Ribosomal DNA, peroxidase and extensin variation in genomic DNA of Medicago laciniata (L.) Miller from Australia and Africa

1994 ◽  
Vol 45 (5) ◽  
pp. 1013 ◽  
Author(s):  
RR Young ◽  
ES Lagudah
Keyword(s):  
Restriction Endonuclease ◽  
South African ◽  
Ribosomal Dna ◽  
Genomic Dna ◽  
Repeat Unit ◽  
Cdna Clones ◽  
Genotypic Differences ◽  
Rdna Repeat ◽  
Eastern Australia ◽  
Rdna Repeat Unit

Fifty-four Medicago laciniata (L.) Miller accessions from diverse locations in eastern Australia, Africa and Israel were characterized for genotypic differences by restriction endonuclease cleavage of genomic DNA and probing with radio-labelled DNA sequences to detect restriction fragment length polymorphisms (RFLP). Digestion of the genomic DNA with the restriction endonuclease, Bam HI, and probing with the complete ribosomal DNA (rDNA) repeat unit of soybean (pGmrl) and its subclones revealed that the variable region in M. laciniata spans the Bam H1 sites of the intergenic spacer region between the 18s and 26s DNA. The length variation in the rDNA repeat unit clearly distinguished South African from Australian accessions. The rDNA variants from SA1847 (Morocco) and SA7750 (Tunisia) were the same as the Australian accessions and slightly larger than the rDNA spacer variant unique to SA3428 (Israel). When Eco R1 digested M. laciniata genomic DNA was probed with peroxidase and extensin cDNA clones, all Australian accessions were again characterized by the same RFLP genotype with further differentiation between African and Israeli accessions. An accession of unknown origin, SA3412, possessed the same RFLP genotype as the Australian accessions for all endonuclease and probe combinations. For the African accessions, differences in RFLP genotype were more frequent than differences in phenotype (leaflet laciniation and colour). However, of three South African accessions with the same RFLP genotype, SA26844, SA26847, and SA26848, SA26847 had more pronounced leaflet laciniation.

Polymorphism in ribosomal DNA repeat units of 12 Hordeum species

Genome ◽  
1989 ◽  
Vol 32 (6) ◽  
pp. 1124-1127 ◽  
Author(s):  
Stephen J. Molnar ◽  
George Fedak
Keyword(s):  
Ribosomal Dna ◽  
Repeat Unit ◽  
Unit Length ◽  
Intergenic Spacer ◽  
Rdna Repeat ◽  
Repeat Units ◽  
Dna Repeat ◽  
Rdna Repeat Unit ◽  
Bamhi Restriction Site ◽  
Hordeum Species

Total genomic DNA was isolated from leaves of individual accessions of 12 Hordeum species. SacI, HindIII, and BamHI restriction fragments hybridizing to the wheat rDNA probe pTA71 were compared. Thirteen rDNA repeat unit length variants were recovered, which combined to produce 11 distinct phenotypes. All rDNA repeat units had two SacI sites and no HindIII sites. The rDNA repeat units of H. secalinum, H. hrasdanicum, and H. distichum all had 3 BamHI sites, but in different configurations. The rDNA repeat units of the other species had at least 4 BamHI sites. Ladders of small hybridizing fragments in 8 of 9 of the latter accessions indicated the presence of occasional BamHI sites in some subrepeats within the intergenic spacer regions of the rDNA repeat units. Different distributions of BamHI restriction site maps within the Hordeum sections strengthen the concept of using variation in rDNA restriction sites as a taxonomic character.Key words: Hordeum, ribosomal DNA, polymorphism.

Genomic variability within laboratory and wild subspecies of Heligmosomoides polygyrus

1994 ◽  
Vol 68 (2) ◽  
pp. 93-96 ◽  
Author(s):  
M.A. Abu-Madi ◽  
A.P. Reid ◽  
J.W. Lewis ◽  
W.M. Hominick
Keyword(s):  
Restriction Endonuclease ◽  
Ribosomal Dna ◽  
Dna Hybridization ◽  
Genomic Dna ◽  
Dna Probes ◽  
Heligmosomoides Polygyrus ◽  
Banding Patterns ◽  
Genomic Variability

AbstractGenomic DNA extracted from laboratory and wild subspecies of the trichostrongyle nematode Heligmosomoides polygyrus were compared using RFLP and DNA/DNA hybridization techniques. Eight restriction endonuclease digests of the genomic DNA of the two subspecies were hybridized with heterologous ribosomal DNA probes and the total radio-isotope labelled DNA of the laboratory subspecies. DNA hybridization of the two subspecies of H. polygyrus yielded different banding patterns when probed with the rDNA clones in Pvu II digests and when total genomic DNA was used as the probe in Hind III and Pvu II digests. The remaining hybridization profiles of both subspecies were identical.

Use of virulence and length variability within the rDNA repeat unit to distinguish isolates ofPuccinia graminis f. sp. triticirace QCC

1995 ◽  
Vol 17 (3) ◽  
pp. 197-204 ◽  
Author(s):  
S.L. Fox ◽  
D.E. Harder ◽  
W.K. Kim
Keyword(s):  
Repeat Unit ◽  
Rdna Repeat ◽  
Rdna Repeat Unit

Cloning and characterization of the rDNA repeat unit of Podospora anserina

1985 ◽  
Vol 199 (1) ◽  
pp. 154-157 ◽  
Author(s):  
N. Labat ◽  
M. Perrot ◽  
J. Bégueret
Keyword(s):  
Repeat Unit ◽  
Podospora Anserina ◽  
Rdna Repeat ◽  
Rdna Repeat Unit

Cloning of the rDNA repeat unit from a British entomopathogenic nematode (Steinernematidae) and its potential for species identification

Parasitology ◽  
1993 ◽  
Vol 107 (5) ◽  
pp. 529-536 ◽  
Author(s):  
A. P. Reid ◽  
W. M. Hominick
Keyword(s):  
Entomopathogenic Nematode ◽  
Repeat Unit ◽  
Unit Length ◽  
Soil Survey ◽  
Rdna Repeat ◽  
Dna Repeat ◽  
Length Polymorphisms ◽  
Rdna Repeat Unit ◽  
Unique Restriction ◽  
Plasmid Puc18

SUMMARYThe entire ribosomal DNA repeat unit of a steinernematid species (Nashes isolate) was cloned as three separate EcoR I fragments in the plasmid pUC18. An equimolar cocktail of these three clones was used to identify Steinernema species on Southern blots as each species displays its own unique restriction fragment length polymorphisms. The clones also identified two new species isolated in a soil survey of coastal regions of Britain. One of the clones (pSn4.0) can detect length heterogeneities in the rDNA repeat unit of various isolates of some of the species, particularly the most common in the United Kingdom, S. feltiae. These differences in the rDNA repeat unit length remained constant over several years for one isolate of S. feltiae, but were different for each of the geographical isolates studied to date.

DNA restriction fragment length polymorphisms in the rDNA repeat unit of Entomophaga

1990 ◽  
Vol 14 (4) ◽  
pp. 381-392 ◽  
Author(s):  
Scott R.A. Walsh ◽  
David Tyrrell ◽  
Richard A. Humber ◽  
Julie C. Silver
Keyword(s):  
Restriction Fragment ◽  
Fragment Length ◽  
Repeat Unit ◽  
Restriction Fragment Length Polymorphisms ◽  
Rdna Repeat ◽  
Length Polymorphisms ◽  
Rdna Repeat Unit ◽  
Dna Restriction ◽  
Restriction Fragment Length

scholarly journals Molecular and FISH analysis of 45S rDNA on BAC molecule of Saccharina Japonica

2021 ◽  
Author(s):  
Peng-Fei Liu ◽  
Yan-Hui Bi ◽  
Li Liu ◽  
Zhi-Gang Zhou
Keyword(s):  
Physical Map ◽  
Repeat Unit ◽  
Gc Content ◽  
Intergenic Spacer ◽  
Saccharina Japonica ◽  
Fish Analysis ◽  
45S Rdna ◽  
Rdna Repeat ◽  
Bac Clone ◽  
Rdna Repeat Unit

Abstract IGS is abundant in polymorphism, which is widely used in the analysis of intraspecific genetic diversity and phylogenetic relationships among geographical populations. In this study, the 45S rDNA repeat unit of Saccharina japonica was obtained for the first time by BAC clone sequencing. The total length of 45S rDNA repeat unit of S. japonica was 8995 bp, including 5420 bp of 18s-5.8s-25s rDNA and 3575 bp of IGS (Intergenic Spacer), with the GC content of 51.4%. IGS was composed of 465 bp 3’-outer transcribed spacer (ETS), 874 bp 5’-ETS, and 2236 bp non transcribed spacer (NTS), with the GC content of 50.1%.Fiber-FISH (fiber-fluorescence in situ hybridization, fiber-FISH) analysis of 45S rDNA on the BAC molecule of female gametophytes of S. japonica illustrated that each fiber had at least five continuous moniliform hybridization signal points, indicating the distribution of 45S rDNA repeat unit on the bacterial artificial chromosome. This study provided a new candidate molecular marker for detecting intraspecific polymorphisms of S. japonica, and the successful fiber-FISH analysis of 45S rDNA on BAC molecule would contribute to the construction of the physical map and Map-based cloning of this kelp.

scholarly journals Molecular Structure of rDNA Repeat Unit inMagnaporthe grisea

2000 ◽  
Vol 64 (8) ◽  
pp. 1733-1736 ◽  
Author(s):  
Teruo SONE ◽  
Satoru FUKIYA ◽  
Megumi KODAMA ◽  
Fusao TOMITA
Keyword(s):  
Molecular Structure ◽  
Repeat Unit ◽  
Rdna Repeat ◽  
Rdna Repeat Unit

Restriction fragment length polymorphisms within the ribosomal DNA repeat unit of British entomopathogenic nematodes (Rhabditida: Steinernematidae)

Parasitology ◽  
1992 ◽  
Vol 105 (2) ◽  
pp. 317-323 ◽  
Author(s):  
A. P. Reid ◽  
W. M. Hominick
Keyword(s):  
Restriction Fragment ◽  
Ribosomal Dna ◽  
Fragment Length ◽  
Genomic Dna ◽  
Entomopathogenic Nematodes ◽  
Repeat Unit ◽  
Geographical Location ◽  
Steinernema Feltiae ◽  
Dna Repeat ◽  
Restriction Fragment Length

SUMMARYGenomic DNA extracted from entomopathogenic nematodes isolated from 89 soil samples taken throughout the United Kingdom was hybridized with the ribosomal DNA clone from Caenorhabditis elegans (pCe7). When the DNA was digested with EcoR I and Hind III in a double digest, 5 distinct RFLP (restriction fragment length polymorphism) types were observed. While the prevalence of the 5 types was not equal, no correlation with geographical location, soil type or habitat could be detected. Subsequent hybridizations of total genomic DNA from the various RFLP types divided them into 2 groups. The most prevalent group, identified as Steinernema feltiae ( = bibionis), contained 2 of the RFLP types (Al and A2). The other group contained the remaining 3 RFLP types (B1, B2 and B3). Although similar to S. feltiae ( = bibionis), the members of the B-types can be distinguished from this species on morphological grounds and preliminary crossbreeding experiments have demonstrated that the 2 groups are reproductively isolated.

A New rDNA Repeat Unit in Human Giardia

1994 ◽  
Vol 41 (6) ◽  
pp. 639-642 ◽  
Author(s):  
JACQUELINE A. UPCROFT ◽  
ANDREW HEALEY ◽  
PETER UPCROFT
Keyword(s):  
Repeat Unit ◽  
Rdna Repeat ◽  
Rdna Repeat Unit
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