Functional Analysis of lethal (2) k12914 In Drosophila Development

Open Access
Author:
Cui, Chang
Area of Honors:
Biochemistry and Molecular Biology
Degree:
Bachelor of Science
Document Type:
Thesis
Thesis Supervisors:
  • Zhi Chun Lai, Thesis Supervisor
  • David Scott Gilmour, Honors Advisor
Keywords:
  • Drosophila development
  • Apoptosis
  • N-linked glycosylation
  • lethal (2) k12914
  • DAD1
Abstract:
In multicellular organisms, apoptosis is the most common form of programmed cell death; it is critical in various processes, including embryonic development, immune system maturation, and a homeostatic mechanism to maintain cell population. Since inappropriate apoptosis could lead to many diseases, especially cancer, understanding the regulation of this cellular self-destruction machinery is very important. Over the past decades, research has been focused on the elucidation and analysis of apoptotic genes and other factors in apoptosis signaling pathways. DAD1, the defender against apoptotic cell death, was identified as a mammalian cell death suppressor in 1993. Although previous studies have shown that the highly conserved DAD1 protein is a subunit of the mammalian oligosaccharyltransferase, involved in N-linked glycosylation, the underlying principle of its roles in apoptosis remains unknown. To understand the mechanism of DAD1 in apoptotic regulation of tissue growth, I use Drosophila as a genetic model to study the homologous gene of human DAD1, lethal (2) k12914. Here, by using RNAi under the control of the GAL4-UAS system, I show that loss of lethal (2) k12914 induces apoptosis as evidenced by the significant reduction of the adult wing size, accompanied with the positive results from the caspase-3 assay. In addition, transgenic flies of lethal (2) k12914 are created through φC31 integrase-mediated site-specific germ-line transformation for overexpression functional analysis; I find that overexpression of lethal (2) k12914 causes a moderate increase in wing size. In conclusion, lethal (2) k12914 plays an important role in anti-apoptosis in Drosophila development.