Regional specialization of Sarcodes sanguinea (Ericaceae) on a single fungal symbiont from the Rhizopogon ellenae (Rhizopogonaceae) species complex

We have sampled the mycorrhizal roots of 76 snow plants (Sarcodes sanguinea, Monotropoideae, Ericaceae) in two areas of the Sierra Nevada of California that are ～180 km apart. To identify the fungal symbionts associated with these plants, we first analyzed restriction fragment length polymorphisms (RFLPs) of the internal transcribed spacer region (ITS) of the fungal nuclear ribosomal repeat. Fungal ITS-RFLPs were successfully produced from 57 of the 76 plants sampled, and all symbionts shared the same DNA fragment pattern. The morphology of S. sanguinea mycorrhizae was consistent with that expected from a Rhizopogon species in section Amylopogon. To confirm and refine this identification, a total of six fungal ITS sequences were determined from S. sanguinea mycorrhizae. These sequences were analyzed together with eight existing and eight newly determined ITS sequences from Rhizopogon section Amylopogon. The newly determined sequences include an ITS sequence from the fungal symbiont of pine drops (Pterospora andromedea, Monotropoideae, Ericaceae), a plant that was previously reported to be exclusively associated with the Rhizopogon subcaerulescens group. When these sequences were analyzed together, the Sarcodes symbionts grouped tightly with several collections of R. ellenae including the holotype, one collection of R. idahoensis, and one collection of R. semireticulatus. A different lineage comprised collections of R. subgelatinosus, R. subcaerulescens, another collection of R. semireticulatus, and the Pterospora symbiont. We conclude that S. sanguinea associates exclusively with a single species in the R. ellenae species complex throughout our sampling range. These results indicate a much higher level of specificity in S. sanguinea than was previously reported and confirm the emerging pattern that nonphotosynthetic, monotropoid plants generally associate very specifically with a narrow range of ectomycorrhizal fungi.     

From one to ten in a single stroke--resolving the European Eumidasanguinea (Phyllodocidae, Annelida) species complex

We investigate the genetic structure of European lineages of the polychaete Eumida sanguinea with mitochondrial COI and nuclear ITS, and demonstrate the presence of ten cryptic species. Within the E. sanguinea species complex there are six different white pigmentation patterns but only three of these are unique for a single species. No other consistent morphological differences were observed. We give new species names to seven of the lineages from our study, providing examples of combined morphological and molecular diagnoses, apply the available name E. sanguinea to one species, and leave two lineages with single representatives unnamed. We also include new data and a diagnosis for the poorly known E. notata, which also belongs to the E. sanguinea species complex.     

The potential spread of terrestrial planarians Artioposthia triangulata and Australoplana sanguinea var. alba to continental Europe

A survey in Great Britain of the introduced terrestrial planarians Artioposthia triangulata and Australoplana sanguinea var. alba, which are obligate predators of earthworms, indicates that after 30 years Artioposthia triangulata is established throughout Scotland. However, apart from an initial record in 1965, Artioposthia triangulata was unrecorded from England until it was found again in 1992; currently there are 25 records.
There are fewer records of Australoplana sanguinea var. alba and these are mainly from the south and west of England. Ecoclimatic data from Edinburgh, where Artioposthia triangulata is common, and Plymouth, close to where Australopiana sanguinea var. alba has been recorded, were used by the computer programme CLIMEX to predict the potential spread of these planarians within Europe. Results suggest that Artioposthia triangulata could become established in north west Europe, including areas of Scandinavia, Germany and Poland, whereas Australoplana sanguinea var. alba would be confined to western Europe, including northern Spain. To slow their spread within Britain and prevent their establishment on continental Europe it is suggested that all nurseries and garden centres which sell containerised plants should initiate and maintain stringent hygiene regimes.     

Directly acting geno- and cytotoxic agents from a wild mushroom Dermocybe sanguinea.

The wild mushroom, Dermocybe sanguinea, contains several anthraquinone pigments, of which emodin (1,3,8-trihydroxy-6-methylanthraquinone) is quantitatively the most important. In our preliminary tests, Dermocybe sanguinea extracts were genotoxic without metabolic activation. The ethanol extract of Dermocybe sanguinea was fractionated by flash chromatography, and the emodin contents of the fractions were determined by HPLC. Their genotoxicities were assayed using a bacterial repair assay and sister-chromatid exchange analysis. The cytotoxicity of the fractions was assayed with mouse hepatoma cells using growth inhibition as the endpoint. The results of the biological tests were compared with those obtained with pure emodin. It was concluded that, in addition to emodin, Dermocybe sanguinea contains several other geno- and cytotoxic compounds.     

THIS ARTICLE HAS BEEN RETRACTEDDevelopment of microsatellite markers in the noxious red tide‐causing dinoflagellate Heterocapsa circularisquama (Dinophyceae)

We isolated 15 polymorphic microsatellites from one of the most noxious red tide‐causing dinoflagellate species, Heterocapsa circularisquama. These loci provide one class of highly variable genetic markers, as the number of alleles ranged from two to six, and the estimate of gene diversity was from 0.205 to 0.684 across the 15 microsatellites. These loci have the potential to reveal genetic structure and gene flow among H. circularisquama populations.     

Complete sequence and secondary structure of the large subunit ribosomal RNA from the harmful unarmored dinoflagellate Akashiwo sanguinea.

This is the first report of the complete DNA sequence of the gene encoding the ribosomal large subunit (LSU rDNA, 3336 bp) from the naked gymnodinioid dinoflagellate Akashiwo sanguinea. No introns were found in the LSU rDNA coding region and secondary structures were predicted for both the LSU and 5.8S rRNAs. The predicted LSU structure showed most of the features seen in the consensus secondary structure model proposed for the eukaryotic nuclear LSU rRNAs. However, six helices (C1_1, C1_2, C1_3, D10, D20_1 and H1_2) are not present in the A. sanguinea LSU structure. Particularly, the C branch area (or D2 domain), was extremely reduced compared to the eukaryotic consensus sequence due to nucleotide deletion. Phylogenetic resolution against 12 divergent (D) domains and cores in LSU rDNA showed that the D1, D2 and D12 domains were highly variable and could be used as genetic markers within low taxonomic levels, particularly in the gymnodinioid complex.     

Development of microsatellite markers in the noxious red tide‐causing dinoflagellate Heterocapsa circularisquama (Dinophyceae)

We isolated 15 polymorphic microsatellites from one of the most noxious red tide‐causing dinoflagellate species, Heterocapsa circularisquama. These loci provide one class of highly variable genetic markers, as the number of alleles ranged from two to six, and the estimate of gene diversity from 0.205 to 0.684 across the 15 microsatellites. These loci have the potential to reveal genetic structure and gene flow among H. circularisquama populations.     

Multilocus methods for estimating population sizes, migration rates and divergence time, with applications to the divergence of Drosophila pseudoobscura and D. persimilis

The genetic study of diverging, closely related populations is required for basic questions on demography and speciation, as well as for biodiversity and conservation research. However, it is often unclear whether divergence is due simply to separation or whether populations have also experienced gene flow. These questions can be addressed with a full model of population separation with gene flow, by applying a Markov chain Monte Carlo method for estimating the posterior probability distribution of model parameters. We have generalized this method and made it applicable to data from multiple unlinked loci. These loci can vary in their modes of inheritance, and inheritance scalars can be implemented either as constants or as parameters to be estimated. By treating inheritance scalars as parameters it is also possible to address variation among loci in the impact via linkage of recurrent selective sweeps or background selection. These methods are applied to a large multilocus data set from Drosophila pseudoobscura and D. persimilis. The species are estimated to have diverged approximately 500,000 years ago. Several loci have nonzero estimates of gene flow since the initial separation of the species, with considerable variation in gene flow estimates among loci, in both directions between the species.     

Allozyme variation in stable flies (Diptera: Muscidae)

Polyacrylamide gel electrophoresis was used to resolve allozymes in the cosmopolitan blood-feeding stable fly,Stomoxys calcitrans (L.). Nineteen of 38 loci were polymorphic (53%). Mean heterozygosities among all loci and among only polymorphic loci were 0.096 and 0.182, respectively. These gene diversity measures are about half those among other muscid Diptera. Variation in gene frequencies was examined in 10 natural stable fly populations from Iowa and Minnesota. Gene frequencies were homogeneous at five of eight loci among six populations in 1990 and eight of eight loci among four populations in 1992. Wright'sF statistics showed no significant departure from random mating among stable flies. It was concluded that gene flow compensates for any local differentiation in stable fly populations.     

Evolution of histone gene loci in chironomid midges.

In the present study we have localized the histone genes in the chromosomes of 16 different Chironomus species as well as in Prodiamesa olivacea, Glyptotendipes barbipes, and Acricotopus lucidus. In the genus of Chironomus we find four, five, or six different "major" chromosomal loci hybridizing with a histone gene cluster probe isolated from the genome of Chironomus thummi. These major histone gene loci probably contain clustered histone gene repeating units ("clustered" loci). They are located on one and the same chromosome arm in all but one of the species investigated. This shows that the histone gene clusters are rather conservative in their location over a long period of evolution. The comparison of the histone loci pattern from the chromosomes of the different chironomid species shows that there is good agreement with previously established chromosome maps and phylogenetic studies based on the chromosomal banding pattern. Stringent in situ hybridization with various histone gene containing clones suggest that the "clustered" histone gene loci are organized in a locus-specific way. In addition to the linked "clustered" histone gene loci, we found an isolated histone gene group ("orphon") present on chromosome IV in most Chironomus species. This gene group might be organized differently from the histone gene repeating unit described previously.     

Development of compound microsatellite markers in the harmful dinoflagellate Cochlodinium polykrikoides (Dinophyceae)

We isolated 15 polymorphic microsatellites from Cochlodinium polykrikoides. These loci provide a class of highly variable genetic markers, as the number of alleles ranged from two to 15, and the estimate of gene diversity was from 0.083 to 0.880 across the 15 microsatellites. We consider that these loci have a potential to reveal the genetic structure and gene flow among C. polykrikoides populations.     

Sequence-tagged sites (STSs) for a set of mapped markers on chromosome 21.

Sequence tagged sites (STSs) have been proposed as a "common language" for comparing physical and genetic maps of the human genome produced by a variety of techniques. We have produced 44 STSs from 38 mapped loci on human chromosome 21. The STSs represent most of the loci designated as genetic reference or ordered physical framework markers, along with a number of others chosen to span all regions of 21q. Of the STSs, 12 are from gene segments, including 4 from exons of the APP gene encoding the amyloid beta protein precursor, and 32 mark anonymous DNA loci. These STSs make each of the corresponding loci readily accessible to the research community without the need for exchange of clones. These sites also represent multiple start points for the isolation of YAC clones that should permit overlapping the entire chromosome 21 long arm as cloned DNA.     

The murine genes Hox-5.1 and Hox-4.1 belong to the same HOX complex on chromosome 2

Two different loci of Antennapedia-related homeobox-containing genes have been shown to map to mouse chromosome 2: the HOX-5 complex and the Hox-4.1 gene. These independently derived loci are likely to be parts of a single gene complex, although their close linkage has not yet been demonstrated. Since cosmid walks to extend the HOX-5 cluster and to potentially link the two loci were unsuccessful, we have used large restriction fragments separated by pulsed-field gel electrophoresis to demonstrate the linkage between probes from the HOX-5 region and sequences near Hox-4.1. To further define the distance between the two linked loci, we screened a NotI jumping library with sequences near the Hox-5.1 gene to obtain a marker within the region predicted to contain Hox-4.1. The jumping endpoint lies within genomic clones from a lambda phage walk extending from the 5' end of Hox-4.1, and thus provides clear evidence of linkage between the two Hox loci. Our results demonstrate that Hox-4.1 lies approximately 35 kb downstream of the Hox-5.1 gene and that the two loci do indeed thus constitute parts of the same HOX complex.     

Fifteen polymorphic microsatellite markers for the giant spiny frog, Paa spinosa

We characterized 15 polymorphic microsatellite loci for the giant spiny frog, Paa spinosa. These loci were highly polymorphic when screened in 38 individuals from two different populations, with nine to 23 alleles per locus. The range of observed and expected heterozygosities was 0.231-0.916 and 0.296-0.944, respectively. These polymorphic loci will be useful for assessing genetic diversity, population structure, gene flow, population assignment and determining paternity in the giant spiny frog.     

Development and characterization of polymorphic microsatellite markers in Linum usitatissimum

Thirty-five microsatellite loci were isolated and characterized in Linum usitatissimum using enriched genomic libraries. These loci were screened in eight cultivars from different countries and regions and were found to be polymorphic, with the number of alleles per locus ranging from two to six, and observed and expected heterozygosities ranging from 0.125 to 0.375 (mean 0.013) and from 0.233 to 0.842 (mean 0.601), respectively. These polymorphic new microsatellite loci will be useful for genetic linkage map construction, germplasm classification and identification, gene identification and quantitative trait loci mapping, and marker-assisted selection in breeding in L. usitatissimum.     

Water relations of drought hardy shrubs: osmotic potential and stomatal reactivity

Abstract. Diurnal measurements of total water potential and stomatal opening were made at six sites. Pressure-volume curves were established on parallel leaf samples. In eastern Austria, the species investigated were Cornus mas L., Cornus sanguinea L., Crateagus monogyna Jacq., Sorbus aria (L.) Crantz and Viburnum lantana L. in southern France Crateagus monogyna , and in southern Turkey Crateagus monogyna and Olea europaea L. Osmotic adjustment, defined as a change in osmotic potential larger than the passive change resulting from the loss of cell water, was relatively small from day to day or week to week in mature, non-senescing leaves. Cornus sanguinea was an exception. A recently suggested method for the demonstration of diurnal active osmotic adjustment seems not to be reliable without further independent corroboration. Changes in the leaf water potential threshold for stomatal closure were either insignificant when the pressure-volume characteristics of the plant material were stable, or significant when shifts in such parameters as the turgor loss point occurred ( Cornus sanguinea ).     

PERMANENT GENETIC RESOURCES: Development of microsatellite markers in Rhinanthus angustifolius and cross-species amplification

Fifteen polymorphic microsatellite loci were developed from an enriched genomic library of the annual plant Rhinanthus angustifolius and characterized using 36 individuals. These markers provided high polymorphism ranging from two to 15 alleles per locus. Four loci showed significant departure from Hardy-Weinberg equilibrium, probably because of the occurrence of null alleles. No significant linkage disequilibrium was detected between pairs of loci. Tests of cross-species transferability were performed on four congeners with a success rate of 100% in Rhinanthus minor, 93% in R. mediterraneus and R. glacialis, and 80% in R. alectorolophus. These microsatellite loci will be useful tools to study mating system, gene flow and hybridization in the genus Rhinanthus.     

Relationship between heterozygosity and genetic distance in the three major races of man

In pairwise comparisons of gene frequency data from the three major races of man, the single locus measures of the heterozygosity within and the genetic distance between races are shown to be strongly correlated across the loci coding for red cell proteins and enzymes. The intercept of the regression line of genetic distance on heterozygosity in protein enzyme loci is statistically insignificant. These findings suggest that the genetic variability at the enzyme and protein loci in man is probably maintained by a balance of mutation and random genetic drift. At the blood group loci, however, the observed relationship between genetic distance and heterozygosity does not follow the expectation of the neutral mutation hypothesis. These observations are discussed in terms of the changes in probability of identical monomorphism in two populations during the process of gene differentiation.     

PERMANENT GENETIC RESOURCES: Ten polymorphic microsatellite markers for the pygmy rabbit (Brachylagus idahoensis)

We developed 10 polymorphic microsatellite loci for the pygmy rabbit (Brachylagus idahoensis). Nine of the 10 loci amplified reliably and had a low frequency of null alleles. Number of alleles per locus ranged from four to 12, and observed and expected heterozygosities ranged from 0.26 to 0.89 and from 0.63 to 0.88, respectively. These loci will be useful in determining population genetic structure and assessing patterns of gene flow in the pygmy rabbit.     

Characterization of 22 microsatellite marker loci in the Madagascar rousette (Rousettus madagascariensis)

Twenty-two nuclear microsatellite loci were isolated from a genomic DNA library derived from Madagascar’s Rousettus madagascariensis. Marker characteristics were determined from a single population (37 individuals) from Fort Dauphin (southeastern Madagascar). Sixteen of the 22 loci were within Hardy–Weinberg expectations. These loci are highly informative with polymorphic information content values ranging between 0.757 and 0.916. These loci will provide valuable information for the study of population genetics and gene flow within this species of bats. Due to the dramatic reduction and alteration of their habitat, data generated utilizing this marker suite will potentially provide additional information for the effective long-term management of this near-threatened bat species.