bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effect of cooked and raw egg consumption on ovalbumin content of human milk: a randomized, double‐blind, cross‐over trial
Authors: Palmer D. J. , Gold M. S. , Makrides M. 
Published: February 2005

SummaryBackground
Maternal avoidance of egg intake has been recommended to treat egg allergy in breastfed infants.Objective
To determine if the concentration of ovalbumin (OVA) in human milk is directly related to the quantity and form of egg consumed by breastfeeding mothers.Methods
Randomized, blinded, cross‐over, intervention trial. Breastfeeding women (n=41) attended four clinic days between 11 and 14 weeks of lactation and on each day were randomly allocated to receive a test breakfast, identical except for the egg content (no egg, one raw egg, half a cooked egg or one cooked egg). Breast milk samples were collected at two hourly intervals for 8 h and their OVA concentration measured by ELISA.Results
There was a direct, dose–response between the amount of cooked egg ingested and the peak OVA concentration (no egg 0.05 ng/mL [95% confidence interval (CI), 0.01–0.11], half a cooked egg 2.24 ng/mL [95% CI, 0.57–3.91], one cooked egg 3.16 ng/mL [95% CI, 1.41–4.91], n=41, P<0.05) as well as the total OVA excretion (no egg 0.18 ng/mL/h [95% CI, 0.04–0.39], half a cooked egg 4.93 ng/mL/h [95% CI, 1.40–8.46], one cooked egg 9.14 ng/mL/h [95% CI, 4.25–14.03], n=41, P<0.05). The peak concentration and total OVA excretion in response to one raw egg did not differ from ingesting half a cooked egg. There was no detectable OVA in the breast milk of 24% (10/41) women up to 8 h after any egg challenge.Conclusion
OVA was detected in the breast milk of lactating women up to 8 h after a controlled intake of egg. A dose–response correlation was indicated. As excretion of OVA in human milk appears to be a normal phenomenon, further studies need to determine the threshold of OVA excretion that leads to symptoms in egg‐allergic breastfed infants.
Cytoplasmic and nuclear markers reveal contrasting patterns of spatial genetic structure in a naturalIpomopsishybrid zone
Authors: WU CARRIE A. , CAMPBELL DIANE R. 
Published: February 2005

AbstractSpatial variation in natural selection may play an important role in determining the genetic structure of hybridizing populations. Previous studies have found that F1hybrids between naturally hybridizingIpomopsis aggregataandIpomopsis tenuitubain central Colorado differ in fitness depending on both genotype and environment: hybrids had higher survival whenI. aggregatawas the maternal parent, except in the centre of the hybrid zone where both hybrid types had high survival. Here, we developed both maternally (cpDNA PCR‐RFLP) and biparentally inherited (nuclear AFLP) species‐diagnostic markers to characterize the spatial genetic structure of the naturalIpomopsishybrid zone, and tested the prediction that the majority of natural hybrids haveI. aggregatacytoplasm, except in areas near the centre of the hybrid zone. Analyses of 352 individuals from across the hybrid zone indicate that cytoplasmic gene flow is bidirectional, but contrary to expectation, most plants in the hybrid zone haveI. tenuitubacytoplasm. This cytotype distribution is consistent with a hybrid zone in historical transition, withI. aggregatanuclear genes advancing into the contact zone. Further, nuclear data show a much more gradual cline than cpDNA markers that is consistent with morphological patterns across the hybrid populations. A mixture of environment‐ and pollinator‐mediated selection may contribute to the current genetic structure of this hybrid system.
Rapid screening of invertebrate predators for multiple prey DNA targets
Authors: HARPER G. L. , KING R. A. , DODD C. S. , HARWOOD J. D. , GLEN D. M. , BRUFORD M. W. , SYMONDSON W. O. C. 
Published: February 2005

AbstractDNA‐based techniques are providing valuable new approaches to tracking predator–prey interactions. The gut contents of invertebrate predators can be analysed using species‐specific primers to amplify prey DNA to confirm trophic links. The problem is that each predator needs to be analysed with primers for the tens of potential prey available at a field site, even though the mean number of species detected in each gut may be as few as one or two. Conducting all these PCRs (polymerase chain reactions) is a lengthy process, and effectively precludes the analysis of the hundreds of predators that might be required for a meaningful ecological study. We report a rapid, more sensitive and practical approach. Multiplex PCRs, incorporating fluorescent markers, were found to be effective at amplifying degraded DNA from predators’ guts and could amplify mitochondrial DNA fragments from 10+ species simultaneously without ‘drop outs’. The combined PCR products were then separated by size on polyacrylamide gels on an ABI377 sequencer. New primers to detect the remains of aphids, earthworms, weevils and molluscs in the guts of carabid predators were developed and characterized. The multiplex‐sequencer approach was then applied to field‐caught beetles, some of which contained DNA from as many as four different prey at once. The main prey detected in the beetles proved to be earthworms and molluscs, although aphids and weevils were also consumed. The potential of this system for use in food‐web research is discussed.
Genetic changes associated to declining populations ofFormicaants in fragmented forest landscape
Authors: MÄKI‐PETÄYS H. , ZAKHAROV A. , VILJAKAINEN L. , CORANDER J. , PAMILO P. 
Published: February 2005

AbstractWe monitored populations of two wood ant species,Formica aquiloniaandFormica lugubris, through annual mapping of the colonies in a fragmenting forest landscape from 1966 to 1998. The genetic population structure was studied at the end of the study period by using 12 microsatellite loci. Fragmentation of forest led to a decline and spatial redistribution of populations. Changes in the spatial distribution were particularly pronounced in the highly polygynous (many queens in a single nest) speciesF. aquilonia, whose local populations declined or became extinct, or relocated themselves and colonized new patches. The genetic relationships of the remaining subpopulations indicated the historical developments, revealing the boundaries of the historical populations (high values of genetic differentiation,FST), recolonization histories (genetic affinities revealed by Bayesian analyses) and population decline (reduced variation). Big genetic differences could be detected over short distances, so differentiation also depended on social factors. Our results showed that a genetic study can be reliably used to dissect the recent historical changes underlying the present population structure, and that species with different social structures can respond differently to habitat changes. Combining our demographic and genetic results suggests that habitat fragmentation forms a clear threat on a local scale with large negative effects on ant population viability.
Standardizing for microsatellite length in comparisons of genetic diversity
Authors: PETIT RÉMY J. , DEGUILLOUX MARIE‐FRANCE , CHAT JOËLLE , GRIVET DELPHINE , GARNIER‐GÉRÉ PAULINE , VENDRAMIN GIOVANNI G. 
Published: February 2005

AbstractMutation rates at microsatellites tend to increase with the number of repeats of the motif, leading to higher levels of polymorphism at long microsatellites. To standardize levels of diversity when microsatellites differ in size, we investigate the relationship between tract length and variation and provide a formula to adjust allelic richness to a fixed mean number of repeats in the specific case of chloroplast microsatellites. A comparison between 39 loci from eight species of conifers (where chloroplast DNA is paternally inherited) and 64 loci from 12 species of angiosperms (where chloroplast DNA is generally predominantly maternally inherited) indicates that the greater allelic richness found in conifers remains significant after controlling for number of repeats. The approach stresses the advantage of reporting variation in number of repeats instead of relative fragment sizes.
Phylogeographic analysis of the red seaweed Palmaria palmata reveals a Pleistocene marine glacial refugium in the English Channel
Authors: PROVAN JIM , WATTIER REMI A. , MAGGS CHRISTINE A. 
Published: February 2005

AbstractPhylogeography has provided a new approach to the analysis of the postglacial history of a wide range of taxa but, to date, little is known about the effect of glacial periods on the marine biota of Europe. We have utilized a combination of nuclear, plastid and mitochondrial genetic markers to study the biogeographic history of the red seaweed Palmaria palmata in the North Atlantic. Analysis of the nuclear rDNA operon (ITS1‐5.8S‐ITS2), the plastid 16S‐trnI‐trnA‐23S‐5S, rbcL‐rbcS and rpl12‐rps31‐rpl9 regions and the mitochondrial cox2–3 spacer has revealed the existence of a previously unidentified marine refugium in the English Channel, along with possible secondary refugia off the southwest coast of Ireland and in northeast North America and/or Iceland. Coalescent and mismatch analyses date the expansion of European populations from approximately 128 000 bp and suggest a continued period of exponential growth since then. Consequently, we postulate that the penultimate (Saale) glacial maximum was the main event in shaping the biogeographic history of European P. palmata populations which persisted throughout the last (Weichselian) glacial maximum (c. 20 000 bp) in the Hurd Deep, an enigmatic trench in the English Channel.
Universal primers and PCR of gut contents to study marine invertebrate diets
Authors: BLANKENSHIP L. E. , YAYANOS A. A. 
Published: February 2005

AbstractDetermining the diets of marine invertebrates by gut content analysis is problematic. Many consumed organisms become unrecognizable once partly digested, while those with hard remains (e.g. diatom skeletons) may bias the analysis. Here, we adapt DNA‐based methods similar to those used for microbial diversity surveys as a novel approach to study the diets of macrophagous (the deep‐sea amphipodsScopelocheirus schellenbergiandEurythenes gryllus) and microphagous (the bivalveLucinoma aequizonata) feeders in the deep sea. Polymerase chain reaction (PCR) in conjunction with ‘universal’ primers amplified portions of the mitochondrial cytochromecoxidase I (COI) gene for animals ingested byS. schellenbergiandE. gryllusand the18S rRNAgene for lesser eukaryotes ingested byL. aequizonata. Amplified sequences were combined with sequences from GenBank to construct phylogenetic trees of ingested organisms. Our analyses indicate thatS. schellenbergi,E. gryllusandL. aequizonatadiets are considerably more diverse than previously thought, casting new light on the foraging strategies of these species. Finally, we discuss the strengths and weaknesses of this technique and its potential applicability to diet analyses of other invertebrates.
Multiple paternity and postcopulatory sexual selection in a hermaphrodite: what influences sperm precedence in the garden snail Helix aspersa?
Authors: EVANNO GUILLAUME , MADEC LUC , ARNAUD JEAN‐FRANÇOIS 
Published: February 2005

AbstractSperm competition has been studied in many gonochoric animals but little is known about its occurrence in simultaneous hermaphrodites, especially in land snails. The reproductive behaviour of the land snail Helix aspersa involves several features, like multiple mating, long‐term sperm storage and dart‐shooting behaviour, which may promote sperm competition. Cryptic female choice may also occur through a spermatheca subdivided into tubules, which potentially allows compartmentalized sperm storage of successive mates. In order to determine the outcome of postcopulatory sexual selection in this species, we designed a cross‐breeding experiment where a recipient (‘female’) mated with two sperm donors (‘males’). Mates came from either the same population as the recipient or from a distinct one. To test for the influence a recipient can have on the paternity of its offspring, we excluded the effects of dart shooting by using only virgin snails as sperm donors because they do not shoot any dart before their first copulation. We measured the effects of size of mates as well as time to first and second mating on second mate sperm precedence (P2; established using microsatellite markers). Multiple paternity was detected in 62.5% of clutches and overall there was first‐mate sperm precedence with a mean P2 of 0.24. Generalized linear modelling revealed that the best predictors of paternity were the time between matings and the time before first mating. Overall, both first and second mates that copulated quickly got greater parentage, which may suggest that postcopulatory events influence patterns of sperm precedence in the garden snail.
Task‐specific expression of the foraging gene in harvester ants
Authors: INGRAM KRISTA K. , OEFNER PETER , GORDON DEBORAH M. 
Published: February 2005

AbstractIn social insects, groups of workers perform various tasks such as brood care and foraging. Transitions in workers from one task to another are important in the organization and ecological success of colonies. Regulation of genetic pathways can lead to plasticity in social insect task behaviour. The colony organization of advanced eusocial insects evolved independently in ants, bees, and wasps and it is not known whether the genetic mechanisms that influence behavioural plasticity are conserved across species. Here we show that a gene associated with foraging behaviour is conserved across social insect species, but the expression patterns of this gene are not. We cloned the red harvester ant (Pogonomyrmex barbatus) ortholog (Pbfor) to foraging, one of few genes implicated in social organization, and found that foraging behaviour in harvester ants is associated with the expression of this gene; young (callow) worker brains have significantly higher levels of Pbfor mRNA than foragers. Levels of Pbfor mRNA in other worker task groups vary among harvester ant colonies. However, foragers always have the lowest expression levels compared to other task groups. The association between foraging behaviour and the foraging gene is conserved across social insects but ants and bees have an inverse relationship between foraging expression and behaviour.
Population genetics of the diamondback terrapin (Malaclemys terrapin)
Authors: HAUSWALDT J. SUSANNE , GLENN TRAVIS C. 
Published: February 2005

AbstractWe examined the population genetic structure of the diamondback terrapins (Malaclemys terrapin), within and among estuaries. Based on mark‐recapture studies, these estuarine turtles have high site fidelity that is likely to make them vulnerable to local extinctions. We tested if observed site fidelity of adults would be reflected in intraestuarine population genetic structure of six highly polymorphic microsatellite loci (five tetranucleotide and one dinucleotide). No evidence was found for population structuring within the Charleston estuary nor among three different estuaries in South Carolina. We then examined four other terrapin populations from North Carolina to New York, as well as from the Florida Keys and from Texas. With increasing geographical distance, genetic differentiation increased from South Carolina through New York, but overall values were low. The dinucleotide locus contributed significantly more to the genetic differentiation of some population comparisons than any of the other loci. Interestingly, terrapins from South Carolina to New York were much more genetically similar to those from Texas (ρ = 0.154) than to those from Florida (ρ = 0.357). We attribute this pattern to extensive translocations of terrapins during the early 20th century to replenish diminished populations and to provide turtle farms with stocks. Terrapins collected in Texas were especially sought for shipment to the northeastern US because of their larger size. Our study indicates no population structure within or among adjacent estuaries. Thus, the mark‐recapture information from adult and subadult feeding locations is a poor predictor of population genetic structure. Additionally, it appears that past human activities may have drastically altered the genetics of current populations. Finally, our data suggest that translocation of eggs or head starting of terrapins within estuaries or among adjacent estuaries is acceptable from a genetic standpoint.
Phenotypic divergence despite high levels of gene flow in Galápagos lava lizards (Microlophus albemarlensis)
Authors: JORDAN M. A. , SNELL H. L. , SNELL H. M. , JORDAN W. C. 
Published: February 2005

AbstractThe extent of evolutionary divergence of phenotypes between habitats is predominantly the result of the balance of differential natural selection and gene flow. Lava lizards (Microlophus albemarlensis) on the small island of Plaza Sur in the Galápagos archipelago inhabit contrasting habitats: dense vegetation on the western end of the island thins rapidly in a transitional area, before becoming absent on the eastern half. Associated with these habitats are phenotypic differences in traits linked to predator avoidance (increased wariness, sprint speed, and endurance in lizards from the sparsely vegetated habitat). This population provides an opportunity to test the hypothesis that reduced gene flow is necessary for phenotypic differentiation. There was no evidence of any differences among habitats in allele frequencies at six out of seven microsatellite loci examined, nor was there any indication of congruence between patterns of genetic variability and the change in vegetation regime. We infer that gene flow between the habitats on Plaza Sur must be sufficiently high to overcome genetic drift within habitats but that it does not preclude phenotypic differentiation.
Clonal diversity and population genetic structure of arbuscular mycorrhizal fungi (Glomus spp.) studied by multilocus genotyping of single spores
Authors: STUKENBROCK EVA H. , ROSENDAHL SØREN 
Published: February 2005

AbstractA nested multiplex PCR (polymerase chain reaction) approach was used for multilocus genotyping of arbuscular mycorrhizal fungal populations. This method allowed us to amplify multiple loci from Glomus single spores in a single PCR amplification. Variable introns in the two protein coding genes GmFOX2 and GmTOR2 were applied as codominant genetic markers together with the LSU rDNA. Genetic structure of Glomus spp. populations from an organically and a conventionally cultured field were compared by hierarchical sampling of spores from four plots in each field. Multilocus genotypes were characterized by SSCP (single stranded conformation polymorphism) and sequencing. All spore genotypes were unique suggesting that no recombination was taking place in the populations. There were no overall differences in the distribution of genotypes in the two fields and identical genotypes could be sampled from both fields. Analysis of gene diversity indicated that Glomus populations are subdivided between plots within each field. There were however, no subdivision between the fields.
Is genome size influenced by colonization of new environments in dipteran species?
Authors: NARDON C. , DECELIERE G. , LŒVENBRUCK C. , WEISS M. , VIEIRA C. , BIÉMONT C. 
Published: February 2005

AbstractGenome size differences are usually attributed to the amplification and deletion of various repeated DNA sequences, including transposable elements (TEs). Because environmental changes may promote modifications in the amount of these repeated sequences, it has been postulated that when a species colonizes new environments this could be followed by an increase in its genome size. We tested this hypothesis by estimating the genome size of geographically distinct populations ofDrosophila ananassae,Drosophila malerkotliana,Drosophila melanogaster,Drosophila simulans,Drosophila subobscura,andZaprionus indianus,all of which have known colonization capacities. There was no strong statistical differences between continents for most species. However, we found that populations ofD. melanogasterfrom east Africa have smaller genomes than more recent populations. For species in which colonization is a recent event, the differences between genome sizes do not thus seem to be related to colonization history. These findings suggest either that genome size is seldom modified in a significant way during colonization or that it takes time for genome size of invading species to change significantly.
Treatment of localized lesions of canine atopic dermatitis with tacrolimus ointment: a blinded randomized controlled trial
Authors: BENSIGNOR EMMANUEL , OLIVRY THIERRY 
Published: February 2005

Abstract  This investigator‐blinded randomized controlled trial was designed to determine whether tacrolimus ointment (Protopic, Fujisawa Healthcare) decreased the severity of localized lesions of canine atopic dermatitis (AD). Twenty dogs with AD were enrolled if they exhibited lesions on both front metacarpi. Each foot was randomized to be treated with 0.1% tacrolimus or placebo (vaseline) ointment twice daily for 6 weeks. Before, and every 2 weeks during the study, erythema, lichenification, oozing and excoriations each were graded on a 10‐point scale (maximal total score: 40). The primary outcome measures were the percentage reduction from baseline of lesional scores and the number of subjects whose scores had decreased by 50% or greater at study end. Intention‐to‐treat analyses were used. At study onset, lesional scores were not significantly different between sites treated with tacrolimus or placebo. After 6 weeks, the percentage reduction from baseline scores was higher for tacrolimus‐treated sites (median: 63%; 95% confidence interval: 39–67) than for placebo‐treated feet (median: 3%; confidence interval: −2–13) (Wilcoxon test; P = 0.0003). When tacrolimus was applied, lesions decreased by 50% or greater in 15/20 dogs (75%); these dogs were those that completed the study. In contrast, this benchmark was not reached for any placebo‐treated feet (Fisher's test; P < 0.0001). Adverse drug events consisted of minor irritation in some lesional areas treated with tacrolimus. Results of this trial suggest that the application of 0.1% tacrolimus ointment is useful for reducing the severity of localized skin lesions of canine AD.