Cytoplasmic incompatibility involving <Emphasis Type="Italic">Cardinium</Emphasis> and <Emphasis Type="Italic">Wolbachia</Emphasis> in the white-backed planthopper <Emphasis Type="Italic">Sogatella furcifera</Emphasis> (Hemiptera: Delphacidae)

Cytoplasmic incompatibility (CI) is a reproductive phenotype induced by bacterial endosymbionts in arthropods. Measured as a reduction in egg hatchability resulting from the crossing of uninfected females with bacteria-infected males, CI increases the frequency of bacteria-infected hosts by restricting the fertilization opportunities of uninfected hosts in populations. Wolbachia, a type of alpha-proteobacteria, is well known as a CI inducer in a wide range of arthropod species, while Cardinium, a member of the phylum Bacteroidetes, is known to cause CI in one wasp and three spider mite species. In this study, dual infection with Cardinium and Wolbachia induced strong CI in a single host, Sogatella furcifera (Horváth), a planthopper species that is naturally infected with both bacteria. Specifically, infection with Cardinium alone was found to cause a 76 % reduction in egg development, and dual infection with Cardinium and Wolbachia a 96 % reduction, indicating that Cardinium induces CI and the dual infection raises the CI level. This study was the first to document reproductive alteration by Cardinium in a diploid host species.     

Evolution of <Emphasis Type="Italic">Hox3</Emphasis> and <Emphasis Type="Italic">ftz</Emphasis> in arthropods: insights from the crustacean <Emphasis Type="Italic">Daphnia pulex</Emphasis>

The Drosophila melanogaster genes zerknüllt (zen) and fushi tarazu (ftz) are members of the Hox gene family whose roles have changed significantly in the insect lineage and thus provide an opportunity to study the mechanisms underlying the functional evolution of Hox proteins. We have studied the expression of orthologs of zen (DpuHox3) and ftz (Dpuftz) in the crustacean Daphnia pulex (Branchiopoda), both of which show a dynamic expression pattern. DpuHox3 is expressed in a complex pattern in early embryogenesis, with the most anterior boundary of expression lying at the anterior limit of the second antennal segment as well as a ring of expression around the embryo. In later embryos, DpuHox3 expression is restricted to the mesoderm of mandibular limb buds. Dpuftz is first expressed in a ring around the embryo following the posterior limit of the mandibular segment. Later, Dpuftz is restricted to the posterior part of the mandibular segment. This is the first report of expression of a Hox3 ortholog in a crustacean, and together with Dpuftz data, the results presented here show that Hox3 and ftz have retained a Hox-like expression pattern in crustaceans. This is in accordance with the proposed model of Hox3 and ftz evolution in arthropods and allows a more precise pinpointing of the loss of ftz “Hox-like behaviour”: in the lineage between the Branchiopoda and the basal insect Thysanura.     

Phylogenetic Framework for Trema (Celtidaceae)

We used ITS and trnL sequence data, analyzed separately and combined by MP, to explore species relationships and concepts in Trema (Celtidaceae), a pantropical genus of pioneer trees. Whether Trema is monophyletic or includes Parasponia is still unresolved. Three clades within Trema received moderate to high support, one from the New World and two from the Old World, but their relationships were not resolved. In the New World, specimens of T. micrantha formed two groups consistent with endocarp morphology. Group I, with smaller brown endocarps, is a highly supported clade sister to T. lamarckiana. Group II, with larger black endocarps, is poorly resolved with several subclades, including the highly supported T. integerrima clade. Both Old World clades contain Asian and African species, with three or more species in each region. Trema orientalis is not monophyletic: specimens from Africa formed a highly supported clade sister to T. africana, while those from Asia were sister to T. aspera from Australia.     

Properties and Application of the Location-Test V (n,k)

The present paper is concerned with the properties of a test statistic V(n, k) to test location differences in the one-sample case with known hypothetical distribution G(x). The test is similar to the WILCOXON two-sample statistic after replacement of the second sample by quantiles of the hypothetical distribution. A comparison with the exact distribution of V(n, k) shows that an approximation by means of the normal distribution provides good results even for small sample sizes. The V-test is unbiased against one-tailed alternatives and it is consistent with a restriction which is hardly relevant in practical applications. With regard to the application we are interested especially in the power and robustness against extreme observations for small sample size n. It is shown that in a normal distribution with known standard deviation V(n, k) is more powerful than STUDENT's t for small n and more robust in the sense considered here. The test statistic is based on grouping of the observations into classes of equal expected frequency. A generalization to arbitrary classes provides an essential extension of applicability such as to discrete distributions and to situations where only relative frequencies of G(x) in fixed classes are known.     

Sargassum boreale sp. nov. (Fucales, Phaeophyceae) from Hokkaido, Japan

A new species, Sargassum boreale Yoshida et Horiguchi is described. It belongs to the subgenus Bactrophycus section Teretia, with cylindrical receptacles and is distinct from Sargassum confusum C. Agardh, S. pallidum (Turner) C. Agardh and Sargassum microceratium (Turner) C. Agardh in having a rather elongated stem with smooth surface and distantly issuing main branches, with narrow leaves. The distinction between S. boreale and these species is also revealed by a difference in internal transcribed spacer 2 (ITS‐2) sequences. In addition to the base substitutions, the existence of a large gap in S. boreale distinguishes this species from others. Sargassum boreale is distributed around Hokkaido and Saghalien to 50°N latitude. A key to the species of section Teretia is provided.     

Theropod and Ornithischian Footprints from the Middle Jurassic Yanan Formation of Zizhou County,Shaanxi, China

New tracksites reported from the Zizhou area elucidate the nature of the Early-Middle Jurassic dinosaurian ichnofaunas in Shaanxi Province. The assemblage is composed of footprints and trackways of medium- to large-sized theropods that show similarities with both the ichnogenera Kayentapus and Eubrontes and of small bipedal ornithischians that are referred to AS Anomoepus isp. Additionally tracks of a quadruped are present and assigned to Deltapodus isp. that may be related to a stegosaurian. Anomoepus isp. is similar to the holotype of Shensipus tungchuanensis which is, although apparently lost, re-assigned here and considered to be a subjective junior synonym of Anomoepus. It is therefore placed in new combination as Anomoepus tungchuanensis comb. nov. Identical tracks have been reported from well-preserved trackways both in the Zizhou and Shenmu areas, where they also co-occur with theropod tracks (Kayentapus and Grallator) and tracks of quadrupedal ornithischians (Shenmuichnus and Deltapodus). Thus, it appears that the carbonaceous (coal-bearing) facies of the region reveal ichnofaunas with both relatively abundant saurischian (theropod) and ornithischian tracks. This is in contrast with many areas where the ichnofaunas are heavily or exclusively saurischian (theropod) dominated.     

STRUCTURE,LIFE HISTORY AND SYSTEMATICS OF RHOICOSPHENIA (BACILLARIOPHYTA). I. THE VEGETATIVE CELL OF RH. CURVATA1

Rhoicosphenia Grun. has been placed by some authors in the monoraphid group with Achnanthes Bory and Cocconeis Ehrenb., and by others near Gomphonema Ehrenb. In order to clarify the systematic position of the genus, the morphology and anatomy of the vegetative cells of Rh. curvata (Kütz.) Grun. were investigated using light and electron microscopy. The structure and formation of the two types of valve are described, and the heterovalvy shown to be of a different type from that of the monoraphids; on the basis of raphe, valve and girdle structure a close relationship between these and Rhoicosphenia is unlikely. Rhoicosphenia shows many resemblances to Gomphonema but the types of pore occlusion present, coupled with apparently slight differences in the mucilage-secreting structures and the girdle, suggest that classification in the same family is unwise. The cryptic asymmetry of the valves, and in particular of the raphe system, is noted and explained with reference to their formation; with respect to this asymmetry two configurations of the valves can occur (named cis and trans types) and the distribution of these in raphid genera is discussed briefly. In view of the lack of evidence in raphid diatoms supporting a classification of bands into copulae and pleurae, it is recommended that this practice be suspended.     

Fine Structure of the Mastigont System in Tritrichomonas muris (Grassi)*

SYNOPSIS. Tritrichomonas muris shares many fine-structural details with the previously described members of the family Trichomonadidae, and especially with the organisms belonging to the subfamily Tritrichomonadinae. Among the features which T. muris has in common with all Trichomonadidae and in all probability with other Trichomonadida are the arrangement and structure of: the kinetosomes; many rootlet filaments, including the sigmoid filaments of kinetosome #2; the parabasal apparatus; and the pelta-axostyle complex. The structures which T. muris-type flagellates share with other Tritrichomonadinae, and especially with Tritrichomonas augusta-type species (including T. foetus), but not with Trichomonadinae that have been studied to date, are: the Type A costa; a comb-like structure, which appears to have replaced the costal base of Trichomonadinae and of Hypotrichomonas; the suprakinetosomal body, rudimentary in T. muris; and the infrakinetosomal body. The undulating membrane, like that of T. augusta-type organisms, consists of a proximal and a distal part. The proximal part, which contains the proximal marginal lamella, is less developed in T. muris than in T. augusta-type flagellates, being represented by a relatively low ridge for the entire length of the organism. The distal part of the membrane in T. muris, on the other hand, is more highly developed; it is a heavy cord, with a distal marginal lamella which consists of a large triangular organelle having a highly ordered structure and 2 less well defined cords distal to this organelle. The tubules of the recurrent flagellum occupy the area distal to the cords. The sigmoid filaments of kinetosome #2, unlike those of other Trichomonadidae examined to date, extend posteriorly to the peltar-axostylar junction; they seem to terminate within the cytoplasm near, but not connected to the axostyle. In addition to the Type A costa, there is a small rootlet filament, which appears to be homologous to the rudimentary costa noted in Hypotrichomonas. Some of the paraxostylar and paracostal granules consist of an outer, relatively dense layer and an inner “core” of moderate density; between the 2 there is a lucent ring. The discussion deals in some detail with the possible nature of the paraxostylar and paracostal granules in trichomonads. The taxonomic status of Tritrichomonas cricetus (Wantland) [Tritrichomonas criceti (Wantland) emend. Levine] and Trichomonas criceti Ray & Sen Gupta is discussed in an appendix; it is concluded that both of these names are synonyms of T. muris (Grassi).     

Transgenic animals as a tool for studying the effect of the c-myc proto-oncogene on cardiac development

Transgenic animals provide a model system to elucidate the role of specific proteins in development. This model is now being used increasingly in the cardiovascular system to study cardiac growth and differentiation. During cardiac myocyte development a transition occurs from hyperplastic to hypertrophic growth. In the heart the switch from myocyte proliferation to terminal differentiation is synchronous with a decrease in c-myc mRNA abundance. To determine whether c-myc functions to regulate myocyte proliferation and/or differentiation, we examined the in vivo effect of increasing c-myc expression during fetal development and of preventing the decrease in c-myc mRNA expression that normally occurs during myocyte development. The model system used was a strain of transgenic mice exhibiting constitutive expression of c-myc mRNA in cardiac myocytes throughout development. Increased c-myc mRNA expression is associated with both atrial and ventricular enlargement in the transgenic mice. This increase in cardiac mass is secondary to myocyte hyperplasia, with the transgenic hearts containing greater than twice as many myocytes as nontransgenic hearts. The results of this study indicate that constitutive expression of c-myc mRNA in the heart during development results in enhanced hyperplastic growth, and suggest a regulatory role for the c-myc protooncogene in cardiac myogenesis.     

Effects of microbial floras on the distributions of five domestic Drosophila species across fruit resources

Summary The distributions of five Drosophila species and four components of the microflora have been compared across a total of 48 traps baited with four different fruit and vegetable substrates in two domestic compost heaps in Canberra (Australia). Large and consistent differences are found, both among the Drosophila and among the microbial classes, in their distributions across traps baited with different substrates. Moreover the distribution of each Drosophila species shows a unique set of strong associations with the microbial distributions. Thus the distributions of both D. simulans and D. melanogaster are found to be strongly negatively correlated with the abundance of bacteria while D. simulans is also strongly positively correlated with the titre of fermenter yeasts. D. immigrans is strongly positively correlated both with bacteria and with non-fermenter yeasts. D. hydei is positively correlated with nonfermentery yeasts and D. busckii is negatively correlated with fermenter yeasts. Moulds are the only microbial class not consistently associated with the distribution of any of the Drosophila species. The correlations with the other microbial classes are sufficient to explain the majority of the abundance differences of the Drosophila species among the trap types. It is therefore proposed that the clear partitioning of the fruit resources by the Drosophila is due to their differing primary interactions with the microflora.     

Some new species and new combinations of marine red algae from the central Pacific

Six new species in five genera of Rhodophyta are described. A new combination for Polyopes hakalauensis is also proposed. These taxa were encountered while preparing a manual of marine red algae of the Hawaiian Islands. Among the Halymeniales, two blade-like species of Halymenia, H. cromwellii sp. nov. and H. stipi-tata sp. nov., are distinguished from other species by habit and anatomical differences, including the possession of a stipe by the second. Halymenia hakalauensis Tilden 1902 is transferred to Polyopes as P. hakalauensis (Tilden) Abbott, replacing P. hawaiiensis Kajimura which is considered a synonym. A new species of Prionitis, P. corymbifera sp. nov., shows a corymbose branching pattern different from the mostly pinnate to subdichotomous branching of Japanese and Californian species. In the Gigartinales, Chondracanthus okamurae Abbott is named for a specimen which Okamura included in his understanding of Gigartina (now Chondracanthus tenellus), but which has terete axes, differing from C. tenellus (Harvey) Hommersand which is com-planate throughout. Chondracanthus intermedius (Sur-ingar) Hommersand is placed in synonymy with C. tenellus. The occurrence of C. tenellus in Hawai'i is a new distribution record from Asia. Three new species are added to the Ceramiales, Ceramium tranquillum Meneses (Ceramiaceae), Dasya kristeniae sp. nov. and Dasya murrayana Abbott & Millar (Dasyaceae). Distinctive features of Ceramium tranquillum are internodes that are three to five times longer than the height of nodes, and nodes that never project beyond the diameter of the internodes, giving straight margins except when fertile. Dasya kristeniae is a diminutive epiphyte which is nearly ecorticate, with tetrasporangial stichidia that are rectangular having apices that are curved or nodding, and cystocarps that have flaring ostioles above a constricted pericarp. Dasya murrayana was earlier misidentified with Dasya iyengarii Børgesen, and re-examination of those plants show continuous cortication throughout, where cortication is almost completely lacking in D. iyengarii except near the base. Dasya murrayana has a tufted habit, with indeterminate branches about the same sizes as the main axes, the plants growing on rock, whereas plants of D. iyengarii are not tufted, with indeterminate branches attenuate, and an epiphytic habit.     

A new species and three new combinations in Cyphellophora, with a note on the taxonomic affinities of the genus, and its relation to Kumbhamaya and Pseudomicrodochium.

Cyphellophora guyanensis sp. nov., isolated from leaf litter in French Guyana, is described and illustrated. This fungus is characterized by ampulliform to flask-shaped phialides, with a conspicuous, funnel-shaped collarette, and nearly straight to falcate or slightly sigmoid, (2−)3–6 septate conidia. Cyphellophora guyanensis is compared to the other Cyphellophora species, and the latter genus is compared to Kumbhamaya and Pseudomicrodochium. Kumbhamaya indica, P. fusarioides, and P. suttonii are transferred to Cyphellophora. The phylogenetic relationships of Cyphellophora with other genera of ascomycetes and related mitosporic fungi were inferred from the analysis of the partial nuclear ribosomal DNA SSU sequences data. The analysis supports a placement of Cyphellophora in Chaetothyriales, and probably in the Herpotrichiellaceae This revised version was published online in August 2006 with corrections to the Cover Date.     

A new genus of pliosaur (Reptilia: Sauropterygia) from the Lower Jurassic of Holzmaden,Germany

Abstract: The exquisitely preserved holotype of the pliosaur ‘Rhomaleosaurus’victor (SMNS 12478) is described from the Toarcian Posidonien‐Schiefer (Upper Lias, Lower Jurassic) of Holzmaden (Baden‐Württemberg), Germany. The specimen presents a novel combination of synapomorphies and unique morphometric proportions separating it from Rhomaleosaurus sensu stricto and warranting the erection of a new genus, Meyerasaurus gen. nov. Historically, the name ‘Thaumatosaurus’ has been interchangeable with Rhomaleosaurus and is frequently associated with SMNS 12478 in the literature. However, this is an invalid taxon and cannot be reinstated. The anatomy of Meyerasaurus victor is compared in detail with other pliosaurs, and its taxonomic affinity is reviewed. M. victor belongs to the family Rhomaleosauridae and shares several anatomical characters with Rhomaleosaurus including a short and robust premaxillary rostrum (length‐to‐width ratio c. 1.0), parallel premaxilla–maxilla sutures anterior to the nares, vomers contacting the maxillae posterior to the internal nares, and c. 28 cervical vertebrae minus the atlas–axis. The known geographical distribution of Rhomaleosaurus, which previously extended across the German and English palaeobiogeographical zones, is reduced to the English zone as a consequence of the referral of SMNS 12478 to a new genus. This is significant because it contributes to an ongoing trend of increasing generic separation between the German and English zones, while increasing the generic diversity within the German zone itself.     

A frequently occurring mutation that blocks the expression of fruiting genes in Schizophyllum commune

Summary Fruiting in the basidiomycete Schizophyllum commune readily occurs in a homokaryon with constitutive mutations in both the A and B mating-type genes. Such a homokaryon frequently expresses a mutation, fbf, which completely blocks fruiting and leads to a somewhat faster growth rate. The mutation is unlinked to the A and B genes, frequently reverts to its wild-type allele, and is recessive with respect to fruiting in matings with wild-type homokaryons. The mutation suppresses the accumulation of a number of mRNAs which are regulated by the mating-types genes and are specific for fruiting. The expression of the Sc-3 gene, structurally related to two of the fruiting genes (Sc-1 and Sc-4) but not regulated by the mating-type genes, is unaffected.     

Evolution of Phage-Type RNA Polymerases in Higher Plants: Characterization of the Single Phage-Type RNA Polymerase Gene from <Emphasis Type="Italic">Selaginella moellendorffii</Emphasis>

Selaginella moellendorfii (spikemoss) sequence trace data encoding a polypeptide highly similar to angiosperm and moss phage-type organelle RNA polymerases (RpoTs) were used to isolate a BAC clone containing the full-length gene SmRpoT as well as the corresponding cDNA. The SmRpoT mRNA comprises 3452 nt with an open reading frame of 3006 nt, encoding a putative protein of 1002 amino acids with a molecular mass of 113 kDa. The SmRpoT gene comprises 19 exons and 18 introns, conserved in their position with those of the angiosperm and Physcomitrella RpoT genes. In phylogenetic analyses, the Selaginella RpoT polymerase is in a sister position to all other phage-type polymerases of angiosperms. However, according to its conserved exon–intron structure, the Selaginella RpoT gene is representative of the molecular evolutionary lineage giving rise to the RpoT gene family of flowering plants. The N-terminal transit peptide of SmRpoT is shown to confer targeting of green fluorescent protein exclusively to mitochondria after transient expression in Arabidopsis and Selaginella protoplasts. Angiosperms and the moss P. patens possess small gene families encoding RpoTs, which include mitochondrial- and chloroplast-targeted RNA polymerases. In striking contrast, the Selaginella RpoT gene is shown to be single-copy, although Selaginella, as a lycophyte, has a phylogenetic position between Physcomitrella and angiosperms. Thus, there is no evidence that Selaginella may contain a nuclear-encoded phage-type chloroplast RNA polymerase.     

Analysis of a case of somatic instability in a strain of maize from India

A case of somatic instability affecting aleurone colour in a strain of maize from India with flint background was analysed. The somatic instability is localized to theC ¹ (Inhibitor) allele ofC locus on the short arm of chromosome 9. Molecular tests indicated thatAc is not present in the Indian stock and the evidence is consistent with the involvement of theEn (Spm) transposable element in the instability. The presence of theEn (Spm)-like element in the stock would suggest that these elements have been present in the maize genome for a long time. A new allele ofshrunken (sh1) gene with a somewhat unorthodox breeding behaviour is also described.     

Oocyte development in four species of scyphomedusa in the northern Adriatic Sea

Oocyte development was followed in 4 species of Scyphomedusae. In Pelagia noctiluca a centrifugal maturity gradient is present. Vitellogenesis may be related first to exogenous endodermal production and later to oocyte endogenous activity. Simultaneously, the paraovular body (POB) develops from the secondary endoderm; it is connected to the oocyte and controls secretion of mucus, which envelops the oocyte during spawning. In Aurelia aurita, there is no maturity gradient, nor any differentiated structures of endodermal origin, associated with oocytes. In Discomedusa lobata a maturity gradient is absent. Its vitellogenesis is similar to that in P. noctiluca, and is associated with structural modification of the secondary endoderm in the area contacting the oocyte. This structure is cytologically similar to the POB of P. noctiluca, though less differentiated. Spawning is similar to that of P. noctiluca, with fenestration of the surrounding endodermal cells as the oocyte passes from the ovary to the genital sinus. In Rhizostoma pulmo a maturity gradient is absent. An early and fairly evident development of the vitelline membrane was observed.