Santa's Little Helper dog's Christmas-inspired name to be a sign. However, the greyhound finishes last. As Homer and Bart leave the track, they watch the dog's owner abandon him for losing the race. Bart pleads with Homer to keep the dog as a pet and he agrees after it affectionately licks him on the cheek. When Bart and Homer return home, Santa's Little Helper is assumed by the rest of the family to be a Christmas present. In various episodes, Santa's Little Helper can be seen chewing on newspapers and other objects in the Simpsons' household, destroying furniture, and digging holes in the
Helper dependent virus and capsid encoding DNA, plus helper DNA. Every cell that is successfully transfected with all three DNA fragments will produce the necessary proteins to produce infective viruses. These viruses will only have transgenic DNA encapsidated and therefore once they've infected a patient's cell, they will not be capable of reproducing. Helper dependent viruses can also occur in nature without being "gutted". The term satellite virus has been given to a large group of viruses that all require the presence of another virus to replicate. Many of these are plant viruses, but animal viruses can be seen in the case of