In a groundbreaking study published in Nature Communications, researchers from the University of California San Diego have unraveled the intricate assembly of apical extracellular matrices (aECMs) in the roundworm Caenorhabditis elegans at the nanoscale. Apical extracellular matrices are complex structures found on the outermost layers of organisms, including humans, forming matrix patterns crucial for various functions.
The research focused on the roundworm, a model organism known for its transparent structure, allowing researchers to examine its skin and internal structures. Using a powerful super-resolution microscope, the scientists delved into the nanoscale organization of struts, tiny pillars connecting different layers of the matrix, which play a pivotal role in the proper development and functioning of aECMs.
“Struts are like tiny pillars that connect the different layers of the matrix and serve as a type of scaffolding,” explained Andrew Chisholm, a professor in the School of Biological Sciences and the senior author of the paper.
Despite the roundworm’s simple, transparent body, it features intricate architectures beneath the surface. With nearly 20,000 genes, similar to the number in humans, the roundworm provides valuable insights into the structure and function of more complex organisms.
The study focused on the roundworm’s exoskeleton, known as the cuticle, where defects in struts were found to result in unnatural layer swelling or “blistering.” The researchers honed in on collagens, the most abundant family of proteins in the human body, which play a crucial role in maintaining the integrity of bodily materials.
“The struts hold the critical layers together. Without them, the layers separate and cause disorders such as blistering. In blistering mutants, you don’t see any struts,” explained Chisholm.
Advanced instrumentation, specifically 3D-structured illumination super-resolution microscopy (3D-SIM) from Assistant Professor Andreas Ernst’s laboratory, allowed the researchers to achieve stunning focus on the struts, providing detailed insights into their nanoscale organization and previously undocumented levels of patterning in the cuticle layer.
“We could see exactly where these proteins were going in the matrix. This is potentially a paradigm for how the matrix assembles into very complex structures and very intricate patterning,” said Chisholm.
The study’s first authors, Jennifer Adams (senior research associate) and Murugesan Pooranachithra (postdoctoral fellow), made equal contributions to the research. The findings not only deepen our understanding of aECMs in roundworms but also present a potential paradigm for comprehending the assembly of matrices in other organisms.