Home » Tian Xia

Tian Xia

Tian Xia

Preferred Name:



B.S. Biochemistry and Molecular Biology, Minor in Psychology

Class of 2021

Pennsylvania State University, State College PA 

From: Shenzhen, China

Joined David Lab: January 2022

Outside of the lab: I play Guzheng, a traditional Chinese instrument; I love baking cakes and cooking; I also enjoy traveling and exploring foods.

Research in David Lab:

As a consequence of cellular respiration, reactive oxygen species would form and pose threats to the integrity of the genome. A common product of oxidized guanine is 8-oxo-7,8-dihydroguanine (8-oxoG), in which the syn conformation promotes a Hoogsteen pairing with adenine. Misincorporation of adenine instead of cytosine and subsequent replication would lead to a G:C to A:T mutation. The accumulation of mutation in the Adenomatous Polyposis Coli (APC) gene is correlated to the early onset of colorectal cancer (CRC). As a defense against the mutation, MUTYH, a base excision repair (BER) enzyme, cleaves the adenine paired opposite to 8-oxoG. Germ-line mutations in MUTYH have been linked to an autosomal recessive form of familial CRC termed MUTYH-associated Polyposis (MAP). It is crucial to understand the structure and mechanism of MUTYH to predict and prevent disease. I’m interested in elucidating the structure and function of MUTYH through cellular repair assay. To be more specific, I generate MUTYH mutants by site-directed mutagenesis and measure the OG:A repair percentage by mutant cell lines using a reporter assay. The result would provide support to our proposed MUTYH structure. 


RSS Science Daily News

  • Down goes antimatter! Gravity's effect on matter's elusive twin is revealed September 27, 2023
    For the first time, in a unique laboratory experiment at CERN, researchers have observed individual atoms of antihydrogen fall under the effects of gravity. In confirming antimatter and regular matter are gravitationally attracted, the finding rules out gravitational repulsion as the reason why antimatter is largely missing from the observable universe.
  • Decreasing biodiversity may promote spread of viruses September 27, 2023
    How are environmental changes, loss of biodiversity, and the spread of pathogens connected? The answer is a puzzle. Researchers have now described one piece of that puzzle, showing that the destruction of tropical rainforests harms the diversity of mosquito species. At the same time, more resilient species of mosquitoes become more prevalent -- which also […]
  • Study sheds new light on strange lava worlds September 27, 2023
    In a new study, scientists have shown that sweeping molten oceans have a large influence on the observed properties of hot rocky Super-Earths, such as their size and evolutionary path.
  • New insights into the atmosphere and star of an exoplanet September 25, 2023
    A new study of the intriguing TRAPPIST-1 exoplanetary system has demonstrated the complex interaction between the activity of the system's star and its planetary features.
  • Did life exist on Mars? Other planets? With AI's help, we may know soon September 25, 2023
    Scientists have discovered a simple and reliable test for signs of past or present life on other planets -- 'the holy grail of astrobiology.' Researchers report that, with 90% accuracy, their artificial intelligence-based method distinguished modern and ancient biological samples from those of abiotic origin.


Dr. Sheila S. David

Department of Chemistry
One Shields Ave.
Davis, CA 95616