Crystal HernandezMajor: Biology Mentor: Dr. Jennifer Curtiss, Associate ProfessorBiology at New Mexico State University
Currently I am a majoring in Biology and minoring in Chemistry. I am pursuing to graduate with a Bachelors in Science in Spring 2018. I am participating in the New Mexico AMP Undergraduate Research Scholars program. I have been part of the IMBRE-NISE program during the summer of 2016 at New Mexico State University. Participating in both the AMP-URS and the IMBRE-NISE program allowed me to experience what research is and interested me in pursuing a master of science along with a medical degree after I graduate with a Bachelor’s degree. My research is based on understanding the mechanisms in which cells communicate for cell proliferation and differentiation to occur. For my research, I use the Drosophila melanogaster eye as a model to study the different signaling pathways that a cell goes through to differentiate. Working in a lab has allowed me to increase my academic skills and understand various concepts in Biology, Chemistry, and Fluorescence microscopy.
Rap1 affects recruitment of R7 photoreceptors and of cone cells in Drosophila ommatidia
Cell fate specification is controlled in part by signaling among cells, but the mechanisms remain unclear. Each of the 800 facets (ommatidia) of the Drosophila melanogaster eye contains 8 photoreceptors (R1-6 detectmotion and R7,8 detect color), as well as 4 cone cells that produce a lens. The identity of each ommatidial cell is specified entirely by the order in which it is recruited via signaling among ommatidial precursors. Here, we show that expression of a dominant negative version of the Rap1 small GTPase (Rap1N17) in the R4 precursor results in an increase in R7 photoreceptors and a decrease in cone cells at the pupal stage. Expression of the constitutively activeRap1 (Rap1V12) in the R4 precursor results in a decrease in R7 photoreceptors and an increase in cone cells in pupae. The R7 fate is interchangeable with cone and other photoreceptor cell fates depending on the relative levels of RTK and Notch signaling they receive. Thus, our results suggest that Rap1 affects RTK and/or Notch signaling during cell fate specification in the Drosophila eye.