Incipient reproductive isolation between two morphs of Drosophila elegans (Diptera: Drosophilidae)

Drosophila elegans is a flower-breeding species occurring in tropical and subtropical regions of Asia. Two morphs, brown and black, are known in this species. The brown morph is recorded from southern China, Philippines, Indonesia and New Guinea, while the black morph is from the Okinawa islands and Taiwan. The present crossing experiment suggests that the difference of body colour between them was due to alleles on a single locus or closely linked loci on an autosome; F₁ hybrids exhibited intermediate body colour. Female choice tests revealed asymmetrical premating isolation between the brown and black morphs; isolation indices ranged from 0.55 to 0.83 in the tests using females of the black morph (deviation from random mating was significant), but from — 0.03 to 0.50 in the tests using females of the brown morph (deviation from random mating was insignificant). However, body colour was not used as a criterion of mate choice by females. A weak and asymmetrical postmating isolation was also observed between the brown and black morphs; viability was lowered in F₂ progenies of crosses between females of the brown morph and males of the black morph. No premating or postmating isolation was observed between geographic strains of each morph. Under irradiation, body temperature was higher in the black morph than in the brown morph. On the other hand, no significant difference was observed in tolerance to cold, heat and desiccation between the brown and black morphs.     

RAPD fingerprinting for the distinction of Prevotella intermedia sensu stricto from Prevotella nigrescens

A collection of 70 oral strains including reference strains and clinical isolates identified as Prevotella intermedia sensu lato was constituted to cover a large clinical and geographical diversity. Electrophoresis of the enzyme malate dehydrogenase allowed the identification of the 70 study strains as Prevotella intermedia sensu stricto (n= 36), Prevotella nigrescens (n= 31) and three unclassified strains. By using four primers, DNA fingerprints were generated from 20 strains as random amplified polymorphic DNA (RAPD). Matching co-migrating amplicon positions by pairwise comparison allowed the clustering of the fingerprints as two groups coincident with the P. intermedia/P. nigrescens assignment by enzyme electrophoresis of malate dehydrogenase. Our data suggest that isolates identified asP. intermedia sensu lato by conventional criteria can be speciated asP. intermedia sensu stricto or P. nigrescens by RAPD fingerprinting.     

The Molecular Identification and Antifungal Susceptibilities of Aspergillus Species Causing Otomycosis in Tochigi,Japan

Aspergillus species are the most common pathogenic fungi involved in otomycosis, an infection of the outer ear canal. In this study, we examined the incidence of Aspergillus infections and the antifungal susceptibilities of 30 Aspergillus species isolates from patients with otomycosis who visited Saiseikai Utsunomiya Hospital between August 2013 and July 2016. Based on the morphological test results, the strains were identified as Aspergillus niger sensu lato (20 strains), A. terreus sensu lato (7 strains), and A. fumigatus sensu lato (3 strains). In contrast, the molecular identifications based on analyzing the isolates’ partial β-tubulin gene sequences revealed them to be A. niger sensu stricto (12 strains), A. tubingensis (8 strains), A. terreus sensu stricto (7 strains), and A. fumigatus sensu stricto (3 strains). The antifungal susceptibility test results indicated that strains of A. tubingensis and A. niger sensu stricto displayed lower susceptibilities to ravuconazole, compared with the other isolates. The Aspergillus strains from this study showed low minimum inhibitory concentrations toward the azole-based drugs efinaconazole, lanoconazole, and luliconazole. Therefore, these topical therapeutic agents may be effective for the treatment of otomycosis.

     

Population genetic analyses of an amphi-Atlantic species: Lychnis alpina (Caryophyllaceae)

Lychnis alpina is a perennial caryophyllaceous plant with an amphi-Atlantic distribution. 27 populations are described on the basis of allozyme data from 11 electro-phoretic loci. L. alpina has a relatively low level of genetic variation, 3 of the loci are polymorphic ( P.,_%= 20.2%) and the mean expected heterozygosity per indivindual is H³= 0.233 the three polymorphic loci included (H = 0.064, 11 loci included). Despite relatively low level of genetic variation, the genetic diversity among populations is relatively high with F_ST= 0.51. A hierarchial analysis of genetic diversity demonstrates that most of the genetic diversity exists as interpopulational, intra-regional diversity. Genetic identity is not associated with the intercontinental geographical distribution of the populations, neither is the diversity correspondant to taxonomic relationships.     

The influence of darkness and visual contrast on oviposition by Anopheles gambiae in moist and dry substrates

Abstract.  The influence of substrate brightness (value), contrast and colour (hue) on oviposition is quantified under low night-light levels of 1.2 × 10⁻⁴ w m⁻² in choice-tests using caged Anopheles gambiae sensu stricto laboratory strains and/or gravid An. gambiae sensu lato from a natural population in Western Kenya. Egg output increases as darkness of the substrate increases against a white background. Black substrates elicit the most oviposition by both laboratory and house-collected mosquitoes, whereas white elicits the least. Contrast between patches of substrate and background also influences egg placement. In four-choice tests, a black ovipositional dish against a white floor receives many more eggs than does black–black, white–white, and white–black dish vs. floor combinations. In a similar test presenting four grey vs. black combinations of dish vs. floor, females respond similarly to grey vs. black dishes and deposit nearly as many eggs on the dry floors as on wet dishes. Illumination at 2.1 × 10⁻³ w m⁻², equivalent to late dusk and early dawn, improves discrimination between black dishes and grey floors. Under the experimental conditions, An. gambiae females respond almost equally to dishes of water placed over red, yellow, green, blue and purple paper disks matching the brightness and saturation values of their neutral (grey) counterparts. Thus, no evidence is found for wavelength discrimination on oviposition. It is concluded that visual contrast strongly influences the search patterns for prospective ovipositional sites whereas darkness of substrate and moisture are strong releasers of oviposition.     

Borrelia burgdorferi sensu lato, Anaplasma phagocytophilum, Francisella tularensis and their co-infections in host-seeking Ixodes ricinus ticks collected in Serbia

To evaluate the prevalence rate of tick-borne bacterial pathogens, unfed adult Ixodes ricinus ticks were collected from vegetation in 2001, 2003, and 2004 at 18 localities throughout Serbia. A total of 287 ticks were examined by PCR technique for the presence of Borrelia burgdorferi sensu lato, Anaplasma phagocytophilum, and Francisella tularensis. The highest prevalence rate was that for B. burgdorferi sensu lato (42.5%), followed by A. phagocytophilum (13.9%) and F. tularensis (3.8%). The presence of five B. burgdorferi sensu lato genospecies, namely, B. burgdorferi sensu stricto, B. afzelii, B. garinii, B. lusitaniae, and B. valaisiana was identified by restriction fragment length polymorphism (RFLP) analysis. The most frequent B. burgdorferi sensu lato genospecies was B. lusitaniae, followed by B. burgdorferi sensu stricto. Co-infection by B. burgdorferi sensu stricto and B. lusitaniae was frequently observed. Co-infection by B. burgdorferi sensu lato and A. phagocytophilum and co-infection by B. burgdorferi sensu lato and F. tularensis appeared in 24 ticks. Sequencing of p44/msp2 paralogs of Serbian A. phagocytophilum showed that they were unique and distinct from those of A. phagocytophilum in US and UK. This is the first report of B. garinii, B. lusitaniae, B. valaisiana, as well as A. phagocytophilum and F. tularensis infected ticks in Serbia. These findings indicate a public health threat in Serbia of tick-borne diseases caused by B. burgdorferi sensu lato, A. phagocytophilum and F. tularensis.     

Re-identification of <Emphasis Type="Italic">Aspergillus fumigatus</Emphasis> sensu lato based on a new concept of species delimitation

The species concept of Aspergillus fumigatus sensu stricto has recently been defined by polyphasic taxonomy. Based on the new concept of species delimitations, 146 worldwide strains of Aspergillus fumigatus sensu lato were re-identified. Of those 146 strains, 140 (95.8%) could be identified as A. fumigatus sensu stricto, 3 (2.1%) as A. lentulus, and the remaining 3 strains as A. viridinutans complex, Neosartorya udagawae, and N. cf. nishimurae. Of 98 clinical strains, only 1 from dolphin nostril was identified as A. lentulus and not A. fumigatus sensu stricto. Random amplification of polymorphic DNA-polymerase chain reaction (RAPD-PCR) with primers PELF and URP1F produced nearly the same band patterns among 136 strains of A. fumigatus sensu stricto while discriminated the species from its related species. We also discussed about identification of several atypical A. fumigatus strains from clinical environments.     

Gene flow and melanism in Lake Erie garter snake populations

Melanistic garter snakes ( Thamnophis sirtalis ) are unusually common near Lake Erie, apparently because selection for thermoregulatory ability in cool lake-shore habitats (which favours melanistic morphs) outweighs selection for crypsis (which favours striped morphs). However, morph frequencies are highly variable among sites, suggesting that random genetic drift also influences colour pattern. In an effort to better understand the evolutionary processes influencing garter snake colour patterns, we estimated Fx and Nm (the number of migrants per generation) among island and mainland populations from patterns of allozymic variation detected using electrophoresis. Estimates of Nm were high, ranging from 2.7 to 37.6 between pairs of study sites and making it unlikely that differences in morph frequencies among sites were solely the result of random genetic drift. Furthermore, differences in F _st estimates between colour pattern (a one-locus two-allele trait) and allozyme loci suggest that colour pattern alleles are not in Hardy-Weinberg equilibrium, most likely as a result of natural selection. Comparison of allozymic data from Lake Erie with those from more distant sites suggests that gene flow occurs over long distances in T. sirtalis.     

Horizontal Transfer of Genetic Material among Saccharomyces Yeasts

The genus Saccharomyces consists of several species divided into the sensu stricto and the sensu lato groups. The genomes of these species differ in the number and organization of nuclear chromosomes and in the size and organization of mitochondrial DNA (mtDNA). In the present experiments we examined whether these yeasts can exchange DNA and thereby create novel combinations of genetic material. Several putative haploid, heterothallic yeast strains were isolated from different Saccharomyces species. All of these strains secreted an a- or alpha-like pheromone recognized by S. cerevisiae tester strains. When interspecific crosses were performed by mass mating between these strains, hybrid zygotes were often detected. In general, the less related the two parental species were, the fewer hybrids they gave. For some crosses, viable hybrids could be obtained by selection on minimal medium and their nuclear chromosomes and mtDNA were examined. Often the frequency of viable hybrids was very low. Sometimes putative hybrids could not be propagated at all. In the case of sensu stricto yeasts, stable viable hybrids were obtained. These contained both parental sets of chromosomes but mtDNA from only one parent. In the case of sensu lato hybrids, during genetic stabilization one set of the parental chromosomes was partially or completely lost and the stable mtDNA originated from the same parent as the majority of the nuclear chromosomes. Apparently, the interspecific hybrid genome was genetically more or less stable when the genetic material originated from phylogenetically relatively closely related parents; both sets of nuclear genetic material could be transmitted and preserved in the progeny. In the case of more distantly related parents, only one parental set, and perhaps some fragments of the other one, could be found in genetically stabilized hybrid lines. The results obtained indicate that Saccharomyces yeasts have a potential to exchange genetic material. If Saccharomyces isolates could mate freely in nature, horizontal transfer of genetic material could have occurred during the evolution of modern yeast species.     

Enzyme activities ofBorrelia burgdorferi sensu lato

Activities of 19 enzymes were tested by the API ZYM system in 13 strains ofBorrelia burgdorferi sensu lato (B. burgdorferi sensu stricto,B. afzelii, B. garinii, B. lusitaniae, B. valaisiana) grown in liquid BSK-H medium supplemented with rabbit serum. All strains produced acid phosphatase, esterase (C4), esterase-lipase (C8), leucine arylamidase and naphthol-AS-BI-phosphohydrolase. Nine strains also produced alkaline phosphatase, and three strains produced α-glucosidase. The API ZYM system probably cannot be used for differentiation betweenB. burgdorferi sensu lato genomospecies.     

The complement regulator factor H binds to the surface protein OspE of Borrelia burgdorferi

Spirochete bacteria of the Borrelia burgdorferi sensu lato complex cause Lyme borreliosis. The three pathogenic subspecies Borrelia garinii, Borrelia afzelii, and Borrelia burgdorferi sensu stricto differ in their disease profiles and susceptibility to complement lysis. We investigated whether complement resistance of Borreliae could be due to acquisition of the main soluble inhibitors of the alternative complement pathway, factor H and the factor H-like protein 1. When exposed to nonimmune EDTA-plasma, the serum-resistant B. afzelii and B. burgdorferi sensu stricto strains bound factor H/factor H-like protein 1 to their surfaces. Assays with radiolabeled proteins showed that factor H bound strongly to the B. burgdorferi sensu stricto strain. To identify factor H ligands on the borrelial surface, we analyzed a panel of outer surface proteins of B. burgdorferi sensu stricto with the surface plasmon resonance technique. The outer surface lipoprotein OspE was identified as a specific ligand for factor H. Using recombinant constructs of factor H, the binding site for OspE was localized to the C-terminal short consensus repeat domains 15-20. Specific binding of factor H to B. burgdorferi sensu stricto OspE may help the pathogen to evade complement attack and phagocytosis.     

A rapid method for differentiating Saccharomyces sensu stricto strains from other yeast species in an enological environment

During programs for the selection of enological yeasts, several hundred natural isolates are usually screened. The scope of these operations is to isolate strains possessing good fermentative properties without necessarily arriving at a precise species designation: in other words, to detect strains belonging to the Saccharomyces sensu stricto complex. In the present study, a pair of primers, designed within the variable D1/D2 region of the 26S subunit of ribosomal yeast RNA, have been constructed. These generate an amplification fragment of 471 bp that is specific for the seven Saccharomyces sensu stricto species, while no signal was obtained for Saccharomyces sensu lato strains (17 species) or for another 18 selected species commonly found in enological environments. A second pair of primers was also constructed, within the 18S rRNA gene, composed of perfectly conserved sequences common for all 42 yeast species examined, which generate a 900 bp (c.) band for all strains. This was used as a positive experimental control in multiplex PCR analysis using all four primers.     

Phylogenetic relationships within Pyrenodesmia sensu lato and the role of pigments in its taxonomic interpretation

Most lichens of the family Teloschistaceae (Ascomycota) produce yellow-orange-red anthraquinone pigments. However, the genus Pyrenodesmia encompasses species in which anthraquinones are absent and replaced by a gray pigment Sedifolia-gray. It was shown recently that these species are related to taxa with both anthraquinones and Sedifolia-gray (Caloplaca xerica group, C. haematites group, and C. cretensis) and to species with a brown pigment instead of both anthraquinones and Sedifolia-gray (C. demissa, C. obscurella, and C. reptans). Nevertheless, relationships between mentioned anthraquinone-containing and anthraquinone-lacking species remained unclear. In total, 8 DNA loci from 41 species were used here to resolve these uncertainties. We concluded that C. demissa, C. obscurella, and C. reptans are rather distant from the core of Pyrenodesmia, and we place them outside of Pyrenodesmia sensu lato. Within Pyrenodesmia sensu lato, three lineages were revealed and recognized on a generic level: the genus Pyrenodesmia sensu stricto (21 species), the genus Kuettlingeria (14 species), which is resurrected here, and the genus Sanguineodiscus (4 species), which is newly described here. The genus Pyrenodesmia includes taxa that never contain anthraquinones, but Sedifolia-gray. It matches with the former C. variabilis group. Taxa of the genera Kuettlingeria and Sanguineodiscus have anthraquinones in their apothecia and Sedifolia-gray in their thalli. The genus Kuettlingeria includes the former C. xerica group plus C. cretensis and C. diphyodes. The genus Sanguineodiscus includes the former C. haematites group and C. bicolor. The identity of Kuettlingeria (Caloplaca) diphyodes was clarified and the name Pyrenodesmia helygeoides was resurrected. Twenty-four new combinations were proposed.     

Karyological studies on Spanish Boraginaceae: Lithospermum L. sensu lato

LUQUE, T. & VALDÉS, B., 1984. Karyological studies on Spanish Boraginaceae: Lithospenum L. sensu lato . All of the Spanish taxa of Lithospermum L. sensu lato (Lithospermum sensu stricto, Neatostema, Buglossoides and Lithodora ), with the exception of Buglossoides gartonii (Bentham) I. M. Johnston, have been studied karyologically. The karyological characters allow the separation of three groups which do not correspond exactly with the morphological limits of the four genera actually recognized for Spain within Lithospermum sensu lato .
Se estudian cariológicamente los taxones españoles de Lithospermum L. sensu lato (Lithospennum sensu stricto, Neatostema, Buglossoides y Lithodora ), salvo Buglossoides gastonii (Bentham) I. M. Johnston. Por los caracteres cariológicos se pueden separar tres grupos cuyos límites no coinciden exactamente con los de los cuatro géneros actualrnente reconocidos para España dentro de Lithospcnum sensu lato .     

Differential Transmission of the Genospecies of Borrelia burgdorferi Sensu Lato by Game Birds and Small Rodents in England

The genetic diversity of Borrelia burgdorferi sensu lato was assessed in a focus of Lyme borreliosis in southern Britain dominated by game birds. Ticks, rodents, and pheasants were analyzed for spirochete infections by PCR targeting the 23S-5S rRNA genes, followed by genotyping by the reverse line blot method. In questing Ixodes ricinus ticks, three genospecies of B. burgdorferi sensu lato were detected, with the highest prevalences found for Borrelia garinii and Borrelia valaisiana. B. burgdorferi sensu stricto was rare (<1%) in all tick stages. Borrelia afzelii was not detected in any of the samples. More than 50% of engorged nymphs collected from pheasants were infected with borreliae, mainly B. garinii and/or B. valaisiana. Although 19% of the rodents harbored B. burgdorferi sensu stricto and/or B. garinii in internal organs, only B. burgdorferi sensu stricto was transmitted to xenodiagnostic tick larvae (it was transmitted to 1% of the larvae). The data indicate that different genospecies of B. burgdorferi sensu lato can be maintained in nature by distinct transmission cycles involving the same vector tick species but different vertebrate host species. Wildlife management may have an influence on the relative risk of different clinical forms of Lyme borreliosis.     

广义竹叶青蛇属Trimeresurus (sensu lato)的分类和系统学研究进展

广义的竹叶青蛇属于Trimeresurus(sensu lato)包含有40多个物种,广泛分布在南亚和东南亚国家和地区。目前,该类群已经相继被划分为6个属：Trimeresurus(sensu stricto)、Tropidolaemus、Ovophis Protobothrops,Triceratolepidophis,Zhaoermia本文从形态、细胞以及分了系统学等方面对Trimeresurus(sensu lato)的分类和系统学研究进行综述。     

Analysis of the enzyme polymorphism in a plaice, Pleuronectes platessa L., population from the north-west coast of Brittany, France

A study of enzyme polymorphism by electrophoretical techniques permitted the genetic structure and the homogeneity degree of the plaice population present in the Abers Wrac'h and Benoit along the north-west coast of Brittany to be determined. Thirteen enzymic systems encoded by 21 loci were analysed and nine of these loci were polymorphic at the 5% level. The comparison of allelic frequencies and of observed heterozygosity h _obs did not show significant differences between these two individual groups. Nei's genetic identity ( I = 0.998) and distance ( D = 0.002) as estimated from allelic frequencies showed that the plaice of the two estuaries are very similar.
Thus, the plaice of A. Wrac'h and of A. Benoit belong to the same population in which the average level of polymorphism per locus P is 47% and the observed average heterozygosity per individual H _obs is 0.163 ± 0.094.     

Alcohol dehydrogenase isozymes in the mouse: Genetic regulation, allelic variation among inbred strains and sex differences of liver and kidney A2 isozyme activity

Genetic analysis of a proposed cis-acting temporal locus ( Adh-3t ), which regulates alcohol dehydrogenase C₂ (ADH-C₂) acitivity in mouse epididymis extracts, among F₁ (ddN × BALB/c) × ddN male backcross progeny provided evidence for genetic distinctness between the structural ( Adh-3 ) and temporal ( Adh-3t ) loci on chromosome 3. Genetic analysis also confirmed the close, linkage of Adh-1 (encoding liver and kidney ADH-A₂) and Adh-3 (encoding stomach ADH-C₂) to within 0.3 centimorgans on the mouse genome. Evidence is presented for a proposed closely linked cis-acting temporal locus (designated Adh-1t ) for the A₂ isozyme (encoded by Adh-1 ) controlling the activity of this enzyme in mouse kidney extracts, but having no apparent affect on liver and intestine ADH-A₂ activities. An extensive survey of the distribution of Adh-1, Adh-3 and Adh-3t alleles among 65 strains of mice is reported — with the exception of two Japanese strains (ddN and KF), linkage disequilibrium between Adh-3 and Adh-3t was observed. Sex differences in mouse liver and kidney ADH-A₂ activities were observed, with male/female ratios of approximately 0.6 and 3 respectively for these tissue extracts.     

The hidden lifestyles of Bacillus cereus and relatives

Bacillus cereus sensu lato, the species group comprising Bacillus anthracis, Bacillus thuringiensis and B. cereus (sensu stricto), has previously been scrutinized regarding interspecies genetic correlation and pathogenic characteristics. So far, little attention has been paid to analysing the biological and ecological properties of the three species in their natural environments. In this review, we describe the B. cereus sensu lato living in a world on its own; all B. cereus sensu lato can grow saprophytically under nutrient-rich conditions, which are only occasionally found in the environment, except where nutrients are actively collected. As such, members of the B. cereus group have recently been discovered as common inhabitants of the invertebrate gut. We speculate that all members disclose symbiotic relationships with appropriate invertebrate hosts and only occasionally enter a pathogenic life cycle in which the individual species infects suitable hosts and multiplies almost unrestrained.     

Evolutionary insight into the Peripatopsis balfouri sensu lato species complex (Onychophora: Peripatopsidae) reveals novel lineages and zoogeographic patterning

Evolutionary relationships in the widely distributed velvet worm Peripatopsis balfouri sensu lato species complex were examined using DNA sequence data, gross and SEM morphology. Sequence data were generated for the COI mtDNA and the 18S rRNA loci and analysed using a Bayesian inference approach, maximum likelihood and maximum parsimony. Phylogenetic analyses of the combined DNA sequence data revealed that Peripatopsis clavigera specimens from the southern Cape (clade 1) was sister to P. balfouri sensu lato specimens from the Cederberg Mountains (clade 2). Within the main P. balfouri sensu lato species complex, three addition clades could be discerned (clades 3, 4 and 5). The obligatory troglobitic species Peripatopsis alba was equidistant between the Cape Peninsula and adjacent interior (clade 3) and the two Boland and Hottentots Holland Mountains (clades 4 and 5). On the Cape Peninsula, P. stelliporata specimens nested among the sympatric P. balfouri sensu lato specimens. The Cape Peninsula specimens were sister to specimens from Jonkershoek site 1, Kogelberg and Simonsberg. Two Boland clades were retrieved, comprising Du Toit's Kloof, Bain's Kloof and Mitchell's Pass and sister (in clade 4) to specimens from the Boland and adjacent Hottentots Holland Mountains in clade 5. These results revealed complex biogeographic patterning in the P. balfouri sensu lato species complex. The presence of sympatric, yet genetically discrete species pairs at six of the sample localities (Du Toit's Kloof, Simonsberg, Jonkershoek sites 1 and 2, Kogelberg and Landroskop) suggests that there is reproductive isolation between the lineages. Divergence time estimations suggest a Miocene/Pliocene/Pleistocene cladogenesis. A taxonomic revision of the P. balfouri sensu lato species complex was undertaken to stabilize the taxonomy. P. clavigera is monophyletic and retained for the southern Cape specimens, P. balfouri sensu stricto is now confined to the Cape Peninsula and adjacent interior, while P. stelliporata is regarded as a junior synonym of the latter taxon, P. alba is endemic to the Wynberg Cave systems on the Cape Peninsula. Three novel species (Peripatopsis cederbergiensis, sp. n., Peripatopsis bolandi sp. n. and Peripatopsis purpureus, sp. n.) are described.