PMID- 16357054
OWN - NLM
STAT- MEDLINE
DCOM- 20060322
LR  - 20240322
IS  - 0305-7364 (Print)
IS  - 1095-8290 (Electronic)
IS  - 0305-7364 (Linking)
VI  - 97
IP  - 2
DP  - 2006 Feb
TI  - Comparative analysis of rDNA distribution in chromosomes of various species of 
      Brassicaceae.
PG  - 205-16
AB  - BACKGROUND AND AIMS: The Brassicaceae family encompasses numerous species of 
      great agronomic importance, belonging to such genera, as Brassica, Raphanus, 
      Sinapis and Armoracia. Many of them are characterized by extensive intraspecific 
      diversity of phenotypes. The present study focuses on the polymorphism of number, 
      appearance and chromosomal localization of ribosomal DNA (rDNA) sites and, when 
      possible, in relation to polyploidy, in 42 accessions of Brassica species and ten 
      accessions of Diplotaxis, Eruca, Raphanus and Sinapis species. METHODS: 
      Chromosomal localization of ribosomal DNA was carried out using dual colour 
      fluorescence in situ hybridization (FISH) with 5S rDNA and 25S rDNA sequences as 
      probes on enzymatically digested root-tip meristematic cells. KEY RESULTS: Loci 
      for 5S and 18S-5.8S-25S rDNA were determined for the first time in six taxa, and 
      previously unreported rDNA constellations were described in an additional 12 
      accessions. FISH revealed frequent polymorphism in number, appearance and 
      chromosomal localization of both 5S and 25S rDNA sites. This phenomenon was most 
      commonly observed in the A genome of Brassica, where it involves exclusively 
      pericentromeric sites of 5S and 25S rRNA genes. The intraspecific polymorphism 
      was between subspecies/varieties or within a variety or cultivar (i.e. 
      interindividual). CONCLUSIONS: The number of rDNA sites can differ up to 5-fold 
      in species with the same chromosome number. In addition to the eight previously 
      reported chromosomal types with ribosomal genes, three new variant types are 
      described. The extent of polymorphism is genome dependent. Comparing the A, B and 
      C genomes revealed the highest rDNA polymorphism in the A genome. The loci 
      carrying presumably inactive ribosomal RNA genes are particularly prone to 
      polymorphism. It can also be concluded that there is no obvious 
      polyploidization-related tendency to reduce the number of ribosomal DNA loci in 
      the allotetraploid species, when compared with their putative diploid 
      progenitors. The observed differences are rather caused by the prevailing 
      polymorphism within the diploids and allotetraploids. This would make it 
      difficult to predict expected numbers of rDNA loci in natural polyploids.
FAU - Hasterok, Robert
AU  - Hasterok R
AD  - Department of Plant Anatomy and Cytology, University of Silesia, Jagiellonska 28, 
      40-032 Katowice, Poland. hasterok@us.edu.pl
FAU - Wolny, Elzbieta
AU  - Wolny E
FAU - Hosiawa, Marta
AU  - Hosiawa M
FAU - Kowalczyk, Malgorzata
AU  - Kowalczyk M
FAU - Kulak-Ksiazczyk, Sylwia
AU  - Kulak-Ksiazczyk S
FAU - Ksiazczyk, Tomasz
AU  - Ksiazczyk T
FAU - Heneen, Waheeb K
AU  - Heneen WK
FAU - Maluszynska, Jolanta
AU  - Maluszynska J
LA  - eng
PT  - Comparative Study
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
DEP - 20051215
PL  - England
TA  - Ann Bot
JT  - Annals of botany
JID - 0372347
RN  - 0 (DNA, Ribosomal)
SB  - IM
MH  - Brassicaceae/*genetics
MH  - Chromosome Mapping
MH  - Chromosomes, Plant/*chemistry
MH  - DNA, Ribosomal/*analysis
MH  - Genetic Variation
MH  - Genome, Plant
MH  - In Situ Hybridization, Fluorescence
MH  - Phenotype
MH  - Polymorphism, Genetic
MH  - Polyploidy
PMC - PMC2803362
EDAT- 2005/12/17 09:00
MHDA- 2006/03/23 09:00
PMCR- 2007/02/01
CRDT- 2005/12/17 09:00
PHST- 2005/12/17 09:00 [pubmed]
PHST- 2006/03/23 09:00 [medline]
PHST- 2005/12/17 09:00 [entrez]
PHST- 2007/02/01 00:00 [pmc-release]
AID - mcj031 [pii]
AID - 10.1093/aob/mcj031 [doi]
PST - ppublish
SO  - Ann Bot. 2006 Feb;97(2):205-16. doi: 10.1093/aob/mcj031. Epub 2005 Dec 15.