A Genetic Screen for Proteins Involved in ASP Invasion
Grade Level at Time of Presentation
Secondary School
Institution
Western Kentucky University
Faculty Advisor/ Mentor
Ajay Srivastava, PhD
Department
Department of Biology
Abstract
Fruit flies (D. melanogaster) are ideal genetic model organisms that can closely replicate human genetic anomalies and characteristics. The invasion of the Air Sac Primordia (ASP), an organ analogous to the human lung, into the Wing Imaginal Disc (WID) of larval fruit flies is closely related to tumor metastasis in humans, as both processes use similar mechanisms to break down the basement membrane. By studying genes responsible for ASP invasion, researchers may be able to identify analogous genes in humans responsible for tumor metastasis. A genetic screen, using 65 protein trap lines, was conducted to find genes expressed in ASP and potentially involved in ASP invasion. The protein trap lines tagged endogenous proteins with a Green Fluorescent Protein (GFP) to indicate tissue localization of selected proteins under a fluorescent microscope. WID were isolated from 10 third instar larvae of each line and imaged using fluorescence microscopy. Thirteen of the 65 lines screened exhibited GFP expression in the WID, but not in the ASP. Only one of the 65 lines exhibited GFP expression in the ASP. The gene responsible was Apontic (apt). Apontic’s role in ASP invasion will be further investigated using RNA interference to knock down the gene. The screen is ongoing and we hope to be able to identify more genes expressed in the ASP.
A Genetic Screen for Proteins Involved in ASP Invasion
Fruit flies (D. melanogaster) are ideal genetic model organisms that can closely replicate human genetic anomalies and characteristics. The invasion of the Air Sac Primordia (ASP), an organ analogous to the human lung, into the Wing Imaginal Disc (WID) of larval fruit flies is closely related to tumor metastasis in humans, as both processes use similar mechanisms to break down the basement membrane. By studying genes responsible for ASP invasion, researchers may be able to identify analogous genes in humans responsible for tumor metastasis. A genetic screen, using 65 protein trap lines, was conducted to find genes expressed in ASP and potentially involved in ASP invasion. The protein trap lines tagged endogenous proteins with a Green Fluorescent Protein (GFP) to indicate tissue localization of selected proteins under a fluorescent microscope. WID were isolated from 10 third instar larvae of each line and imaged using fluorescence microscopy. Thirteen of the 65 lines screened exhibited GFP expression in the WID, but not in the ASP. Only one of the 65 lines exhibited GFP expression in the ASP. The gene responsible was Apontic (apt). Apontic’s role in ASP invasion will be further investigated using RNA interference to knock down the gene. The screen is ongoing and we hope to be able to identify more genes expressed in the ASP.