School of Science Division of Life Science 21 DNA Replication-initiation Proteins in Budding Yeast Supervisor: LIANG Chun / LIFS Student: TSUI Nok / BIBU ZHANG Cancan / SSCI Course: UROP1000, Summer UROP1000, Summer The nucleolar complex-associated protein 3 (Noc3) is essential for the initiation of DNA replication. Understanding the role and function of this protein in DNA replication will lay the groundwork for future applications in cancer treatment. Noc3p is bound to chromatin throughout the cell cycle and plays an essential role in the formation of the pre-RC complex during G1 phase. A temperature sensitive mutant yeast strain, noc3-9, was transformed with a plasmid expressing FLAG-Orc2 and Orc2-Myc. CoImmunoprecipitation Assays (Co-IP) were performed using G1-phase cells expressing the aforementioned proteins. The results indicate that at the permissive temperature, positive co-IP between FLAG-Orc2 and Orc2-Myc was possible. Contrastingly, at the non-permissive temperature the co-IP results were negative. The data suggest Noc3p is required for ORC dimerization in G1-phase. Molecular Regulation of Axon Regeneration Supervisor: LIU Kai / LIFS Student: GAO Zhouyang / BCB Course: UROP4100, Fall Every year, more than 250,000 patients are facing the difficulties from spinal cord injury. Unfortunately, for now there is no effective treatment to the spinal cord injury. Though function recovery can be achieved in injury to peripheral nervous system of human, injury on spinal cord, a component of the central nervous system, faces failure of axon regeneration. Therefore, understanding the difference between PNS and CNS axon regeneration can provide important insight to the treatment permanent disabilities from spina cord injury. Previously, we have used DRG cell as a model to study the intrinsic mechanism of axon regeneration. Currently, we are looking into PC12 cells as another effective system to facilitate the process of finding novel gens involved in axon regeneration. Molecular Regulation of Axon Regeneration Supervisor: LIU Kai / LIFS Student: HARTANTO KWEE Jeffrey / SENG Course: UROP1000, Summer Nerves in the peripheral nervous system (PNS) are capable of axon regeneration, but those in the central nervous system (CNS) are not. It is thought that the ability of axons to regenerate declines throughout development. Gene expression patterns changes from development to adulthood, and scientists are trying to identify the genes that inhibit or promote axon regeneration. Scientists study nerves that can grow back in all kinds of species, and through overexpression or inhibition of genes, try to enable axon regeneration in the CNS. Axon regeneration is currently possible in vitro, and scientists are working to ensure regeneration is quick and leads to functional recovery. This report aims to summarize some background information on axon regeneration and presents the results of some of the experiments that I have done.