POPULATION IMMORTALITY. “One problem that arises in discussing the nature of the germ line is nomenclature and the use of the terms ‘immortal’ and ‘totipotent’. Although the germ line is frequently referred to as ‘immortal’, this is only valid at the level of the entire population and, more specifically, only the genome residing within the cells that compose the germ line may be viewed as immortal.”
http://www.reproduction-online.org/content/revreprod/5/2/93.full.pdf