Systematic revision of the subgenus Ceratitis MacLeay s.s. (Diptera, Tephritidae)

The fruit fly genus Ceratitis MacLeay (Diptera, Tephritidae) comprises several important pest species attacking a wide range of unrelated fruits. This is the third paper in a series revising the genus, and deals with representatives of the subgenus Ceratitis s.s . Eight species are recognized: Ceratitis brachychaeta Freidberg, C. caetrata Munro, C. capitata (Wiedemann), C. catoirii Guerin-Meneville, C. comuta (Bezzi), C. malgassa Munro, C. manjakatompo Hancock and C. pinax Munro. Lectotypes are designated for C. catoirii and C. pinax . A key for both sexes is provided, with illustrations of cephalic bristles, mesonotal and wing patterns, and shape of aculeus. All species are Afrotropical, except for 67. capitata , which has become widespread. The phylogeny and biogeography of Ceratitis s.s . are discussed, based on a cladistic analysis, and showing indications that the mediterranean fruit fly, C. capitata , may have its origins in eastern Africa. The relationship of this subgenus within the genus Ceratitis s.l . is also outlined.     

Copper complexation in eutrophic and humic Lake Tjeukemeer, The Netherlands

SUMMARY. 1. Copper(II) complexation in the eutrophic. humus-rich Lake Tjeukemeer was measured fortnightly for several years by copper titration (Ion Selective Electrode) and by copper solubilization. Additionally, the copper speciation during titration was followed by ultrafiltration.
2. The Tjeukemeer showed high ligand concentrations able to complex up to 8.5X10^-5 M Cu.
3. Scatchard plots and affinity spectra of the titration data allowed the discrimination of at least three different binding sites. In Scatchard plots log K values ranged from 5 to 9, in affinity spectra from 4.5 to 8.
4. The highest log K values coincided with relatively low humus concentrations and blooms of algae, mainly Cyanobacteria.
5. The ultrafiltration experiments indicated that relatively small size fractions (<10 nm) have the highest copper binding affinity.     

Antisense oligonucleotide to insulin-like growth factorⅡ induces apoptosis in human ovarian cancer AO cellline

INTRODUCTIONOvariancancerisoneofthemostcommonfatalgynecologicmalignanciesin1.Towhomcorrespondenceshouldbeaddressed.theworld[1].Clinicaltreatmentofovariancancer,thoughwithgreatprogress,hasbeenimpededbyresistencetochemicaltherapy.Recently,inductionofapoptos…     

Comparative scanning electron microscopy of third-instar Hypoderma spp. (Diptera: Oestridae)

Scanning electron microscope study of third-instar larvae of four species of Hypoderma revealed differences among species in the pattern of spination, spine morphology and morphology of the spiracular plates. These observations identify characters that enable the differentiation of Hypoderma actaeon and H. diana, parasitizing red deer ( Cervus elaphus ) in Europe, and provide additional characters for differentiating H. bovis and H. lineatum parasitizing cattle.     

MICROEVOLUTION AND PHENOTYPIC PLASTICITY IN DONAX SERRA RODING (BIVALVIA: DONACIDAE) ON HIGH ENERGY SANDY BEACHES

Morphological differences between populations of the wedge clamDonax serra inhabiting two different coasts and biogeographicregions of South Africa were investigated. Both adults and juvenilesoccupied different positions along the beach gradient dependingon the coast: on the southeast coast adults occurred in themid intertidal and juveniles and recruits were low intertidalto subtidal; on the west coast the zonation pattern was reversed.Not only adults but also juvenile clams had shapes differingsignificantly between the two coasts; west coast clams werethinner, rounder and had a higher body density than the southeastones-recruits were less dense in the former coast. Differencesin shell shape between coasts are probably the result of directionalselection on the adults with the microevolutionary changes beingmaintained by geographical isolation. Shell density, on theother hand, seems to be environmentally determined through physiologicalcontrol of shell calcification, i.e. more mobile intertidalclams having lower shell density than less mobile subtidal clams.Ontogenetic changes in shape and density are presumably adaptiveand appear to be related to mobility, i.e. the larger, heavierand denser adults being more stable in the substrate, and thesmaller, thinner and less dense juveniles being more mobileand dispersive. Phenotypic plasticity in present D. serra populationsis an important factor that enabled this species to occupy differenthabitats and biogeographic regions and to survive 5 millionyears of environmental changes. ¹ Present address: Laboratory for Ecology and Aquaculture, ZoologicalInstitute, Katholic Universiteit, Leuven, Naamsestraat 59 B-3000,Leuven, Belgium. E-mail: agsoares{at}eudoramail.com (Received 15 October 1997; accepted 5 January 1998)     

Genital and allozyme similarity between Arion urbiae and A. anguloi (Mollusca: Pulmonata)

A comparison of the genital features of Arion urbiae and A. anguloi suggests that the species are extremely similar, if not identical. This hypothesis is supported by an electrophoretic analysis of 13 putative enzynme loci, which shows that the two species are also genetically yery similar (I = 0.947), while the related A. subfuscus consists of two distinct genetic types (I = 0.421). These results are further confirmed by a study of esterase profiles obtained with isoelectric focusing. It is therefore concluded that A. urbiae and A. anguloi are most probably conspecifie, whereas the genetic types of A. subfuscus may represent two different species.     

A new species of Festuca L.from Spain

A new species of Festuca (Festuca rivas-martinezii de la Fuente & Ortúñez) is described from the Sierra de Ayllón, Sierra de Guadarrama, Sierra de Gredos and associated chains (northcentral Spain: provinces of Avila, Guadalajara, Madrid and Segovia. Some morphological, anatomical and cytological characters of the taxon are presented.     

Molecular evolution of a multigene family in group A streptococci

The emm genes are members of a gene family in group A streptococci (GAS) that encode for antiphagocytic cell-surface proteins and/or immunoglobulin-binding proteins. Previously sequenced genes in this family have been named "emm," "fcrA," "enn," "arp," "protH," and "mrp"; herein they will be referred to as the "emm gene family." The genes in the emm family are located in a cluster occupying 3-6 kb between the genes mry and scpA on the chromosome of Streptococcus pyogenes. Most GAS strains contain one to three tandemly arranged copies of emm-family genes in the cluster, but the alleles within the cluster vary among different strains. Phylogenetic analysis of the conserved sequences at the 3' end of these genes differentiates all known members of this family into four evolutionarily distinct emm subfamilies. As a starting point to analyze how the different subfamilies are related evolutionarily, the structure of the emm chromosomal region was mapped in a number of diverse GAS strains by using subfamily-specific primers in the polymerase chain reaction. Nine distinct chromosomal patterns of the genes in the emm gene cluster were found. These nine chromosomal patterns support a model for the evolution of the emm gene family in which gene duplication followed by sequence divergence resulted in the generation of four major-gene subfamilies in this locus.      

Effects of climate change on productivity of cereals and legumes; model evaluation of observed year-to-year variability of the CO2 response

The effect of elevated [CO₂] on the productivity of spring wheat, winter wheat and faba bean was studied in experiments in climatized crop enclosures in the Wageningen Rhizolab in 1991–93. Simulation models for crop growth were used to explore possible causes for the observed differences in the CO₂ response. Measurements of the canopy gas exchange (CO₂ and water vapour) were made continuously from emergence until harvest. At an external [CO₂] of 700 μmol mol^?1 Maximum Canopy CO₂ Exchange Rate (CCERmax) at canopy closure was stimulated by 51% for spring wheat and by 71% for faba bean. At the end of the growing season, above ground biomass increase at 700 μmol mol^?1 was 58% (faba bean), 35% (spring wheat) and 19% (winter wheat) and the harvest index did not change. For model exploration, weather data sets for the period 1975-88 and 1991–93 were used, assuming adequate water supply and [CO₂] at 350 and 700 μmol mol^?1. For spring wheat the simulated responses (35–50%) were at the upper end of the experimental results. In agreement with experiments, simulations showed smaller responses for winter wheat and larger responses for faba bean. Further model explorations showed that this differential effect in the CO₂ response may not be primarily due to fundamental physiological differences between the crops, but may be at least partly due to differences in the daily air temperatures during comparable stages of growth of these crops. Simulations also showed that variations between years in CO₂ response can be largely explained by differences in weather conditions (especially temperature) between growing seasons.