bluuebunny/crossref_metadata_2025 huggingface dataset:
Responses of Glossina austeni to sticky panels and odours
Authors: Vreysen M. J. B. , Saleh K. M. , Zhu Z. ‐R. , Suleiman F. W.
Published: March 2003

The responses of male tsetse Glossina austeni Newstead (Diptera: Glossinidae) towards blue and white sticky legged panels, baited with odour attractants, and towards modified panels were studied in the Jozani forest of Unguja Island, Zanzibar. Increasing the height of the body of a standard panel from 30 to 60 or 90 cm, increased the catch two‐fold. Increasing the height of the legs (from 15 to 60 or 120 cm) or raising the device more than 5 cm above the ground reduced the catch significantly. The legs of the panels were the preferred landing sites of the flies, irrespective of the height of the body of the panel. Acetone (300 mg/h) combined with cow urine (60–130 mg/h) significantly increased the catches two‐ to threefold during the rainy season, but not during the dry season. Acetone had no effect during the dry season and its effect during the rainy season was less consistent. There was no effect of octenol (2.5–12.5 mg/h), used alone or in combination with acetone. Likewise, the catch did not increase through the addition of cow sebum, pig urine (60–860 mg/h), pig urine combined with acetone and octenol. The observed seasonal differences in the response of G. austeni towards odours are discussed in relation to host location strategies.
Insecticide resistance spectra and resistance mechanisms in populations of Japanese encephalitis vector mosquitoes, Culex tritaeniorhynchus and Cx. gelidus, in Sri Lanka
Authors: Karunaratne S. H. P. P. , Hemingway J.
Published: March 2003

Culex tritaeniorhynchus Giles and Cx. gelidus Theobald (Diptera: Culicidae), both vectors of Japanese encephalitis, were collected in 1984 and 1998 from two disease endemic localities in Sri Lanka: Anaradhapura and Kandy. Using wild‐caught adult mosquitoes from light traps, log dosage‐probit mortality curves for insecticide bioassays were obtained for three insecticides: malathion (organophosphate), propoxur (carbamate) and permethrin (pyrethroid). LD50 values showed that, in 1998, Cx. tritaeniorhynchus was ∼100‐fold more resistant to malathion and 10‐fold more resistant to propoxur than was Cx. gelidus. This difference was attributed to Cx. tritaeniorhynchus breeding mostly in irrigated rice paddy fields, where it would have been exposed to pesticide selection pressure, whereas Cx. gelidus breeds in other types of aquatic habitats less prone to pesticide applications. Resistance in Cx. tritaeniorhynchus increased between 1984 and 1998, whereas Cx. gelidus remained predominantly susceptible.

Propoxur inhibition of acetylcholinesterase (AChE) activity (the target site of organophosphates and carbamates) indicated that in 1998, frequencies of insensitive AChE‐based resistance were 9% in Cx. gelidus and 2–23% in Cx. tritaeniorhynchus, whereas in 1984 this resistance mechanism was detected only in 2% of the latter species from Anaradhapura. The AChE inhibition coefficient (ki) with propoxur was 1.86 ± 0.24 × 105 m−1 min−1 for Cx. tritaeniorhynchus from Anaradhapura in 1998.

Both species were tested for activity levels of detoxifying glutathione S‐trans‐ ferases (GSTs) and malathion‐specific as well as general carboxylesterases. High activities of GSTs and carboxylesterases were detected in Cx. tritaeniorhynchus but not Cx. gelidus. Malathion‐specific carboxylesterase was absent from both species.

Native polyacrylamide gel electrophoresis resolved two elevated general carboxylesterases, CtrEstβ1 and CtrEstα1, from Cx. tritaeniorhynchus and none from Cx. gelidus. CtrEstβ1 was the most intensely staining band. Gel inhibition experiments showed that both elevated esterases were inhibited by organophosphates and carbamates but not by pyrethroids.

The major elevated esterase CtrEstβ1 was partially purified (15‐fold) by sequential Q‐Sepharose and phenyl Sepharose column chromatography. The bimolecular rate constant (ka) and the deacylation rate constant (k3) for the malaoxon/ enzyme interaction were 9.9 ± 1.1 × 103 m−1 min−1 and 3.5 ± 0.05 × 10−4m−1 min−1, respectively, demonstrating that the role of this enzyme in organophosphorus insecticide resistance is sequestration.
Isoenzymes of human lice: Pediculus humanus and P. capitis
Authors: Amevigbe M. D. D. , Ferrer A. , Champorie S. , Monteny N. , Deunff J. , Richard‐Lenoble D.
Published: March 2003

Human lice (Phthiraptera: Pediculidae) from Africa, America and Europe were electrophoresed for 28 enzymes, with special interest in metabolic factors likely to be involved with insecticide resistance. Zymogram profiles of the body louse (Pediculus humanus L. from France and U.S.A.) and the head louse (P. capitis DeGeer from France, Madagascar, Mali & Senegal) were compared. Only two enzymes, phosphoglucomutase (Pgm) and esterase 3 (Est‐3), showed electrophoretic variation. In our starch gel electrophoresis conditions, P. humanus showed three electromorphs of Pgm migrating anodally 6, 11 and 16 mm (designated alleles a, b, c, respectively). Of the putative Pgm alleles, b and c occurred in all samples of both species of lice, whereas allele a was found only in P. humanus lab strain from U.S.A. Esterase 3 had four electromorphs migrating 23, 26, 30 and 35 mm (designated alleles a, b, c and d). Among putative Est alleles, a was found only in P. capitis from Bamako (all 14 specimens aa homozygotes), allele d was found only in P. capitis from Dakar (39% frequency), whereas Est‐3 alleles b and c showed apparently balanced polymorphism in all samples of both P. humanus and P. capitis except that from Bamako. Despite the limited amount of isoenzyme variation detected (only 2/31 polymorphic loci), divergences of Est‐3 and Pgm among Pediculus populations may be relevant to their biosystematics and resistance.
Efficacy of three insect repellents against the malaria vector Anopheles arabiensis
Authors: Govere J. , Durrheim D. N. , Baker L. , Hunt R. , Coetzee M.
Published: March 2003

Three commercial repellents marketed in South Africa: Bio‐SkincareTM (BSC, oils of coconut, jojoba, rapeseed and vitamin E), MosiguardTM towelletes with 0.574 g quwenling (p‐menthane‐3,8‐diol, PMD) and the standard deet (15% diethyl‐3‐methylbenzamide, TabardTM lotion), were compared against a laboratory colony of the mosquito Anopheles arabiensis Patton (Diptera: Culicidae), the predominant malaria vector in South Africa. Human forearms were treated with 1.2 g BSC, 0.8 g PMD towelette or 0.5 g deet and exposed to 200 hungry An. arabiensis females for 1 min, at intervals of 1–6 h post‐treatment. Tests were conducted by three adult male volunteers (aged 30–45 years, crossover controlled test design for 3 consecutive days), using their left arm for treatment and right arm for untreated control. Biting rates averaged 39–52 bites/min on untreated arms. All three repellents provided complete protection against An. arabiensis for up to 3–4 h post‐application; deet and PMD gave 90–100% protection up to 5–6 h, but BSC declined to only 52% protection 6 h post‐treatment. These results are interpreted to show that all three repellent products give satisfactory levels of personal protection against An. arabiensis for 4–5 h, justifying further evaluation in the field.
Quantification of pyrethroid insecticides from treated bednets using a mosquito recombinant glutathione S‐transferase
Authors: Enayati A. A. , Vontas J. G. , Small G. J. , McCarroll L. , Hemingway J.
Published: March 2003

Recombinant glutathione S‐transferase (agGST1–6) from the malaria vector mosquito Anopheles gambiae Giles (Diptera: Culicidae) was expressed in Esherichia coli using a pET3a vector system. The expressed enzyme was biochemically active with reduced glutathione (GSH) and 1‐chloro‐2, 4‐dinitrobenzene (CDNB). Activity of agGST1–6 with GSH and CDNB was inhibited to different degrees by both α‐cyano and non‐α‐cyano pyrethroid insecticides. This inhibition was used to develop an assay for quantification of pyrethroids. Standard curves of insecticide concentration against percentage of enzyme inhibition or volume of iodine solution were established by spectrophotometry and iodine volumetric titration, respectively, for permethrin and deltamethrin. These assays allowed estimation of pyrethroid concentrations both spectrophotometrically and visually. For the residue assay of each insecticide, a cut‐off point of 50% of the initial pyrethroid impregnation concentration was used, which should differentiate between biologically active and inactive treated bednets. The cross‐reactivity of the primary permethrin photodegradants (3‐phenoxyalcohol and 3‐phenoxybenzoic acid) with the recombinant agGST1–6 was assayed in the same system. No agGST1–6 inhibition by the insecticide metabolites was observed, suggesting that the system is unaffected by primary permethrin metabolites and will accurately measure insecticide parent compound concentrations. The estimated pyrethroid insecticide concentrations, given spectrophotometrically and by iodine titration assay, were comparable to those obtained by direct HPLC quantification of residues extracted from bednets. Hence, it should be relatively easy to adapt this method to produce a test kit for residue quantification in the field.
Phylogenetic analysis of the mitochondrial cytochrome oxidase subunit I gene of five species of the Culicoides imicola species complex
Authors: Linton Y.‐M. , Mordue (luntz) A. J. , Cruickshank R. H. , Meiswinkel R. , Mellor P. S. , Dallas J. F.
Published: March 2003

Abstract The phylogenetic status of members of the Culicoides imicola Kieffer (Diptera: Ceratopogonidae) species complex of haematophagous midges is unknown, and simple means to identify the members using all life stages are unavailable. In this study, the status of three confirmed (C. imicola s.s., C. bolitinos Meiswinkel and C. loxodontis Meiswinkel) and two provisional (C. tuttifrutti Meiswinkel and C. kwagga Meiswinkel) members of the complex from South Africa was assessed using phylogenetic analysis of partial DNA and amino acid sequences of the mitochondrial cytochrome oxidase subunit I (COI) gene. The four or five individuals of each species analysed contained one or two haplotypes each. Interspecific divergence was significant and characterized by strong A↔T transversion bias. Phylogenetic trees constructed using neighbour‐ joining, parsimony and maximum likelihood showed each species to be distinct. Combinations of sites for two restriction enzymes in the COI sequences were species‐specific and could form the basis of a diagnostic PCR assay.
Host selection by Anopheles arabiensis and An. quadriannulatus feeding on cattle in Zimbabwe
Authors: Prior A. , Torr S. J.
Published: March 2003

Abstract In the Zambezi valley, mosquito females of the Anopheles gambiae Giles complex (Diptera: Culicidae) were collected from a hut containing pairs of cattle distinguishable by known DNA markers. DNA was extracted from the blood‐fed mosquito abdomens and primer sets for ungulate and mosquito DNA loci were used to identify the mosquito sibling species and individual host source(s) of their bloodmeals. The 67 mosquitoes comprised a mixture of An. arabiensis Patton (31%) and An. quadriannulatus Theobald (69%). DNA from one or both of the cattle present in the hut was detected in 91% of samples. When the hut contained an adult and a calf, the percentage of bloodmeals from the adult, the calf and adult + calf were 58%, 27% and 15%, respectively; the trend towards meals from the adult host was consistent but not always significant. When the pair of cattle comprised two adults of roughly equal size and age, then mosquitoes generally showed no significant bias towards feeding from one individual. There was no significant difference in the pattern of host selection made by An. arabiensis and An. quadriannulatus but the former had a significantly higher percentage (20%) of mixed meals than An. quadriannulatus (9%). These two members of the An. gambiae complex appear to be less selective in their choice of cattle hosts compared to day‐active Diptera such as tsetse and Stomoxys, possibly because the hosts are generally asleep when Anopheles are active and there is therefore less selective pressure to adapt to host defensive behaviour. The slight bias of Anopheles towards older and/or larger cattle may be related to the host's larger surface area.
Perfectionism, the impostor phenomenon and psychological adjustment in medical, dental, nursing and pharmacy students
Authors: Henning Kris , Ey Sydney , Shaw Darlene
Published: March 2003

Extensive attention has been paid over the past three decades to the stressors involved in training in the health professions. Although empirical studies have identified demographic subgroups of students most likely to become distressed during training, less research has been carried out to evaluate the impact of students' personality characteristics on their adjustment. Severe perfectionism is one such personality trait that has been shown to increase the risk for anxiety and depressive disorders in other populations. Another set of personality traits linked to increased psychological problems has been labelled the `impostor phenomenon', which occurs when high achieving individuals chronically question their abilities and fear that others will discover them to be intellectual frauds. Both perfectionism and the impostor phenomenon would seem to be pertinent factors in the adjustment of health professional students; however, these character traits have not been empirically examined in this population. In the present study psychological distress, perfectionism and impostor feelings were assessed in 477 medical, dental, nursing and pharmacy students. Consistent with previous reports, the results showed that a higher than expected percentage of students (27·5%) were currently experiencing psychiatric levels of distress. Strong associations were found between current psychological distress, perfectionism and impostor feelings within each programme and these character traits were stronger predictors of psychological adjustment than most of the demographic variables associated previously with distress in health professional students. Implications for future research, limitations of this study and clinical recommendations are discussed.
Training for health care in developing countries: the work of the Tropical Health and Education Trust
Authors: Parry Eldryd , Parry Victoria
Published: March 2003

The Tropical Health and Education Trust (THET) was established to strengthen medical education and training for health care in developing countries. The Trust responds to requests from training institutions with a wide range of activities and programmes. Projects to meet specific needs are planned in outline with the Deans or Directors of institutions, as a basis for a long‐term link with a similar institution in the United Kingdom. These links are now the preferred method for meeting requests to develop skills, strengthen services and promote staff development. However, funding is always necessary for their support. THET has promoted students' community‐based training by enabling students in a team‐training programme in Ethiopia to make interventions in primary health care. A prize for the best students' community, clinical or laboratory projects in six African countries encourages enquiry by the students, promotes independent learning, and relates academic work to problems in health care. Work with Ministries of Health includes a continuing medical education programme for rural medical officers in Uganda, courses in basic and life‐saving surgery for Ethiopian health and medical officers, and a programme to update the skills of laboratory technologists in rural hospitals in Ghana. The range of projects that THET supports is wide because the needs, defined by those who are working in, and responsible for, training in the health service are diverse.
Mitochondrial DNA diversity and historical biogeography of a wet forest‐restricted frog (Litoria pearsoniana) from mid‐east Australia
Authors: McGUIGAN K. , McDONALD K. , PARRIS K. , MORITZ C.
Published: March 2003

MtDNA sequencing was used to investigate the genetic population structure of Litoria pearsoniana, a wet forest‐restricted hylid frog, endemic to southeast Queensland and northeast New South Wales, Australia. L. pearsoniana is regarded as endangered under Queensland legislation. Significant genetic divergence among populations of frogs from different rainforest isolates was identified, but the lack of reciprocal monophyly among adjacent isolates suggests this is the result of a relatively recent disruption to gene flow. A paired catchment study within a single rainforest isolate, the Conondale Range, revealed no substantial genetic structuring, indicating the occurrence of terrestrial dispersal among nearby streams either in the recent past or currently. Two major reciprocally monophyletic clades of mtDNA alleles were identified. These corresponded to two geographical regions separated by the Brisbane River valley; one consisting of the Conondale and D’Aguilar Ranges, and the other of the southern isolates in the Main, Border and Gibraltar Ranges. Sequence divergence between the two regions was more consistent with a late Miocene or Pliocene rather than late Pleistocene separation, and is similar to that found among phylogeographic divisions of rainforest reptiles and amphibians in north Queensland rainforests. The molecular evidence for long‐term separation of these two regions is corroborated by the pattern of species turnover in the distributions of species of rainforest‐restricted amphibians and reptiles. Bioclimatic modelling suggests that appropriate conditions for L. pearsoniana would have been restricted to isolated refuges in each phylogeographic division under cooler and drier climates, such as predicted for the last glacial maximum. Currently isolated montane areas may have been connected transiently during the past 2000 years. Identification of long‐term zoogeographic divisions among southeast Queensland rainforest herpetofauna has important implications for conservation and management. Conservation management of L. pearsoniana should be applied at the scale of major rainforest isolates and the conservation status of the species should be assessed independently north and south of the historical division.
Temporal persistence and spatial distribution of an American inoculant strain of the ectomycorrhizal basidiomycete Laccaria bicolor in a French forest plantation
Authors: SELOSSE M.‐A. , JACQUOT D. , BOUCHARD D. , MARTIN F. , LE TACON F.
Published: March 2003

Selected strains of ectomycorrhizal fungi, such as the basidiomycete Laccaria bicolor, are currently being used as inoculants in nurseries to improve growth of forest trees after outplanting. Information is needed on the survival of these introduced strains in forests and their impact on indigenous biodiversity. Dissemination and persistence of an American strain, L. bicolor S238N, were studied 10 years after outplanting in a Douglas fir plantation located at Saint‐Brisson (Morvan, France). About 430 Laccaria spp. sporophores were collected over 3 years. Inheritance of nuclear ribosomal DNA, as well as RAPD markers, was characterized in L. bicolor S238N, using a haploid progeny set of 91 monokaryons. More than 50 markers were identified (19 heterozygous and 33 homozygous or cytoplasmic markers), which unambiguously confirmed that the introduced strain was still present in the inoculated plots. Neither selfing (P < 0.0008) nor introgression with indigenous strains was detected although in vitro interfertility between the American strain and indigenous L. bicolor was identified. No ingress of the introduced genet into adjacent uninoculated plots colonized by various local Laccaria genets was detected. It is proposed that the spatial distributions identified have developed through mycelial propagation of the introduced strain and intraspecific competition with native genets. Although longer‐term data is still lacking, the stability of the inoculant strain and the limited disturbance to indigenous populations described support large‐scale nursery production of this host‐fungal combination.
Assortative mating among rock‐dwelling cichlid fishes supports high estimates of species richness from Lake Malawi
Authors: VAN OPPEN MADELEINE J. H. , TURNER GEORGE F. , RICO CIRO , ROBINSON ROSANNA L. , DEUTSCH JAMES C. , GENNER MARTIN J. , HEWITT GODFREY M.
Published: March 2003

It has been estimated that Lake Malawi, Africa, contains 500–650 endemic species of cichlid fishes, the largest number of vertebrate species endemic to any comparable sized area on the planet. As many of these putative species cannot be distinguished anatomically, these estimates of species richness depend to a great extent on the assumption that sympatrically occurring male colour morphs represent biological species. We have tested this assumption using a combination of behavioural observations of courtship and microsatellite DNA analysis for six putative species of the Pseudotropheus (Tropheops) complex and three of the Pseudotropheus (Maylandia) complex occurring sympatrically at Nkhata Bay. We were unable to demonstrate assortative courtship for the species pairs Pseudotropheus (Maylandia) zebra/P. ‘gold zebra’ or P. (Tropheops) ‘band’/P. (T.) ‘rust’ because we were unable to distinguish between the females of these taxa. All other taxa showed clear assortative courtship, except for P. (T.) ‘deep’, a deep‐water species which was rarely observed. Fixation indices (θST for the infinite allele model, and RST for the stepwise mutation model) calculated from six microsatellite DNA loci demonstrated significant deviations from panmixia in all pairwise comparisons of putative species, indicating little or no gene flow between populations. All taxa showed high levels of allelic diversity providing evidence that genetic bottlenecking may have been of limited importance in the speciation process. Assortative mating among taxa differing only in male colouration is supportive of theories that speciation in these fishes has been driven by sexual selection by female choice.
Patterns of polymorphism and gene flow of gender‐associated mitochondrial DNA lineages in European mussel populations
Authors: QUESADA H. , GALLAGHER C. , SKIBINSKI D. A. G. , SKIBINSKI D. O. F.
Published: March 2003

Mussels of the genus Mytilus have two types of mitochondrial DNA (mtDNA). The M type is transmitted paternally and the F type is transmitted maternally. RFLP analysis is used to assess phylogenetic relationships and nucleotide diversity and divergence for both mtDNA genomes in European populations of M. edulis and Atlantic and Mediterranean forms of M. galloprovincialis. Ten restriction endonucleases were used to assay variation in regions of the ND2 and COIII genes for a total of 77 individuals. F and M genomes show a concordant phylogenetic split into two major divergent clades, one specific to Mediterranean M. galloprovincialis and the other containing haplotypes from the three taxa. For both genomes, the geographical distribution of mtDNA variation suggests: (i) extensive levels of mtDNA introgression; (ii) asymmetric mtDNA gene flow from Atlantic to Mediterranean populations; and (iii) recurrent historical hybridization events. Significantly higher mtDNA diversity and divergence are observed for the M than F genome in all three Mytilus taxa, although the evolutionary forces responsible for these differences cannot be resolved. The extensive mtDNA gene flow between European Mytilus taxa conflicts with the restricted mtDNA introgression observed in American mussels, implying geographical variation in the nature of nuclear/mtDNA interactions regulating biparental inheritance.
No genetic variation detected within isolated relict populations of Saxifraga cernua in the Alps using RAPD markers
Authors: BAUERT M. R. , KÄLIN M. , BALTISBERGER M. , EDWARDS P. J.
Published: March 2003

Genetic variation in seven relict populations of Saxifraga cernua from three regions of the Alps was investigated using RAPD (random amplified polymorphic DNA) markers. No variation, either within the populations or within the regions, could be demonstrated. Nevertheless, each alpine region was characterized by a unique RAPD phenotype. Absence of genetic variation in these relict populations is attributed to population bottlenecks and founder effects during or following the ice ages. Contrasting hypotheses about the history of these populations, either as survivors of the glacial period or as products of postglacial immigration, are discussed in the light of the data presented.
Bank voles in linear habitats show restricted gene flow as revealed by mitochondrial DNA (mtDNA)
Authors: AARS J. , IMS R. A. , LIU H.‐P. , MULVEY M. , SMITH M. H.
Published: March 2003

Genetic structure of bank vole populations in linear river bank habitat in southeast Norway was determined from analyses of DNA sequences for the mitochondrial D‐loop. Animals were sampled at sites separated by 1 km, along two forested river banks separated by ≈ 100 m of open water. Twenty‐six distinct haplotypes were found among 120 voles. The voles showed significant deviation from panmixis on both sides of the river. Animals from the same site or from sites 1 km apart were more likely to share haplotypes than animals 2 km apart or more. Common haplotypes were widespread on both river banks, and had a wider distribution than relatively rare haplotypes. Some rare haplotypes were found on both banks, but most were restricted to a single bank. The results suggest that short‐term gene flow may be restricted for female bank voles in linear habitats. Female territorial behaviour may vary with habitat geometry. In the linear habitat described here, females defend only two territorial borders and may effectively limit female dispersal. Results were compared to a previous study of bank voles from this region in a two‐dimensional habitat. Gene flow in the linear habitat was much more restricted than gene flow in the two‐dimensional habitat. Probable mechanisms underlying this difference are discussed.
No evidence for adjustment of sex allocation in relation to paternal ornamentation and paternity in barn swallows
Authors: SAINO N. , ELLEGREN H. , MØLLER A. P.
Published: March 2003

Sex allocation theory predicts that parents should adjust investment in sons and daughters according to relative fitness of differently sexed offspring. In species with female preference for highly ornamented males, one advantage potentially accruing to parents from investing more in sons of the most ornamented males is that male offspring will inherit characters ensuring sexual attractiveness or high‐quality genes, if ornaments honestly reveal male genetic quality. Furthermore, in species where extra‐pair fertilizations occur, offspring sired by an extra‐pair male are expected to more frequently be male than those of the legitimate male if the latter is of lower quality than the extra‐pair male. We investigated adjustment of sex ratio of offspring in relation to ornamentation of the extra‐pair and the social mate of females by direct manipulation of tails of male barn swallowsHirundo rustica. Molecular sexing of the offspring was performed using the W chromosome‐linked avian chromo‐helicase‐DNA‐binding protein (CHD) gene while paternity assessment was conducted by typing of hypervariable microsatellite loci. Extra‐pair offspring sex ratio was not affected by ornamentation of their biological fathers relative to the experimental ornamentation of the parental male. Experimental ornamentation of the parental males did not affect the sex ratio of nestlings in their broods. Female barn swallows might be unable to bias offspring sex ratio at hatching according to the quality of the biological father. Alternatively, fitness benefits in terms of sexual attractiveness of sons might be balanced by the cost of compensating for little parental care provided by highly ornamented parental males, if sons are more costly to rear than daughters, or the advantage of producing more daughters, if males with large ornaments contribute differentially more to the viability of daughters than sons.
Computer software for performing likelihood tests of pedigree relationship using genetic markers
Authors: Goodnight K. F. , Queller D. C.
Published: March 2003

Molecular techniques are making ever more genetic markers available for use in parentage assignment, and measures of relatedness. We present a program, Kinship, designed to use likelihood techniques to test for any non‐inbred pedigree relationship between pairs of individuals, using single‐locus codominant genetic markers. Kinship calculates the likelihood that each pair of individuals in a data set are related by a given pedigree hypothesis, and likelihood ratios for any pair of hypotheses. The program also uses a simulation routine to attach statistical significance to its results.
Application of genomics in assessing biodiversity in wild and cultivated barley
Authors: Marmiroli N. , Maestri E. , Liviero L. , Massari A. , Malcevschi A. , Monciardini P.
Published: March 2003

Biodiversity, the substrate for natural selection and adaptation to the environment, is of foremost importance in species conservation. Genomics, the study of the structure and function of complex genomes, can be applied to the assessment of the genetic component of biodiversity in animals and plants. Genomic analysis within the genus Hordeum, in cultivars of H. vulgare and in wild accessions of H. spontaneum, was performed by different types of molecular markers, such as restriction fragment length polymorphisms (RFLP) and long primer–polymerase chain reaction (LP–PCR), and simple sequence repeats (SSR). The aim of this approach was to compare the correlation existing between genotypic variation at specific regions of the genome, as targeted with the different probes obtained from stress‐responsive genes, and phenotypic variation, as shown by adaptation to different environments and climates. H. vulgare cultivars with contrasting growth habits (spring or winter) and H. spontaneum accessions adapted to different locations in Israel have been analysed. The results showed the existence of some tight associations between adaptive traits and markers (RFLP, LP–PCR) derived from specific genes induced in response to environmental stress. The correlation between adaptive phenotypes and genetic variation obtained with these markers was similar to that observed with SSRs. However, a considerable amount of the global genetic variation (83% in H. vulgare and 65% in H. spontaneum) seemed to have no direct correlation with the particular genetic traits involved in differentiating the individuals. Molecular markers are therefore a useful tool to target genomic regions involved in adaptation to the environment.
Random amplified polymorphic DNA (RAPD) and quantitative trait analyses across a major phylogeographical break in the Mediterranean ragwort Senecio gallicus Vill. (Asteraceae)
Authors: Comes Hans Peter , Abbott Richard J.
Published: March 2003

Random amplified polymorphic DNA (RAPD) and quantitative trait variation of the widespread and ephemeral Senecio gallicus were surveyed in 11 populations sampled from the Iberian Peninsula and southern France. The aim of the study was to compare population relationships and levels of geographical differentiation with chloroplast (cp) DNA and allozyme variation assessed previously in the same populations. Employing multivariate statistics, a moderate level of intraspecific differentiation was observed among populations from Iberian coastal and inland regions for both RAPDs and quantitative traits. However, RAPDs provided greater resolution in identifying additional population structure within the hypothesized, Pleistocene refugial source area of the species in coastal Iberia. A major part of the geographical subdivision in RAPD and quantitative traits was concordant with the coastal vs. inland divergence as previously inferred from cpDNA haplotype frequencies, but strongly contrasted with the geographical uniformity of the species for allozymes. This concordance across various nuclear and cytoplasmic markers (RAPDs/quantitative traits, cpDNA) suggests that geographical uniformity for allozymes is more attributable to low rates of evolution and/or small genome sampling rather than high rates of pollen dispersal, slow rates of nuclear lineage sorting, or indirect balancing selection. The present study underscores the value of using additional classes of nuclear markers for narrowing the numbers of competing causal hypotheses about intraspecific cpDNA–allozyme discrepancies and their underlying evolutionary processes.
Comparison of genetic diversity of the invasive weed Rubus alceifolius Poir. (Rosaceae) in its native range and in areas of introduction, using amplified fragment length polymorphism (AFLP) markers
Authors: Amsellem L. , Noyer J. L. , Le Bourgeois T. , Hossaert‐Mckey M.
Published: March 2003

Theory predicts that colonization of new areas will be associated with population bottlenecks that reduce within‐population genetic diversity and increase genetic differentiation among populations. This should be especially true for weedy plant species, which are often characterized by self‐compatible breeding systems and vegetative propagation. To test this prediction, and to evaluate alternative scenarios for the history of introduction, the genetic diversity of Rubus alceifolius was studied with amplified fragment length polymorphism (AFLP) markers in its native range in southeast Asia and in several areas where this plant has been introduced and is now a serious weed (Indian Ocean islands, Australia). In its native range, R. alceifolius showed great genetic variability within populations and among geographically close populations (populations sampled ranging from northern Vietnam to Java). In Madagascar, genetic variability was somewhat lower than in its native range, but still considerable. Each population sampled in the other Indian Ocean islands (Mayotte, La Réunion, Mauritius) was characterized by a single different genotype of R. alceifolius for the markers studied, and closely related to individuals from Madagascar. Queensland populations also included only a single genotype, identical to that found in Mauritius. These results suggest that R. alceifolius was first introduced into Madagascar, perhaps on multiple occasions, and that Madagascan individuals were the immediate source of plants that colonized other areas of introduction. Successive nested founder events appear to have resulted in cumulative reduction in genetic diversity. Possible explanations for the monoclonality of R. alceifolius in many areas of introduction are discussed.
Nested cladistic analysis, phylogeography and speciation in the Timarcha goettingensis complex (Coleoptera, Chrysomelidae)
Authors: Gómez‐Zurita J. , Petitpierre E. , Juan C.
Published: March 2003

The Timarcha goettingensis complex is a monophyletic assemblage of closely related leaf beetles (Chrysomelidae), distributed from the north half of the Iberian Peninsula to Central Europe. Oligophagy, mountainous habitat and apterism are factors which are assumed to promote speciation in these beetles. We have used cytochrome oxidase subunit II mitochondrial DNA genealogies obtained from 31 sampling localities and a nested geographical distance analysis to assess the population structure and demographic factors explaining the geographical distributions of the mtDNA haplotypes in the T. goettingensis complex. The results show that there is a significant association between genetic structuring and geography. Inferences about the historical population processes in the species complex are discussed, being in general in accordance with contiguous range expansions and past fragmentations. The use of the cohesion species concept approach suggests the existence of several systematic ranks among the different T. goettingensis populations, which is in part supported by ecological traits such as trophic selection and altitudinal distribution.
Phylogeography of the bullhead Cottus gobio (Pisces: Teleostei: Cottidae) suggests a pre‐Pleistocene origin of the major central European populations
Authors: Englbrecht C. C. , Freyhof J. , Nolte A. , Rassmann K. , Schliewen U. , Tautz D.
Published: March 2003

The bullhead Cottus gobio is a small, bottom‐dwelling fish consisting of populations that have not been subject to transplantations or artificial stocking. It is therefore an ideal model species for studying the colonization history of central European freshwater systems, in particular with respect to the possible influences of the Pleistocene glaciation cycles. We sampled Cottus populations across most of its distribution range, with a special emphasis on southern Germany where the major European drainage systems are in closest contact. Mitochondrial
d‐loop sequencing of more than 400 specimens and phylogenetic network analysis allowed us to draw a detailed picture of the colonization of Europe by C. gobio. Moreover, the molecular distances between the haplotypes enabled us to infer an approximate time frame for the origin of the various populations. The founder population of C. gobio stems apparently from the Paratethys and invaded Europe in the Pliocene. From there, the first colonization into central Europe occurred via the ancient lower Danube, with a separate colonization of the eastern European territories. During the late Pliocene, one of the central European populations must have reached the North Sea in a second step after which it then started to colonize the Atlantic drainages via coastal lines. Accordingly, we found very distinct populations in the upper and lower Rhine, which can be explained by the fact that the lower Rhine was disconnected from the upper Rhine until ≈ 1 million years ago (Ma). More closely related, but still distinct, populations were found in the Elbe, the Main and the upper Danube, all presumably of Pleistocene origin. Intriguingly, they have largely maintained their population identity, despite the strong disturbance caused by the glaciation cycles in these areas. On the other hand, a mixing of populations during postglacial recolonization could be detected in the lower Rhine and its tributaries. However, the general pattern that emerges from our analysis suggests that the glaciation cycles did not have a major impact on the general population structure of C. gobio in central Europe.
Relative fitness components measured with competitive PCR
Authors: Wooninck L. M. , Warner R. R. , Fleischer R. C.
Published: March 2003

In mating systems with sperm competition, paternity is frequently established with modern DNA techniques. These methods are often expensive and cumbersome, and can be especially difficult for highly fecund species. An additional objective of many paternity studies is to discover the relationship between sperm number and paternity. We present here a competitive polymerase chain reaction (PCR) protocol, coupled with the use of an automated sequencer, that has two functions: (i) to measure directly relative sperm output of males in sperm competition; and (ii) to estimate paternity distributions of large numbers of offspring simultaneously. Our technique was calibrated using a microsatellite locus of the bluehead wrasse, Thalassoma bifasciatum, with the result that product ratio after competitive PCR accurately reflected the initial template proportions of known mixtures of DNA. When we applied our technique to multiple larvae of separate mating events we found that paternity distributions estimated with the competitive PCR technique closely matched the estimates derived from the traditional method of pooling paternity data from individual larvae. Finally, we compared paternity of these spawns with relative sperm contribution estimates. This comparison suggests that ejaculate size alone does not predict a male’s proportion of paternity within the group.
Genetic variation within and among patches of the clonal species, Vaccinium stamineum L.
Authors: Kreher S. A. , Foré S. A. , Collins B. S.
Published: March 2003

Once thought to be dominated by a few genets, clonal plant populations can contain high levels of genetic diversity. Sexual reproduction and vegetative growth strategy affect the amount and distribution of genetic diversity within clonal plant populations. We determined the scale of genetic diversity in a population of Vaccinium stamineum, a clonal shrub that forms discrete patches. Using the random amplified polymorphic DNA (RAPD) technique, we surveyed the genetic diversity of V. stamineum within and among patches from a 1‐ha site. We found 67 unique RAPD profiles among the 99 sampled individuals from 22 patches. In two patches, all the sampled individuals had the same RAPD profile. In seven patches, every individual sampled had a different RAPD profile. The remaining patches showed mixed RAPD profiles which suggested both clonal and sexual reproduction. Each unique RAPD profile was restricted to one patch (with one exception), which suggests that clonal growth occurs at the patch scale. High levels of genetic variation within some patches may be explained by somatic mutation; however, seedling recruitment is a more likely explanation.
Microsatellite analysis of genetic diversity in African buffalo (Syncerus caffer) populations throughout Africa
Authors: Van Hooft W. F. , Groen A. F. , Prins H. H. T.
Published: March 2003

Genetic diversity in nine African buffalo (Syncerus caffer) populations throughout Africa was analysed with 14 microsatellites to study the effects of rinderpest epidemics and habitat fragmentation during the 20th century. A gradient of declining expected heterozygosity was observed among populations in Save Valley Conservancy (Zimbabwe), and northern and southern Kruger National Park (South Africa). This was explained by a high mortality in northern Kruger National Park during the rinderpest pandemic at the end of the 19th century followed by recolonization from neighbouring populations, resulting in intermediate heterozygosity levels in northern Kruger National Park. In other populations expected heterozygosity was very high, indicating that rinderpest and recent habitat fragmentation had a limited effect on genetic diversity. From expected heterozygosity, estimates of long‐term effective population size were derived. Migration rates among populations in eastern and southern Africa were very high, as shown by a weak isolation by distance and significant correlation in allele frequencies between populations. However, there were indications that dry habitats could limit migration. Genetic distances within buffalo in central Africa were relatively large, supporting their status as distinct subspecies. Finally, it was observed that the higher polymorphic microsatellites were less sensitive at detecting isolation by distance and differences inNe, which may be a result of the high mutation pressure at these loci.
Microsatellite determination of male reproductive success in a natural population of the territorial ornate dragon lizard, Ctenophorus ornatus
Authors: Lebas N. R.
Published: March 2003

It is now evident that the genetic mating system can be very different to the observed mating system. However, it is less well known what makes particular individuals more (or less) successful than expected from the observed system. In this study the observed territorial structure of a field population of the agamid lizard, Ctenophorus ornatus, was compared with the mating system as evidenced by microsatellite parentage assignment. This study also investigated whether any male traits predicted reproductive success. Sixty‐five per cent of clutches were sired at least partially by a male other than the main territory‐holding male and 35% of clutches were sired by a male with no overlap of the female’s territory. Multiple paternity was moderately frequent at 25% of clutches. Male chest patch size predicted territory size and the number of females in the territory, but did not predict reproductive success. Instead, male head depth and body size were independently related to the number of offspring sired. As male head depth also predicted the number of females in a territory, these males are likely to be gaining increased reproductive success as a consequence of the higher number of females in their territories. Larger body size males, however, did not have a greater number of females in their territory and instead had more extra‐territorial copulations. Whether these extra‐territorial copulations are due to female choice or success in male competition is unknown.
Evidence for broadscale introgressive hybridization between two redfish (genusSebastes) in the North‐west Atlantic: a rare marine example
Authors: Roques SÉverine , SÉvigny Jean‐Marie , Bernatchez Louis
Published: March 2003

The evolutionary importance of introgressive hybridization has long been recognized by plant evolutionists, and there is now a growing recognition for its potential role in animals as well. Detailed empirical investigations of this evolutionary process, however, are still lacking in many animal groups, particularly in the marine environment. Using integrated microsatellite DNA data (eight loci analysed over 803 individuals representing 17 sampling locations) and multivariate statistical procedures (principal component, factorial correspondence and admixture proportion analyses), we: (i) provide a detailed dissection of the dynamics of introgressive hybridization betweenSebastes fasciatusandS. mentella, two economically important redfishes from the North‐west Atlantic; and (ii) infer the factors potentially involved in the maintenance of the hybrid zone observed in the gulf of St. Lawrence and south of Newfoundland. This study provided one of the rare examples of extensive introgressive hybridization in the ocean, and highlighted the predominant role of this process in shaping the extent of genetic diversity, interspecific differences and population structuring among redfishes from the North‐west Atlantic. The extensive (average rate of introgression = 15%) but geographically circumscribed and asymmetrical pattern of introgressive hybridization, the sympatric persistence of two reproductively isolated introgressed groups, the differential patterns of linkage disequilibrium among samples, and the maintenance of genetic integrity of both species outside the defined zone of introgression despite high potential for gene flow, all implicated selection in promoting and maintaining the observed pattern of introgression.