FISH on an intact tissue from C. elegans. Image credit: Fields, Nguyen et al. (CC BY 4.0)
DNA contains the instructions needed to build and maintain a living organism. How DNA is physically arranged inside a cell is not random, and DNA organization is important because it can affect, for example, which genes are active, and which are not.
Researchers often use a technique called “fluorescence in situ hybridization” (or FISH for short) to study how DNA is organized in cells. FISH tethers fluorescent molecules to defined sections of DNA, making those sections glow under the right wavelength of light. It is possible to collect images of the fluorescent DNA regions under a microscope to see where they are in relation to each other and to the rest of the cell.
Fields, Nguyen et al. have now created a new library of FISH molecules that can be used to analyze the DNA of a microscopic worm known as Caenorhabditis elegans – a model organism that is widely used to study genetics, animal development, and cell biology. The library can be used to visualize the worm’s whole genome at different scales. The library enables accurate and reliable investigations of how DNA is organized inside C. elegans, including in intact worms, meaning it also offers the first chance to study DNA organization in a whole organism through all stages of its life cycle.
This new resource could help to reveal the relationships between DNA organization, cell specialization and gene activity in different cells at different stages of development. This could help to clarify the relationships between physical DNA organization and biological change. This design strategy behind this whole genome library should also be adaptable for similar studies in other animal species.
