bluuebunny/crossref_metadata_2025 huggingface dataset:
Serotonin: a review
Authors: MOHAMMAD‐ZADEH L. F. , MOSES L. , GWALTNEY‐BRANT S. M.
Published: April 2008

5‐Hydroxytryptamine, or serotonin, is a biogenic amine most noted for its role as a neurotransmitter. Manipulation of serotonin in animal models was used as a tool for studying its role in humans. Through such research serotonin has been shown to modulate gastrointestinal motility, peripheral vascular tone, cerebral vascular tone, and platelet function and has been implicated in the pathophysiology of mood disorders, emesis, migraine, irritable bowel syndrome (IBS), and pulmonary and systemic hypertension. The knowledge gained is being directly applied back to animals in research on drugs that manipulate the serotonergic system in dogs and cats. Increasing use and availability of drugs that manipulate the serotonergic system has created a circumstance through which a novel toxicity was discovered in both humans and animals. Serotonin Syndrome describes the clinical picture seen in humans and animals with serotonin toxicity. This paper provides a review the physiology of serotonin and its involvement in the pathophysiologic mechanisms of various conditions, including the Serotonin Syndrome.
Population pharmacokinetics of enrofloxacin and its active metabolite ciprofloxacin in ill cows
Authors: FU L. X. , JIANG Z. G. , DING H. Z. , LIU Y. H.
Published: April 2008

This study was performed in 105 ill cows to determine the best practical individualized dose of enrofloxacin after i.m. (2.5 mg/kg) single‐dose administration. Samples were collected from each cow at random time to ensure the percentage of samples distributed equally in the absorption phase, distribution phase, and elimination phase of the drug. Drug concentrations were determined by high‐performance liquid chromatography with fluorometric detector, analyzed by population pharmacokinetic (PPK) modeling with NONMEM. The concentration–time data for enrofloxacin in plasma and ciprofloxacin were fitted to the one‐compartment model with first‐order absorption and elimination. The final covariate model indicated that body weight and daily milk productions have significant influence on clearance (CL) of enrofloxacin and ciprofloxacin, and the volume (V) of distribution of enrofloxacin. The typical PPK parameters wereKa= 3.33 h−1, CL = 1.25 L/h/kg, andV = 2.98 L/kg of enrofloxacin, and the interindividual variability for CL andVwere 20.2% and 24.3%, respectively, the population mean estimates ofKa, CL, andVfor ciprofloxacin were 1.12 h−1, 2.36 L/h/kg, 8.20 L/kg, respectively, and their interindividual variability was 36.9%, 15.8% and 14.1%, respectively.
Intramuscular, intravenous and oral levetiracetam in dogs: safety and pharmacokinetics
Authors: PATTERSON E. E. , GOEL V. , CLOYD J. C. , O’BRIEN T. D. , FISHER J. E. , DUNN A. W. , LEPPIK I. E.
Published: April 2008

Intravenous (IV) levetiracetam (LEV) is available for humans for bridge therapy when the oral route is unavailable. We investigated the safety and pharmacokinetics of LEV administered intramuscularly (IM), IV, and orally to dogs.

Six Hound dogs received 19.5–22.6 mg/kg of LEV IM, IV and orally with a wash‐out period in between. All dogs received 500 mg LEV orally and 5 mL of 100 mg/mL LEV IM. Three dogs received 500 mg of LEV IV and three dogs received 250 mg LEV IV with 250 mg given perivascularly to approximate extravasation. Safety was assessed using a pain scale at time of IM administration and histopathological examination 24 h to 5 days after injection.

Intravenous LEV half‐life was 180 ± 18 min. Bioavailability of IM LEV was 100%. Mean time to Tmaxafter IM was 40 ± 16 min. The mean CmaxIM was 30.3 ± 3 μg/mL compared to the C0of 37 ± 5 μg/mL for IV. Mean inflammation score (0–4 scale) for IM LEV was 0.28 and for saline 0.62. Extravasation did not cause tissue damage.

Parenteral LEV is well tolerated and appears safe following IM and IV injections in dogs. Parenteral LEV should be evaluated for use in dogs with epilepsy.
Pharmacokinetics of controlled‐release carbimazole tablets support once daily dosing in cats
Authors: FRÉNAIS R. , BURGAUD S. , HORSPOOL L. J. I.
Published: April 2008

Carbimazole, a prodrug of methimazole, is used in the treatment of hyperthyroidism in cats. The pharmacokinetics of methimazole was investigated in healthy cats following oral administration of 15 mg of carbimazole as a controlled‐release tablet (Vidalta®, Intervet). The controlled‐release tablet did not produce a pronounced concentration peak and methimazole was present in the circulation for a sustained period, compared with a conventional tablet formulation. The time to reach peak concentrations after carbimazole administration was quite long (tmax 6 h). The absolute bioavailability of carbimazole was around 88 ± 11%. Repeated oral administration daily for 13 consecutive days did not lead to accumulation of methimazole in plasma. The extent of absorption of carbimazole was about 40% higher when administered to cats that had been fed compared to fasted cats. The relative oral bioavailability of methimazole following administration of the controlled‐release tablets was similar to that of a conventional release formulation (83 ± 21%). The pharmacokinetics of this controlled‐release formulation of carbimazole supports its use as a once daily treatment (both as a starting dose and for maintenance therapy) for cats with hyperthyroidism.
Pharmacokinetics of difloxacin in pigs and broilers following intravenous, intramuscular, and oral single‐dose applications
Authors: DING H. Z. , YANG G. X. , HUANG X. H. , CHEN Z. L. , ZENG Z. L.
Published: April 2008

Pharmacokinetics of difloxacin, a fluoroquinolone antibiotic, was determined in pigs and broilers after intravenous (i.v.), intramuscular (i.m.), or oral (p.o.) administration at a single dose of five (pigs) or 10 mg/kg (broilers). Plasma concentration profiles were analyzed by a compartmental pharmacokinetic method. Following i.v., i.m. and p.o. doses, the elimination half‐lives (t1/2β) were 17.14 ± 4.14, 25.79 ± 8.10, 16.67 ± 4.04 (pigs) and 6.11 ± 1.50, 5.64 ± 0.74, 8.20 ± 3.12 h (broilers), respectively. After single i.m. and p.o. administration, difloxacin was rapidly absorbed, with peak plasma concentrations (Cmax) of 1.77 ± 0.66, 2.29 ± 0.85 (pigs) and 2.51 ± 0.36, 1.00 ± 0.21 μg/mL (broilers) attained at tmax of 1.29 ± 0.26, 1.41 ± 0.88 (pigs) and 0.86 ± 0.4, 4.34 ± 2.40 h (broilers), respectively. Bioavailabilities (F) were (95.3 ± 28.9)% and (105.7 ± 37.1)% (pigs) and (77.0 ± 11.8)% and (54.2 ± 12.6)% (broilers) after i.m. and p.o. doses, respectively. Apparent distribution volumes(Vd(area)) of 4.91 ± 1.88 and 3.10 ± 0.67 L/kg and total body clearances(ClB) of 0.20 ± 0.06 and 0.37 ± 0.10 L/kg/h were determined in pigs and broilers, respectively. Areas under the curve (AUC), the half‐lives of both absorption and distribution(t1/2ka, t1/2α) were also determined. Based on the single‐dose pharmacokinetic parameters determined, multiple dosage regimens were recommended as: a dosage of 5 mg/kg given intramuscularly every 24 h in pigs, or administered orally every 24 h at the dosage of 10 mg/kg in broilers, can maintain effective plasma concentrations with bacteria infections, in which MIC90 are <0.25 μg/mL and <0.1 μg/mL respectively.
Pharmacokinetics and pharmacodynamics of ramipril and ramiprilat in healthy cats
Authors: DESMOULINS P. O. , BURGAUD S. , HORSPOOL L. J. I.
Published: April 2008

The pharmacokinetics of ramipril and its active metabolite, ramiprilat, was determined in cats following single and repeated oral doses of ramipril (Vasotop® tablets) (once daily for 9 days) at dose rates of 0.125, 0.25, 0.5 and 1.0 mg/kg. The pharmacodynamic effects were assessed by measuring plasma angiotensin‐converting enzyme (ACE) activity. Maximum ramipril concentrations were attained within 30 min following a single dose and declined rapidly (concentrations were below the limit of quantification 4 h after treatment). Peak ramiprilat concentrations were detected at approximately 1.5 h. The apparent terminal half‐life (t½β) was ≥20 h irrespective of the dose. Ramiprilat accumulated in plasma (ratio of accumulation 1.3 to 1.9 depending on the dose rate) following repeated administration. Steady‐state conditions were attained after the second dose. Excretion was predominant in faeces (87%) and to a lesser extent in urine (11%). The rate and extent of absorption of ramipril as well as its conversion to ramiprilat were not significantly influenced by the presence of food in the gastrointestinal tract. Plasma‐ACE activity was almost completely abolished 0.5–2.0 h after treatment, irrespective of the dose rate. Significant inhibition of ACE activity of 54.7 to 82.6% (depending on the dosage) was still present 24 h after treatment. Treatment was well‐tolerated in all cats. Ramipril at a dose rate of 0.125 mg/kg once daily produces significant and long‐lasting inhibition of ACE activity in healthy cats. The appropriateness of this dosage regime needs to be confirmed in diseased cats.
DNA fingerprinting in clonal organisms
Authors: BROOKFIELD J. F. Y.
Published: April 2008

The use of DNA fingerprinting to identify members of the same clone in completely or partially asexual organisms requires that the individuals within a clone share a recent common ancestor. By considering the expected distributions of band–sharing values in asexual and sexual organisms, it is shown that DNA fingerprinting may be effective in distinguishing members of the same clone, provided that the frequency of sexual reproduction is considerably greater than the minisatellite mutation rate.
Unusual mitochondrial DNA polymorphism in two local populations of blue tit Parus caeruleus
Authors: TABERLET P. , MEYER A. , BOUVETV J.
Published: April 2008

Mitochondrial DNA (mtDNA) from 25 blue tits Parus caeruleus sampled from two populations of the Grenoble region (France) was assayed for polymorphism with 17 restriction endonucleases. Nine genotypes were found. Several mtDNA genotypes were also analysed by amplification via the polymerase chain reaction (PCR) and direct sequencing of 903 bp of the cytochrome b gene. The mtDNA polymorphism is greater in P. caeruleus than in other comparable bird species and results from the presence of two clearly differentiated mitochondrial lineages. Using the data of restriction polymorphism, the mean sequence divergence between individuals of the two lineages is 1.23%. Therefore, P. caeruleus should fall into the category II of phylogeographic pattern sensu Avise et al. (1987): discontinuous mtDNA genotypes which co–occur in the same region. P. caeruleus, like humans and other mobile species with high gene flow, seems to have lost its geographic structure in terms of mtDNA phylogeny. This unusual mitochondrial polymorphism can be explained by the recent admixture of two long–term isolated populations. This could be accounted for by two different scenarios. One assumes a simultaneous post–glacial colonization of the Grenoble region by two isolated European populations of P. caeruleus. Alternatively, hybridization between P. caeruleus and P. cyanus could have caused the observed pattern of mtDNA variation.
Last–male sperm precedence in the bushcricket Poecilimon veluchianus (Orthoptera, Tettigonioidea) demonstrated by DNA fingerprinting
Authors: ACHMANN R. , HELLER K.–G. , EPPLEN J. T.
Published: April 2008

Males of the bushcricket Poecilimon veluchianus pass a large spermatophore to the female during mating. The spermatophore is eaten by the female after copulation. Because females mate with several males during their reproductive life, the competition between spermatozoa of different males affects a male's reproductive success. In order to determine the outcome of sperm competition, the paternity of the progeny of double–mated females was established by DNA fingerprinting with the oligonucleotide (GATA)4. Typical P. veluchianus DNA fingerprints consisted of 15 scoreable fragments per individual. The proportion of bands shared between presumably unrelated bushcrickets was 17%. After the second copulation the second mating male clearly predominated at fertilization. The mean proportion of eggs fertilized by the second male was 90.1%. There was no significant relationship between the level of sperm precedence and the time of ovipositions after the second mating. If female P. veluchianus increase the fitness of their offspring by the incorporation of spermatophore–derived substances in developing eggs, there is little chance for the feeding male to fertilize eggs containing his nutrients, because of the very short mating intervals of females and the observed high level of last–male sperm precedence in this species. Under such conditions the last mating male would fertilize many eggs containing nutrients from a prior male. Because nuptial gifts, like the tettigoniid spermatophore, function only as paternal investment if the donating male's progeny benefit from the gift, a paternal investment function of the P. veluchianus spermatophore seems to be unlikely.
Applications of random amplified polymorphic DNA (RAPD) in molecular ecology
Authors: HADRYS H. , BALICK M. , SCHIERWATER B.
Published: April 2008

Molecular genetic markers have been developed into powerful tools to analyse genetic relationships and genetic diversity. As an extension to the variety of existing techniques using polymorphic DNA markers, the Random Amplified Polymorphic DNA (RAPD) technique may be used in molecular ecology to determine taxonomic identity, assess kinship relationships, analyse mixed genome samples, and create specific probes. Main advantages of the RAPD technology include (i) suitability for work on anonymous genomes, (ii) applicability to problems where only limited quantities of DNA are available, (iii) efficiency and low expense.
Use of fragment–sharing estimates from DNA fingerprinting to determine relatedness in a tropical wren
Authors: PIPER W. H. , RABENOLD P. PARKER
Published: April 2008

We assessed the usefulness of DNA fragment–sharing scores from DNA fingerprints for assigning relatedness to unknown pairs of individuals in a population of stripe–backed wrens (Campylorhynchus nuchalis). Preliminary investigation of scoring biases revealed consistency both within and between scorers in relative band–sharing scores, but a tendency for scores to be inflated and for inter–scorer agreement to decline as distance between lanes on an autoradiograph increased. Distributions of band–sharing values matched expected distributions well, which suggests that variability in scores is mostly inherent and not a result of errors in scoring. Confidence intervals based on band–sharing scores or means of scores across enzymes, probes and scorers revealed that unrelated (r= 0) and first–order dyads (r=Vi) could be distinguished on the basis of single band–sharing scores from the best combination of enzyme and probe (HaeIII/33.15) and that first– and second–order dyads could be distinguished when confidence intervals were based on means of band–sharing scores across two enzymes, two probes and two scorers.
Biodegradation of phenoxyacetic acid in soil by Pseudomonas putida PP0301(pR0103), a constitutive degrader of 2, 4–dichlorophenoxyacetate
Authors: SHORT K. A. , KING R. J. , SEIDLER R. J. , OLSEN R. H.
Published: April 2008

The efficacy of using genetically engineered microbes (GEMs) to degrade recalcitrant environmental toxicants was demonstrated by the application of Pseudomonas putida PP0301(pR0103) to an Oregon agricultural soil amended with 500 u.g/g of a model xenobiotic, phenoxyacetic acid (PAA). P. putida PP0301(pR0103) is a constitutive degrader of 2, 4–dichlorophenoxyacetate (2, 4–D) and is also active on the non–inducing substrate, PAA. PAA is the parental compound of 2, 4–dichlorophenoxyacetic acid (2, 4–D) and whilst the indigenous soil microbiota degraded 500 ng/g 2, 4–D to less than 10 J–g/g, PAA degradation was insignificant during a 40–day period. No significant degradation of PAA occurred in soil inoculated with the parental strain P. putida PP0301 or the inducible 2, 4–D degrader P. putida PP0301(pR0101). Moreover, co–amendment of soil with 2, 4–D and PAA induced the microbiota to degrade 2, 4–D; PAA was not degraded. P. putida PP0301–(pR0103) mineralized 500–μg/g PAA to trace levels within 13 days and relieved phytotoxicity of PAA to Raphanus sativus (radish) seeds with 100% germination in the presence of the GEM and 7% germination in its absence. In unamended soil, survival of the plasmid–free parental strain P. putida PP0301 was similar to the survival of the GEM strain P. putida PP0301(pR0103). However, in PAA amended soil, survival of the parent strain was over 10 000–fold lower (< 3 colony forming units per gram of soil) than survival of the GEM strain after 39 days.
Sexuality in a natural population of bacteria–Bacillus subtilis challenges the clonal paradigm
Authors: ISTOCK C. A. , DUNCAN K. E. , FERGUSON N. , ZHOU X.
Published: April 2008

Reproduction by binary fission necessarily establishes a clonal genotypic structure in bacterial populations unless a high rate of genetic recombination opposes it. Several genetic properties were examined for a wild population of Bacillus subtilis in the Sonoran Desert of Arizona to assess the extent of recombination in a natural population. These properties included allozyme variation revealed by multilocus enzyme electrophoresis, phage and antibiotic resistance, and restriction fragment length polymorphism with Southern hybridization. Evidence of extensive genetic recombination was found along “with evidence of modest clonal structure. Recombination must be frequent relative to binary fission in this population. This mixed population structure provides broader options for bacterial evolution than would a purely clonal structure.
Conservation genetics of whales and dolphins
Authors: HOELZEL A. R.
Published: April 2008

Whales and dolphins (cetaceans) are found in all the world's oceans and in some of the major rivers, yet little is known about the distribution and behaviour of many species. At the same time, cetaceans are under threat from a variety of pressures including direct and indirect takes, pollution, and competition for habitat and prey. To ensure their long–term survival it will be necessary to preserve genetic diversity through the identification and protection of differentiated populations, the assessment of variation within local populations, and through a better understanding of reproductive and dispersal behaviour. The application of molecular genetic techniques is helping to provide answers to some of these previously intractable questions. Early results suggest few consistent patterns. Obvious geographic boundaries correlate to genetic distance in some species, and not in others. Furthermore, morphological variation within species can be fairly extensive without correlating to genetic distance, or relatively minor between morphotypes that are as genetically distinct as some species. These examples emphasize the need for further study.
Cross–species hybridization of a single–locus minisatellite probe in passerine birds
Authors: HANOTTE O. , CAIRNS E. , ROBSON T. , DOUBLE M.C. , BURKE T.
Published: April 2008

We report here the isolation in the house sparrow Passer domesticus of a highly variable minisatellite locus. When used as a probe at high stringency, this minisatellite crosshybridizes to a specific and variable locus in many different species in the family Passeridae. Moreover, it also detects a variable locus in species belonging to several other families of passerines which suggests that this probe will be useful in at least one–third, and perhaps about one–half, of all bird species.
Deterministic paternity exclusion using RAPD markers
Authors: LEWIS P. O. , SNOW A. A.
Published: April 2008

The Random Amplified Polymorphic DNA (RAPD) technique can potentially provide hundreds of polymorphic markers for use by ecologists studying mating systems in natural populations. We consider here the implications of the dominance displayed by RAPD markers for deterministic paternity assignment. Our goal was to provide a means for assessing the costs associated with such a study for ecologists who might be considering the use of RAPD markers for paternity analysis. The theoretical expected proportion of offspring for which all males except the true father can be excluded (PET) is calculated for both dominant and codominant marker systems. The ability to assign paternity unambiguously generally increases with the number of loci and the frequency of the recessive allele (but only up to a point), and decreases with increasing sample size (number of individuals surveyed). The gain in PET with decreasing sample size is unexpectedly slight. Not surprisingly, the performance of dominant markers at paternity exclusion is, in general, greatly exceeded by codominant markers, with the exception of the case in which the frequency of the recessive allele is high at all loci. In this case, codominant markers perform only slightly better than do dominant markers. Thus, a researcher should expect to score more than 50 RAPD loci for each offspring for most applications of paternity exclusion analysis. While this may at first seem too costly, ameliorating factors include (i) more than one locus can often be scored from one primer, (ii) one can ‘pick‐andchoose’ the loci of greatest value from among those identified in a preliminary survey, (iii) a considerable degree of automation of the technique is possible, and (iv) some applications may be less stringent in the degree of exclusion required (i.e. fractional paternity assignment).
Influence of DNA supercoiling on the loss of culturability of Escherichia coli cells incubated in seawater
Authors: GAUTHIER M.J. , LABEDAN B. , BREITTMAYER V.A.
Published: April 2008

The relationship between the loss of culturability of Escherichia coli cells in seawater and the DNA supercoiling level of a reporter plasmid (pUC8) have been studied under different experimental conditions. Transfer to seawater of cells grown at low osmolarity decreased their ability to grow without apparent modification of the plasmid supercoiling. We found that E. coli cells could be protected against seawater‐induced loss of culturability by increasing their DNA‐negative supercoiling in response to environmental factors: either a growth at high osmolarity before the transfer to seawater, or addition of organic matter (50‐mg/l peptone) in seawater. We further found conditions where a DNAinduced relaxation was accompanied by an increase in seawater sensitivity. Indeed, inactivation of either one of the subunits A and B of DNA gyrase, which leads to important DNA relaxation, was accompanied in both cases by an increased loss of culturability of conditional mutants after transfer to seawater which could not be explained uniquely by the increase in the temperature required to inactivate the gyrase. Similarly, a strain harbouring a mutation in topoisomerase I, compensated by another mutation in subunit B of the gyrase, was more sensitive to seawater than the isogenic wild‐type cell and this greater sensitivity was correlated to a relaxation of plasmid DNA. Again, in these different cases, a previous growth at high osmolarity protected against this seawater sensitivity. We thus propose that the ability of E. coli cells to survive in seawater and maintain their ability to grow on culture media could be linked, at least in part, to the topological state of their DNA. This latter state might govern expression of genes whose products could allow restoration of cellular homeostasis in this medium.
The identification of sex in the starling Sturnus vulgaris using a molecular DNA technique
Authors: GRIFFITHS R. , TIWARI B. , BECHER S. A.
Published: April 2008

Female birds can be identified through the presence of a W‐chromosome. We describe a procedure for amplifying a W‐linked DNA marker in the starling (Sturnus vulgaris) by the polymerase chain reaction (PCR) so allowing the diagnosis of sex in this species. The technique is sensitive, allowing even the smallest chicks to be sexed from a blood sample. The method possesses a positive internal control to ensure accuracy. It is also applicable to the spotless starling (S. unicolor) but not to two bird species outside the genus. The nucleotide sequence of the female‐specific PCR product is given.
Survival and detection of an introduced Escherichia coli containing the porcine somatotropin gene from a waste treatment microcosm
Authors: GEALT M. D. , SELVARATNAM S. , ABRAMS L. , SYNENKI R. M.
Published: April 2008

The number Escherichia coli containing the porcine somatotropin (pST) gene cloned into plasmid pBR322 recovered from a laboratory‐scale waste treatment microcosm decreased over a period of several days following their introduction. The pST gene was detected by hybridization analysis in these bacteria when recovered from authentic wastewater at 72 h after introduction, but the gene was not detected in bacteria recovered at 144 h. No significant difference in recovery, as judged by auxotrophic and antibiotic‐resistance markers, was noted between the pST‐containing strain and an isogenic E. coli without pST, indicating that presence of the pST gene confers no survival advantage or disadvantage on the bacterial host.
The structure and interrelationship of fungal populations in native and cultivated soils
Authors: GORDON T. R. , OKAMOTO D. , MILGROOM M. G.
Published: April 2008

Mitochondrial DNA haplotypes have been characterized for 120 isolates of the asexual fungus Fusarium oxysporum. Sixty of these isolates were obtained from soil in a native grassland in the San Joaquin Valley of California, including 20 isolates from each of six different sampling locations. The same sampling strategy was used to obtain 60 additional isolates from an agricultural field of the same soil type directly adjacent to the native soil. Twenty‐three different mitochondrial DNA haplotypes were identified among the 120 isolates, including 11 haplotypes represented by two or more isolates and 12 that were unique. The five most common mitochondrial DNA haplotypes accounted for 93 (78%) of the 120 isolates. Isolates representing each of these five mitochondrial DNA haplotypes were found both in the cultivated and in the native soil. Seventy‐two per cent of the isolates found in the cultivated soil were associated with the same mitochondrial DNA haplotype as one or more isolates in the native soil. The remaining isolates in the cultivated soil were associated with comparatively rare mitochondrial DNA haplotypes, most of which showed a close relationship to one of the haplotypes found in the native soil. Hierarchial gene diversity analysis indicated that a significant proportion of the mitochondrial DNA haplotype diversity was attributable to differences between sampling sites in the native soil but not in the cultivated soil. This may reflect significant spatial structuring of genetic diversity in populations of F. oxysporum in a native soil. The proportion of mtDNA haplotype diversity attributable to differences between populations in the native and cultivated soils was not significant. This suggests that our entire collection, encompassing strains from both native and cultivated soils, is representative of a single population of F. oxysporum.
Discriminate suckling in pipistrelle bats is supported by DNA fingerprinting
Authors: BISHOP C. M. , JONES G. , LAZARUS C. M. , RACEY P. A.
Published: April 2008

DNA fingerprints were obtained by using Jeffreys' probes 33.6 and 33.15 with DNA extracted from nine mother‐young pairs of pipistrelle bats Pipistrellus pipistrellns to investigate the feasibility of this technique for determining relatedness in this species. The bats had mated in the wild and gave birth in captivity. All of nine pairs in which infants were found attached showed band‐sharing coefficients higher than those for individuals presumed to be unrelated but run in adjacent lanes of the gels. We therefore conclude that all attached infants were probably true offspring.
Molecular phylogeographic evidence for multiple shifts in habitat preference in the diversification of an amphipod species
Authors: STANHOPE M. J. , HARTWICK B. , BAILLIE D.
Published: April 2008

An earlier study of ours demonstrated polygenic control of habitat preference between sympatric populations of an estuarine amphipod (Stanhope et al. 1992). Knowledge of the ecological history in this estuary suggested that two new and distinct habitat types (wood debris andFucus) had been formed immediately adjacent to each other, in an area which was previously the habitat type common to the rest of the estuary (bank). This suggested the possibility that the ancestral population had been split into two resource specialists (disruptive selection on habitat preference). The genetic relatedness of these three populations (the proposed ancestor and the two proposed descendants) and six others occupying the same three habitat types were investigated on a regional geographic scale, using an extensive set of genomic DNA RFLPs. These data were combined with measures of habitat preference (including genetic tests) in the additional populations. A very strongly supported phylogeographic tree, unequivocally supported a shift in habitat preference in the wood‐debris population of this estuary. The data did not, however, support the hypothesis of disruptive selection on the ancestor (bank) with a consequent split into two resource specialists. Instead, it clearly indicated that the occupants of theFucushabitat type were members of a habitat specific race, and thus their presence in this estuary reflected the expansion of an old resource base. Furthermore, the combined RFLP and habitat preference data, for all nine populations, indicated that the same polygenically based shift in habitat preference that had occurred in the original estuary had occurred independently, in another estuary, 700 km removed, that had similar environmental circumstances.
ITS primers with enhanced specificity for basidiomycetes ‐ application to the identification of mycorrhizae and rusts
Authors: GARDES M. , BRUNS T. D.
Published: April 2008

We have designed two taxon‐selective primers for the internal transcribed spacer (ITS) region in the nuclear ribosomal repeat unit. These primers, ITS1‐F and ITS4‐B, were intended to be specific to fungi and basidiomycetes, respectively. We have tested the specificity of these primers against 13 species of ascomycetes, 14 of basidiomycetes, and 15 of plants. Our results showed that ITS4‐B, when paired with either a ‘universal’ primer ITS1 or the fungal‐specific primer ITS1‐F, efficiently amplified DNA from all basidiomycetes and discriminated against ascomycete DNAs. The results with plants were not as clearcut. The ITS1‐F/ITS4‐B primer pair produced a small amount of PCR product for certain plant species, but the quantity was in most cases less than that produced by the ‘universal’ ITS primers. However, under conditions where both plant and fungal DNAs were present, the fungal DNA was amplified to the apparent exclusion of plant DNA. ITS1‐F/ITS4‐B preferential amplification was shown to be particularly useful for detection and analysis of the basidiomycete component in ectomycorrhizae and in rust‐infected tissues. These primers can be used to study the structure of ectomycorrhizal communities or the distribution of rusts on alternate hosts.
Molecular tools for the identification of ectomycorrhizal fungi — taxon‐specific oligonucleotide probes for suilloid fungi
Authors: BRUNS T. D. , GARDES M.
Published: April 2008

Five taxon‐specific oligonucleotide probes are described that can be used to help identify the fungal components of ectomycorrhizae. Comparisons among partial sequence from the mitochondrial large subunit rRNA gene (mt‐LrRNA) were used to select the probes, which were intended to be specific to several taxa within the suilloid group of the Boletales (Basidiomycota). Probes S1, R1, and G1 were targeted at the genera Suillus, Rhizopogon and Gomphidius; probe G2 was designed to recognize the family, Gomphidiaceae, and probe US1 was designed to recognize all of these taxa and any other members of the suilloid group. The specificity of each probe was determined empirically by testing their ability to hybridize to PCR amplified fragments derived from 84 species of basidiomycetes. Although none of the probes exhibited their intended specificity, all specifically hybridized to useful subsets of taxa, and collectively they can be used to identify many suilloid taxa to the generic level or below. The probes were also tested for their ability to identify field collected mycorrhizae and were found to perform well.
Use of random amplified polymorphic DNA (RAPD) for generating specific DNA probes for microorganisms
Authors: FANI R. , DAMIANI G. , SERIO C. DI , GALLORI E. , GRIFONI A. , BAZZICALUPO M.
Published: April 2008

We report the rapid generation of DNA probes for several Azospirillum strains. This method does not require any knowledge of the genetics and/or the molecular biology of the organism (genome) to be investigated. The procedure is based on the generation of random amplified polymorphic DNA (RAPD) fingerprints using primers with an embedded restriction site. The amplification product(s) peculiar to one strain or common to two or more strains can be purified, cloned, sequenced and used as molecular probes in hybridization experiments for the detection and identification of microorganisms. We have tested this methodology in the nitrogen‐fixing bacterium Azospirillum by amplyfing the total DNA extracted from several Azospirillum strains. We have used amplification bands with different specificity as molecular probes in hybridization experiments performed on amplified DNA. Results obtained have demonstrated the usefulness of this methodology for Azospirillum. Its use in microbial ecology studies as a general strategy to generate specific DNA probes is also discussed.
Genetic consequences of an invasion through a patchy environment — the cynipid gallwasp Andricus quercuscalicis (Hymenoptera: Cynipidae)
Authors: STONE G.N. , SUNNUCKS P.
Published: April 2008

Over the last 300–400 years, the cynipid gallwasp Andricus quercuscalicis has invaded northern and western Europe following human introduction of an obligate host plant, the Turkey oak (Quercus cerris) from south‐eastern Europe. In the introduced range, distances between Turkey oak patches are greater and the numbers of oaks in each patch are far lower than in its native range. These changes in spatial distribution of Turkey oak are predicted to result in high genetic subdivision of A. quercuscalicis in invaded areas relative to its native range. Allozyme electrophoresis was used to examine genetic variation in 823 gall wasps from 39 populations of A. quercuscalicis. No new electrophoretic variants were found in the invaded range and both allelic diversity and mean heterozygosity decreased significantly with distance from the native range. Spatial autocorrelation analysis and values of Wright's Fst indicate that differences in allele frequences between populations were substantially greater in the invaded range than in the native range. Spatial autocorrelation analysis also suggests that changes in allele frequencies across Europe are unlikely to be the results of selection, but rather of strong directional migration followed by limited gene flow between populations. Patterns of genetic differentiation across Europe suggest that populations of A. quercuscalicis have been founded sequentially from the east through a process of random genetic subsampling and not by source‐sink colonization directly from the native range.
Comparison of geographically distant populations of Rhizobium isolated from root nodules of Phaseolus vulgaris
Authors: GENIAUX E. , LAGUERRE G. , AMARGER N.
Published: April 2008

Seventy‐two rhizobial strains were isolated from the root nodules of french beans (Phaseolus vulgaris). They were sampled from two geographically distant field populations and 18 additional different sites in France. They were characterized by a) plasmid profiles, (b) RFLP analysis of total cellular DNA using various chromosomal and symbiotic gene probes (including nifH from Rhizobium etli bv. phaseoli) and c) their ability to nodulate a potential alternative host, L. leucocephala. Over half of the isolates were ascribed to Rhizobium leguminosarum bv. phaseoli on the basis of the hybridization analysis, the possession of multiple copies of nifH and their inability to nodulate L. leucocephala. The remaining isolates belonged to 2 groups which were shown to be genomically distinct from R. leguminosarum bv. phaseoli, R. etli bv. phaseoli and R. tropici. Most members of these two groups shared with R. tropici the ability to nodulate L. leucocephala and, for isolates of only one of these groups, the presence of one copy of nif H. Members of each of the 3 taxa were widely distributed in France and circumstantial evidence of pSym transfer between them was shown. R. leguminosarum bv. phaseoli and one of the two novel groups co‐occurred within the two geographically distant populations. Individual genotypes were conserved between them. The finding of a third taxon at various other locations indicated additional diversity among rhizobia nodulating beans.
Recombinant and wild‐type Pseudomonas aureofaciens strains in soil: survival, respiratory activity and effects on nodulation of whitebean Phaseolus vulgaris L. by Rhizobiutn species
Authors: ENGLAND L. S. , LEE H. , TREVORS J. T.
Published: April 2008

Survival and respiratory activity of a genetically engineered Pseudomonas aureofaciens Ps3732RNL11 were compared to the parental wild‐type P. aureofaciens Ps3732RN in loam and sandy loam soils over 17‐ and 28‐day periods. Survival and respiratory activity of P. aureofaciens Ps3732RNL11 was not statistically significantly different from that of P. aureofaciens Ps3732RN. Soil texture had an effect on respiratory activity; carbon dioxide evolution was significantly higher in the sandy loam soil. This effect was observed on days 2, 10 and 18 but not on day 24. The presence of P. aureofaciens Ps3732RNL11 and Ps3732RN did not significantly affect growth of whitebean (Phaseolus vulgaris L.) in vermiculite, loam, or sandy loam soils. There was no significant difference (95% level) in numbers of nodules produced in the presence of P. aureofaciens Ps3732RNL11 and Ps3732RN as a result of the symbiotic relationship between Rhizobium phaseoli and the whitebean roots in vermiculite. Enumeration of nodules on whitebean roots in loam and sandy loam soils was not conducted due to difficulties in removing intact roots from the soils.
Nontarget and ecological effects of transgenically altered disease resistance in crops ‐possible effects on the mycorrhizal symbiosis
Authors: MILLER R.M.
Published: April 2008

The ability to increase crop disease resistance by using transgenic (TG) means has recently been demonstrated for several crops. The current TG procedures alter the temporal expression of transgene pathogenesis‐related (PR) proteins, so that the usually inducible PR proteins are expressed constitutively in the foreign host. The constitutive expression of the transgene PR protein chitinase is believed to increase the host's nonspecific basic resistance to pathogens. A potential nontarget effect of constitutively expressing chitinase may be a decrease in the activity of beneficial microbes, especially vesicular‐arbuscular mycorrhizal fungi. The decrease in activity of mycorrhizal fungi is related to reduced susceptibility of TG plant roots to colonization by these fungi, which is in turn associated with lysis of fungal cell walls by the constitutively expressed chitinase. An argument is presented that use of TG means to alter the temporal expression of PR proteins ignores a legacy of past evolutionary trade‐offs in vascular plants. A major nontarget effect of expressing transgene chitinase is a reduction in the susceptibility of roots to colonization by mycorrhizal fungi. This reduction in mycorrhizal susceptibility occurs without alteration of the mycorrhizal dependence of the host on symbiont‐supplied nutrients. Data are presented in support of this contention that demonstrate a strong negative association between host pathogen resistance and mycorrhizal colonization. An ecological consequence of reducing mycorrhizal colonization is a decrease in the soil's mycorrhizal propagule reserve that diminishes the next crop's production, especially under low‐input cropping practices. A further consequence that has both ecological and evolutionary outcomes is the escape of the transgene for improved pathogen resistance into wild populations. By increasing a crop's disease resistance by TG means, we may inadvertently be creating a ‘super weed’ when the TG plant or the transgene escapes into wild relatives through hybridization. Hybridization of wild relatives with TG plants would be especially relevant for crops, such as sugar beet, rapeseed, and many modern cereal cultivars that have close relatives in the wild but have a relatively low requirement for symbiont supplied nutrients or are nondependent.
Using molecular and ecological data to diagnose endangered populations of the puritan tiger beetle Cicindela puritana
Authors: VOGLER A. P. , KNISLEY C. B. , GLUECK S. B. , HILL J. M. , DESALLE R.
Published: April 2008

Populations of the puritan tiger beetle Cicindela puritana in the eastern United States were found to be highly threatened at the Connecticut River, whereas several large populations on the western shore and newly discovered populations on the eastern shore of the Chesapeake Bay appeared to be less endangered. We assessed if the disjunct C. puritana subgroups are genetically distinct and therefore should be treated as separate units for conservation purposes. A total of 13 individuals from the Connecticut River and 27 individuals from the Chesapeake Bay were each analysed by sequencing of up to 837 base pairs of mitochondrial DNA per individual. Five different haplotypes could be distinguished. In a phylogenetic analysis of these DNA sequences that included four related Cicindela species as out‐groups, haplotypes from the Chesapeake Bay represent a distinct clade. The conservation status of these populations was evaluated using a phylogenetic approach based on cladistic analysis and the framework of the phylogenetic species concept. According to this analysis, beetles from the Connecticut River and the Chesapeake Bay have to be considered as independent units. Populations from the eastern and western shore of Chesapeake Bay are not split in more than one unit using the same criteria, although they exhibited some degree of genetic subdivision. The results from the mtDNA analysis were corroborated by ecological parameters in that the Chesapeake Bay populations can be distinguished from all congeners by their different tat association.
Molecular evidence for mating asymmetry and female choice in a pocket gopher (Thomomys) hybrid zone
Authors: PATTON J.L. , SMITH M.F.
Published: April 2008

This paper presents circumstantial evidence that the mating system of the North American pocket gophers (Rodentia: Geomyidae) is a promiscuous one, with female choice at its base. A molecular marker (a length variant in the mitochondrial Control region [D‐loop]) is used to show mating asymmetry in a hybrid zone between the species Thomomys bottae and Thomomys townsendii in north‐eastern California. All hybrids result from a bottae mother ×townsendii father cross. Because of significant differences in body size and resulting burrow diameter, bottae females must have actively sought their respective townsendii mates for the asymmetry in mating to have occurred, signalling female choice in these subterranean mammals that are otherwise characterized by exclusive‐use territories, skewed adult sex ratio in favour of females, and high variance in male reproductive success.
Plasmid dynamics in a model soil column
Authors: Sun L. , BAZIN M. J. , LYNCH J. M.
Published: April 2008

Continuous‐flow column reactors were used to study the dynamics of plasmid exchange in a structured, thermodynamically open system containing either Enterobacter cloacae or Pseudomonas cepacia, both carrying the transmissible recombinant plasmid R388::Tn1721. Plasmid transfer rates were higher in vermiculite and sterile soil columns supplied with nutrient solution than those in sterile and non‐sterile soil columns without input of nutrient solution. For both species, donor and recipient strains took about 5 days to reach their maximum densities in effluents from the columns supplied with nutrient solution. After about 8 day s the donor and transconjugant populations of P. cepacia in the effluent solution decreased exponentially, whereas E. cloacae donor, recipient and transconjugant strains maintained steady‐state concentrations. The difference between plasmid stability in the two species may have significant consequences in terms of releasing plasmid‐bearing genetically modified microorganisms into the natural environment. The plasmid is persistent in E. cloacae in non‐sterile soil even though its transfer to the marked recipient in non‐sterile soil was minimal.
Distribution of streptothricin acetyltransferase encodi determinants among environmental bacteria
Authors: SMALLA K. , PRAGER R. , ISEMANN M. , PUKALL R. , TIETZE E. , ELSAS J. D. VAN , TSCHÄPE H.
Published: April 2008

In this paper we report about a screening for streptothricin‐ (St)‐resistant phenotypes and genotypes among environmental bacteria from a St virgin area. St‐resistant bacteria were isolated from river water, sewage, manure and soil by selective plating. The resistance quotient was typical of an area without selective pressure. The occurrence of streptothricin acetyltransferase‐encoding determinants and their localization on a Tn7‐like transposon was tested by the application of a set of gene probes. Sat genes could be detected in 22.5% of the tested St‐resistant bacteria but in 100% of the checked Enterobacteriaceae. However, we could not detect sat genes in St‐resistant bacteria from soil samples. Surprisingly the sat genes were found to be located on conjugative or mobilizable plasmids for a rather high number of strains. The determined plasmid species and their restriction patterns showed a high degree of similarities to those observed from an area of strong selective pressure.
Plasmid and chromosomally encoded luminescence marker systems for detection of Pseudomonas fluorescens in soil
Authors: AMIN‐HANJANI S. , MEIKLE A. , GLOVER L. A. , PROSSER J. I. , KILLHAM K.
Published: April 2008

Luminescent strains of Pseudomonas fluorescens 10586 were constructed in which luciferase production was constitutive by introduction of Vibrio fischeri luxABE genes on the chromosome and on a multicopy plasmid. Light production in liquid batch culture was directly proportional to biomass concentration during exponential growth and enabled detection by luminometry of 1.7 × 103 and 8.9 × 104 cells/ml for the plasmid and chromosomally marked strains, respectively. Luminescent colonies of both strains were detectable by eye, enabling viable cell enumeration on solid media against a background of non‐luminescent strains. Following inoculation into sterile and non‐sterile soil lower levels of detection were increased but detection of 8.1–59 × 103and 2.2–30 × 103 cells per g of soil was possible for plasmid and chromosomally marked strains. Maximum specific growth rate in liquid culture was unaffected by introduction of lux marker genes on the chromosome, but was reduced in the plasmid marked strain. The chromosomally encoded marker was stable in both liquid culture and in soil, but the plasmid was unstable during continuous subculturing in liquid medium and during growth in soil. The chromosomally encoded luminescence‐marker system therefore provides a convenient, non‐extractive technique for quantification of genetically modified soil microbial inocula.