No, the endoplasmic reticulum (ER) does not have its own DNA.
While some organelles, like mitochondria and chloroplasts, possess their own DNA, the endoplasmic reticulum relies on the cell's nuclear DNA for its function and replication. The ER is a network of membranes within eukaryotic cells involved in protein and lipid synthesis, folding, modification, and transport. The genes encoding the proteins that make up and operate within the ER are located in the nucleus and transcribed into mRNA, which is then translated into proteins by ribosomes. These ribosomes may be freely floating in the cytosol or bound to the ER membrane (forming rough ER).
Therefore, the statement in the provided reference claiming that the endoplasmic reticulum has its own DNA is incorrect. The presence of its own DNA is a feature primarily associated with organelles that have evolved from endosymbiotic events, which does not include the ER.
