Intragenomic and interspecific 5S rDNA sequence variation in five Asian pines

2003 ◽  
Vol 90 (1) ◽  
pp. 17-24 ◽  
Author(s):  
Z.-L. Liu ◽  
D. Zhang ◽  
X.-Q. Wang ◽  
X.-F. Ma ◽  
X.-R. Wang
Keyword(s):  
Sequence Variation ◽  
5S Rdna ◽  
Rdna Sequence ◽  
5S Rdna Sequence

Organization of the 5S rRNA genes in the soybean Glycine max (L.) Merrill and conservation of the 5S rDNA repeat structure in higher plants

Genome ◽  
1990 ◽  
Vol 33 (4) ◽  
pp. 486-494 ◽  
Author(s):  
S. G. Gottlob-McHugh ◽  
M. Lévesque ◽  
K. MacKenzie ◽  
M. Olson ◽  
O. Yarosh ◽  
...  
Keyword(s):  
Glycine Max ◽  
Tandem Repeats ◽  
Higher Plants ◽  
5S Rdna ◽  
Rdna Sequence ◽  
5S Rrna ◽  
Rrna Genes ◽  
Rrna Gene ◽  
Glycine Max L ◽  
5S Rdna Sequence

The 5S rRNA gene of the soybean Glycine max (L.) Merr. has been cloned on a 556-bp fragment of DNA and sequenced. This fragment contains two copies of the soybean 5S rDNA sequence, one intact and one truncated, separated by noncoding DNA. We have used this clone to investigate the organization of the 5S genes within the soybean genome and the extent of their methylation. Our results demonstrate that soybean 5S genes are clustered, organized into tandem repeats of 330 bp, and extensively methylated. Hybridization of the 5S sequence to Southern transfers of soybean DNA digested with BamHI reveals a striking ladderlike pattern. Hybridization of the soybean 5S sequence to a wide variety of plant DNAs results in similar patterns, suggesting that the 5S rDNA sequence, gene organization, and methylation pattern are conserved in many higher plants.Key words: 5S rDNA, sequence, methylation, soybean, repeat conservation.

The 5S rRNA gene in sea barley (Hordeum marinum Hudson sensu lato): sequence variation among repeat units and relationship to the X haplome in barley (Hordeum)

Genome ◽  
1998 ◽  
Vol 41 (5) ◽  
pp. 652-661 ◽  
Author(s):  
Bernard R Baum ◽  
Douglas A Johnson
Keyword(s):  
Sequence Variation ◽  
Current Knowledge ◽  
Cladistic Analysis ◽  
5S Rdna ◽  
The Other ◽  
Rrna Gene ◽  
Repeat Units ◽  
Unit Classes ◽  
Unit Class ◽  
5S Rrna Gene

We have investigated the molecular diversity of the 5S rDNA units in sea barley, comprising Hordeum marinum and Hordeum geniculatum. Although we were unable to detect "short" units after screening of 639 clones, we found two unit classes, one 602-607 bp long and the other 507-512 bp long. We classify the shortest unit class of the two as belonging to the "long H1" unit class, identified in previous papers. The longest unit class is not similar to any unit class so far identified, and is therefore unique. It was coined by us as the "long X1," to reflect the X haplome. We present a summary of all the unit classes so far described in Hordeum. We carried out a cladistic analysis, based on the "long H1" (orthologous) sequences, that included H. vulgare, H. spontaneum, H. bulbosum, H. marinum, H. geniculatum, and H. bogdanii. As a result, the first three grouped in one clade, and the other three in the other clade, with the latter clade being more isolated. These results reflect current knowledge of relationships based on morphology, cytology, and genome analysis. Furthermore, the sequences from the 5S unit classes may be potentially useful as DNA probes for genomic identification and genetic transfer in the Triticeae.Key words: 5S rDNA, genomes, X haplome, sea barley, Triticeae.

Morphological and LSU rDNA sequence variation within the Gonyaulax spinifera-Spiniferites group (Dinophyceae) and proposal of G. elongata comb. nov. and G. membranacea comb. nov.

Phycologia ◽  
2003 ◽  
Vol 42 (2) ◽  
pp. 151-164 ◽  
Author(s):  
Marianne Ellegaard ◽  
Niels Daugbjerg ◽  
André Rochon ◽  
Jane Lewis ◽  
Ian Harding
Keyword(s):  
Sequence Variation ◽  
Rdna Sequence ◽  
Lsu Rdna

Physical mapping of four sites of 5S rDNA sequences and one site of the α-amylase-2 gene in barley (Hordeum vulgare)

Genome ◽  
1993 ◽  
Vol 36 (3) ◽  
pp. 517-523 ◽  
Author(s):  
I. J. Leitch ◽  
J. S. Heslop-Harrison
Keyword(s):  
In Situ Hybridization ◽  
Hordeum Vulgare ◽  
Physical Mapping ◽  
5S Rdna ◽  
Chromosome 1 ◽  
Chromosome 2 ◽  
Hordeum Vulgare L ◽  
Rdna Sequences ◽  
5S Rdna Sequence

The 5S rDNA sequences have been mapped on four pairs of barley (Hordeum vulgare L.) chromosomes using in situ hybridization and barley monotelotrisomic lines. The 5S rDNA sequences are located, genetically and physically, on the short arm of chromosome 1 (7I) and the long arms of chromosomes 2 (2I) and 3 (3I). The 5S rDNA sequence is also located on the physically long arm of chromosome 4 (4I). Only one site on chromosome 2(2I) has previously been reported. The characteristic locations of the 5S rDNA sequences make them useful as molecular markers to identify each barley chromosome. The physical position of the low-copy α-amylase-2 gene was determined using in situ hybridization; the location of this gene on the long arm of chromosome 1 (7I) was confirmed by reprobing the same preparation with the 5S rDNA probe. The results show that there is a discrepancy between the physical and genetic position of the α-amylase-2 gene.Key words: genetic mapping, physical mapping, barley, mapping, 5S DNA, α-amylase, in situ hybridization.

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