Diversity of ectomycorrhizas associated with Quercus garryana in southern Oregon

2004 ◽  
Vol 82 (1) ◽  
pp. 123-135 ◽  
Author(s):  
L L Valentine ◽  
T L Fiedler ◽  
A N Hart ◽  
C A Petersen ◽  
H K Berninghausen ◽  
...  
Keyword(s):  
Fragment Length Polymorphism ◽  
Soil Cores ◽  
Cenococcum Geophilum ◽  
Ectomycorrhizal Community ◽  
Quercus Garryana ◽  
White Oak ◽  
Hypogeous Fungi ◽  
Dna Restriction Fragments ◽  
Dna Restriction ◽  
Tuber Species

We investigated diversity of ectomycorrhizas associated with Quercus garryana Dougl. ex Hook. (Oregon white oak, or Garry oak) at Whetstone Savanna Preserve in southern Oregon. Based on morphotyping and DNA restriction fragments, we described 39 ectomycorrhizas. The most common five morphotypes were found in 5% or more of 160 soil cores. Cenococcum geophilum, the most abundant morphotype, occurred in 75% of soil cores. Another common morphotype yielded a restriction fragment length polymorphism (RFLP) pattern similar to that of Tuber species. Uncommon morphotypes were responsible for the majority of ectomycorrhizal diversity on Q. garryana. Morphotype diversity of seedlings was more similar to that of their parent tree than to seedlings under other trees. Internal transcribed spacer (ITS) – RFLP patterns of ectomycorrhizas found beneath sporocarps did not match those of the sporocarps fruiting above ground. An understanding of the diversity of the ectomycorrhizal community on Q. garryana will enable us to compare ectomycorrhizas on other oak species and habitats; determine seasonality of ectomycorrhizal growth; evaluate treatments such as fire, grazing, invasion by exotic plants, and other anthropogenic disturbances; and aid restoration protocols.Key words: biocomplexity, biodiversity, ectomycorrhizas, hypogeous fungi, morphotypes, Peziza infossa, Tuber.

Rodent dispersal of fungal spores promotes seedling establishment away from mycorrhizal networks on Quercus garryana

Botany ◽  
2009 ◽  
Vol 87 (9) ◽  
pp. 821-829 ◽  
Author(s):  
J. L. Frank ◽  
S. Anglin ◽  
E. M. Carrington ◽  
D. S. Taylor ◽  
B. Viratos ◽  
...  
Keyword(s):  
Dna Sequences ◽  
Seedling Establishment ◽  
Root Zone ◽  
Fungal Spores ◽  
Soil Cores ◽  
Quercus Garryana ◽  
Mature Trees ◽  
Fecal Pellets ◽  
Hypogeous Fungi ◽  
Mycorrhizal Networks

With global warming and the possible decline of conifers, more habitat may be available to oaks, particularly at higher elevations and more northerly latitudes. Whether oaks expand into new habitats will depend on their ability to disperse and establish at the margins of existing woodlands. Because oaks have a symbiotic relationship with ectomycorrhizal fungi, range expansion requires dispersal of both symbionts: the acorns and the mycorrhizal inoculum. Little is known of this dual dispersal. Here we assess the availability of ectomycorrhizal inoculum as a function of the distance from mature oaks. We examined soil cores for ectomycorrhizal roots and rodent fecal pellets for fungal spores along transects away from mature trees of Quercus garryana Dougl. ex Hook., and planted acorns as bioprobes. We identified spores by microscopy, and mycorrhizas by DNA sequences of the ITS region. Mycorrhizas were present in soil cores 5 m from parent trees, but not beyond. Spores of hypogeous fungi were found in rodent fecal pellets at distances up to 35 m from mature trees. Hypogeous fungi formed ectomycorrhizas with first-year seedlings within the root zone of mature trees and with second-year seedlings beyond the root zone. These data indicate that for seedlings near mature trees, the source of fungal inoculum was the mycorrhizal network of mature trees, and for seedlings beyond that, rodents dispersed the inoculum. We conclude that rodent dispersal of fungal spores promotes seedling establishment away from mycorrhizal networks in Q. garryana.

scholarly journals Estimation of recombination frequencies and construction of RFLP linkage maps in plants from crosses between heterozygous parents.

Genetics ◽  
1990 ◽  
Vol 125 (3) ◽  
pp. 645-654 ◽  
Author(s):  
E Ritter ◽  
C Gebhardt ◽  
F Salamini
Keyword(s):  
Fragment Length Polymorphism ◽  
Recombination Frequency ◽  
General Outline ◽  
Information Functions ◽  
Map Construction ◽  
Special Cases ◽  
Dna Restriction Fragments ◽  
Dna Restriction ◽  
Pure Lines

Abstract The construction of a restriction fragment length polymorphism (RFLP) linkage map is based on the estimation of recombination frequencies between genetic loci and on the determination of the linear order of loci in linkage groups. RFLP loci can be identified as segregations of singular or allelic DNA-restriction fragments. From crosses between heterozygous individuals several allele (fragment) configurations are possible, and this leads to a set of formulas for the evaluation of p, the recombination frequency between two loci. Tables and figures are presented illustrating a general outline of gene mapping using heterozygous populations. The method encompasses as special cases the mapping of loci from segregating populations of pure lines. Formulas for deriving the recombination frequencies and information functions are given for different fragment configurations. Information functions derived for relevant configurations are also compared. A procedure for map construction is presented, as it has been applied to RFLP mapping in an allogamous crop.

Characterization of Cloned Mitochondrial DNA from the Teleost Fundulus heteroclitus and its Usefulness as an Interspecies Hybridization Probe

1986 ◽  
Vol 43 (10) ◽  
pp. 1866-1872 ◽  
Author(s):  
Lucia Irene González-Villaseñor ◽  
Amanda M. Burkhoff ◽  
Víctor Corces ◽  
Dennis A. Powers
Keyword(s):  
Mitochondrial Dna ◽  
Ethidium Bromide ◽  
Fundulus Heteroclitus ◽  
Staining Technique ◽  
Hybridization Probe ◽  
Cross Hybridization ◽  
Restriction Patterns ◽  
Ethidium Bromide Staining ◽  
Dna Restriction Fragments ◽  
Dna Restriction

Analysis of mitochondrial DNA endonuclease restriction patterns is a powerful tool for studying related species and variation within species. The ethidium bromide staining technique has limited the number of digestions of mitochondrial DNA per individual. Because 32P-end-labeling also imposes severe limitations, we have resorted to cloning the fish (Fundulus heteroclitus) mitochondrial genome in the lambda replacement vector EMBL-3. The clone was used as a radioactive probe via Southern blotting to detect mitochondrial DNA restriction fragments obtained by multiple restriction endonuclease digestions from small amounts of tissue. This technique offers much greater sensitivity than ethidium bromide staining. Moreover, it eliminates the expense and time to obtain highly purified mitochondrial DNA for the 32P-end-labeling procedure. It is also useful when the mtDNA is prepared from frozen tissue which has been a problem with the 32P-end-labeling technique. Because the cloned mitochondrial DNA has a high degree of cross-hybridization with the mitochondrial DNA of certain other fishes, it can be used to probe the mitochondrial DNA restriction patterns of a variety of fish species. However, its usefulness is restricted by the degree of relatedness to the species being cloned.

Length-independent separation of DNA restriction fragments in two-dimensional gel electrophoresis

Cell ◽  
1979 ◽  
Vol 16 (1) ◽  
pp. 191-200 ◽  
Author(s):  
Stuart G. Fischer ◽  
Leonard S. Lerman
Keyword(s):  
Gel Electrophoresis ◽  
Two Dimensional ◽  
Two Dimensional Gel Electrophoresis ◽  
Restriction Fragments ◽  
Dna Restriction Fragments ◽  
Dna Restriction

Capillary electrophoresis of DNA restriction fragments: Effect of polymer properties

1997 ◽  
Vol 18 (11) ◽  
pp. 1994-1997 ◽  
Author(s):  
Björn Braun ◽  
Harvey W. Blanch ◽  
John M. Prausnitz
Keyword(s):  
Capillary Electrophoresis ◽  
Restriction Fragments ◽  
Polymer Properties ◽  
Dna Restriction Fragments ◽  
Dna Restriction

Precise localization of m6A in Rous sarcoma virus RNA reveals clustering of methylation sites: implications for RNA processing

1985 ◽  
Vol 5 (9) ◽  
pp. 2298-2306
Author(s):  
S E Kane ◽  
K Beemon
Keyword(s):  
Rous Sarcoma Virus ◽  
Rna Splicing ◽  
Paper Electrophoresis ◽  
Virus Genome ◽  
Rous Sarcoma ◽  
Virus Rna ◽  
Dna Restriction Fragments ◽  
Sarcoma Virus ◽  
Dna Restriction ◽  
Layer Chromatography

N6-methyladenosine (m6A) residues are present as internal base modifications in most higher eucaryotic mRNAs; however, the biological function of this modification is not known. We describe a method for localizing and quantitating m6A within a large RNA molecule, the genomic RNA of Rous sarcoma virus. Specific fragments of 32P-labeled Rous sarcoma virus RNA were isolated by hybridization with complementary DNA restriction fragments spanning nucleotides 6185 to 8050. RNA was digested with RNase and finger-printed, and individual oligonucleotides were analyzed for the presence of m6A by paper electrophoresis and thin-layer chromatography. With this technique, seven sites of methylation in this region of the Rous sarcoma virus genome were localized at nucleotides 6394, 6447, 6507, 6718, 7414, 7424, and 8014. Further, m6A was observed at two additional sites whose nucleotide assignments remain ambiguous. A clustering of two or more m6A residues was seen at three positions within the RNA analyzed. Modification at certain sites was found to be heterogeneous, in that different molecules of RNA appeared to be methylated differently. Previous studies have determined that methylation occurs only in the sequences Gm6AC and Am6AC. We observed a high frequency of methylation at PuGm6ACU sequences. The possible involvement of m6A in RNA splicing events is discussed.

Differentiation of two mouse cell lines is associated with hypomethylation of their genomes

1984 ◽  
Vol 4 (9) ◽  
pp. 1800-1806
Author(s):  
T H Bestor ◽  
S B Hellewell ◽  
V M Ingram
Keyword(s):  
Dna Methyltransferase ◽  
Cell Types ◽  
Mouse Cell ◽  
F9 Cells ◽  
Dna Restriction Fragments ◽  
Dna Restriction ◽  
F9 Embryonal Carcinoma Cells ◽  
Murine Erythroleukemia ◽  
Kinetics Of

Methyl-accepting assays and a sensitive method for labeling specific CpG sites have been used to show that the DNA of F9 embryonal carcinoma cells decreases in 5-methylcytosine content by ca. 9% during retinoic acid-induced differentiation, whereas the DNA of dimethyl sulfoxide-induced Friend murine erythroleukemia (MEL) cells loses ca. 3.8% of its methyl groups. These values correspond to the demethylation of 2.2 X 10(6) and 0.9 X 10(6) 5'-CpG-3' sites per haploid genome in differentiating F9 and MEL cells, respectively. Fluorography of DNA restriction fragments methylated in vitro and displayed on agarose gels showed that demethylation occurred throughout the genome. In uninduced F9 cells, the sequence TCGA tended to be more heavily methylated than did the sequence CCGG, whereas this tendency was reversed in MEL cells. The kinetics of in vitro DNA methylation reactions catalyzed by MEL cell DNA methyltransferase showed that substantial numbers of hemimethylated sites accumulate in the DNA of terminally differentiating F9 and MEL cells, implying that a partial loss of DNA-methylating activity may accompany terminal differentiation in these two cell types.

Molecular and Conventional Typing Methods for Listeria monocytogenes: The UK Approach

1996 ◽  
Vol 59 (10) ◽  
pp. 1102-1105 ◽  
Author(s):  
J. McLAUCHLIN
Keyword(s):  
Listeria Monocytogenes ◽  
Fragment Length Polymorphism ◽  
Work Load ◽  
Polymorphism Analysis ◽  
Laboratory Service ◽  
The Public ◽  
Dna Restriction ◽  
Typing Methods ◽  
The Uk ◽  
Index Of Diversity

Subtyping systems for Listeria monocytogenes have proved to be of great use in the elucidation of the epidemiology of listeriosis. Considerations for devising strategies to subtype this organism are discussed, together with the surveillance methods, work load, and resources used by the Public Health Laboratory Service in London (England). A combination of both molecular and conventional typing methods are currently in use, and these comprise the established techniques of serotyping, phage-typing, and DNA restriction-fragment length polymorphism analysis, together with the experimental procedures of resistance to arsenite and cadmium and the detection of plasmid DNA. The efficacy of this approach is assessed using Simpson's index of diversity.

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