Santa's Little Helper greyhound's lack of intelligence. In an article that compared "The Simpsons" to the animated series "Family Guy", Todd Camp of the "Fort Worth Star-Telegram" noted that "though Santa's Little Helper may be the only Simpson who's dumber than Homer, the Griffins' pooch <nowiki>[</nowiki>Brian Griffin<nowiki>]</nowiki> is the brainiest member of the household". In 1991, Copley News Service's Alison Ashton described Santa's Little Helper as a "sweet and stupid dog". Tom Coombe of "The Morning Call" wrote in 2002 that "fans of "The Simpsons" will tell you that the cartoon family's dog [...] is often dumb, disobedient and skittish. Fans of 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