Marriage of Microscopy Techniques Reveals 3D Structure of Critical Protein Complex

In meiosis, the cell copies all its chromosomes, pairs them up, and then divides them into eggs or sperm. This carefully choreographed process is helped along by the synaptonemal complex, an assembly of proteins that forms between the paired homologous chromosomes and keeps them properly aligned and in position. Errors during meiosis are a leading cause of miscarriages in humans.

In a recent report, scientists in the lab of Investigator Scott Hawley, PhD, along with other Stowers colleagues, describe the three-dimensional structure of a protein complex that is essential to meiosis. By merging two advanced microscopy techniques, the researchers discovered that this structure, known as the synaptonemal complex, looks like two sets of railroad tracks stacked on top of each other.

“This was a really incredible insight, a technical leap using this new methodology of expansion microscopy and merging it with structured illumination to create a way to look at a structure that hasn’t been resolved before,” says Hawley. “There is a lot more we can learn. The deeper we dive into structure, the more complexity we see, the more amazing the structure becomes. Structure provides so much insight into function.”

This work was published online July 31, 2017, in the Proceedings of the National Academy of Sciences.