A recent study published in the journal Nature Cell Biology reports that researchers have discovered a new structure in human cells. The researchers were at Karolinska Institutet in Sweden and were working with colleagues in the United Kingdom.

The newly discovered structure seems to play an important role in cell division. The discovery may help scientists find an answer to the mystery of how cells remain attached to the surrounding matrix as they divide.

According to scientific estimates, there are anywhere from 75 to 100 trillion cells in the human body. Individually, these cells are round-ish blobs, but they can attach to one another because of a net-like structure that surrounds them. This structure, called the extracellular matrix, only admits cells with special receptor molecules, known as adhesion complexes.

Most adhesion complexes connect the cell interior to the outside and transmit information to the cell about its immediate surroundings. That information affects the cell’s properties and behaviors. The newly discovered structure is the same in this aspect, but unlike previously known adhesion, this new structure does not dissolve during cell division.

Instead, the new structure, which the research team named reticular adhesions, remains together and works to attach the cell during cell division. According to the study, reticular adhesions control the destinations of daughter cells after they’re made during division. This supervised direction ensures that they assume the right place in the overall tissue. When researchers would block the reticular adhesions during this process, they would interrupt the memory function that allowed the daughter cells to get in place.

The research team looked at exclusively human cell lines with confocal microscopy and mass spectrometry during their study. The next step of this discovery will be to examine the adhesion complex in other living organisms.

According to Professor Staffan Stromblad, the principal investigator of the study, the team believes that the reticular adhesions could be involved in processes other than cell division as well. Those functions will also have to be discovered in further studies. For now, the team was shocked that they could discover a new structure at all.

“It’s incredibly surprising that there’s a new cell structure left to discover in 2018. The existence of this type of adhesion complex has completely passed us by,” said Professor Stromblad.