Pulling the strings: How stem cells in the developing fruit fly brain organize their DNA from outside the nucleus
Cells are very particular about the proper locations of their contents. For example, DNA is packaged in the nucleus in a highly specific way, but researchers are still trying to understand how this happens. For stem cells in the brain of a larval fruit fly – model organisms used to study processes such as early development – the DNA is organized so that the center of each strand, called the centromere, is at the top of the nucleus. In a paper published Oct. 14 in the Journal of Cell Biology, UW researchers describe how proteins outside the nucleus work alongside proteins inside the nucleus to control the position of centromeres. The researchers observed this mechanism by imaging stem cells within larval fruit fly brains and then using machine learning to measure how centromere locations change when specific proteins are removed. The research team also followed the locations of two specific genes that are far away from the centromeres. Both genes lost their usual positions in the nucleus when the centromeres strayed from their normal location, suggesting that proper centromere positioning may be important for orienting the rest of the DNA in the nucleus. Studying how and why DNA is organized in these stem cells can help researchers better understand how stem cells are regulated and how brains develop.
