Abstract :
The factors that are important in limiting the number of functional genes contained within the genome of an organism are presently unknown. Here, it is suggested that in organisms that contain an adaptive immune response, the number of genes in the genome might be limited by the need to delete autoreactive T cells, thus preventing autoimmunity. The more genes an organism has, the more autoantigens are generated, necessitating an increase in the proportion of T cells that are deleted.
