Čížková, J., Hřibová, E., Humplíková, L., Christelová, P., Suchánková, P., Doležel, J.
PLoS ONE
8:
e54808,
2013
Keywords:
Abstract:
Satellite DNA sequences consist of tandemly arranged repetitive units up to thousands nucleotides long in head-to-tail
orientation. The evolutionary processes by which satellites arise and evolve include unequal crossing over, gene conversion,
transposition and extra chromosomal circular DNA formation. Large blocks of satellite DNA are often observed in
heterochromatic regions of chromosomes and are a typical component of centromeric and telomeric regions. Satellite-rich
loci may show specific banding patterns and facilitate chromosome identification and analysis of structural chromosome
changes. Unlike many other genomes, nuclear genomes of banana (Musa spp.) are poor in satellite DNA and the information
on this class of DNA remains limited. The banana cultivars are seed sterile clones originating mostly from natural intraspecific
crosses within M. acuminata (A genome) and inter-specific crosses between M. acuminata and M. balbisiana (B
genome). Previous studies revealed the closely related nature of the A and B genomes, including similarities in repetitive
DNA. In this study we focused on two main banana DNA satellites, which were previously identified in silico. Their genomic
organization and molecular diversity was analyzed in a set of nineteen Musa accessions, including representatives of A, B
and S (M. schizocarpa) genomes and their inter-specific hybrids. The two DNA satellites showed a high level of sequence
conservation within, and a high homology between Musa species. FISH with probes for the satellite DNA sequences, rRNA
genes and a single-copy BAC clone 2G17 resulted in characteristic chromosome banding patterns in M. acuminata and M.
balbisiana which may aid in determining genomic constitution in interspecific hybrids. In addition to improving the
knowledge on Musa satellite DNA, our study increases the number of cytogenetic markers and the number of individual
chromosomes, which can be identified in Musa.
Fulltext: contact IEB authors
IEB authors: Pavla Christelová,
Jana Čížková,
Jaroslav Doležel,
Eva Hřibová,
Pavla Suchánková
Čeština
English