Discipline: Biological Sciences
Subcategory: Cell and Molecular Biology
Room: Exhibit Hall A
Rebekah Townsley - University of Arkansas
Co-Author(s): Sanika Pandit, Chapman University, Orange, California; Emmanuel Tadjuidje PhD, Alabama State University, Montgomery, Alabama
Cholesterol is an important molecule that helps maintain membrane permeability and fluidity; modulate transmembrane signaling; and synthesize steroid hormones, bile and vitamin D. It is distributed throughout the cell via Niemann-Pick Type C1 and C2 (NPC1/NPC2) protein dependent mechanisms. Previous studies have shown that disrupting cholesterol trafficking by chemical inhibitors, such as Fatostatin and U18666A, can cause severe neurological issues. Fatostatin inhibits the trafficking of cholesterol between the Endoplasmic Reticulum (ER) and Golgi Apparatus. It interferes with the cell?s ability to sense steroids because it binds to sterol regulatory element-binding (SREBP) cleavage-activating protein (SCAP) and inhibits SREBP activation. U18666A inhibits the trafficking of cholesterol between late endosomes and ER by mutating the NPC1 gene. In this study, we looked at how chemically interfering with cholesterol trafficking could effect embryonic development. Fatostatin and U18666A were used to inhibit cholesterol trafficking in Xenopus laevis embryos. The embryos were treated at the blastula stage and checked daily until the tadpole stage. In the Fatostatin treatment, the embryos developed smaller eyes that were fused to the brain, curved tails, delayed intestinal looping, and swollen faces. The U18666A treatment developed a lack of pigmentation and slightly curved tails. Not only did both groups exhibit significant phenotypes by stage 42, but both groups also had significant mortality rates, as compared to the control groups. These results suggest that an interference with cholesterol trafficking effects the developing embryos and can be potentially toxic, but further studies are needed in order to understand the specific signal transduction pathways that are being inhibited and the genes that are affected.
Funder Acknowledgement(s): This work was supported by NSF-REU (DBI-1659166) to Dr. Komal Vig (PI) and by NSFCREST (HRD-1241701) to Dr. Shree S. Singh (PI).
Faculty Advisor: Emmanuel Tadjuidje Ph.D, firstname.lastname@example.org
Role: I was a part of implementing the procedures of this experiment and analyzing the data. I injected the frogs with Human chorionic gonadotropin hormones to induce ovulation and subsequently fertilized the eggs. The developing embryos were then treated with Fatostatin and U1866A which disrupts cholesterol trafficking. Embryos were grouped according to phenotypes shown and a statistical analysis was performed to correlate the use of the drugs with specific phenotypes.