Genetics of yeast hexokinase

Two independent isolates of Saccharomyces cerevisiae lacking hexokinase activity (EC 2.7.1.1) are described. Both mutant strains grow on glucose but are unable to grow on fructose, and contain two mutant genes hxk1 and hxk2 each. The mutations are recessive and noncomplementing. Genetic analysis suggests that these two unlinked genes hxk1 and hxk2 determine, independently of each other, the synthesis of hexokinase isozymes P1 and P2, respectively. hxk1 is located on chromosome VIR distal to met10, and hxk2 is on chromosome IIIR distal to MAL2. Of four hexokinase-positive spontaneous reversions, one is very tightly linked to hxk1 and the other three to the hxk2 locus. The reverted enzymes are considerably more thermolabile than the respective wild-type enzymes, and in one case show altered immunological properties. Data are presented which suggest that the hxk1 and hxk2 mutations are missense mutations in the structural genes of hexokinase P1 and hexokinase P2, respectively. These are presumably the only enzymes that allow S. cerevisiae to grow on fructose.     

A Contribution to our Knowledge of the Mermithidae (Nematoda)

The genera of the insect parasitic nematode family Mermithidae axe reviewed, and 16 of them axe redescribed and illustrated. Information is given on methods of rearing adult mermithid specimens and on host specificity. The four types of merrnithid life cycles axe described in detail. One figure shows the variety of insects parasitized by merrnithids and the location and size of the nematode within the insect. Several mermithid eggs are illustrated, and their usefulness in identification is discussed.Taxonomically, the primary emphasis is on the adult stages of the merrnithJds with larval and egg characteristics supplementaxy. An emended family diagnosis is given. Merrnis subnigrescens is considered a synonym of M. nigrescens, and M. tahitiensis is synonymized with M. mirabilis. Hydromermis contorta is accepted, leaving the genus Paramermis in an uncertain position. Study of the Steiner collections of Limnornermis bathybia indicates that Limnornerrnis is accepted as a valid genus. The adults of Agamermis decaudata are descried and illustrated for the first time. The genus Gastromermis is limited to the long single-spiculed forms, as it is now apparent that five or more genera have ventrally shifted mouth orifices. Amphirnermis tinyi n. sp. is described from damselflies from Louisiana. The genus Lanceimermis is accepted, and three species in this genus are illustrated. The taxon Reesimermis nielseni has been accepted for this important parasite of more than 20 mosquito species. This nematode previously has been referred to as Romanomermis sp. Romanomermis iyengari is transferred to the genus Reesirnermis. Diximermis peterseni n. gen., n. sp., from anopheline mosquitoes, is described and iUustrated. The adults of Agamomermis culicis which parasitize Aedes sollicitans, are described for the first time, and the species placed in a new genus, Perutilimermis. The new genus Neornesornermis is proposed for Mesomermis flumenalis Welch, 1962. Several problems on mermithid morphology and taxonomy are discussed. Type material is established for some of the taxa.     

Revision of the Taiwanese millipede genus Chamberlinius Wang, 1956, with descriptions of two new species and a reclassification of the tribe Chamberlinini (Diplopoda, Polydesmida, Paradoxosomatidae, Paradoxosomatinae)

The millipede genus Chamberlinius is basically confined to Taiwan, with only one of the four known species presumably introduced to southern Japan. Both previously known species are redescribed, based on new material: Chamberlinius hualienensis Wang, 1956 (the type species) and Chamberlinius piceofasciatus (Gressitt, 1941), the latter being a new subjective senior synonym of Chamberlinius shengmui Wang, 1957, syn. n. Two further congeners are described as new: Chamberlinius pessior sp. n. and Chamberlinius sublaevus sp. n. The genus is re-diagnosed, all of its four species are keyed, and their distributions mapped. The tribe Chamberlinini is reclassified and, based on gonopod traits, shown to comprise the following five genera: Chamberlinius Wang, 1956, Haplogonosoma Brölemann, 1916, Riukiupeltis Verhoeff, 1939, Aponedyopus Verhoeff, 1939 and Geniculodesmus Chen, Golovatch and Chang, 2008.     

Notes on some plant-inhabiting fungi collected from the Nansei Islands (2)

In this paper, four fungi collected in Nansei Islands are reported. One is Strasseria garciniae, which must be transferred to the genus Phyllosticta. This fungus was collected in Okinawa Main Island and Iriomote Island. The other three fungi are newly added to the Japanese fungal flora. Phyllosticta ghaesembillae on Codiaeum variegatum and Cercospora asplenii on Asplenium antiquum were collected in Yoron Island. The last one, Coniella australiensis on Eucalyptus robusta was collected in Okinawa Main Island. Their morphology and symptoms on the host plant are described, with some mycological notes.     

A new Brazilian Passiflora leafminer: Spinivalva gaucha,gen. n., sp. n. (Lepidoptera,Gracillariidae, Gracillariinae), the first gracillariid without a sap-feeding instar

Male, female, pupa, larva and egg of a new genus and species of Gracillariidae (Gracillariinae), Spinivalva gaucha Moreira and Vargas from southern Brazil are described and illustrated with the aid of optical and scanning electron microscopy. A preliminary analysis of mitochondrial DNA sequences including members of related lineages is also provided. The immature stages are associated with Passiflora actinia, Passiflora misera and Passiflora suberosa (Passifloraceae), and build mines on the adaxial leaf surface. Initially the mines are serpentine in shape, but later in larval ontogeny become a blotch type. Although the larvae are hypermetamorphic as in other Gracillariidae, there is no sap-feeding instar in Spinivalva gaucha; the larva feeds on the palisade parenchyma, thus producing granular frass during all instars. Pupation occurs outside the mine; prior to pupating, the larva excretes numerous bubbles that are placed in rows on the lateral margins of the cocoon external surface. This is the second genus of gracillariid moth described for the Atlantic Rain Forest, and the second gracillariid species known to be associated with Passifloraceae.     

On the systematic position of the genus Petroschmidtia Taranetz et Andriashev, 1934 (Perciformes: Zoarcidae)

Following a comparative analysis of the morphological characters of the representatives of the genera Petroschmidtia and Lycodes, some previously proposed diagnostic characters of Petroschmidtia are confirmed and ascertained and several additional characters are suggested. The conclusion on the taxonomic validity of the genus Petroschmidtia is confirmed. Petroschmidtia differs from Lycodes in the following features: teeth and tooth plates on the vomer and palatinum are lacking; bone fontanels of the supraorbital canal on the frontale are lacking; the vomer is shortened; the ethmoidalia lateralia are narrowed, bearing a pocketlike cavity inside the lateral lobes; the fan-like expanded outgrowth of the supraoccipitale is short, blunt; the dentale is shortened; the radialia are dorsoventrally flattened, the lowest of which is the largest. The genus Petroschmidtia is assumed to be morphologically more closely related to Lycodes than any other of the Lycodinae.     

On the cicada genus Nipponosemia Kato,with description of one new species from China (Hemiptera,?Cicadidae)

The cicada genus Nipponosemia Kato is reviewed. Four species are illustrated, photographed and described, including three known species and one new species. A key to all species of this genusis presented, and information on the biology of Nipponosemia are provided. The systematic status of the tribe Cicadatrini and biogeography of Nipponosemia are discussed.     

The genus Trachionus Haliday, 1833 (Hymenoptera,Braconidae, Alysiinae) new for China,with description of four new species

The genus Trachionus Haliday, 1833 (Hymenoptera, Braconidae, Alysiinae, Dacnusini) is reported for the first time from China. The genus is represented by four new species from Shaanxi province (NW China), which are described and illustrated. An identification key to the species in China is presented, a key to the genera of the Trachionus group and notes on the relationships with other Palaearctic species are added.     

On the spider genus Arboricaria with the description of a new species (Araneae,Gnaphosidae)

The spider genus Arboricaria Bosmans, 2000 is redefined and an updated diagnosis given. The differences between Arboricaria and Micaria Westring, 1851 are discussed in detail. A key to all five species of the genus is provided. One new species, Arboricaria zonsteini sp. n. (♂♀), is described based on specimens from Kyrgyzstan and Azerbaijan. One new synonym is proposed: Arboricaria koeni Bosmans in Bosmans & Blick, 2000, syn. n. is assigned to Arboricaria sociabilis Kulczyński in Chyzer & Kulczyński, 1897. Data on the distribution of Arboricaria in Russia and adjacent countries are presented with references to the papers on local spider faunas.     

Computational investigation on redox-switchable nonlinear optical properties of a series of polycyclic p-quinodimethane molecules

The polycyclic p-quinodimethanes are proposed to be the novel candidates of the high-performance nonlinear optical (NLO) materials because of their large third order polarizabilities (γ). We investigate the switchable NLO responses of a series of polycyclic p-quinodimethanes with redox properties by employing the density functional theory (DFT). The polycyclic p-quinodimethanes are forecasted to exhibit obvious pure diradical characters because of their large y ₀ index (the y ₀ index is a value between 0 [closed-shell state] and 1 [pure biradical state]). The γ values of these polycyclic p-quinodimethanes and their corresponding one-electron and two-electron reduced/oxidized species are calculated by the (U)BHandHLYP method. The γ values of polycyclic p-quinodimethanes and their corresponding one-electron reduced species are all positive and significantly different. The large differences of the γ values are due to a change in the transition energy and are related to the different delocalization of the spin density, which demonstrates that the NLO switching is more effective on one-electron reduction reactions. Therefore, the study on these polycyclic p-quinodimethanes provides a guideline for a molecular design of highly efficient NLO switching.

Identity of the downy mildew pathogens of basil, coleus, and sage with implications for quarantine measures

The downy mildew pathogen of basil (Ocimum spp.) has caused considerable damage throughout the past five years, and an end to the epidemics is not in sight. The downy mildew of coleus (Solenostemon spp.) is just emerging and here we report that it was very recently introduced into Germany. Although it has been recognised that these pathogens are a major threat, the identity of the pathogens is still unresolved, and so it is difficult to devise quarantine measures against them. Using morphological comparison and molecular phylogenetic reconstructions we confirmed in this study that the downy mildews of basil and coleus are unrelated to Peronospora lamii, which is a common pathogen of the weed Lamium purpureum. In addition, we conclude by the investigation of the type specimen of P. swingleii and downy mildew specimens on Salvia officinalis that the newly occurring pathogens are not identical to P. swingleii on Salvia reflexa. The taxonomy of the downy mildew pathogens of hosts from the Lamiaceae and, in particular, from the tribes Mentheae and Elsholtzieae, is discussed, and a new species is described to accommodate the downy mildew pathogen of basil and coleus, which is the first downy mildew pathogen known to be parasitic to hosts of the tribe Ocimeae.     

Description of Telamoptilia grewiae sp. n. and the consequences for the definition of the genera Telamoptilia and Spulerina (Lepidoptera,Gracillariidae, Gracillariinae)

The new species Telamoptilia grewiae, reared from leafmines on Grewia biloba (Malvaceae) is described with details on adult and immature stages. The larval head and the pupa are described for the first time in Telamoptilia Kumata & Kuroko, 1988, and are illustrated with scanning electron micrographs and line drawings. Photographs of adult habitus, wing venation, male and female genitalia, as well as host plant and mines are provided. The apomorphic adult and larval characters of the new species in Telamoptilia are discussed in relation to the recognition of the genera Telamoptilia and Spulerina Vári, 1961.     

More Sex-Determination Mutants of CAENORHABDITIS ELEGANS

Sex determination in Caenorhabditis elegans is controlled by the X chromosome: autosome ratio, i.e. 2A;XX animals are hermaphrodite, and 2A;XO animals are male. A procedure for isolating 2A;XO animals that are transformed into hermaphrodites has been developed. Nine mutations causing this transformation have been obtained: eight are recessive, and all of these fall into a new autosomal complementation group, her-1 V. The remaining mutation (her-2) is dominant and has a genetic map location similar to that of tra-1 III. Recessive mutations of tra-1 cause the reverse transformation, transforming 2A;XX animals into males. Therefore, the her-2 mutation may result in constitutive expression of tra-1. Mutations in her-1 are without effect on XX animals, but the her-2 mutation prevents sperm production in both XX and XO animals, in addition to its effect on the sexual phenotype of XO animals. The epistatic relationships between tra and her genes are used to deduce a model for the action of these genes in controlling sex determination.     

The Late Cambrian acritarch Cristallinium randomense: morphology,taxonomy and stratigraphical extension

The holotype of Cristallinium randomense Martin and other figured specimens are re-examined. The processes are often grouped as those of typical Vulcanisphaera species. Probable connections between Cristallinium and Vulcanisphaera are indicated. These genera form a plexus in which Retisphaeridium is also possibly involved. A complete bibliographical list of C. randomense is provided. Few published specimens are demonstrated to belong to this species. As a consequence, some stratigraphical dates, based on the restricted Late Cambrian range of the species, are questioned. The new combination Retisphaeridium ovillense (Cramer and Diez de Cramer) Vanguestaine nov. comb. is proposed.     

Phylogeny and host-plant relationships of the Australian?Myrtaceae leafmining moth genus Pectinivalva (Lepidoptera,Nepticulidae), with?new?subgenera and species

The phylogeny of the mainly Australian nepticulid genus Pectinivalva Scoble, 1983 is investigated on the basis of morphology, and a division into three monophyletic subgenera is proposed on the basis of these results. These subgenera (Pectinivalva, Casanovula Hoare, subgen. n. and Menurella Hoare, subgen. n. ) are described and diagnosed, the described species of Pectinivalva are assigned to them, and representative new species are described in each: Pectinivalva (Pectinivalva) mystaconota Hoare, sp. n., Pectinivalva (Casanovula) brevipalpa Hoare, sp. n., Pectinivalva (Casanovula) minotaurus Hoare, sp. n., Pectinivalva (Menurella) scotodes Hoare, sp. n., Pectinivalva (Menurella) acmenae Hoare, sp. n., Pectinivalva (Menurella) xenadelpha Van Nieukerken & Hoare, sp. n., Pectinivalva (Menurella) quintiniae Hoare & Van Nieukerken, sp. n., and Pectinivalva (Menurella) tribulatrix Van Nieukerken & Hoare, sp. n. Pectinivalva (Menurella) quintiniae (from Quintinia verdonii, Paracryphiaceae) is the first known member of the genus with a host-plant not belonging to Myrtaceae. Pectinivalva (Menurella) xenadelpha from Mt Gunung Lumut, Kalimantan, Borneo, is the first pectinivalvine reported from outside Australia. Keys to the subgenera of Nepticulidae known from Australia, based on adults, male and female genitalia, and larvae, are presented. Host-plant relationships of Pectinivalva are discussed with relation to the phylogeny, and a list of known host-plants of Pectinivalva, including hosts of undescribed species, is presented. DNA barcodes are provided for most of the new and several unnamed species.