Hřibová, E., Čížková, J., Christelová, P., Taudien, S., de Langhe, E., Doležel, J.
PLoS ONE
6(3):
e17863,
2011
Keywords:
Abstract:
Genes coding for 45S ribosomal RNA are organized in tandem arrays of up to several thousand copies and contain 18S, 5.8S
and 26S rRNA units separated by internal transcribed spacers ITS1 and ITS2. While the rRNA units are evolutionary
conserved, ITS show high level of interspecific divergence and have been used frequently in genetic diversity and
phylogenetic studies. In this work we report on the structure and diversity of the ITS region in 87 representatives of the
family Musaceae. We provide the first detailed information on ITS sequence diversity in the genus Musa and describe the
presence of more than one type of ITS sequence within individual species. Both Sanger sequencing of amplified ITS regions
and whole genome 454 sequencing lead to similar phylogenetic inferences. We show that it is necessary to identify putative
pseudogenic ITS sequences, which may have negative effect on phylogenetic reconstruction at lower taxonomic levels.
Phylogenetic reconstruction based on ITS sequence showed that the genus Musa is divided into two distinct clades –
Callimusa and Australimusa and Eumusa and Rhodochlamys. Most of the intraspecific banana hybrids analyzed contain
conserved parental ITS sequences, indicating incomplete concerted evolution of rDNA loci. Independent evolution of
parental rDNA in hybrids enables determination of genomic constitution of hybrids using ITS. The observation of only one
type of ITS sequence in some of the presumed interspecific hybrid clones warrants further study to confirm their hybrid
origin and to unravel processes leading to evolution of their genomes.
Fulltext: contact IEB authors
IEB authors: Pavla Christelová,
Jana Čížková,
Jaroslav Doležel,
Eva Hřibová
Čeština
English