sensitive to perturbation. Therefore, we developed a set of transcriptional switches for cell states control that were constructed by the inversion effect of site-specific recombinases on terminators. Such a switch could respond to a pulse signal and maintain the new state by itself until the next input. With a bottom-up design principle, we first characterized the terminators and recombinases. Then the mutual interference was studied to select compatible pairs, which were used to achieve one-time and two-time state transitions. Finally, we constructed a biological seven-segment display as a demonstration to prove such switch's immense potential for application.

Bringing scientific research education closer to undergraduates through International Genetically Engineered Machine competition / 生物工程学报

In recent years, the International Genetically Engineered Machine (iGEM) competition has experienced rapid global development. In 2017 alone, the number of iGEM teams registered around the globe reached an unprecedented 313, with 98 iGEM teams from China having enrolled in the competition and obtained outstanding results. In contrast to the many college students' innovation projects and scientific research training programs in China, iGEM's organization mode is focused on student-centered research learning. Moreover, it achieved a rich educational effect, embodying a new educational idea, which gives it great significance for the extracurricular scientific research training of undergraduates in Chinese universities. In this article, we took Peking University's participation in the iGEM competition as a starting point. The first part introduces the background and general situation of the iGEM competition. The second part reproduces the general procedure of one iGEM season and organization of Peking University's team. The third part compares iGEM's organization mode with those of other undergraduate research training courses and discusses them in detail. The fourth part sums up the experience with iGEM activities as well as explains its effect on developing the research capacity of undergraduate students as well as inspiring them to organize an undergraduate scientific research competition. This article aims to provide a reference for the organization of iGEM activities in domestic universities and for the reform of undergraduate education.