Two TGS Students Receive Howard Hughes Medical Institute (HHMI) Fellowships
Nicolas Pelaez (IBiS, Molecular Biosciences, who is from Colombia) and Sebastian Ahrens (IGP, who is from Germany) are recipients of the prestigious Howard Hughes Medical Institute Fellowship. Offered for the first time this year, the award funds international students who are several years into their PhD program in science, allowing them to focus on their research without having to worry about funding. View more information and the full list of recipients at the HHMI website.
About Nicolas Pelaez’s research:
Development of animal organs and maintenance of adult health requires that undifferentiated cells transit from multipotent stem progenitors to differentiated cells. During this transit stem cells that have not acquired an adult identity differentiate and adopt their adult cell fate. Proper regulation of the stem to differentiated cell transition is critical since errors in this developmental decision can cause adult organ mispatterning or diseases such as cancer.
Biochemical networks coordinate the activities of many molecules that regulate the transition from stem to differentiated cells. Such networks can be affected by mutations, random fluctuations in the abundance of network components or by environmental perturbations that affect network performance. As result the ability for cells to correctly transit correctly from a stem to a differentiated state can be compromised. It is still unknown how these networks can safeguard cells from incorrectly switching from a stem to a differentiated state during organ development.
I use the developing fruit fly eye as a model to study how a biochemical network can safeguard cells against genetic and environmental perturbations that could disrupt the normal transit from stem-like progenitors to differentiated cells. During retina pattering each eye repeats hundreds of times, in a stereotyped fashion, the transit from eye stem-like progenitors to differentiated cells. The regularity of the developing eye, plus the genetic tools available make the fly eye a good model system to study the stem to differentiated cell transition. These studies could shield light into systems-level principles that cells use to properly regulate developmental decisions.
About Sebastian Ahrens’s research:
In the Satchell Lab, we characterize the role of accessory toxins such as the Multifunctional Autoprocessing repeats-in-toxin (MARTX) of Vibrio cholera during infection and their importance during colonization of the gut epithelium. One of the functional domains of the MARTX is the Rho-inactivation domain (RID) that causes inactivation of small Rho GTPases and cell rounding. My research focuses on understanding the structural and molecular interactions necessary for the toxin to disable Rho signaling.
