Biologists have found that correcting the disorganization in DNA can help diagnose genetic diseases caused by mutations.
The authors of the new work conducted a study with mouse cells grown in a laboratory and found that there is a protein that helps to form a structural network under the surface of the cell’s nucleus – this is how DNA remains ordered.
In the following experiments, the researchers highlighted the role of a protein called lamin C, which is useful in the diagnosis and treatment of various genetic disorders associated with DNA disorganization.
It is believed that gene mutations – or mistakes in the genetic code – cause hereditary diseases. Likewise, disorganized genes can have a similar effect. The authors note that genetic tests generally do not take into account the mechanics of DNA organization, although this can be an important basis for the study and treatment of genetic diseases.
The researchers set out to understand how lamines affect how the cell uses and organizes its DNA. They used fluorescent dyes to track three types of lamin proteins – A, B, and C – through cell division, where DNA from one cell is duplicated and then split between two offspring cells.
Lamin B was easy to distinguish, but lamin A and lamin C were previously considered duplicate proteins because they were created from the same gene. But there is growing evidence that type A and type C laminas play different roles.
The research team decided to figure this out and created mouse embryonic cells to either remove the gene that creates lamin B or the gene that contains both lamin A and C. They then used microscopes to observe the behavior of the lamins and whether the cells’ nuclear DNA remained organized when she shared.
The research team found that nuclear DNA in cells lacking lamin B looks much the same as when normal cells divide. This means that lamin B may not be essential for DNA reorganization after cell division. But the nuclear DNA in cells without lamins A and C was not rearranged and became entangled.
The researchers then used a series of specialized chemicals to turn off lamin A or lamin C in mouse cells and test each protein independently.
Cells without lamin A were able to reorganize after division as efficiently as normal cells. But the organization of nuclear DNA without Lamin C was in disarray again.
The researchers believe modified Lamin C helps guide DNA into place during reorganization. Once the DNA is organized, lamin Closes its molecular label and binds to the rest of the laminas at the edge of the nucleus.
The researchers note that these results raise questions about the role of lamins in DNA organization and regulation. The team hopes to determine how lamin proteins and genomes behave when one particular type of lamin is mutated or disrupted.