Peering through a microscope, Mike Haven (CELL ’26) contemplates the beginning of life. Under the lens lies a fertilized chicken egg. Through a careful procedure, he’s cut a small hole in the shell, allowing him to observe the embryo inside.
For the past two years, Haven has been immersed in embryology research under the direction of cell biology and physiology professor Jeffery Barrow. His work focuses on the way claudin, a structural protein that adheres cells to one another, interacts with an important signaling pathway referred to as Sonic Hedgehog (SHH).
Born without a thyroid, Haven’s own developmental difference is part of what motivates his research. “I've been really interested in how these processes work and how an embryo grows, and what different aspects are involved,” he says.
The Sonic Hedgehog Pathway
Originally named for its structural resemblance to a hedgehog, the name “Sonic” was added when scientists found a similar gene used in vertebrates in limb development. SHH is a signaling pathway critical in embryonic development for many organisms, helping to shape limbs and organs by signaling to cells where to grow and what to become. Haven explained that while claudin has long been recognized for its mechanical role in holding cells together, this project investigates whether it can directly influence a chemical signaling process like SHH.
“We are investigating a new connection between two major cell systems,” Haven says. “We’ve already shown the connection in test tubes, and our experiment is nailing it down in living systems.”
From Test Tubes to Chick Limbs
The experiment begins with incubating fertilized eggs for several days, then delicately removing the tops of the shells to access the embryos. Haven places microscopic beads soaked in claudin onto the anterior portion of the developing chick’s limb.
The goal is to see whether the claudin protein can induce the same developmental response as SHH, which is typically active in the posterior part of the limb. If successful, the experiment will demonstrate that a physical protein—claudin—can produce an effect similar to that of a chemical messenger like SHH, meaning that claudin, a mechanical signal, can produce the same results as a hormonal signal. “This relationship would be unique in biochemistry,” Haven explains.
This kind of interaction is rarely observed, and Haven sees potential implications beyond embryology. Since claudins are also involved in the behavior of cancer cells, especially in metastasis, understanding how they interact with signaling pathways like SHH could have applications in cancer research.
Studying embryos has solidified his decision to pursue medical school and continue to conduct medical research to help others. Reflecting on his work in the lab, Haven sees more than just cells and signals. He sees the beauty and intricacy of God’s creations. “Heavenly Father made a really fascinating world,” Haven shares, “and that teaches me that He wants us to learn about it.”