Postdoctoral Fellow

National Cancer Institute, Cancer & Developmental Biology Lab Posted 8/6/2026 Fellowship position to investigate dynamics of Shh regulation and function in mouse limb bud. Mackem lab is recruiting for NIH-funded post-doc position in developmental morphogenesis to study the roles of Shh in vertebrate limb patterning (different digit types, numbers, adaptations) using molecular-genetic and genomic approaches. Our long-term goal is understanding how regulatory networks instruct the formation of complex structures with distinct shapes, such as the varying bony segments and joint numbers in different digits, arising from the same tissues and not based in cell fate changes per se. Current work focuses on genome-wide approaches to identify key Shh relay signals and their relation to late signaling centers, comparative evolutionary analyses to reveal regulatory mechanisms underlying morphology-based adaptations and combined genetic/genomic strategies to explore the dynamic, robust nature of Shh-producing cells. We recently showed that Shh acts as a trigger, not morphogen, to initiate digit patterning, but the critical targets remain unknown. We have discovered that the Shh-producing ZPA domain in the limb is not a static population but arises from progenitors at the limb border that contribute to ongoing ZPA renewal and plan to characterize progenitor pool regulation. We have also found that the widespread phenomenon of autocrine non-responsiveness in Shh-producing cells is an intrinsic feature of these cells, not due to negative-feedback, and are examining its mechanistic basis. Applicants should have a strong background in developmental and/or evo-devo biology. Prior experience with cutting-edge genomic approaches is desirable. For more information, please contact Susan Mackem (View email address on click.appcast.io ) directly (Senior Investigator, Cancer & Dev. Biology Lab., CCR/NCI-Frederick). Patel and Mackem (2025) PNAS . 122: e2427249122. doi.org/10.1073/pnas.2427249122 #J-18808-Ljbffr