Martis, M.M., Klemme, S., Banaei-Moghaddam, A.M., Blattner, F.R., Macas, J., Schmutzer, T., Scholz, U., Gundlach, H., Wicker, T., Šimková, H., Novák, P., Neumann, P., Kubaláková, M., Bauer, E., Haseneyer, G., Fuchs, J., Doležel, J., Stein, N., Mayer, K.F.X., Houben, A.
PROCEEDINGS OF THE NAS OF THE USA
109:
33,
2012
Klíčová slova:
centromere, genome evolution, promiscuous DNA, non-Mendelian chromosome transmission
Abstrakt:
Supernumerary B chromosomes are optional additions to the basic
set of A chromosomes, and occur in all eukaryotic groups. They
differ from the basic complement in morphology, pairing behavior,
and inheritance and are not required for normal growth and
development. The current view is that B chromosomes are parasitic
elements comparable to selfish DNA, like transposons. In contrast to
transposons, they are autonomously inherited independent of the
host genome and have their own mechanisms of mitotic or meiotic
drive. Although B chromosomes were first described a century ago,
little is known about their origin and molecular makeup. The widely
accepted view is that they are derived from fragments of A
chromosomes and/or generated in response to interspecific hybridization.
Through next-generation sequencing of sorted A and B
chromosomes, we show that B chromosomes of rye are rich in genederived
sequences, allowing us to trace their origin to fragments ofA
chromosomes, with the largest parts corresponding to rye chromosomes
3R and 7R. Compared with A chromosomes, B chromosomes
were also found to accumulate large amounts of specific repeats and
insertions of organellar DNA. The origin of rye B chromosomes
occurred an estimated ∼1.1–1.3 Mya, overlapping in time with the
onset of the genus Secale (1.7 Mya). We propose a comprehensive
model of B chromosome evolution, including its origin by recombination
of several A chromosomes followed by capturing of additional
A-derived and organellar sequences and amplification of Bspecific
repeats.
Fulltext: kontaktujte autory z ÚEB
Autoři z ÚEB: Jaroslav Doležel,
Marie Kubaláková,
Hana Šimková
Čeština
English