Expression of Spaetzle Homologs 2-6 in Drosophila Larvae Hemocytes

Abstract

In Drosophila, the gene spaetzle (Spz) encodes a protein involved in the production of an immune cell called a hemocyte. Specifically, this protein triggers a signal transduction cascade (a series of intracellular chain reactions) in order to produce the immune cell. However, there are 5 other Spz homologs (genes that are similar to one another), and little is known about their role in hemocyte production. My goal was to specifically examine the expression of each Spz homolog in hemocyte cells. Using RNA extracted from hemocytes of Drosophila larvae, a RT-PCR (a method of amplifying RNA via a DNA intermediate) was conducted using primers specific to each homolog, and the PCR products were then run out through gel electrophoresis. The bands produced on the gel were then compared to the expected cDNA sizes of each Spz homolog from flybase to determine if there was expression of the homologs in hemocytes. The Spz homologs 2, and 3 consistently showed expression in Drosophila larvae hemocytes, while the homologs Spz 4, Spz 5 and Spz 6 also showed expression. However, the expression seen with these three homologs was not as consistent compared to the others. Therefore, the homologs Spz 2 and Spz 3 are clearly expressed in Drosophila larvae hemocyte cells.

Faculty Mentor: Agata Becalska

Department: Biological Science