School of Science Division of Life Science 13 Construction of a Signal Transduction Pathway Reporter Indicator for Monitoring Signaling Strength Supervisor: CHOW King Lau / LIFS Student: YUEN Yan Yi Macy / BIOT Course: UROP2100, Summer This project will manipulate the genetic model system, Caenorhabditis elegans, to recruit two of the gene components regulated by the transforming growth factor-β related ligand, DBL-1, as the indirect indicators of the dbl-1 signaling strength. Sma-6, one of the target genes for the project, encodes the type I receptor for DBL-1 ligands and is positively regulated by the dbl-1 signaling. The second gene, gcy-28, is a receptortype guanylate cyclase and acts as a repression target to the BMP pathway. Thus, the gene expression of sma-6 and gcy-28 can reflect the intensity of the BMP transduction signal. This experiment will develop the sma-6 and gcy-28 transcription reporters responding to the dbl-1 signaling and amplify the readout of signal strength through the manipulation of these two reporters in a variety of dbl-1 mutant strains. Evolutionary Art at the Fast Track Supervisor: CHOW King Lau / LIFS Student: SIU Kwong Tai / PHYS Course: UROP1100, Fall In this study, we continue to learn the loss of antibiotics resistance of E.coli in various concentrations of antibiotics. By using chloramphenicol as our antibiotics sample, we have already shown that the loss of antibiotics resistant gene become significant when the concentration of antibiotics is greater than 50µg/ml for a 1-day growth. Base on this observation, we first perform similar measurements with a shorter time step. However, we reach an inconsistent observation. Thus we turn to work out the possible reason for causing this inconsistent and check whether we could reproduce the previous results when we wipe out the relevant factors. Evolutionary Art at the Fast Track Supervisor: CHOW King Lau / LIFS Student: LI Wa Hei / BTGBM Course: UROP1000, Summer With the extensive use of antibiotics and improper sewage treatment, antibiotic-resistant bacteria are a crucial problem worldwide even in the developed countries. Detection of mild concentration of antibiotics in rivers triggers the study of the effect of low antibiotic concentration on antibiotic-resistant plasmid retention in bacteria. In this study, we monitor the loss rate of the PBS-F21A3.3p- (4969 bp) plasmid in E. coli RR1 and it is concluded that the bacteria have highly preserved its antibiotic-resistant plasmid under 40 ng/ml of AMP. However, the effect of lower AMP concentration on plasmid retention requires further studies.