Fig. 8
From: Dealing with the adaptive immune system during de novo evolution of genes from intergenic sequences
Scheme for the emergence of new genes. (Left) General scheme that was proposed by Neme and Tautz [38] that considers the emergence of de novo transcripts from non-genic sequences during a stochastic phase of genome evolution, where only random mutations allow the initial transcription of a given region. If this transcript is sufficiently stable, i.e. if it includes a poly-A tail and escapes other RNA destruction mechanisms in the cell, it would form a protogene that could become functional if adaptive conditions allow this. (Right) Extended version of the model, where the transcript would in addition have to be transcribed in thymus and/or spleen to avoid negative selection due to autoimmunity. This applies evidently only to transcripts with a translated open reading frame