Imperial College London


Faculty of MedicineSchool of Public Health

Senior Lecturer in Bacterial Genomics



+44 (0)20 7594 3820n.croucher




UG5Norfolk PlaceSt Mary's Campus






BibTex format

author = {Apagyi, KJ and Fraser, C and Croucher, NJ},
doi = {molbev/msx309},
journal = {Mol Biol Evol},
title = {Transformation asymmetry and the evolution of the bacterial accessory genome.},
url = {},
year = {2017}

RIS format (EndNote, RefMan)

AB - Bacterial transformation can insert or delete genomic islands (GIs), depending on the donor and recipient genotypes, if an homologous recombination spans the GI's integration site and includes sufficiently long flanking homologous arms. Combining mathematical models of recombination with experiments using pneumococci found GI insertion rates declined geometrically with the GI's size. The decrease in acquisition frequency with length (1.08x10-3 bp-1) was higher than a previous estimate of the analogous rate at which core genome recombinations terminated. Although most efficient for shorter GIs, transformation-mediated deletion frequencies did not vary consistently with GI length, with removal of 10 kb GIs approximately 50% as efficient as acquisition of base substitutions. Fragments of two kilobases, typical of transformation event sizes, could drive all these deletions independent of island length. The strong asymmetry of transformation, and its capacity to efficiently remove GIs, suggests non-mobile accessory loci will decline in frequency without preservation by selection.
AU - Apagyi,KJ
AU - Fraser,C
AU - Croucher,NJ
DO - molbev/msx309
PY - 2017///
TI - Transformation asymmetry and the evolution of the bacterial accessory genome.
T2 - Mol Biol Evol
UR -
UR -
UR -
ER -