On the stability of sequences inserted into viral genomes

Willemsen, Anouk; Zwart, Mark P

Inserted sequences can be unstable in ssDNA phages, which like their dsDNA counterparts also can have an upper limit to genome size. Inserts of up to 163 bp were stable in X174, despite markedly reducing fitness (Russell and Muller 1984) . Genomes with larger insertions were still infectious, although the insert was then rapidly lost. Later, it was shown that short palindromic sequences could be inserted in X174, but that these inserts become more unstable as the number of repeats is increased and when the identity of the repeats is identical (Williams and Mü ller 1987) . In other work, it has been shown that phage display (Wu et al. 2016) can be used to select clones coding for peptides with high affinity for a particular target, although selection for M13 phages with no insert-due to their presumed faster replication-can hamper 'phage panning' (Tur et al. 2001) .