Physalins E and H,new physalins from Physalis angulata and P. lancifolia

From the stems and leaves of Physalis angulata and P. lancifolia, the isolation of five new physalins E, F, G, H and I is reported. The structures of physalins E and H are established respectively as 5,6-dihydro-5α,7α-dihydroxy and 7β-hydroxy derivatives of physalin B.     

Two new species of Pergalumna (Acari,Oribatida, Galumnidae) from Costa Rica,including a key to all species of the genus from the Neotropical region

Two new species of oribatid mites of the genus Pergalumna (Oribatida, Galumnidae), P. elongatiporosa sp. n. and P. striatiprodorsum sp. n., are described from leaf litter of a secondary forest in Costa Rica. Pergalumna elongatiporosa sp. n. is most similar morphologically to P. horvathorum P. Balogh, 1997 and P. sura P. Balogh, 1997, however, it differs from both by the body size, body surface ornamentation and morphology of notogastral porose areas A1 and A3. Pergalumna striatiprodorsum sp. n. is most similar morphologically to P. hawaiiensis hawaiiensis (Jacot, 1934) and P. strigulata Mahunka, 1978, however, it differs from P. hawaiiensis by the length of interlamellar setae and surface ornamentation of the prodorsum; from P. strigulata by the surface of ornamentation of the notogaster, length of interlamellar setae and morphology of bothridial setae. An identification key to known species of Pergalumna from the Neotropical region is given.     

Paraiotonchium muscadomesticae n. sp. (Tylenchida: lotonchiidae) a Parasite of the House Fly (Musca domestica) in Brazil and a Key to Species of the Genus Paraiotonchium

Paraiotonchium muscadomesticae n. sp., a parasite of the house fly, Musca domestica L., is described and illustrated from material collected in Brazil. The life cycle of P. muscadomesticae is similar to that of P. autumnale (Nickle), consisting of alternating gamogenetic and parthenogenetic generations. Paraiotonchium muscadomesticae n. sp. can be distinguished from P. nicholasi Slobodyanyuk, P. autumnale (Nickle) Slobodyanyuk, and P. crassirostris (Yatham &Rao) Siddiqi by the shorter body length of young heterosexual females, 652 g.m (530-709) for P. muscadomesticae compared to 750 μm or more (801-1,050) for the others. Paraiotonchium muscadomesticae is close to P. nicholosi but differs from it by V ratio and spicule length (V = 80-84; spicule = 16-21 p.m in P. muscadomesticae compared to V = 73-78; spicule = 25-35 μm in P. nicholasi). Paraiotonchium muscadomesticae and P. nicholasi differ from all species of this genus by the absence of a bursa on males of these two species.     

A review of the Nearctic genus Prostoia (Ricker) (Plecoptera,Nemouridae), with the description of a new species and a surprising range extension for P. hallasi Kondratieff & Kirchner

The Nearctic genus Prostoia (Plecoptera: Nemouridae) is reviewed. Prostoia ozarkensis sp. n. is described from the male and female adult stages mainly from the Interior Highland region encompassing portions of Arkansas, Missouri, and Oklahoma. Prostoia ozarkensis sp. n. appears most closely related to two species, one distributed broadly across the western Nearctic region, P. besametsa (Ricker), and one found widely throughout the central and eastern Nearctic regions, P. completa (Walker). A surprising range extension is noted for P. hallasi Kondratieff & Kirchner, a species once known only from the Great Dismal Swamp, from small upland streams in southern Illinois. Additional new state records are documented for P. besametsa, P. completa, P. hallasi and P. similis (Hagen). Taxonomic keys to Prostoia males and females are provided, and scanning electron micrographs of adult genitalia of all species are given.     

Pachybrachis (Coleoptera,Chrysomelidae, Cryptocephalinae) of Eastern Canada

Seventeen Pachybrachis species occurring in eastern Canada [Ontario (ON), Québec (QC), New Brunswick (NB), Nova Scotia (NS), and Prince Edward Island (PE)] are treated by the authors. Two new national records were discovered, both from southernmost Ontario: P. cephalicus Fall and P. luctuosus Suffrian. Four species were new provincial records: P. cephalicus (ON), P. luctuosus (ON, QC), P. obsoletus Suffrian (NB), P. peccans (PE). A fully illustrated key to the Pachybrachis of eastern Canada is provided and supported with extensive photographs, distribution maps, and plant associations. Three species were distributed from southern Ontario into at least one province in the Maritimes (P. nigricornis (Say), P. obsoletus Suffrianand P. peccans Suffrian). Six species were distributed along the shores of the Great Lakes (Erie, Michigan, and Ontario) and rivers (Ottawa, Saguenay and St. Lawrence), but unknown from central and northern ON and QC (P. bivittatus (Say), P. hepaticus hepaticus (F. E. Melsheimer), P. othonus othonus (Say), P. pectoralis (F. E. Melsheimer), P. spumarius Suffrianand P. trinotatus (F. E. Melsheimer)). Seven species were rare, five being found exclusively from southern ON (P. calcaratus Fall, P. cephalicus, P. luridus (Fabricius), P. subfasciatus (J. E. LeConte)and P. tridens (F. E. Melsheimer)), with two having, in addition, a disjunct population in QC (P. atomarius (F. E. Melsheimer)and P. luctuosus). One species was found to be the northern most extension of an eastern United States (US) distribution into the eastern townships of QC (P. m-nigrum (F. E. Melsheimer)). There were no Pachybrachis that could be considered arctic, subarctic, or boreal species; no specimens were found from Labrador and Newfoundland, and all species had southern affinities. Pachybrachis atomarius, P. calcaratus, P. luridus, P. subfaciatus, and P. tridens, not seen over the last 30–70 years, may be extirpated from eastern Canada.     

Systematics of a widely distributed western North American springsnail,Pyrgulopsis?micrococcus (Caenogastropoda,Hydrobiidae), with descriptions?of?three new congeners

We describe three new species of springsnails (genus Pyrgulopsis) from the Amargosa River basin, California and Nevada (P. licina sp. n., P. perforata sp. n., P. sanchezi sp. n.), each of which was previously considered to be part of P. micrococcus. We also restrict P. micrococcus to its type locality area (Oasis Valley) and redefine a regional congener, P. turbatrix, to include populations from the central Death Valley region and San Bernardino Mountains that had been previously identified as P. micrococcus. The five species treated herein form genetically distinct lineages that differ from each other by 4.2–12.6% for mtCOI and 5.2–13.6% for mtNDI (based on previously published and newly obtained data), and are diagnosable by shell and/or penial characters. The new molecular data presented herein confirm sympatry of P. licina and P. sanchezi in Ash Meadows (consistent with morphological evidence) and delineate an additional lineage of P. micrococcus (in the broad sense) that we do not treat taxonomically owing to the paucity of morphological material. Conservation measures are needed to ensure the long term persistence of populations of P. micrococcus and a genetically differentiated lineage of P. sanchezi which live in disturbed habitats on private lands.     

Review of genus Pseudorthocladius Goetghebuer, 1943 (Diptera,Chironomidae) from China

The genus Pseudorthocladius Goetghebuer, 1943 from China, including 12 species, is reviewed. Five new species, P. (P.) binarius sp. n., P. (P.) cylindratus sp. n., P. (P.) digitus sp. n., P. (P.) ovatus sp. n. and P. (P.) paucus sp. n. are described and illustrated as adult males. P. (P.) cristagus Stur & Sæther, 2004, P. (P.) jintutridecima (Sasa, 1996), P. (P.) macrovirgatus Sæther & Sublette, 1983, P. (P.) morsei Sæther & Sublette, 1983, P. (P.) uniserratus Sæther & Sublette, 1983, P. (L.) wingoi Sæther & Sublette, 1983 are newly recorded in Oriental Region. A key to the males of Pseudorthocladius in China is presented.     

Comparison of Populations of Pratylenchus brachyurus Based on Isozyme Phenotypes

Enzymes from females of five Pratylenchus brachyurus populations and one P. scribneri population were analyzed by isoelectric focusing electrophoresis. Of the 18 enzyme systems investigated, only malate dehydrogenase (MDH), phosphoglucomutase (PGM), and phosphoglucose isomerase (PGI) were detected from all five P. brachyurus populations and P. scribneri. Faint bands were detected for isocitrate dehydrogenase and phosphogluconate dehydrogenase from one P. brachyurus population. Three distinct phenotypic groups were found in the MDH and PGM systems for P. brachyurus populations, but only a single electromorph was detected for PGI. Multiple electromorphs for MDH, PGM, and PGI were detected for P. scribneri; there was no similarity among these patterns with those from P. brachyurus. No phenotypic differences in PGI were observed between females and mixed juveniles of one population of P. brachyurus.     

A new species of Harpacticella Sars, 1908 (Copepoda,Harpacticoida), from a tidal pool on Jeju Island,Korea

A new species of the genus Harpacticella Sars, 1908 is described from a tidal pool on Jeju Island, Korea. Harpacticella jejuensis sp. n. is closely related to Harpacticella itoi Chang & Kim, 1991, with regard to the structure of P1 exp-1 and enp-1, the length of P1 exp-1 and exp-2, and the setal number of the P5 exopod in males. However, the new species is clearly distinguishable from Harpacticella itoi by the combined following characters: six setae on the P5 exopod in females, one naked seta on the inner margin of P1 exp-2, the short endopod of P1 compared to the exopod, and a naked long seta on the proximal inner margin of the P5 exopod of males. The mtCOI partial sequence is provided as a DNA barcode for the new species.     

Functional and structural insight into the flexibility of cytochrome P450 reductases from Sorghum bicolor and its implications for lignin composition

Plant NADPH-dependent cytochrome P450 reductase (CPR) is a multidomain enzyme that donates electrons for hydroxylation reactions catalyzed by class II cytochrome P450 monooxygenases involved in the synthesis of many primary and secondary metabolites. These P450 enzymes include trans-cinnamate-4-hydroxylase, p-coumarate-3′-hydroxylase, and ferulate-5-hydroxylase involved in monolignol biosynthesis. Because of its role in monolignol biosynthesis, alterations in CPR activity could change the composition and overall output of lignin. Therefore, to understand the structure and function of three CPR subunits from sorghum, recombinant subunits SbCPR2a, SbCPR2b, and SbCPR2c were subjected to X-ray crystallography and kinetic assays. Steady-state kinetic analyses demonstrated that all three CPR subunits supported the oxidation reactions catalyzed by SbC4H1 (CYP73A33) and SbC3′H (CYP98A1). Furthermore, comparing the SbCPR2b structure with the well-investigated CPRs from mammals enabled us to identify critical residues of functional importance and suggested that the plant flavin mononucleotide–binding domain might be more flexible than mammalian homologs. In addition, the elucidated structure of SbCPR2b included the first observation of NADP⁺ in a native CPR. Overall, we conclude that the connecting domain of SbCPR2, especially its hinge region, could serve as a target to alter biomass composition in bioenergy and forage sorghums through protein engineering.     

Axenizing and Culturing Endomigratory Plant-Parasitic Nematodes using Pluronic F127, Including its Effects,on Population Dynamics of Pratylenchus penetrans

A non-chemical technique for surface sterilizing plant-parasitic nematodes for aseptic cultures is described. The method is most applicable to nematodes with active migratory infective stages and requires only a few starting specimens. Rate of achieving a primary aseptic culture with the technique ranged from 60%-100% depending on the conditions of the specimens collected for culturing. Aseptic cultures of species of Meloidogyne, Rotylenchuluz, Pratylenchus, and Radopholus initiated with the method remained contamination-free after 12 months of maintenance in tomato root explant or alfalfa callus cultures. Further studies of Pluronic F127, a polyol gel medium employed in the technique to confine the spread of contaminating bacteria or fungi associated with the nematodes, showed that the polyol gel was a suitable support medium for culturing corn root explant, alfalfa callus tissues, and consequently Pratylenchus species including P. agilis, P. brachyurus, P. scribneri, and P. penetrans. During the course of 10 months, P. penetrans reared in polyol-base medium followed a standard biological growth curve, multiplied to a higher population density, maintained a similar female-to-male ratio, and possessed a similar tendency to reside inside or outside host tissues as did P. penetrans reared in agar-base medium. The percentages of P. penetrans juveniles in the sub-populations residing outside or inside the host tissues reared in polyol-base medium also were similar to and fluctuated temporally in like manner as those reared in agar-base medium. Members of these sub-populations from the polyol- or agar-base were equally infective and reproductive after 9 months of culturing.     

Mycobacterium tuberculosis UsfX (Rv3287c) exhibits novel nucleotide binding and hydrolysis properties

The Mycobacterium tuberculosis UsfX protein is an anti-sigma factor which regulates its cognate sigma factor SigF. UsfX shares low sequence homology with other anti-sigma factors making it difficult to identify the nucleotide binding site and characterize its properties. We have identified that the NTP binding site occurs close to Trp106 and the area around the nucleotide binding site is predominantly negatively charged. UsfX binds to a variety of nucleotides unlike other reported anti-sigma factors and exhibits an unusual dual NTPase activity. In silico computational experiments have identified a XGSFS motif close to the nucleotide binding site for metal ion binding. This motif is analogous to the DXSXS motif reported earlier in the human integrin CR3 protein superfamily. Overall, the experiments suggest that the M. tuberculosis UsfX represents a distinct anti-sigma factor family with a novel nucleotide binding motif.     

Cellular retinoid-binding proteins transfer retinoids to human cytochrome P450 27C1 for desaturation

Cytochrome P450 27C1 (P450 27C1) is a retinoid desaturase expressed in the skin that catalyzes the formation of 3,4-dehydroretinoids from all-trans retinoids. Within the skin, retinoids are important regulators of proliferation and differentiation. In vivo, retinoids are bound to cellular retinol-binding proteins (CRBPs) and cellular retinoic acid–binding proteins (CRABPs). Interaction with these binding proteins is a defining characteristic of physiologically relevant enzymes in retinoid metabolism. Previous studies that characterized the catalytic activity of human P450 27C1 utilized a reconstituted in vitro system with free retinoids. However, it was unknown whether P450 27C1 could directly interact with holo-retinoid-binding proteins to receive all-trans retinoid substrates. To assess this, steady-state kinetic assays were conducted with free all-trans retinoids and holo-CRBP-1, holo-CRABP-1, and holo-CRABP-2. For holo-CRBP-1 and holo-CRABP-2, the k_cat/K_m values either decreased 5-fold or were equal to the respective free retinoid values. The k_cat/K_m value for holo-CRABP-1, however, decreased ∼65-fold in comparison with reactions with free all-trans retinoic acid. These results suggest that P450 27C1 directly accepts all-trans retinol and retinaldehyde from CRBP-1 and all-trans retinoic acid from CRABP-2, but not from CRABP-1. A difference in substrate channeling between CRABP-1 and CRABP-2 was also supported by isotope dilution experiments. Analysis of retinoid transfer from holo-CRABPs to P450 27C1 suggests that the decrease in k_cat observed in steady-state kinetic assays is due to retinoid transfer becoming rate-limiting in the P450 27C1 catalytic cycle. Overall, these results illustrate that, like the CYP26 enzymes involved in retinoic acid metabolism, P450 27C1 interacts with cellular retinoid-binding proteins.     

Then there were five: a reexamination of the ant genus Paratrechina (Hymenoptera,Formicidae)

The ant genus Paratrechina is reexamined based on the discovery of two new species from Madagascar (P. ankarana sp. n. and P. antsingy sp. n.). Paratrechina kohli, a species known from central Africa, is transferred to Paratrechina from Prenolepis based on a new morphological interpretation of the genus and an updated morphological diagnosis of the genus is provided. This means that other than the widespread P. longicornis, whose origins remain uncertain, all Paratrechina are restricted either to the Afrotropical or Malagasy regions. It would also appear that of the five Paratrechina species now known, three are from dry forest habitats. With this reexamination of the genus, the possible origins of P. longicornis are discussed. A key to the genera of the Prenolepis genus-group is provided, as is a key to the workers of Paratrechina. In addition, we also designate a lectotype for Paratrechina kohli.     

Pratylenchoides hispaniensis n. sp. (Nemata: Pratylenchidae)

Pratylenchoides hispaniensis n. sp. is described and illustrated from a bisexual population found in a natural habitat at Santa Elena, Jaen, central Spain. Its main distinctive characters are very long esophageal gland lobe (81-117 μm; N'' = 51-71) overlapping the intestine 3 to 5 times the body width; lateral field with six incisures; stylet knobs sloping posteriorly; labial disc encircled by the irregular sectors of the first annule; tail cylindrical, extremity annulated, and frequently with a slight dorsal indentation of the hyaline portion at the end of the lateral field. Pratylcnchoides hispaniensis n. sp. appears closely related to P. megalobatus and P. nevadensis. It differs from the former primarily by its longer body length (761-998 vs. 430-621 μm), longer stylet length (20.5-24.4 vs. 18-21 μm), six incisures in the lateral field vs. four for P. megalobatus, and posteriorly sloping stylet knobs vs. rounded or anteriorly flattened knobs in P. megalobatus. It differs from P. nevadensis mainly by the shape of the stylet knobs (sloping in P. hispaniensis vs. rounded in P. nevadensis), length of esophageal lobe (81-117 vs. 34-82 μm), and position of esophageal gland nuclei (all posterior to esophago-intestinal junction in P. hispaniensis vs. at least one nucleus anterior to junction in P. nevadensis).