Analysis of rye B-chromosome structure using fluorescence in situ hybridization (FISH).
Fluorescence in situ hybridization (FISH) has been used to analyse the structure of the rye B chromosome. Genomic in situ hybridization (GISH) demonstrates the high level of overall similarity between A and B chromosomes of rye, as well as the presence of a number of specific sequences. The B-specific repeat families D1100 and E3900 have been analysed in terms of their physical location and possible contiguity. Rye Bs contain members of the rye-specific dispersed repetitive family R173, as well as centromeric regions similar to those of the As. The B chromosomes analysed in our study lack detectable rDNA sequences. Anomalous results have been obtained with a number of subtelomeric repetitive probes from rye. Bs usually lack these sequences, but evidence is presented that in some cases A-B translocation events may relocate such sequences from the As to the Bs. These data are discussed in the context of current models for the origin of the B chromosome.
Wilkes
T M
TM
Institute of Biological Sciences, University of Wales, Aberystwyth, UK.
Francki
M G
MG
Langridge
P
P
Karp
A
A
Jones
R N
RN
Forster
J W
JW
D002875:Chromosomes / Q000648:ultrastructure*; D018744:DNA, Plant / Q000235:genetics; D004275:DNA, Ribosomal / Q000235:genetics; D006570:Heterochromatin / Q000648:ultrastructure; D017404:In Situ Hybridization, Fluorescence; D012091:Repetitive Sequences, Nucleic Acid; D012434:Secale / Q000235:genetics* / Q000648:ultrastructure
D018744:DNA, Plant; D004275:DNA, Ribosomal; D006570:Heterochromatin