Accumulation of chloroplast DNA sequences on the Y chromosome of Silene latifolia

Časopis: GENETICA 128, 167-175
Autoři: Kejnovsky, E., Kubat, Z., Hobza, R., Lengerova, M., Sato, S., Tabata, S., Fukui, K., Matsunaga, S., Vyskot, B.
Rok: 2006


Silene latifolia is a model dioecious plant with heteromorphic sex chromosomes. The Y chromosome is the largest in this species. Theoretical models propose an accumulation of repetitive DNA sequences in non-recombining parts of the Y chromosome. In this study, we isolated a BAC7H5 clone preferentially hybridizing to the Y chromosome of S. latifolia. Sequence analysis revealed that this BAC7H5 contains part of the chloroplast genome, indicating that these chloroplast sequences have accumulated on the Y chromosome and also may contribute to its large size. We constructed Y chromosome- and X chromosome-specific libraries and screened them to find Y- and/or X-linked copies of chloroplast sequences. Sequence analysis revealed higher divergence of a non-genic region of the chloroplast sequences located on the Y chromosome while genic regions tested showed only very low (max 0.9%) divergence from their chloroplast homologues.