bluuebunny/crossref_metadata_2025 huggingface dataset:
Multiobjective autocalibration for semidistributed water quality models
Authors: van Griensven A. , Bauwens W.
Published: December 2003

ESWAT is a simulator that integrates catchment and river water quantity and quality processes. The integration leads to a high number of model parameters, which complicates model calibration. As the model is semidistributed, the water quality and quantity variables at different observation sites inside the catchment can, and should, be used during this process, in order to use all the available information. A simultaneous use of all the different observed series and a high number of free parameters, however, creates a complex mathematical problem. Existing methods such as Pareto‐optimization are practically very difficult, if not impossible, to implement. We present therefore a new methodology that reduces the many objective functions to a single global criterion in an objective way, excluding the weighting problem. The global criterion then is minimized using a global search algorithm, i.e., the shuffled complex evolution method. The methodology is applied on the Dender River basin (Belgium), a heavily modified river basin with irregular flows.
Parthenogenetic reproduction in neotenics of the subterranean termite Reticulitermes speratus (Isoptera: Rhinotermitidae)
Authors: HAYASHI Yoshinobu , KITADE Osamu , KOJIMA Jun‐ichi
Published: December 2003

Experiments with artificial colonies consisting of only female workers and those of female nymphs and workers of a subterranean termite, Reticulitermes speratus, showed that neotenics (ergatoids and nymphoids) can reproduce parthenogenetically. The larvae hatched from the eggs produced partheno‐genetically by the neotenics were all female and did not have any aberrant external morphology. They had 42 chromosomes and were diploid. The analysis of genotypes at microsatellite loci revealed that the eggs produced parthenogenetically had only one of the two alleles that the mother neotenics possessed, indicating that the eggs were produced by automixis.
Japanese species of the genus Amphiareus Distant (Heteroptera: Anthocoridae), with descriptions of two new species
Authors: YAMADA Kazutaka , HIROWATARI Toshiya
Published: December 2003

Japanese species of the genus Amphiareus Distant of the lyctocorine flower bug are revised. Two new species, A. ruficollaris and A. ochraceus, are described and illustrated, and descriptions of three known species, A. constrictus (Stål), A. morimotoi (Hiura) and A. obscuriceps (Poppius), are revised. A key is provided to distinguish the Japanese species.
Genus Tisis Walker from the Philippines, with descriptions of three new species (Lepidoptera: Lecithoceridae)
Authors: PARK Kyu‐Tek
Published: December 2003

Three new species of the genus Tisis, T. xantholepidos sp. nov., T. sophistica sp. nov. and T. aurantiella sp. nov., are described from the Philippines, with pictures of the male and female genitalia. Keys to the species are given and descriptions of the male genitalia are provided.
The role of mitochondrial targeting in arsenic trioxide‐induced apoptosis in myeloid cell lines
Authors: Körper Sixten , Nolte Florian , Thiel Eckhard , Schrezenmeier Hubert , Rojewski Markus T.
Published: December 2003

Data regarding the role of mitochondria in arsenic trioxide (As2O3)‐induced apoptosis are controversial. We investigated the contribution of caspases and mitochondrial depolarization to As2O3‐induced apoptosis in the myeloid cell lines NB‐4, HL‐60 and U‐937. Caspase inhibition reduced the amount of cells with As2O3 (20 μmol/l)‐induced mitochondrial depolarization by about 50% in all cell lines. As2O3 also induced dose‐dependent phosphatidylserine exposure in cells without depolarized mitochondria. We conclude that caspase activation is of similar importance in As2O3‐induced apoptosis in myeloid cell lines as direct mitochondrial targeting and mitochondria are not necessary for caspase activation downstream of mitochondria.
The value of alloantibody detection in predicting response to HLA‐matched platelet transfusions
Authors: Levin Mark‐David , Kappers‐Klunne Mies , Sintnicolaas Kees , Holt Bronno van der , Van Vliet Huub H. D. M. , Löwenberg Bob , Van't Veer Mars B.
Published: December 2003

Alloantibody tests demonstrate immunological causes of insufficient increments in random platelet transfusions. The value of a positive or negative test result in predicting the outcome of human leucocyte antigen (HLA)‐matched transfusions in patients refractory to leucodepleted random platelet transfusions has not been assessed. We retrospectively evaluated the outcome of the first HLA‐matched platelet transfusion in 72 patients with haematological diseases in two ways: first, the strategy according to which the patient was selected for HLA‐matched platelet transfusions was analysed. The strategies were: (i) results of alloantibody tests were not available, (ii) a positive alloantibody test, (iii) a negative alloantibody test. Secondly, the outcome of the first HLA‐matched transfusion was investigated relative to the results of alloantibody tests, irrespective of the decision strategy. No significant association was found between the decision strategy and the outcome of the first HLA‐matched platelet transfusion. Positive alloantibody tests, however, predicted a better outcome of the first HLA‐matched platelet transfusion (P = 0·04 and P = 0·03 after 1 and 16 h respectively). In patients refractory to random platelet transfusions, positive alloantibody tests predicted a better outcome of HLA‐matched platelet transfusions. Patients with negative alloantibody tests, however, may benefit from HLA‐matched platelet transfusions.
β+45 G → C: a novel silent β‐thalassaemia mutation, the first in the Kozak sequence
Authors: De Angioletti Maria , Lacerra Giuseppina , Sabato Vincenzo , Carestia Clementina
Published: December 2003

A family from the Southeast of Italy was found to have a novel β‐globin mutant, β+45 G→C, with the features of a silent β‐thalassaemia mutation. It was asymptomatic in two heterozygotes, but its interaction with the severe thalassaemia mutation β‐IVS‐II‐654 C→T worsened the haematological and biosynthetic phenotype in two compound heterozygotes; moreover, another compound heterozygote, who was also heterozygote for the αααanti3·7, suffered from thalassaemia intermedia. The mutation was found associated in cis with the IVS‐II‐754 T→C substitution, which did not lead to abnormally spliced mRNA. Furthermore, the amount of β+45 mRNA was the same as the βA mRNA in the reticulocytes of the carriers. In vitro transcription/translation experiments demonstrated that the β+45 G→C decreased the efficiency of translation of the β‐globin chain by about 30%: this slight impairment was consistent with the observed clinical phenotype. The β+45 G→C is the first mutation found in the Kozak sequence (GACACCATGG) of the β‐globin gene and the first one at the position ‐6 upstream the ATG. The Kozak consensus sequence plays a major role in the initiation of translation process. The present finding supports the hypothesis that the G in position ‐6 is important in this process.
Filgrastim‐induced stem cell mobilization in chronic myeloid leukaemia patients during imatinib therapy: safety, feasibility and evidence for an efficient in vivo purging
Authors: Kreuzer Karl‐Anton , Klühs Christine , Baskaynak Gökben , Movassaghi Kamran , Dörken Bernd , le Coutre Philipp
Published: December 2003

Therapy with imatinib mesylate is limited by cellular resistance in chronic myeloid leukaemia (CML). Further, the limited availability of matching stem cell donors or an unfavourable risk profile for allogeneic stem cell transplantation (SCT) reduces the number of therapeutic options in a number of patients. To assess the possibility of stem cell mobilization (SCM) during imatinib therapy we performed granulocyte colony‐stimulating factor (filgrastim)‐induced SCM and subsequent aphaeresis in 15 chronic phase and three accelerated phase CML patients. Aphaeresis was successful in 13 patients (72%) (≥2·0 × 106 CD34+ cells/kg body weight) and five (28%) harvests could be obtained, which were negative for BCR/ABL mRNA as assessed by nested‐reverse transcription polymerase chain reaction (RT‐PCR). All harvests, except one, were negative after first round RT‐PCR, implicating a low level of CML cell contamination. There was no significant change in peripheral BCR/ABL transcript load after SCM as assessed by quantitative real‐time RT‐PCR. Fifteen patients remained stable in complete cytogenetic remission (CCR) during a median observation period of 9·3 months. One patient achieved a molecular remission shortly after SCM. Another patient who exhibited rising BCR/ABL mRNA levels before SCM achieved CCR after autologous SCT with the generated harvest. One patient with a Philadelphia chromosome‐negative, BCR/ABL‐positive CML showed a cytogenetic relapse 6 months after SCM. We conclude that filgrastim‐induced CD34+ cell aphaeresis under simultaneous imatinib medication is safe and feasible in CML patients. Additionally, we found evidence that this procedure could generate stem cell harvests that exhibit non‐detectable levels of BCR/ABL mRNA.
A thalassaemia array for Southeast Asia
Authors: Chan Kaimin , Wong Man Sim , Chan T. K. , Chan Vivian
Published: December 2003

The α and β thalassaemias are the commonest genetic disorders worldwide. The homozygous state is associated with high morbidity and mortality, thus screening of at‐risk pregnancies and prenatal testing are strongly advocated. A thalassaemia (thal) array has been designed using allele‐specific arrayed primer extension (AS‐APEX) for the simultaneous analysis of 15 non‐deletion α‐gene defects and 23 β‐gene mutations commonly found in southeast Asian countries, where thalassaemias are highly prevalent. This overcomes the problem of using multiple reverse dot blot analysis. The array showed 100% sensitivity and specificity in the detection of 120 β‐thal mutants and 35 non‐deletion α‐thal mutants. It is robust enough to be produced in a single place and shipped to other laboratories for use. The production cost of the array is low, each slide can be used for three different test samples and is therefore amenable to large scale antenatal screening in southeast Asian countries.
Association of T‐786C eNOS gene polymorphism with increased susceptibility to acute chest syndrome in females with sickle cell disease
Authors: Sharan K. , Surrey S. , Ballas S. , Borowski M. , Devoto M. , Wang K.‐F. , Sandler E. , Keller M.
Published: December 2003

Acute chest syndrome (ACS) is a life‐threatening complication of sickle cell disease (SCD). A retrospective study was performed to evaluate the role of endothelial nitric oxide synthase (eNOS) gene polymorphisms (E298D and T‐786C) in African–American SCD patients. The D298 allele showed no association; the C‐786 allele showed a statistically significant association (P = 0·0061) in female ACS cases. Multiple logistic regression analysis showed that relative risk of ACS was 8·695 (P = 0·0076, 95% confidence interval 1·761–42·920) for female carriers of C‐786. eNOS T‐786C is a gender‐specific genetic modifier that is associated with increased susceptibility to ACS in female SCD patients.
Patterns of population subdivision and gene flow in the ant Nothomyrmecia macrops reflected in microsatellite and mitochondrial DNA markers
Authors: Sanetra M. , Crozier R. H.
Published: December 2003

The Australian endemic ant Nothomyrmecia macrops is renowned for having retained a large proportion of ‘primitive’ morphological and behavioural characters. Another less studied peculiarity of this species is the production of short‐winged (brachypterous) female sexuals, which presumably are poor dispersers. The males, in contrast, bear a full set of normally developed wings and thus may disperse widely. We investigated patterns of genetic differentiation within and among three distantly separated populations in South Australia using nine polymorphic microsatellite loci and four regions of mitochondrial DNA (COI, COII, Cytb, lrRNA). We sampled eight subpopulations, one in the Lake Gilles CP, two near Penong and five around Poochera where distances ranged from 360 km to sites separated by 2–10 km. Only little differentiation was found at the local scale (within the assumed dispersal distance of males) using nuclear markers, whereas the three distant locations were moderately differentiated (FST = 0.06). Mitochondrial DNA genetic structure was much more pronounced on all scales (φST = 0.98), with regular differences in both haplotype composition and frequency even occurring among closely located sites. This lack of congruence between nuclear and mitochondrial markers strongly suggests limited female dispersal and male‐biased gene flow among populations. As to the conservation status of the species there is no evidence for severe population reductions in the recent past, which would have left populations genetically depauperate.
Identification of reproductively isolated lineages of Amur grayling (Thymallus grubii Dybowski 1869): concordance between phenotypic and genetic variation
Authors: Froufe E. , Knizhin I. , Koskinen M. T. , Primmer C. R. , Weiss S.
Published: December 2003

We analysed variation at maternally (mitochondrial DNA control region sequences) and bi‐parentally (10 microsatellites) inherited genetic markers, as well as across 12 meristic characters in 7 populations of Amur grayling, Thymallus grubii, from eastern Siberia. All three data sets were concordant in supporting the existence of three diagnosable, reciprocally monophyletic, and most probably reproductively isolated, lineages of grayling within the Amur drainage. There was a significant correlation between genetic and phenotypic divergence, both within and among lineages. Two phenotypically distinct forms (with and without an orange spot on the posterior portion of the dorsal fin), found in sympatry in the lower Amur, most likely result from secondary contact, as they demonstrate 4.6% sequence divergence at the mitochondrial DNA control region. This divergence, together with the existence of at least one nearby population of orange spot grayling outside the Amur drainage (0.8% divergence) underscore the palaeo‐hydrological complexity of the system, which presumably promoted genetic divergence in a shifting allopatric framework throughout the Pleistocene. Grayling from the upper Amur, corresponding to the type locality for the species, formed a sister group (1.4–1.6% divergent) to the orange spot lineage perhaps diverging in the early Pleistocene (1.4–1.6 Ma).
Population genetic structure of male black grouse (Tetrao tetrix L.) in fragmented vs. continuous landscapes
Authors: Caizergues Alain , Rätti Osmo , Helle Pekka , Rotelli Luca , Ellison Laurence , Rasplus Jean‐Yves
Published: December 2003

We investigated the association of habitat fragmentation with genetic structure of male black grouse Tetrao tetrix. Using 14 microsatellites, we compared the genetic differentiation of males among nine localities in continuous lowland habitats in Finland to the genetic differentiation among 14 localities in fragmented habitats in the Alps (France, Switzerland and Italy). In both areas, we found significant genetic differentiation. However, the average differentiation, measured as θ, was more than three times higher in the Alps than in Finland. The greater differentiation found in the Alps is probably due to the presence of mountain ridges rising above natural habitats of the species, which form barriers to gene flow, and to a higher influence of genetic drift resulting from lower effective sizes in highly fragmented habitats. The detection of isolation by distance in the Alps suggests that gene flow among populations does occur. The genetic variability measured as gene diversity HE and allelic richness A was lower in the Alps than in Finland. This could result from the higher fragmentation and/or from the fact that populations in the Alps are isolated from the main species range and have a lower effective size than in Finland. This study suggests that habitat fragmentation can affect genetic structure of avian species with relatively high dispersal propensities.
Hybrid origin of a cichlid population in Lake Malawi: implications for genetic variation and species diversity
Authors: Smith Peter F. , Konings Ad , Kornfield Irv
Published: December 2003

The importance of species recognition to taxonomic diversity among Lake Malawi cichlids has been frequently discussed. Hybridization — the apparent breakdown of species recognition — has been observed sporadically among cichlids and has been viewed as both a constructive and a destructive force with respect to species diversity. Here we provide genetic evidence of a natural hybrid cichlid population with a unique colour phenotype and elevated levels of genetic variation. We discuss the potential evolutionary consequences of interspecific hybridization in Lake Malawi cichlids and propose that the role of hybridization in generating both genetic variability and species diversity of Lake Malawi cichlids warrants further consideration.
Long‐term isolation and recent range expansion from glacial refugia revealed for the endemic springtail Gomphiocephalus hodgsoni from Victoria Land, Antarctica
Authors: Stevens Mark I. , Hogg Ian D.
Published: December 2003

We examined the phylogeography of the endemic Antarctic collembolan Gomphiocephalus hodgsoni using allozymes and mitochondrial DNA (mtDNA; COI) to determine if potentially limited dispersal and long‐term habitat fragmentation have promoted regional genetic differentiation. Allozyme analyses showed that differentiation among 21 populations within the Ross Dependency was high (FST = 0.55) with two main groups each representing a distinct geographical region: (1) Ross Island and Beaufort Island; and (2) all continental sites. Ross Island populations showed low levels of differentiation (FST = 0.05) and no correlation with geographical distance, suggesting their derivation from a single glacial refuge. By contrast, continental regions revealed moderate levels of differentiation (FST = 0.27) and a strong correlation with geographical distance, indicating a much older history with several refugia likely. Two sympatric allozyme genotypes were found at three continental sites from Taylor Valley and were congruent with two mtDNA haplotypes, implying nonrandom breeding groups. Although haplotype sharing between one Ross Island site (Cape Bird) and one continental site (Granite Harbour) was identified, the clades showed mostly fragmented allopatric distributions. The extensive Pleistocene glaciations, in conjunction with limited dispersal opportunities, appear to have promoted isolation and divergence among the fragmented habitats. Furthermore, the McMurdo Sound appears to be an effective isolating barrier to dispersal. However, we suggest that the unaided dispersal capacity of G. hodgsoni is unlikely to account for the limited mixing of haplotypes across the McMurdo Sound and recent human‐ or bird‐mediated dispersal is highly probable.
Genetic markers for analysing symbiotic relationships and lateral gene transfer in Neotropical bradyrhizobia
Authors: Parker M. A.
Published: December 2003

Assays with seven sets of lineage‐specific polymerase chain reaction (PCR) primers in the ribosomal RNA region were performed on 96 isolates of the Bradyrhizobium sp. nodule bacteria from Barro Colorado Island, Panama. The isolates were derived from 10 legume host species in six genera (Centrosema, Desmodium, Dioclea, Inga, Machaerium and Vigna). The PCR assays differentiated 13 composite genotypes, and sequencing of a 5′ 23S rRNA region indicated that all but one had a unique sequence. The most common genotype (seen in 44% of the isolates) was associated with all six legume host genera, and had a marker profile and 5′ 23S rRNA sequence identical to a Bradyrhizobium lineage associated with several other legume genera in Panama and Costa Rica. Another 46% of the isolates had genotypes found to be associated with two to three legume genera. Bradyrhizobium strains with low host specificity thus appear to be prevalent in this tropical forest. Based on 16S rRNA and 5′ 23S rRNA markers, most of the isolates had clear affinities to either B. japonicum or B. elkanii. However, one strain (Cp5–3) with a B. elkanii‐type 16S rRNA marker had a 5′ 23S rRNA region resembling B. japonicum. A partition homogeneity test indicated that relationships of strain Cp5–3 were significantly discordant for 16S rRNA vs. 23S rRNA sequences, and a runs test detected significant mosaic structure across the rRNA region. Lateral gene transfer events have therefore played a role in the evolution of symbiotic bacteria in this environment.
Genetic population structure of the white sifaka (Propithecus verreauxi verreauxi) at Beza Mahafaly Special Reserve, southwest Madagascar (1992–2001)
Authors: Lawler Richard R. , Richard Alison F. , Riley Margaret A.
Published: December 2003

Gene flow within and between social groups is contingent on behaviourally mediated patterns of mating and dispersal. To understand how these patterns affect the genetic structure of primate populations, long‐term data are required. In this study, we analyse 10 years of demographic and genetic data from a wild lemur population (Propithecus verreauxi verreauxi) at Beza Mahafaly Special Reserve, southwest Madagascar. Our goal is to specify how patterns of mating and dispersal determine kinship and genetic diversity among animals in the population. Specifically, we use microsatellite, parentage, and census data to obtain estimates of genetic subdivision (FST), within group homozygosity (FIS), and relatedness (r) within and among social groups in the population. We analyse different classes of individuals (i.e. adults, offspring, males, females) separately in order to discern which classes most strongly influence aspects of population structure. Microsatellite data reveal that, across years, offspring are consistently more heterozygous than expected within social groups (FIS mean = −0.068) while adults show both positive and negative deviations from expected genotypic frequencies within groups (FIS mean = 0.003). Offspring cohorts are more genetically subdivided than adults (FST mean = 0.108 vs. 0.052) and adult females are more genetically subdivided than adult males (FST mean = 0.098 vs. 0.046). As the proportion of females in social groups increases, the proportion of offspring sired by resident males decreases. Offspring are characterized by a heterozygote excess as resident males (vs. nonresident males) sire the majority of offspring within groups. We link these genetic data to patterns of female philopatry, male dispersal, exogamy, and offspring sex‐ratio. Overall, these data reveal how mating and dispersal tactics influence the genetic population structure in this species.
Phylogeography of the vairone (Leuciscus souffia, Risso 1826) in Central Europe
Authors: Salzburger Walter , Brandstätter Anita , Gilles ANDRÉ , Parson Walther , Hempel Melanie , Sturmbauer Christian , Meyer Axel
Published: December 2003

The vairone Leuciscus souffia is a cyprinid fish that inhabits river systems in and around the Alps. The complete mitochondrial DNA control region (945 bp) was sequenced in 295 vairone from 22 populations in Central Europe. A total of 51 haplotypes were identified with a maximum pairwise distance between haplotypes of 5.6%. Phylogenetic analyses revealed two major clades in L. souffia, an ‘Italian’ clade, and an ‘Alpine’ clade. Two hybrid zones exist, in the Mediterranean Alps and in the Soca basin. The position of the sister species of L. souffia, L. turskyi, to the ‘Alpine’ and the ‘Italian’ clade could not be resolved unambiguously. However, a linearized tree analysis indicated that L. turskyi represents a third lineage, that originated at the same time as the ‘Alpine’ and the ‘Italian’ clades of L. souffia. In the ‘Alpine’ clade two groups were resolved, a subclade with haplotypes from the Rhône and Var basins and a cluster with haplotypes from the Danube and Rhine systems. Our data suggest a long history of the vairone in Central Europe, predating Pleistocene glacial cycles. Two main refugia during glaciations must have existed, one in Italy and another one most probably in the Danube system. However, age estimates based on molecular clock calibrations suggest the survival of ‘Alpine’ haplotypes in several drainages during the last glaciation cycles. The Rhine system was only recently colonized.
Molecular approach to aquatic environmental bioreporting: differential response to environmental inducers of cytochrome P450 monooxygenase genes in the detritivorous subalpine planktonic Crustacea, Daphnia pulex
Authors: David P. , Dauphin‐Villemant C. , Mesneau A. , Meyran J. C.
Published: December 2003

In order to examine the usefulness of detoxifying genes as molecular markers in different chemical environments, isolation of cytochrome P450 genes (CYPs) belonging to the CYP4 family was performed in different samples from two subalpine populations of Daphnia pulex. The use of degenerate primers allowed us to isolate seven cDNAs. Four of them were assigned to the CYP4C subfamily, and were closely related to previously isolated crustacean CYP4s while the others were assigned to new CYP4AN and CYP4AP subfamilies. Expression studies, using semiquantitative polymerase chain reaction (PCR) followed by Southern blot hybridization with specific probes revealed differences in CYP4C32 and CYP4AP1 expressions between the two populations, which differ in the polyphenol richness of the vegetation surrounding their aquatic habitat. Further exposure to toxic dietary polyphenols showed different CYP induction patterns. Taken together, these preliminary results suggest a possible involvement of CYP4s in the ecological differentiation of subalpine D. pulex populations related to the polyphenol richness of the environmental vegetation. CYP4s may thus be considered as possible molecular markers in aquatic environmental bioreporting.
Local genetic structure in a white‐bearded manakin population
Authors: Höglund Jacob , Shorey Lisa
Published: December 2003

Local genetic structure was studied in lekking white‐bearded manakins in a study area on northern Trinidad, West Indies. The study population consisted of nine leks, at which a total of 238 birds were caught. By genotyping the individuals at eight polymorphic microsatellite loci we inferred some males on leks to be related (r = 0.25) as we found an average number of 14.8 half‐sib relationships and two full‐sib relationships per lek. We found that the sampled birds belonged to one genetic population that was slightly inbred (FISandFIT = 0.02). Kinship coefficients decreased with increasing geographical distance, indicating that related birds displayed at the same or nearby leks. However, leks did not consist of only one family group because the average genetic distance (aij) between males within leks was higher than when comparing males on leks within close proximity. These patterns suggest limited male dispersal, that some type of kin recognition process between individuals may exist in this species and that males on leks may be more likely to establish themselves as territory‐holding birds if a relative is already present.
Breeding success of male brook trout (Salvelinus fontinalis) in the wild
Authors: Blanchfield Paul J. , Ridgway Mark S. , Wilson Chris C.
Published: December 2003

Competition for females generally results in some males adopting alternative reproductive tactics to acquire matings. For fish, the ecological and evolutionary consequences of these tactics are not well understood because of an inability to link directly the interactions of individuals on the breeding grounds with genetic data. This study combines behavioural observations with genetic estimates of male reproductive success within an intensively studied wild population of lacustrine brook trout (Salvelinus fontinalis). Male brook trout exhibit a conditional reproductive strategy with small males adopting a peripheral position to that of larger dominant males in their proximity to spawning females. Parentage analysis of eggs collected from wild redds confirmed the reproductive success of individual males. Males relegated to peripheral positions during spawning participated frequently in spawning events, but in most cases the first male to spawn was the sole contributor, and no more than two males contributed successfully to a single brood. While behavioural observations of salmonines suggests that reproduction is partitioned among males in a manner dependent upon body size and proximity to spawning females, the genetic evidence from this study suggests a more limited distribution of reproductive success in the field. The genetic contributions of male brook trout are highly skewed towards larger males for this population. A review of the salmonine literature suggests little difference in individual reproductive success for males exhibiting size‐related tactics within a conditional mating strategy vs. precocial maturation. Collectively, these genetic studies provide new insights on the evolution of alternative life histories among salmonines.
Molecular interactions between an insect predator and its herbivore prey on transgenic potato expressing a cysteine proteinase inhibitor from rice
Authors: Bouchard Edith , Michaud Dominique , Cloutier Conrad
Published: December 2003

Transgenic plants expressing resistance to herbivorous insects may represent a safe and sustainable pest control alternative if they do not interfere with the natural enemies of target pests. Here we examined interactions between oryzacystatin I (OCI), a proteinase inhibitor from rice genetically engineered into potato (Solanum tuberosum cv. Kennebec, line K52) to increase resistance to insect herbivory, and the insect predator Perillus bioculatus. This stinkbug is a relatively specialized predator of caterpillars and leaf‐beetle larvae, and may also include plant sap in its predominantly carnivorous diet. One of its preferred prey is Colorado potato beetle (Leptinotarsa decemlineata), a major target of insect resistance development for potato field crops. Gelatin/sodium dodecyl sulphate‐polyacrylamide gel electrophoresis (SDS‐PAGE) confirmed that a major fraction of proteinase (gelatinase) activity in P. bioculatus extracts is OCI‐sensitive. Among five gelatinolytic bands detected, the slowest‐moving one (proteinase I) was inhibited strongly by purified OCI expressed in Escherichia coli or by OCI‐transgenic potato extracts, while three other proteinases were partly sensitive to these treatments. There was also evidence of slight inhibition of proteinase I by untransformed potato foliage, suggesting the presence of a natural inhibitor related to OCI at low level in potato foliage. Interestingly, only about 50% of the maximum potential activity of proteinase I was recovered in extracts of P. bioculatus feeding on L. decemlineata larval prey on a diet of OCI‐potato foliage, indicating that the predator was sensitive to OCI in the midgut of its prey. However, P. bioculatus on OCI‐prey survived, grew and developed normally, indicating ability to compensate prey‐mediated exposure to the OCI inhibitor. Confinement of P. bioculatus to potato foliage provided no evidence that potato plant‐derived nutrition is a viable alternative to predation, restriction to potato foliage in fact being inferior to free water for short‐term survival of nonfeeding first‐instar larvae. These results support the view that OCI, an effective inhibitor of a substantial fraction of digestive enzymatic potential in P. bioculatus, should not interfere with its predation potential when expressed in potato plants fed to its prey at a maximum level of ∼0.8% of total soluble proteins in mature foliage.
Oryzacystatin I expressed in transgenic potato induces digestive compensation in an insect natural predator via its herbivorous prey feeding on the plant
Authors: Bouchard Édith , Cloutier Conrad , Michaud Dominique
Published: December 2003

We observed recently that the rice cysteine proteinase inhibitor, oryzacystatin I (OCI) expressed in transgenic potato does not affect growth and development of the two‐spotted stinkbug predator (Perillus bioculatus) via its herbivorous prey feeding on the plant. Here we monitored the inhibitory activity of recombinant OCI along this potato → herbivore → predator continuum, to determine if the absence of effect was associated with a digestive compensatory response of the predator following inhibition of its proteinases by the recombinant cystatin. After confirming that OCI is present in the plant, and ingested in an active form by potato beetle larvae, quantitative and electrophoretic assays allowed us to determine that the recombinant cystatin (representing about 0.8% of total soluble proteins in leaves) was entirely bound to a ∼30‐kDa target proteinase in the prey's midgut, forming a sodium dodecyl sulphate (SDS)‐stable complex detected on immunoblots with an anti‐OCI polyclonal antibody. Despite the apparent absence of free, residual OCI in the beetle's midgut, digestive protease activity in the predator, known to include OCI‐sensitive activity, was altered negatively when the prey was fed the modified plant. This inhibitory process at the third trophic level was accompanied by a compensatory response in the predator, by which serine‐type proteinases were synthesized de novo. Overall, our data suggest that the affinity between OCI and the predator's OCI‐sensitive proteinases is: (i) as strong as (or stronger than) the affinity between OCI and the potato beetle 30‐kDa‐sensitive proteinase; and (ii) stronger than the affinity between these enzymes and the plant endogenous homologue of OCI, potato multicystatin, induced in the plant by potato beetle feeding. Our results also show that predatory organisms can adapt their digestive metabolism to the presence of plant antidigestive proteins ingested by their herbivorous preys. In a broader context, this study stresses the need to monitor the inhibitory effects of PI‐expressing plants not only on the herbivorous insects targeted, but also on the organisms likely to consume these pests in the environment.
Genome mapping of the orange blotch colour pattern in cichlid fishes
Authors: Streelman J. Todd , Albertson R. Craig , Kocher Thomas D.
Published: December 2003

The dramatic variation of cichlid fish colour pattern is thought to function in mate choice, evolve by sexual selection, and contribute to explosive speciation. Here, we combine linkage mapping and population genetic analyses to identify a single region of the cichlid genome responsible for the orange blotch (OB) colour phenotype. In each analysis, OB is tightly linked to the c‐ski1 gene. Additionally, we use comparative mapping information from the Takifugu rubripes and human genomes to suggest positional candidate loci for OB. Our work should engender a more comprehensive understanding of the molecular ecology of OB and its role in cichlid speciation. Moreover, we have assembled the components of a method to focus upon the genetic basis of evolutionarily and ecologically significant phenotypes.
Oceanic interchange and nonequilibrium population structure in the estuarine dependent Indo‐Pacific tasselfish, Polynemus sheridani
Authors: Chenoweth Stephen F. , Hughes Jane M.
Published: December 2003

We assayed mtDNA haplotype [300 base pairs (bp) control region] geography and genealogy in the Indo‐Pacific tasselfish, Polynemus sheridani from its contiguous estuarine distribution across northern Australia (n = 169). Eight estuaries were sampled from three oceanographic regions (Timor Sea, Gulf of Carpentaria and the Coral Sea) to assess the impact of Pleistocene sea level changes on the historical connectivity among P. sheridani populations. Specifically, we investigated the genetic consequences of disruption to Indian‐Pacific Ocean connectivity brought about by the closure of the Torres Strait. Overall there was significant population subdivision among estuaries (FST = 0.161, ΦST = 0.187). Despite a linear distribution, P. sheridani did not show isolation by distance over the entire sampled range because of genetic similarity of estuaries greater than 3000 km apart. However, significant isolation by distance was detected between estuaries separated by less than 3000 km of coastline. Unlike many genetic studies of Indo–Pacific marine species, there was no evidence for an historical division between eastern and western populations. Instead, phylogeographical patterns were dominated by a starlike intraspecific phylogeny coupled with evidence for population expansion in both the Gulf of Carpentaria and the Coral Sea but not the Timor Sea. This was interpreted as evidence for recent west to east recolonization across of northern Australia following the last postglacial marine advance. We argue that although sufficient time has elapsed postcolonization for populations to approach gene flow‐drift equilibrium over smaller spatial scales (< 3000 km), the signal of historical colonization persists to obscure the expected equilibrium pattern of isolation by distance over large spatial scales (> 3000 km).
Population genetic analysis of white shrimp,Litopenaeus setiferus,using microsatellite genetic markers
Authors: Ball Amy O. , Chapman Robert W.
Published: December 2003

The white shrimp (Litopenaeus setiferus) is a commercially and recreationally valuable species, yet little is known of its population structure or genetic diversity. White shrimp are distributed along the Atlantic coast of the United States and from the west coast of Florida to the Bay of Campeche, Mexico. In this study, shrimp were collected from North Carolina, South Carolina (four separate collections were taken from 1995 to 1999), Georgia, the Atlantic and Gulf coasts of Florida, Louisiana, Texas and Mexico. DNA was isolated from these individuals, and genetic variation was assessed at six microsatellite loci. These loci were, for the most part, highly polymorphic with an average expected heterozygosity of 0.68. Deviations from Hardy–Weinberg proportions were observed over all samples, but experimental results suggested the presence of null alleles, which confounded a biological interpretation of this result. Pairwise tests of the similarity of allele frequency distributions and distance measure analyses showed broad‐scale genetic homogeneity superimposed over occasional indications of random geographical and temporal differentiation.FSTandRSTestimates over all loci and samples were 0.002 or less and indicated little population structure. Weak but significant genetic differentiation was evident only between pooled western Atlantic and pooled Gulf of Mexico samples. Within the Gulf of Mexico or within the western Atlantic, the large‐scale genetic homogeneity observed may be a consequence of genetic mixing resulting from pelagic larvae and adult migrations, while the random local genetic differentiation may be a result of genetic sampling or experimental sampling error. The weak differentiation between shrimp from the Gulf of Mexico and the western Atlantic can be explained by a relatively recent separation of these two populations and/or small amounts of ongoing gene flow.
Estimating seed vs. pollen dispersal from spatial genetic structure in the common ash
Authors: Heuertz M. , Vekemans X. , Hausman J.‐F. , Palada M. , Hardy O. J.
Published: December 2003

Spatial genetic structure was analysed with five highly polymorphic microsatellite loci in a Romanian population of common ash (Fraxinus excelsior L.), a wind‐pollinated and wind‐dispersed tree species occurring in mixed deciduous forests over almost all of Europe. Contributions of seed and pollen dispersal to total gene flow were investigated by analysing the pattern of decrease in kinship coefficients among pairs of individuals with geographical distance and comparing it with simulation results. Plots of kinship against the logarithm of distance were decomposed into a slope and a shape component. Simulations showed that the slope is informative about the global level of gene flow, in agreement with theoretical expectations, whereas the shape component was correlated with the relative importance of seed vs. pollen dispersal. Hence, our results indicate that insights into the relative contributions of seed and pollen dispersal to overall gene flow can be gained from details of the pattern of spatial genetic structure at biparentally inherited loci. In common ash, the slope provided an estimate of total gene dispersal in terms of Wright's neighbourhood size of Nb = 519 individuals. No precise estimate of seed vs. pollen flow could be obtained from the shape because of the stochasticity inherent to the data, but the parameter combinations that best fitted the data indicated restricted seed flow, σs £ 14 m, and moderate pollen flow, 70 m £ σp £ 140 m.
Male dominance, paternity, and relatedness in the Jamaican fruit‐eating bat (Artibeus jamaicensis)
Authors: Ortega Jorge , Maldonado Jesús E. , Wilkinson Gerald S. , Arita Héctor T. , Fleischer Robert C.
Published: December 2003

We analysed variation at 14 nuclear microsatellite loci to assess the genetic structure, relatedness, and paternity of polygynous Jamaican fruit‐eating bats. A total of 84 adults captured in two caves exhibited little genetic differentiation between caves (FST = 0.008). Average relatedness among adult females in 10 harem groups was very low (R = 0.014 ± 0.011), providing no evidence of harem structure. Dominant and subordinate males shared paternity in large groups, while dominant and satellite males shared paternity in smaller groups. However, our results suggest that male rank influences paternity. Dominant males fathered 69% of 40 offspring, followed by satellite (22%) and subordinate males (9%). Overall adult male bats are not closely related, however, in large harem groups we found that subordinate and dominant males exhibited relatedness values consistent with a father‐offspring relationship. Because dominant and subordinate males also sired all the pups in large groups, we propose that their association provides inclusive fitness to them.
Aggressiveness is associated with genetic diversity in landlocked salmon (Salmo salar)
Authors: Tiira Katriina , Laurila Anssi , Peuhkuri Nina , Piironen Jorma , Ranta Esa , Primmer Craig R.
Published: December 2003

The amount of intraindividual genetic variation has often been found to have profound effects on life history traits. However, studies concerning the relationship between behaviour and genetic diversity are scarce. Aggressiveness is an important component of competitive ability in juvenile salmonids affecting their later performance and survival. In this study, we used an experimental approach to test the prediction that juveniles with low estimated genetic diversity should be less aggressive than juveniles with high estimated genetic diversity in fry from a highly endangered population of land‐locked salmon (Salmo salar). This was achieved by using a method enabling the accurate estimation of offspring genetic diversity based on parental microsatellite genotype data. This allowed us to create two groups of offspring expected to have high or low genetic diversity in which aggressive behaviour could be compared. Salmon fry with low estimated genetic diversity were significantly less aggressive than fry with high estimated genetic diversity. Closer analysis of the data suggested that this difference was due to differences in more costly acts of aggression. Our result may reflect a direct effect of genetic variation on a fitness‐related trait; however, we cannot rule out an alternative explanation of allele‐specific phenotype matching, where lowered aggression is expressed towards genetically more similar individuals.
Comparative genetic study confirms exceptionally low genetic variation in the ancient and endangered relictual conifer, Wollemia nobilis (Araucariaceae)
Authors: Peakall Rod , Ebert Daniel , Scott Leon J. , Meagher Patricia F. , Offord Cathy A.
Published: December 2003

The Wollemi pine, Wollemia nobilis (Araucariaceae), was discovered in 1994 as the only extant member of the genus, previously known only from the fossil record. With fewer than 100 trees known from an inaccessible canyon in southeastern Australia, it is one of the most endangered tree species in the world. We conducted a comparative population genetic survey at allozyme, amplified fragment length polymorphism (AFLP) and simple sequence repeat (SSR) loci in W. nobilis, Araucaria cunninghamii and Agathis robusta — representatives of the two sister genera. No polymorphism was detected at 13 allozyme loci, more than 800 AFLP loci or the 20 SSR loci screened in W. nobilis. In Ag. robusta only one of 12 allozyme loci, five of 800 AFLP loci and none of the 15 SSR loci were variable. For A. cunninghamii, 10 of > 800 AFLP loci and five of 20 SSR loci were variable. Thus low genetic diversity characterizes all three species. While not ruling out the existence of genetic variation, we conclude that genetic diversity is exceptionally low in the Wollemi pine. To our knowledge this is the most extreme case known in plants. We conclude that the combination of small population effects, clonality and below‐average genetic variation in the family are probable contributing factors to the low diversity. The exceptionally low genetic diversity of the Wollemi pine, combined with its known susceptibility to exotic fungal pathogens, reinforces current management policies of strict control of access to the pines and secrecy of the pine locations.
Direct selection on allozymes is not required to explain heterogeneity among marker loci across a Mytilus hybrid zone
Authors: Bierne N. , Daguin C. , Bonhomme F. , David P. , Borsa P.
Published: December 2003

Unequal differentiation between two types of loci (allozyme and DNA markers) across a Mytilus hybrid zone has recently been claimed as evidence for direct selection on some allozyme loci. We provide here a counter‐example: a noncoding DNA locus that exhibits as much differentiation as the incriminated allozymes do. The levels of genetic differentiation varied widely among both allozymes and noncoding DNA markers and no clear difference emerged between the two types of markers. This suggests that the strong interlocus variance in genetic differentiation has been confounded with a discrepancy between marker types as a result of an insufficient and unbalanced locus sampling. Heterogeneity in differentiation among neutral loci can be created by stochastic variance during the allopatric divergence preceding a secondary contact. In hybrid zones, a further source of variance is differential introgression among chromosomal regions after the secondary contact owing to the local influence of selected genes on more or less distant markers. However, the degree of differentiation alone gives no way to distinguish indirect pseudo‐selection (a regular and ubiquitous feature of hybrid zones) from direct selection. More generally, we suggest that comparative neutrality tests based on discrepancies among marker types have to be applied with caution when the presence of semi–permeable genetic barriers to gene exchange is suspected.