This paper is dedicated to the memory of Professor Antoni Prevosti.
STRUCTURE AND POPULATION GENETICS OF THE BREAKPOINTS OF A POLYMORPHIC INVERSION IN DROSOPHILA SUBOBSCURA
Article first published online: 19 JUL 2012
© 2012 The Author(s). Evolution© 2012 The Society for the Study of Evolution.
Volume 67, Issue 1, pages 66–79, January 2013
How to Cite
Papaceit, M., Segarra, C. and Aguadé, M. (2013), STRUCTURE AND POPULATION GENETICS OF THE BREAKPOINTS OF A POLYMORPHIC INVERSION IN DROSOPHILA SUBOBSCURA. Evolution, 67: 66–79. doi: 10.1111/j.1558-5646.2012.01731.x
- Issue published online: 4 JAN 2013
- Article first published online: 19 JUL 2012
- Accepted manuscript online: 2 JUL 2012 11:42AM EST
- Received October 11, 2011, Accepted June 14, 2012
- Chromosomal inversion;
- inversion breakpoints;
- nucleotide polymorphism
Drosophila subobscura is a paleartic species of the obscura group with a rich chromosomal polymorphism. To further our understanding on the origin of inversions and on how they regain variation, we have identified and sequenced the two breakpoints of a polymorphic inversion of D. subobscura—inversion 3 of the O chromosome—in a population sample. The breakpoints could be identified as two rather short fragments (∼300 bp and 60 bp long) with no similarity to any known transposable element family or repetitive sequence. The presence of the ∼300-bp fragment at the two breakpoints of inverted chromosomes implies its duplication, an indication of the inversion origin via staggered double-strand breaks. Present results and previous findings support that the mode of origin of inversions is neither related to the inversion age nor species-group specific. The breakpoint regions do not consistently exhibit the lower level of variation within and stronger genetic differentiation between arrangements than more internal regions that would be expected, even in moderately small inversions, if gene conversion were greatly restricted at inversion breakpoints. Comparison of the proximal breakpoint region in species of the obscura group shows that this breakpoint lies in a small high-turnover fragment within a long collinear region (∼300 kb).