Revision of the Australian species of the weevil genus Trigonopterus Fauvel

The Australian species of the genus Trigonopterus Fauvel are revised. Eight previously recognized species are redescribed and 24 additional new species are described: Trigonopterus allaetus Riedel, sp. n., Trigonopterus athertonensis Riedel, sp. n., Trigonopterus australinasutus Riedel, sp. n., Trigonopterus australis Riedel, sp. n., Trigonopterus bisignatus Riedel, sp. n., Trigonopterus bisinuatus Riedel, sp. n., Trigonopterus boolbunensis Riedel, sp. n., Trigonopterus cooktownensis Riedel, sp. n., Trigonopterus daintreensis Riedel, sp. n., Trigonopterus deplanatus Riedel, sp. n., Trigonopterus finniganensis Riedel, sp. n., Trigonopterus fraterculus Riedel, sp. n., Trigonopterus garradungensis Riedel, sp. n., Trigonopterus hasenpuschi Riedel, sp. n., Trigonopterus hartleyensis Riedel, sp. n., Trigonopterus kurandensis Riedel, sp. n., Trigonopterus lewisensis Riedel, sp. n., Trigonopterus montanus Riedel, sp. n., Trigonopterus monteithi Riedel, sp. n., Trigonopterus mossmanensis Riedel, sp. n., Trigonopterus oberprieleri Riedel, sp. n., Trigonopterus robertsi Riedel, sp. n., Trigonopterus terraereginae Riedel, sp. n., Trigonopterus yorkensis Riedel, sp. n.. All new species are authored by the taxonomist-in-charge, Alexander Riedel. Lectotypes are designated for the following names: Idotasia aequalis Pascoe, Idotasia albidosparsa Lea, Idotasia evanida Pascoe, Idotasia laeta Lea, Idotasia rostralis Lea, Idotasia sculptirostris Lea, Idotasia squamosa Lea. A new combination of the name Idotasia striatipennis Lea is proposed: Trigonopterus striatipennis (Lea), comb. n.. A key to the species is provided. Australian Trigonopterus occur in coastal Queensland, narrowly crossing into New South Wales. The southern parts of the range are inhabited by species found on foliage. A rich fauna of 19 edaphic species inhabiting the leaf litter of tropical forests is reported for the first time from the Australian Wet Tropics.     

Phylogenetic analysis of the genus Pseudoroegneria and the Triticeae tribe using the rbcL gene

The Pseudoroegneria species are perennial grasses in the Triticeae tribe, whose St genome has been linked to several important polyploid species. Due to frequent hybridization and complex genetic mechanism, the relationships within Pseudoroegneria, and within the Triticeae have been heavily disputed. Using the chloroplast rbcL gene we estimated the nucleotide diversity of 8 Pseudoroegneria species. We also examined the phylogenetic relationships within Pseudoroegneria and of Pseudoroegneria within the Triticeae. The estimates of nucleotide diversity indicated that Pseudoroegneria tauri and Pseudoroegneria spicata species had the highest diversity, while Pseudoroegneria gracillima had the lowest diversity. The phylogenetic analysis of Pseudoroegneria placed all P. spicata species into a clade separate from the other Pseudoroegneria species, while the relationship of the other Pseudoroegneria species could not be determined. Due to the groupings of Pseudoroegneria with the polyploid Elymus, our results strongly supported Pseudoroegneria as the maternal genome donor to Elymus. There was also weak support that P. spicata may be the maternal donor to the StH Elymus species.     

Organization of the nar genes at the chlZ locus

The two membrane-bound respiratory nitrate reductases of Escherichia coli are encoded by distinct operons at two different loci, chlC and chlZ, on the chromosome. The chlZ locus includes a narK homologue, narU, encoding a nitrite extrusion protein, and narZYWV encoding nitrate reductase Z. No apparent homologue to the narXL operon has been found. Homology between narU and narK on the one hand and narZYWV and narGHJI on the other hand is limited to the coding regions.     

Influence of the acoustic environment on the distribution of the frog Ranidella riparia

At its southern edge the distribution of the frog Ranidella riparia abuts, with only a narrow zone of overlap, that of its allopatric sibling species R. signifera. In previous reports there was no evidence for any reduced survival of R. riparia in the creeks occupied by R. signifera immediately adjacent to the edge of its distribution. Here we examine the hypothesis that the acoustic environment in those creeks might inhibit successful communication by R. riparia. Although the structural characteristics of the R. riparia call were less suitable than those of R. signifera for transmission through the heavily vegetated habitat characteristic of those creeks, this alone did not inhibit successful reproduction by R. riparia. At a distance of 25 cm the average intensity of a call from an R. riparia male was 24 dB lower than one from R. signifera. In addition R. signifera form a continuous chorus in which the minimum sound intensity always exceeds that of single R. riparia calls at 25 cm. We propose that R. riparia cannot colonize creeks adjacent to their present distribution because the loud noise from R. signifera choruses either suppresses their calling activity, or makes them inaudible to potentially receptive females.     

On the occurrence of tuliposides in the liliiflorae

Approximately 200 samples of liliiflorous plants were investigated for the presence of tuliposides. Appreciable amounts of tuliposide A were detected in all species of Erythronium, Tulipa, Gagea, Bomarea and Alstroemeria. Large amounts of tuliposide B seem to be restricted to Erythronium and Tulipa. The occurrence of identical post-inhibitins in Tulipa and allied taxa and in Alstroemeria and allied taxa is interpreted as indicating a close relationship between Lilioideae and Alstroemeriaceae. At the same time the allergenic potentialities of all taxa of Alstroemeria are stressed.     

Effect of atoms evaporated from the anode on the structure of the vacuum arc space charge sheath

The structure of the anode space charge sheath of a vacuum arc is studied with allowance for the dependence of the negative anode fall on the ratio of the directed electron velocity v ₀ to the electron thermal velocity v _T for different values of the flux density of atoms evaporated from the anode. Poisson’s equation for the sheath potential is solved taking into account the electron space charge, fast cathode ions, and slow ions produced due to the ionization of atoms evaporated from the anode. The kinetic equation for atoms and slow anode ions is solved with allowance for ionization in the collision integral. Analytic solutions for the velocity distribution functions of atoms and slow ions and the density of slow ions are obtained. It is shown that the flux of slow ions substantially affects the spatial distribution of the electric field E(z) in the sheath. As the flux density increases, the nonmonotonic dependence E(z) transforms into a monotonic one and the sheath narrows. For a given flux of evaporated atoms Πa, the increase in the ratio of the directed electron velocity to the electron thermal velocity leads again to a nonmonotonic dependence E(z). As z increases, the electric field first increases, passes through the maximum, decreases, passes through the minimum E _min, and then again increases toward the anode. There is a limiting value of the ratio (v ₀/v _T )* at which E _min(z) vanishes. At v ₀/v _T > (v ₀/V _T )*, the condition for the existence of a steady-state sheath is violated and the profiles of the field and potential in the sheath become oscillating. The dependence of (v ₀/v _T )* on the flux density of evaporated atoms Π _a is obtained. It is shown that the domain of existence of steady-state solutions in the sheath broadens with increasing Π _a .     

On the systematic position of the lichen genus Heppia

The systematic position of the lichen genus Heppia in the order Lichinales was investigated. 18S rDNA sequence data were analyzed using a Bayesian approach to infer phylogeny using Markov chain Monte Carlo methods. The Lichinales are divided at family level into the sister groups Lichinaceae and Peltulaceae. The genus Heppia forms a highly supported clade in the family Lichinaceae. It is shown that the genus Heppia is morphologically well circumscribed within the Lichinaceae. As a nomenclatural consequence, the family name Heppiaceae is placed into synonymy under the older name Lichinaceae.     

Trilobite faunal successions across the base of the Furongian Series in the Taebaek Group, Taebaeksan Basin, Korea

The base of the Furongian Series in the Sino-Korean Block has not been clearly defined due to the lack of the index taxon, Glyptagnostus reticulatus. The Sesong Formation of the Taebaek Group, Taebaeksan Basin, Korea, has been known to range from the Guzhangian Stage of the Cambrian Series 3 to the middle Furongian Series, hence embracing the base of the Furongian Series. Silicified polymerid trilobites were recovered from the middle part of the Sesong Formation. Described are a total of 18 polymerid species of 13 genera: Neodrepanura sp. 1, Teinistion sp. 1, Huzhuia sp. 1, Huzhuia sp. 2, Liostracina simesi, Liostracina sp. 1, Parachangshania monkei, Parachangshania rectangularis nov. sp., Placosema bigranulosum, Fenghuangella laevis nov. sp., Baikadamaspis jikdongensis nov. sp., Baikadamaspis sp. 1, Prochuangia mansuyi, Maladioides coreanicus, Alataspis sesongensis nov. gen., nov. sp., Chuangia sp. 1, and ceratopygids genus and species indeterminate 1 and 2. The stratigraphic occurrence of these trilobites provides a basis for recognition of five zones across the base of the Furongian Series (in ascending order): the Neodrepanura, Liostracina simesi, Fenghuangella laevis, Prochuangia mansuyi, and Chuangia zones. The Neodrepanura and Chuangia zones are provisionally adopted from the previous biostratigraphic scheme, while the three other ones are newly proposed. The recommended base of the Furongian Series in the Taebaek Group of Korea coincides with the base of the Fenghuangella laevis Zone, which appears to represent an episode of profound trilobite faunal turnover.     

Silencing the circadian clock gene Clock using RNAi reveals dissociation of the circatidal clock from the circadian clock in the mangrove cricket

Whether a clock that generates a circatidal rhythm shares the same elements as the circadian clock is not fully understood. The mangrove cricket, Apteronemobius asahinai, shows simultaneously two endogenous rhythms in its locomotor activity; the circatidal rhythm generates active and inactive phases, and the circadian rhythm modifies activity levels by suppressing the activity during subjective day. In the present study, we silenced Clock (Clk), a master gene of the circadian clock, in A. asahinai using RNAi to investigate the link between the circatidal and circadian clocks. The abundance of Clk mRNA in the crickets injected with double-stranded RNA of Clk (dsClk) was reduced to a half of that in control crickets. dsClk injection also reduced mRNA abundance of another circadian clock gene period (per) and weakened diel oscillation in per mRNA expression. Examination of the locomotor rhythms under constant conditions revealed that the circadian modification was disrupted after silencing Clk expression, but the circatidal rhythm remained unaffected. There were no significant changes in the free-running period of the circatidal rhythm between the controls and the crickets injected with dsClk. Our results reveal that Clk is essential for the circadian clock, but is not required for the circatidal clock. From these results we propose that the circatidal rhythm of A. asahinai is driven by a clock, the molecular components of which are distinct from that of the circadian clock.     

Chemotaxonomic contribution to the Sideritis species dilemma on the Balkans

Forty-two samples of Sideritis species (Sideritis scardica, Sideritis raeseri, Sideritis syriaca, Sideritis taurica and Sideritis lanata) from the Balkan Peninsula were evaluated for their polyphenolic profiles in order to establish a correlation between the taxonomy, geographical location and nature and content of phenolic compounds.Eight compounds were detected in all analyzed Sideritis samples: 5-caffeoylquinic acid, lavandulifolioside, verbascoside, isoscutellarein 7-O-allosyl(1→2)glucoside, hypolaetin 7-O-[6‴-O-acetyl]-allosyl(1→2)glucoside, isoscutellarein 7-O-[6‴-O-acetyl]-allosyl(1→2)glucoside, 3′-O-methylhypolaetin 7-O-[6‴-O-acetyl]-allosyl(1→2)glucoside and 4′-O-methylhypolaetin 7-O-[6‴-O-acetyl]-allosyl-(1→2)-[6″-O-acetyl]-glucoside). They present from 50 to 80% of total phenolic content in S. scardica, S. raeseri, S. syriaca and S. taurica and up to 90% in S. lanata and the similarity of their polyphenolic profiles implies that they are systematically very closely related.Based on their polyphenolic patterns, very good differentiation between the samples of S. lanata (sect. Hesiodia) and S. scardica, S. syriaca and S. raeseri (sect. Empedoclia) was observed, that is mainly due to the very high content of 5-cafeoylquinic acid and very low amount of phenylethanoid glycosides and flavonoid glycosides.The obtained results demonstrate considerable degree of similarity between S. scardica, S. raeseri and Bulgarian S. syriaca that give contribution to the dilemma that Bulgarian S. syriaca is very similar to Turkish S. taurica and suggest further verification of its taxonomic status.     

Antagonistic Gene Activities Determine the Formation of Pattern Elements along the Mediolateral Axis of the Arabidopsis Fruit

The Arabidopsis fruit mainly consists of a mature ovary that shows three well defined territories that are pattern elements along the mediolateral axis: the replum, located at the medial plane of the flower, and the valve and the valve margin, both of lateral nature. JAG/FIL activity, which includes the combined functions of JAGGED (JAG), FILAMENTOUS FLOWER (FIL), and YABBY3 (YAB3), contributes to the formation of the two lateral pattern elements, whereas the cooperating genes BREVIPEDICELLUS (BP) and REPLUMLESS (RPL) promote replum development. A recent model to explain pattern formation along the mediolateral axis hypothesizes that JAG/FIL activity and BP/RPL function as antagonistic lateral and medial factors, respectively, which tend to repress each other. In this work, we demonstrate the existence of mutual exclusion mechanisms between both kinds of factors, and how this determines the formation and size of the three territories. Medial factors autonomously constrain lateral factors so that they only express outside the replum, and lateral factors negatively regulate the medially expressed BP gene in a non-autonomous fashion to ensure correct replum development. We also have found that ASYMMETRIC LEAVES1 (AS1), previously shown to repress BP both in leaves and ovaries, collaborates with JAG/FIL activity, preventing its repression by BP and showing synergistic interactions with JAG/FIL activity genes. Therefore AS gene function (the function of the interacting genes AS1 and AS2) has been incorporated in the model as a new lateral factor. Our model of antagonistic factors provides explanation for mutant fruit phenotypes in Arabidopsis and also may help to understand natural variation of fruit shape in Brassicaceae and other species, since subtle changes in gene expression may cause conspicuous changes in the size of the different tissue types.     

Two Different Prunus SFB Alleles Have the Same Function in the Self-incompatibility Reaction

Many species in the families of Rosaceae, Solanaceae, and Scrophulariaceae exhibit gametophytic self-incompatibility, a phenomenon controlled by two polymorphic genes at the S-locus, style-S (S-RNase) and pollen-S (SFB). Sequences of both genes show high levels of diversity, characteristic of genes involved in recognition of self-incompatibility systems in plants. In this study, S ₂₄ -RNase and SFB ₂₄ alleles were cloned from Prunus armeniaca cv. Chuanzhihong (Chinese apricot). Sequence comparisons of deduced amino acid sequences revealed that the P. armeniaca S ₂₄ -haplotype has different SFB alleles, but shares a single S-RNase allele with P. armeniaca S ₄ -haplotype. Moreover, P. armeniaca S ₂₄ -RNase haplotype has a single and three different alleles with S ₁ -RNase of P. tenella (dwarf almond) and S ₁ -RNase of P. mira (smooth pit peach), respectively. The functionalities of SFB ₂₄ and SFB ₄ have been evaluated by pollen tube growth and controlled field tests of P. tenella and P. mira. Genetic analysis of the two intercrosses showed that progenies segregated 1:1 into two S-genotype classes, which is consistent with the expected ratio for semi-compatibility. These findings imply that the allelic function of the S ₂₄ -haplotype is identical to that of the S ₄ -haplotype in a self-incompatibility reaction. Thus, these two Prunus S-haplotypes are in fact two neutral variants of the same S-haplotype. The evolution of the S-allele is also discussed in terms of both functions and differences between S ₂₄ - and S ₄ -haplotypes in Prunus.     

Polyphasic approach to the taxonomy of the Rhizopus stolonifer group

Phylogenetic analysis of Rhizopus strains based on the D1/D2 region of LSU rDNA sequences yielded a phylogram with four well-supported clades. The R. microsporus clade concurs with classification obtained by traditional methods. The R. oryzae group was found to include species of the genus Amylomyces. The traditional R. stolonifer group was divided into two well-supported clades in the phylogram, with one clade comprising R. stolonifer var. stolonifer, R. sexualis var. sexualis, and R. sexualis var. americanus and the other clade comprising taxa with recurved sporangiophores; R. reflexus, R. stolonifer var. lyococcus, and R. circinans, identifying recurved sporangiophores as an important taxonomic character. The molecular data supported the recognition of this clade at the species level: R. lyococcus (basionym: Sporotrichum lyococcum).     

Relocation of urf a from the mitochondrion to the nucleus cures the mitochondrial mutator phenotype in the fission yeast Schizosaccharomyces pombe

In previous papers we have reported the characterisation of mitochondrial mutator mutants of Schizosaccharomyces pombe. In contrast to nuclear mutator mutants known from other eucaryotes, this mutator phenotype correlates with mutations in an unassigned open reading frame (urf a) in the mitochondrial genome. Since an efficient biolistic transformation system for fission yeast mitochondria is not yet available, we relocated the mitochondrial urf a gene to the nucleus. As host strain for the ectopic expression, we used the nonsense mutant ana ^r -6, which carries a premature stop codon in the urf a gene. The phenotype of this mutant is characterised by continuous segregation of progeny giving rise to fully respiration competent colonies, colonies that show moderate growth on glycerol and a fraction of colonies that are unable to grow on glycerol. The phenotype of this mutant provides an excellent tool with which to study the effects on the mutator phenotype of ectopic expression of the urf a gene. Since a UGA codon encoding tryptophan is present in the original mitochondrial gene, we constructed two types of expression cassettes containing either the mitochondrial version of the urf a gene (mt-urf a) or a standard genetic code version (nc-urf a; UGA replaced by UGG) fused to the N-terminal import leader sequence of the cox4 gene of Saccharomyces cerevisiae. We show that the expression of the mt-urf a gene in its new location is able to cure, at least in part, the phenotype of mutant ana ^r -6, whereas the expression of the nc-urf a gene completely restores the wild-type (non-mutator) phenotype. The significant similarity of the urf a gene to the mitochondrial var1 gene of S. cerevisiae and homologous genes in other yeasts suggests that the urf a gene product might be a ribosomal protein with a dual function in protein synthesis and maintenance of mitochondrial DNA integrity.     

Allelopathic effects of the dinophyte Prorocentrum minimum on the growth of the bacillariophyte Skeletonema costatum

We investigated growth interactions between the dinophyte Prorocentrum minimum and the bacillariophyte Skeletonema costatum using bi-algal cultures under axenic conditions. When low cell densities of P. minimum and high cell densities of S. costatum were inoculated into the same medium, growth of P. minimum was suppressed. Other inoculum combinations resulted in reduced S. costatum maximum cell densities. A mathematical model was used to simulate growth and interactions of P. minimum and S. costatum in bi-algal cultures. The model indicated that P. minimum always outcompeted S. costatum over time. Enriched filtrate from low-density P. minimum cultures significantly stimulated S. costatum growth, but enriched filtrate from high-density P. minimum cultures notably inhibited the growth of S. costatum. Growth of P. minimum was not affected by enriched filtrate from cultures of P. minimum at any density. Filtrates of P. minimum cultures were fractionated by ultrafiltration (molecular weight cutoff >3000 Da), and retentate that included polysaccharide(s) significantly inhibited the growth of S. costatum.     

Evidence of the Insensitivity of the alpha-inc Allele to the Function of the Homothallic Genes in Saccharomyces Yeasts

The possible function of the α-inc allele (an α mating-type allele that is insensitive to the function of the homothallic gene system) was investigated by means of protoplast fusion. The fusion of protoplasts prepared from haploid strains of α-inc HO HMα HMa and α ho hmα HMa gave rise mainly to nonmating clones (58 of 64 isolates) and a few clones (six of 64 isolates) showing α mating type. Thirty of the 58 nonmating clones showed the diploid cell size and 28 clones had a larger cell size. Tetrad analysis of the nonmating clones with diploid cell size indicated that they were a/α-inc diploid; the normal α allele in α/α-inc cells was preferentially switched to an a allele. This observation further indicated that the HO/ho HMα/hmα HMa/HMa genotype is effective for the conversion of the α to a and that the inconvertibility of the α-inc allele is due to the insensitivity of the mating-type allele to the functional combination of the homothallic genes. It was suspected that fusion products larger than diploid cells might have been caused by multiple fusion of protoplasts.     

On the validity of Epeorella Ulmer, 1939 (Ephemeroptera,Heptageniidae) with general considerations on the Heptageniidae of the Sunda Islands

The type material of Epeorella borneonia Ulmer, 1939, the sole species of the genus Epeorella Ulmer, 1939 is reinvestigated and a lectotype (male imago) is designated. Based on several morphological structures, the synonymy with Epeorus Eaton, 1881 (Rhithrogeninae) is rejected. Epeorella stat. prop., known only at the winged stages, belongs to the subfamily Ecdyonurinae, and is a probable endemic of the island of Borneo. The newly erected genus Darthus Webb & McCafferty, 2007, also endemic to Borneo and only known by one species at the nymphal stage, is shown to be a junior subjective synonym of Epeorella. The new combination Epeorella vadora (Webb & McCafferty, 2007) is proposed for the species. The distribution of known heptageniid species from the Sunda Islands is discussed.     

Studies on the interactions of sperm with the surface of the sea urchin egg

We have examined the relationship between sperm adhesion and fertilization in the cross species insemination of Arbacia punctulata eggs by Strongylocentrotus purpuratus sperm. As previously reported (Kinsey et al., 1980) the addition of S. purpuratus egg jelly results in induction of the acrosome reaction in sperm and significant numbers of S. purpuratus sperm adhere to A. punctulata eggs. However, in the absence of S. purpuratus egg jelly, S. purpuratus sperm fail to bind to A. punctulata eggs. Although at least 200 S. purpuratus sperm bind to an A. punctulata egg in the presence of S. purpuratus jelly, less than 8% of the eggs are fertilized. The adhesion of S. purpuratus sperm meets the same functional criteria as homologous A. punctulata sperm-egg adhesion. Electron microscopy shows that S. purpuratus sperm that have undergone the acrosome reaction adhere to A. punctulata eggs by their bindin-coated acrosomal process in a manner that is morphologically identical to that observed with homologous A. punctulata sperm. We have also compared the ability of S. purpuratus and A. punctulata sperm to fuse and fertilize with A. punctulata eggs after removal of the vitelline layer. Using high levels of sperm of either species, heterologous as well as homologous fertilization is readily detectable. Under these conditions, where stable binding is not demonstrable, there is no difference in the ability of S. purpuratus and A. punctulata sperm to fertilize A. punctulata eggs. These observations suggest that the failure of S. purpuratus sperm to fertilize A. punctulata eggs under normal conditions may be due to their inability to penetrate the vitelline layer so that they can fuse with the egg plasma membrane. In relation to the possible mechanism of vitelline layer penetration, we have also investigated the mode of action of chymostatin, an inhibitor of chymotrypsin that has been reported to inhibit fertilization of sea urchin eggs (Hoshi et al., 1979). Our findings suggest that the fertilization inhibitory activity of chymostatin is not related to its antichymotrypsin activity. Rather, it appears that this inhibition is due to the induction of an abnormal acrosome reaction in sperm that precludes formation of the acrosome process.