bluuebunny/crossref_metadata_2025_split huggingface dataset:
Partitioning nuclear and chloroplast variation at multiple spatial scales in the neotropical epiphytic orchid, Laelia rubescens
Authors: TRAPNELL DORSET W. , HAMRICK J. L. 
Published: August 2004

AbstractInsights into processes that lead to the distribution of genetic variation within plant species require recognition of the importance of both pollen and seed movement. Here we investigate the contributions of pollen and seed movement to overall gene flow in the Central American epiphytic orchid, Laelia rubescens. Genetic diversity and structure were examined at multiple spatial scales in the tropical dry forest of Costa Rica using nuclear (allozymes) and chloroplast restriction fragment length polymorphism (RFLP) markers, which were found to be diverse (allozymes, P = 73.3%; HE = 0.174; cpDNA, HE = 0.741). Nuclear genetic structure (FSTn) was low at every spatial scale (0.005–0.091). Chloroplast markers displayed more structure (0.073–0.254) but relatively similar patterns. Neither genome displayed significant isolation‐by‐distance. Pollen and seed dispersal rates did not differ significantly from one another (mp/ms = 1.40) at the broadest geographical scale, among sites throughout Costa Rica. However, relative contributions of pollen and seeds to gene flow were scale‐dependent, with different mechanisms determining the dominant mode of gene flow at different spatial scales. Much seed dispersal is highly localized within the maternal population, while some seeds enter the air column and are dispersed over considerable distances. At the intermediate scale (10s to 100s of metres) pollinators are responsible for substantial pollen flow. This species appears capable of distributing its genes across the anthropogenically altered landscape that now characterizes its Costa Rican dry forest habitat.
Phylogeography of a high‐dispersal New Zealand sea‐star: does upwelling block gene‐flow?
Authors: WATERS J. M. , ROY M. S. 
Published: August 2004

AbstractNew Zealand's (NZ) geographical isolation, extensive coastline and well‐characterized oceanography offer a valuable system for marine biogeographical research. Here we use mtDNA control region sequences in the abundant endemic sea‐starPatiriella regularisto test the following literature‐based predictions: that coastal upwelling disrupts north–south gene flow and promotes population differentiation (hypothesis 1); and that an invasive Tasmanian population of the species was introduced anthropogenically from southern New Zealand (hypothesis 2). We sequenced 114 samples from 22 geographical locations, including nine sites from North Island, nine from South Island, one from Stewart Island and three from Tasmania. Our analysis of these sequences revealed an abundance of shallow phylogenetic lineages withinP. regularis(68 haplotypes, mean divergence 0.9%). We detected significant genetic heterogeneity between pooled samples from northern vs. southern New Zealand (FST = 0.072;P = 0.0002), consistent with the hypothesis that upwelling disrupts gene flow between these regions (hypothesis 1). However, we are currently unable to rule out the alternative hypothesis that Cook Strait represents a barrier to dispersal (North Island vs. South Island;FST = 0.031;P = 0.0467). The detection of significant spatial structure in NZ samples is consistent with restricted gene flow, and the strong structure evident in northern NZ may be facilitated by distinct ocean current systems. Four shared haplotypes and nonsignificant differentiation (FST = 0.025;P = 0.2525) between southern New Zealand and Tasmanian samples is consistent with an anthropogenic origin for the latter population (hypothesis 2).
Phylogeographical insights into the origins of the Squalius alburnoides complex via multiple hybridization events
Authors: CUNHA C. , COELHO M. M. , CARMONA J. A. , DOADRIO I. 
Published: August 2004

AbstractThe origin, the phylogeographical structure and divergence times of hybridrogenetic Squalius alburnoides complex were analysed based on the complete mitochondrial cytochrome b gene (1140 pb). The molecular phylogenetic analyses suggest that the S. alburnoides complex has at least five asexual lineages of independent origin. The events that produced this ancestral hybridization took place over a long period of time. There have been multiple hybridization events throughout time, beginning in the upper Pliocene and probably continuing into the present. Increased humidity caused by climate changes in the Pliocene, along with tectonic lifting and vasculation of the Iberian Peninsula, led to the formation of current river drainages which, in turn, contributed to these hybridization events. We postulate that the Northwestern (Mondego and Douro) and the Southwest (Quarteira) drainages of the Iberian Peninsula delimited the border of the maternal ancestral distribution and that vicariant events led to the disappearance of the maternal ancestor in these regions, leaving today only the hybrid species. Two hypotheses have been suggested to explain the similarities between the mtDNA diversity observed in S. alburnoides and its maternal ancestor (S. pyrenaicus). The first hypothesizes that mtDNA similarity results from the recent extinction of the paternal ancestor, while the other postulates that: ‘reconstituted non hybrid males’ assumed the place of the extinct bisexual paternal ancestor and produced new hybridizations with S. pyrenaicus females.
Phylogeography of the Patelloida profunda group (Gastropoda: Lottidae): diversification in a dispersal‐driven marine system
Authors: KIRKENDALE LISA A. , MEYER CHRISTOPHER P. 
Published: August 2004

AbstractIn the last decade, greater than expected levels of genetic structure have been reported for many marine taxa with high dispersal capabilities. Although little‐studied to date, it is predicted that taxa with poor dispersal abilities would exhibit even more genetic differentiation than high dispersal taxa. These systems may track biogeographical processes better than more dispersive taxa and, more critically, function as the ‘lowest common denominators’ in MPA design initiatives. We investigate phylogeographical patterns in the poorly dispersing, yet widely distributed Patelloida profunda group and related congeners across the Indo‐west Pacific region. One hundred and twenty‐five individuals were sequenced for COI mtDNA [593 base pairs (bp)] and 44 individuals were sequenced for 16S mtDNA (539 bp). Identified P. profunda group lineages are highly geographically structured, with 12 reciprocally monophyletic lineages reported from 13 localities. Divergences within Indian and Pacific basins range from d = 0.013 to 0.127 and between basins from d = 0.147 to 0.197. The latter split is ancient (> 15 Myr) and cannot be related to Plio‐Pleistocene sea‐level fluctuations, characteristic of previously reported divergences in the same region. Juxtaposed against this structure is genetic connectivity between two widely separated P. profunda populations that share a common haplotype (φST = 0.001). This finding contrasts with previous work in the same geographical region and cautions strongly against single taxon indicators for designing conservation priorities or marine protected areas (MPAs). Historical and/or biological factors may play more significant roles than oceanography alone in determining the genetic structuring of taxa. In light of these findings, we discuss the difficulty in deriving biogeographical process or directionality from phylogenetic trees in dispersal‐driven systems. Even with a well‐resolved, highly supported topology, many equally parsimonious scenarios are possible.
Species boundaries, phylogeography and conservation genetics of the red‐legged frog (Rana aurora/draytonii) complex
Authors: BRADLEY SHAFFER H. , FELLERS G. M. , RANDAL VOSS S. , OLIVER J. C. , PAULY GREGORY B. 
Published: August 2004

AbstractThe red‐legged frog, Rana aurora, has been recognized as both a single, polytypic species and as two distinct species since its original description 150 years ago. It is currently recognized as one species with two geographically contiguous subspecies, aurora and draytonii; the latter is protected under the US Endangered Species Act. We present the results of a survey of 50 populations of red‐legged frogs from across their range plus four outgroup species for variation in a phylogenetically informative, ∼400 base pairs (bp) fragment of the mitochondrial cytochrome b gene. Our mtDNA analysis points to several major results. (1) In accord with several other lines of independent evidence, aurora and draytonii are each diagnosably distinct, evolutionary lineages; the mtDNA data indicate that they do not constitute a monophyletic group, but rather that aurora and R. cascadae from the Pacific northwest are sister taxa; (2) the range of the draytonii mtDNA clade extends about 100 km further north in coastal California than was previously suspected, and corresponds closely with the range limits or phylogeographical breaks of several codistributed taxa; (3) a narrow zone of overlap exists in southern Mendocino County between aurora and draytonii haplotypes, rather than a broad intergradation zone; and (4) the critically endangered population of draytonii in Riverside County, CA forms a distinct clade with frogs from Baja California, Mexico. The currently available evidence favours recognition of aurora and draytonii as separate species with a narrow zone of overlap in northern California.
Microsatellite marker data suggest sex‐biased dispersal in the common frog Rana temporaria
Authors: PALO J. U. , LESBARRÈRES D. , SCHMELLER D. S. , PRIMMER C. R. , MERILÄ J 
Published: August 2004

AbstractDespite being important models in ecological, evolutionary and conservation biology research, very little is known about the dispersal in anuran amphibians, and juvenile dispersal in particular. Using microsatellite data, we assessed signatures of sex‐biased migration in the common frog (Rana temporaria) in Scandinavia. Significant heterozygosity deficiency (FIS) and lower assignment value (mAIc) among females suggest that dispersal in R. temporaria is female biased. Also variance of assignment (vAIc), estimated separately for the two sexes, was consistent with this inference, although the difference was not statistically significant. Possible proximate and ultimate explanations for female‐biased dispersal in amphibians are discussed.
Distinct patterns of genetic differentiation among annelids of eastern Pacific hydrothermal vents
Authors: HURTADO L. A. , LUTZ R. A. , VRIJENHOEK R. C. 
Published: August 2004

AbstractPopulation genetic and phylogenetic analyses of mitochondrial COI from five deep‐sea hydrothermal vent annelids provided insights into their dispersal modes and barriers to gene flow. These polychaetes inhabit vent fields located along the East Pacific Rise (EPR) and Galapagos Rift (GAR), where hundreds to thousands of kilometers can separate island‐like populations. Long‐distance dispersal occurs via larval stages, but larval life histories differ among these taxa. Mitochondrial gene flow between populations of Riftia pachyptila, a siboglinid worm with neutrally buoyant lecithothrophic larvae, is diminished across the Easter Microplate region, which lies at the boundary of Indo‐Pacific and Antarctic deep‐sea provinces. Populations of the siboglinid Tevnia jerichonana are similarly subdivided. Oasisia alvinae is not found on the southern EPR, but northern EPR populations of this siboglinid are subdivided across the Rivera Fracture Zone. Mitochondrial gene flow of Alvinella pompejana, an alvinellid with large negatively buoyant lecithotrophic eggs and arrested embryonic development, is unimpeded across the Easter Microplate region. Gene flow in the polynoid Branchipolynoe symmytilida also is unimpeded across the Easter Microplate region. However, A. pompejana populations are subdivided across the equator, whereas B. symmitilida populations are subdivided between the EPR and GAR axes. The present findings are compared with similar evidence from codistributed species of annelids, molluscs and crustaceans to identify potential dispersal filters in these eastern Pacific ridge systems.
Crossing the Red Sea: phylogeography of the hamadryas baboon, Papio hamadryas hamadryas
Authors: WINNEY BRUCE J. , HAMMOND ROBERT L. , MACASERO WILLIAM , FLORES BENITO , BOUG AHMED , BIQUAND VERONIQUE , BIQUAND SYLVAIN , BRUFORD MICHAEL W. 
Published: August 2004

AbstractThe hamadryas baboon (Papio hamadryas hamadryas) is found both in East Africa and western Arabia and is the only free‐ranging nonhuman primate in Arabia. It has been hypothesized that hamadryas baboons colonized Arabia in the recent past and were possibly even transported there by humans. We investigated the phylogeography of hamadryas baboons by sequencing a portion of the control region of mtDNA in 107 baboons from four Saudi Arabian populations and combing these data with published data from Eritrean (African) P. h. hamadryas. Analysis grouped sequences into three distinct clades, with clade 1 found only in Arabia, clade 3 found only in Africa, but clade 2 found in both Arabian and African P. h. hamadryas and also in the olive baboon, P. h. anubis. Patterns of variation within Arabia are neither compatible with the recent colonization of Arabia, implying that baboons were not transported there by humans, nor with a northerly route of colonization of Arabia. We propose that hamadryas baboons reached Arabia via land bridges that have formed periodically during glacial maxima at the straits of Bab el Mandab in the southern Red Sea. We suggest that the genetic differentiation of Arabian from African populations suggests that Arabian populations have a higher conservation status than recognized previously.
Patterns of variability and gene flow in Medicago citrina, an endangered endemic of islands in the western Mediterranean, as revealed by amplified fragment length polymorphism (AFLP)
Authors: JUAN A. , CRESPO M. B. , COWAN R. S. , LEXER C. , FAY M. F. 
Published: August 2004

Abstract Medicago citrina is an endangered western Mediterranean endemic that grows only on small islets of the Balearic archipelago and off the eastern Spanish coast. Only 10 isolated subpopulations are currently known (four from Ibiza, three from Cabrera, two from Columbretes and one from an offshore islet in northern Alicante province), constituting a severely fragmented genetic system. Data were analysed with the unweighted pair‐group method using arithmetic averages (upgma) and principle coordinates analysis (pcoa), revealing several distinct groups. Genetic diversity indices indicated that Ibizan subpopulations had the highest genetic variability (Nei's index: 0.1463; Shannon's index: 0.228), whereas the lowest variability was found in Alicante (Nei's index: 0.035; Shannon's index: 0.050) and Cabrera (Nei's index: 0.068; Shannon's index: 0.104). These latter populations show the highest FST values (FST = 0.548) revealing high differentiation between them. Columbretes subpopulations formed a defined single group, although it also included some Ibizan samples. The smallest FST values, obtained between Ibiza and Columbretes (FST = 0.185), are not correlated with geographical proximity, but appear to be related to the geologically recent volcanic origin of the Columbretes islands (300 000 years ago). According to the distribution of the Ibizan samples in the dendrogram and the FST values, the best hypothesis is to regard the Ibizan subpopulations as the centre of genetic diversity of the currently known subpopulations. Our results suggest migratory scenarios from Ibiza to Columbretes based mainly on zoochory probably by seabirds. Finally, recommendations are provided for management strategies to facilitate the conservation of this endangered species.
Geographic variation in Mexican jays (Aphelocoma ultramarina): local differentiation, polyphyly or hybridization?
Authors: BHAGABATI NIRMAL K. , BROWN JERRAM L. , BOWEN BONNIE S. 
Published: August 2004

AbstractStudies of genetic variation within highly variable taxa can provide valuable insight into the factors influencing biological diversification. We examined six microsatellite loci, a nuclear intron and the mitochondrial control region to determine if the Mexican jay subspeciesAphelocoma ultramarina couchiiandA. u. potosinahave hybridized with western scrub‐jays (A. californica). We suspected hybridization because these Mexican Jay populations resemble scrub‐jays in several traits. We sampled six Mexican jay (N = 105) and four scrub‐jay (N = 78) populations. Suspected hybrid Mexican Jay populations did not share any mitochondrial types or intron alleles with scrub‐jays. All microsatellite alleles found in the suspected hybrid Mexican jay populations are also found in the control Mexican jay populations. Genetic distance‐based trees from microsatellites supported reciprocal monophyly of Mexican jays and scrub‐jays with bootstrap support > 80%. We randomized genotypes among populations to test scenarios consistent with hybridization. In some areas where Mexican jays and scrub‐jays occur in sympatry or geographical proximity, randomization tests yield results expected under hybridization (100% support for seven of nine scenarios). However, these populations were not the primary candidates for hybridization based on phenotype. Even if low‐level hybridization did occur, hybridization does not appear to be the main reason some Mexican jay populations resemble scrub‐jays more than others. The scrub‐jay‐like traits in these populations may be due to drift, adaptation or plasticity. Alternatively, ancient hybridization, followed by selection for scrub‐jay like traits in some Mexican jay populations, might have given rise to the observed variation.
Measuring vertebrate telomeres: applications and limitations
Authors: NAKAGAWA SHINICHI , GEMMELL NEIL J. , BURKE TERRY 
Published: August 2004

AbstractTelomeres are short tandem repeated sequences of DNA found at the ends of eukaryotic chromosomes that function in stabilizing chromosomal end integrity. In vivo studies of somatic tissue of mammals and birds have shown a correlation between telomere length and organismal age within species, and correlations between telomere shortening rate and lifespan among species. This result presents the tantalizing possibility that telomere length could be used to provide much needed information on age, ageing and survival in natural populations where longitudinal studies are lacking. Here we review methods available for measuring telomere length and discuss the potential uses and limitations of telomeres as age and ageing estimators in the fields of vertebrate ecology, evolution and conservation.
Polymerase chain reaction in the diagnosis of invasive aspergillosis
Authors: Hizel Kenan , Kokturk Nurdan , Kalkanci Ayse , Ozturk Can , Kustimur Semra , Tufan Muge 
Published: August 2004

SummaryIn the present study, we present a patient with invasive pulmonary aspergillosis caused by Aspergillus fumigatus diagnosed by polymerase chain reaction (PCR) technique on blood and bronchoalveolar lavage fluid samples of the patient. The value of PCR in the diagnosis of aspergillosis is discussed.
Paranasal sinus aspergillosis: its categorization to develop a treatment protocol
Authors: Panda N. K. , Balaji P. , Chakrabarti A. , Sharma S. C. , Reddy C. E. E. 
Published: August 2004

SummaryA prospective study was conducted in 25 consecutive patients of paranasal sinus aspergillosis to categorize and treat them based on a fixed treatment protocol. The three types of aspergillosis categorized as per definitive criteria were chronic invasive (six), non‐invasive (fungus ball) (seven) and non‐invasive destructive (12). Adjuvant chemotherapy was employed in non‐invasive destructive and chronic invasive disease. Ketoconazole was used in the first variety and itroconazole in the latter. Only two patients had recurrence after a mean follow‐up of 11 months (range: 6–20 months). They belonged to the non‐invasive destructive category and the recurrence had progressed to invasive variety. It is suggested that non‐invasive destructive disease should be followed up regularly with endoscopic examination, CT and fungal serology to detect recurrence. Categorization of the paranasal sinus aspergillosis helps to institute proper treatment. Adjuvant chemotherapy in the form of ketoconazole along with surgery is effective in non‐invasive destructive disease to prevent recurrence and progression to invasive disease. Chronic invasive disease with its propensity to involve orbit and intracranial cavity should be managed at the earliest with surgery and itraconazole.
In vitro activity of terbinafine and itraconazole against Aspergillus species isolated from otomycosis
Authors: Karaarslan A. , Arikan S. , Ozcan M. , Ozcan K. M. 
Published: August 2004

SummaryThe minimum inhibitory concentrations (MIC, μg ml−1) of itraconazole and terbinafine against overall 34 Aspergillus isolates from the external ear canals with otomycosis have been determined with M38‐P microdilution method suggested by National Committee for Clinical Laboratory Standards (NCCLS). MIC intervals in 48 h determined by taking MIC‐2 value of itraconazole (the lowest drug concentration causing 50% inhibition of visible fungal growth) and MIC‐0 value of terbinafine (the lowest drug concentration causing 100% inhibition of visible fungal growth) as a basis have been found as follows: 0.125–1 and 0.06–0.5 μg ml−1 for A. niger (22 strains), 0.06–0.25 and 0.06–0.125 μg ml−1 for A. flavus (10 strains), 0.125 and 0.125–0.5 μg ml−1 for A. terreus (two strains). It has been observed that both of the antifungal agents showed an in vitro activity against all Aspergillus species tested.
Tinea imbricata: autosomal dominant pattern of susceptibility in a polygamous indigenous family of the Nahuatl zone in Mexico
Authors: Bonifaz A. , Araiza J. , Koffman‐Alfaro Susana , Paredes‐Solis Vanessa , Cuevas‐Covarrubias S. , Rivera M. R. 
Published: August 2004

SummaryWe report on 9 confirmed cases of tinea imbricata (Tokelau, infection due to Trichophyton concentricum) out of 16 family members. They had a common mother with three different fathers. The genetic analysis of the family suggests an autosomal dominant pattern of susceptibility. Most cases (8/9) were presented as concentric and lamellar forms. One patient also had onychomycosis due to T. concentricum. Only two out of nine cases had a positive response to trichophytin.
Isolation of Cryptococcus neoformans in Antwerp Zoo's nocturnal house
Authors: Bauwens L. , Vercammen F. , Wuytack C. , Van Looveren K. , Swinne D. 
Published: August 2004

SummaryCryptococcosis was diagnosed postmortem in a striped grass mouse (Lemniscomys barbarus) housed in the nocturnal department of Antwerp Zoo. Eight of the remaining mice in the cage were captured. Cryptococcus neoformans was isolated from the lung of one animal. Two mice had an elevated serum cryptococcal antigen titre. On examination of the pooled faecal samples collected from 17 animal species housed in 23 cages of the nocturnal department, the pathogenic yeast was isolated from the faeces of the striped grass mice and a degu (Octodon degus). Numerous Cr. neoformans colonies were isolated from a tree‐trunk, tree‐stumps, and decaying wood collected from a hollow tree used to decorate the animals cage. Subsequent examination in four other cages of the nocturnal department revealed that all the sampled tree‐trunks were colonized by Cr. neoformans. The fungus was isolated from the air sampled in the cage of the degu. Air samples collected in the public and service corridors remained negative. All the isolated strains were identified as Cr. neoformans var. neoformans serotype A.