Seth Johnson

Assistant Professor


  • Ph.D. Cell and Molecular Biology, University of Pennsylvania (2016)
  • BA Biology Cell and Molecular Biology/Biochemistry, Colby College (2010)

About Me

Starting with my work with the genetics of nervous system development at Colby, I have always been fascinated with how cells can instruct themselves and each other to produce a fully functioning organism. Investigating how this works and what happens when it doesn't involves understanding how cells can communicate with each other to produce cellular responses. To begin to examine these fascinating processes, I utilize the amazing potential of the fruit fly, which provides excellent opportunities for students to get involved in exciting projects. As a graduate student and postdoctoral fellow, I studied how signaling pathways such as Notch, BMP, Wnt, and others influence cell fate and development of the fly nervous system. We are now just beginning to understand how errors in signaling during nervous system development underly many disorders including Autism Spectrum Disorder (ASD), illustrating why understanding this process in simpler systems like the fly is so important. While I love doing science, teaching, training and mentoring students to help them reach their own potentials and dreams is my true passion. I believe that students learn the best and are most engaged when they see relatable, real-life applications that show why they should care about what they are being taught (and have fun doing it!).

In my free time, I enjoy being outside and going hiking with my family in New Hampshire. I've climbed all 48 of the New Hampshire 4,000 footers with my father except one, can you guess which?

What I Teach

  • General Biology, BIOL 113
  • Cell Biology, BIOL 225

Research/Special Projects

Cell signaling underlies nearly every process during development and remains critical for the proper function of a fully formed organism, and cells rely on signaling mechanisms and pathways to communicate to each other. My research looks at how some of these signaling pathways influence development and morphogenesis of the interface between the neuron and muscle, known as the neuromuscular junction (NMJ). Work from these projects may help explain how developmental and psychiatric disorders, which can arise from errors made in synaptic connections, may develop. To answer these questions, my lab utilizes the fruit fly (Drosophila melanogaster), an ideal model organism with a wide range of resources available for students.

Postsynaptic Translation

Muscle cells in flies are prepared to receive cues from surrounding cells, like the neuron, that will help them rapidly develop into functional neuromuscular junctions. The neuron can help communicate this message by activating translation of factors needed for synaptic transmission at future synapses within the muscle. With this project, we are seeking to understand the signaling pathways that promote postsynaptic translation of synaptic factors as well as the muscle proteins whose expression depends on rapid translational activation.