DNA ligases are essential enzymes that play a crucial role in the process of DNA replication and repair. They function by joining together the sugar-phosphate backbones of DNA strands, sealing any nicks or breaks that may occur. This action is vital for maintaining the integrity of the genetic material within cells. In addition to their role in replication, DNA ligases are also important in various molecular biology techniques, such as cloning and genetic engineering. By facilitating the joining of DNA fragments, they enable scientists to create recombinant DNA molecules, which can be used for research, therapeutic applications, and biotechnology advancements.