Fate of Aegilopsspeltoides-Derived, Repetitive DNA Sequences in Diploid Aegilops Species, Wheat-Aegilops Amphiploids and Derived Chromosome Addition Lines

2010 ◽  
Vol 129 (1-3) ◽  
pp. 47-54 ◽  
Author(s):  
S. Kumar ◽  
B. Friebe ◽  
B.S. Gill
Genetics ◽  
1998 ◽  
Vol 149 (4) ◽  
pp. 2025-2037 ◽  
Author(s):  
E V Ananiev ◽  
R L Phillips ◽  
H W Rines

Abstract The recovery of maize (Zea mays L.) chromosome addition lines of oat (Avena sativa L.) from oat × maize crosses enables us to analyze the structure and composition of specific regions, such as knobs, of individual maize chromosomes. A DNA hybridization blot panel of eight individual maize chromosome addition lines revealed that 180-bp repeats found in knobs are present in each of these maize chromosomes, but the copy number varies from ~100 to 25,000. Cosmid clones with knob DNA segments were isolated from a genomic library of an oat-maize chromosome 9 addition line with the help of the 180-bp knob-associated repeated DNA sequence used as a probe. Cloned knob DNA segments revealed a complex organization in which blocks of tandemly arranged 180-bp repeating units are interrupted by insertions of other repeated DNA sequences, mostly represented by individual full size copies of retrotransposable elements. There is an obvious preference for the integration of retrotransposable elements into certain sites (hot spots) of the 180-bp repeat. Sequence microheterogeneity including point mutations and duplications was found in copies of 180-bp repeats. The 180-bp repeats within an array all had the same polarity. Restriction maps constructed for 23 cloned knob DNA fragments revealed the positions of polymorphic sites and sites of integration of insertion elements. Discovery of the interspersion of retrotransposable elements among blocks of tandem repeats in maize and some other organisms suggests that this pattern may be basic to heterochromatin organization for eukaryotes.


1980 ◽  
Vol 8 (15) ◽  
pp. 3319-3333 ◽  
Author(s):  
Lesley W. Coggins ◽  
G.Joan Grindlay ◽  
J.Keith Vass ◽  
Alison A. Slater ◽  
Paul Montague ◽  
...  

Genetics ◽  
2000 ◽  
Vol 156 (1) ◽  
pp. 327-339 ◽  
Author(s):  
O Riera-Lizarazu ◽  
M I Vales ◽  
E V Ananiev ◽  
H W Rines ◽  
R L Phillips

Abstract In maize (Zea mays L., 2n = 2x = 20), map-based cloning and genome organization studies are often complicated because of the complexity of the genome. Maize chromosome addition lines of hexaploid cultivated oat (Avena sativa L., 2n = 6x = 42), where maize chromosomes can be individually manipulated, represent unique materials for maize genome analysis. Maize chromosome addition lines are particularly suitable for the dissection of a single maize chromosome using radiation because cultivated oat is an allohexaploid in which multiple copies of the oat basic genome provide buffering to chromosomal aberrations and other mutations. Irradiation (gamma rays at 30, 40, and 50 krad) of a monosomic maize chromosome 9 addition line produced maize chromosome 9 radiation hybrids (M9RHs)—oat lines possessing different fragments of maize chromosome 9 including intergenomic translocations and modified maize addition chromosomes with internal and terminal deletions. M9RHs with 1 to 10 radiation-induced breaks per chromosome were identified. We estimated that a panel of 100 informative M9RHs (with an average of 3 breaks per chromosome) would allow mapping at the 0.5- to 1.0-Mb level of resolution. Because mapping with maize chromosome addition lines and radiation hybrid derivatives involves assays for the presence or absence of a given marker, monomorphic markers can be quickly and efficiently mapped to a chromosome region. Radiation hybrid derivatives also represent sources of region-specific DNA for cloning of genes or DNA markers.


2011 ◽  
Vol 30 (9) ◽  
pp. 1779-1786 ◽  
Author(s):  
Kun Yang ◽  
Hecui Zhang ◽  
Richard Converse ◽  
Yong Wang ◽  
Xiaoying Rong ◽  
...  

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