Synthetic peptides identify a second periplasmic site for the plug of the SecYEG protein translocation complex

A short helix in the centre of the SecY subunit serves as a ‘plug’ blocking the protein channel. This site must be vacated if the channel is to open and accommodate translocating protein. We have synthesised a peptide mimic of this plug, and show that it binds to E. coli SecYEG, identifying a distinct and peripheral binding site. We propose that during active translocation the plug moves to this second discrete site and chart its position. Deletion of the plug in SecY increases the stoichiometry of the peptide-SecYEG interaction by also exposing the location it occupies in the channel. Binding of the plug peptide to the channel is unaffected by SecA.     

Don't pull the plug! the Drosophila mating plug preserves fertility

ABSTRACT

Mating plugs are hardened structures—typically a coagulation of seminal fluid components—that are transferred to, or formed within, the female reproductive tract of numerous animal species (both mammals and insects). Analysis of the role(s) of the mating plug in reproduction has been conducted in a wide array of diverse species. These structures have been proposed to have a multitude of functions, which include altering female re-mating rate, acting as a barrier to re-mating and being required for sperm storage or sperm movement to occur in mated females. A recent analysis of the Drosophila melanogaster mating plug has shown that proper formation of the structure is required for optimal fertility in flies: the Drosophila mating plug is required to retain the ejaculate within the female reproductive tract once mating has terminated. Here, we discuss the possible implications of the Drosophila mating plug in the fertility of this species in light of these new results.     

The plug domain of a neisserial TonB-dependent transporter retains structural integrity in the absence of its transmembrane beta-barrel

Transferrin binding protein A (TbpA) is a TonB-dependent outer membrane protein expressed by pathogenic bacteria for iron acquisition from human transferrin. The N-terminal 160 residues (plug domain) of TbpA were overexpressed in both the periplasm and cytoplasm of Escherichia coli. We found this domain to be soluble and monodisperse in solution, exhibiting secondary structure elements found in plug domains of structurally characterized TonB-dependent transporters. Although the TbpA plug domain is apparently correctly folded, we were not able to observe an interaction with human transferrin by isothermal titration calorimetry or nitrocellulose binding assays. These experiments suggest that the plug domain may fold independently of the beta-barrel, but extracellular loops of the beta-barrel are required for ligand binding.     

A poisonous surprise under the coat of the African crested rat

Plant toxins are sequestered by many animals and the toxicity is frequently advertised by aposematic displays to deter potential predators. Such 'unpalatability by appropriation' is common in many invertebrate groups and also found in a few vertebrate groups. However, potentially lethal toxicity by acquisition has so far never been reported for a placental mammal. Here, we describe complex morphological structures and behaviours whereby the African crested rat, Lophiomys imhausi, acquires, dispenses and advertises deterrent toxin. Roots and bark of Acokanthera schimperi (Apocynaceae) trees are gnawed, masticated and slavered onto highly specialized hairs that wick up the compound, to be delivered whenever the animal is bitten or mouthed by a predator. The poison is a cardenolide, closely resembling ouabain, one of the active components in a traditional African arrow poison long celebrated for its power to kill elephants.     

Description of Oculogryphus shuensis sp. n. (Coleoptera,Lampyridae), the first species of the genus in the Sino-Japanese realm,with a modified key to the subfamily Ototretinae

A new species of the lampyrid genus Oculogryphus Jeng, Engel, and Yang, O. shuensis sp. n. from China (Sichuan Province) is described and figured. The genus previously was known only from Vietnam, and the new species is the first representative of the genus in the Sino-Japanese zoogeographic realm. Some morphological variations of Oculogryphus and the allied genus Stenocladius are discussed and a modification to the most recent key to ototretine genera is proposed to accommodate Oculogryphus.     

Generic placement of the Neotropical species of " Phragmatobia" (Erebidae, Arctiinae), with a remarkable matrivorous species from the Peruvian Andes

Phragmatobia Stephens is briefly reviewed and a diagnosis is provided. The South American species currently placed in Phragmatobia Stephens are revised to two new genera, Andesobia Schmidt and De Freina, gen. n., and Patagobia Schmidt and De Freina, gen. n. (subtribe Spilosomina). Both Andesobia and Patagobia exhibit adaptations to high altitude habitats, including micropterous females in Andesobia (Patagobia females are unknown) and diurnal flight of males. The adults, immature stages, and mating behaviour of Andesobia jelskii (Oberthür, 1881) are described. Males of Andesobia jelskii enter the female cocoon to mate, and the micropterous, flightless females remain in the cocoon following oviposition where newly hatched larvae feed initially on the female’s body.Four species are included in Andesobia, Andesobia jelskii comb. n. (= Paracles imitatrix Rothschild, 1922, syn. n.), Andesobia flavata (Hampson, 1901), comb. n., Andesobia boliviana (Gaede, 1923), comb. n. (=Turuptiana flavescens Rothschild, 1933, syn. n.), and Andesobia sanguinea (Hampson, 1907), comb. n. Patagobia includes only Patagobia thursbyi (Rothschild, 1910), comb. n., and Patagobia thursbyi pluto Toulgoët is relegated to its synonymy. Patagobia shows affinities to Phaos Walker, 1855 of Australia, Metacrias Meyrick, 1886 of New Zealand, and Pseudophragmatobia Krüger, 2009 of South Africa, suggesting a common ancestry of circumantarctic origin. Phragmatobia karsholti Toulgoët, 1991 is transferred to Venedictoffia Toulgoët, comb. n., an unrelated genus that is removed from subtribe Arctiina and provisionally placed in the Phaegopterina. Phragmatobia oberthueri Rothschild, 1910, described from Tibet, is a synonym of Lachana alpherakii (Grum-Grzhimailo, 1891) [Erebidae: Lymantriinae], syn. n., comb. n.     

The spider family Selenopidae (Arachnida, Araneae) in Australasia and the Oriental Region

We relimit and revise the family Selenopidae to include four new genera and 27 new species from Australia and the Oriental Region. The family is redefined, as are the genera Anyphops Benoit, Garcorops Corronca, Hovops Benoit, Selenops Latreille, and Siamspinops Dankittipakul & Corronca, to accommodate the new genera and to correct previous inconsistencies in the diagnoses and definitions of the aforementioned genera. The species of Selenops that occur throughout India and China are also reviewed. Three species occur in China: Selenops bursarius Karsch 1879, also known from Japan, Korea and Taiwan, Selenops ollarius Zhu, Sha, & Chen 1990, and Selenops radiatus Latreille 1819, the type of the genus and most widespread selenopid. Selenops cordatus Zhu, Sha & Chen syn. n. is recognized as a junior synonym of Selenops radiatus. Amamanganopsgen. n. is monotypic, with Amamanganops baginawasp. n. (♀; from the Philippines). Godumopsgen. n. is monotypic, with Godumops caritussp. n. (♂; from Papua New Guinea). Karaopsgen. n. occurs throughout Australia and includes 24 species. A new combination is proposed for Karaops australiensis (L. Koch 1875) comb. n. (ex. Selenops), and the new species: Karaops gangariesp. n. (♀, ♂), Karaops monteithisp. n. (♀), Karaops alanlongbottomisp. n. (♂), Karaops keithlongbottomisp. n. (♂), Karaops larryoosp. n. (♂), Karaops jarritsp. n. (♂,♀), Karaops marrayagongsp. n. (♀), Karaops ravenisp. n. (♂,♀), Karaops badgeraddasp. n. (♀), Karaops burbidgeisp. n. (♂,♀), Karaops karrawarlasp. n. (♂,♀), Karaops julianneaesp. n. (♀), Karaops martamartasp. n. (♀), Karaops manaaynsp. n. (♀, ♂), Karaops vadlaadambarasp. n. (♀, ♂), Karaops pilkingtonisp. n. (♀, ♂), Karaops deserticolasp. n. (♀), Karaops ngarutjaranyasp. n. (♂,♀), Karaops francesaesp. n. (♂,♀), Karaops toolbrunupsp. n. (♀, ♂), the type species Karaops ellenaesp. n. (♂,♀), Karaops jenniferaesp. n. (♀), and Karaops dawarasp. n. (♀).The genus Makdiopsgen. n. contains five species from India and Nepal. A new combination is proposed for Makdiops agumbensis (Tikader 1969), comb. n., Makdiops montigenus (Simon 1889), comb. n., Makdiops nilgirensis (Reimoser 1934) comb. n.,(ex. Selenops). Also, there are two new species the type of the genus Makdiops mahishasurasp. n. (♀; from India), and Makdiops shivasp. n. (♀). The genus Pakawopsgen. n. is monotypic. A new combination is proposed for Pakawops formosanus (Kayashima 1943) comb. n. (ex. Selenops), known only from Taiwan. A new combination is proposed for Siamspinops aculeatus (Simon)comb. n. (ex. Selenops). The distribution and diversity of the studied selenopid fauna is discussed. Finally, keys are provided to all of the selenopid genera and to the species of Karaopsgen. n.and Makdiopsgen. n.     

Genome sequence of the reddish-pigmented Rubellimicrobium thermophilum type strain (DSM 16684T), a member of the Roseobacter clade

Rubellimicrobium thermophilum Denner et al. 2006 is the type species of the genus Rubellimicrobium, a representative of the Roseobacter clade within the Rhodobacteraceae. Members of this clade were shown to be abundant especially in coastal and polar waters, but were also found in microbial mats and sediments. They are metabolically versatile and form a physiologically heterogeneous group within the Alphaproteobacteria. Strain C-Ivk-R2A-2^T was isolated from colored deposits in a pulp dryer; however, its natural habitat is so far unknown. Here we describe the features of this organism, together with the draft genome sequence and annotation and novel aspects of its phenotype. The 3,161,245 bp long genome contains 3,243 protein-coding and 45 RNA genes.     

Genome sequence of the exopolysaccharide-producing Salipiger mucosus type strain (DSM 16094T), a moderately halophilic member of the Roseobacter clade

Salipiger mucosus Martínez-Cànovas et al. 2004 is the type species of the genus Salipiger, a moderately halophilic and exopolysaccharide-producing representative of the Roseobacter lineage within the alphaproteobacterial family Rhodobacteraceae. Members of this family were shown to be the most abundant bacteria especially in coastal and polar waters, but were also found in microbial mats and sediments. Here we describe the features of the S. mucosus strain DSM 16094^T together with its genome sequence and annotation. The 5,689,389-bp genome sequence consists of one chromosome and several extrachromosomal elements. It contains 5,650 protein-coding genes and 95 RNA genes. The genome of S. mucosus DSM 16094^T was sequenced as part of the activities of the Transregional Collaborative Research Center 51 (TRR51) funded by the German Research Foundation (DFG).     

A gharial from the Oligocene of Puerto Rico: transoceanic dispersal in the history of a non-marine reptile

The Indian gharial (Gavialis gangeticus) is not found in saltwater, but the geographical distribution of fossil relatives suggests a derivation from ancestors that lived in, or were at least able to withstand, saline conditions. Here, we describe a new Oligocene gharial, Aktiogavialis puertoricensis, from deltaic-coastal deposits of northern Puerto Rico. It is related to a clade of Neogene gharials otherwise restricted to South America. Its geological and geographical settings, along with its phylogenetic relationships, are consistent with two scenarios: (i) that a single trans-Atlantic dispersal event during the Tertiary explains the South American Neogene gharial assemblage and (ii) that stem gharials were coastal animals and their current restriction to freshwater settings is a comparatively recent environmental shift for the group. This discovery highlights the importance of including fossil information in a phylogenetic context when assessing the ecological history of modern organisms.     

果蝇实验中的2个实用小制作

果蝇实验是最常见的生物学实验。而培养与麻醉果蝇是果蝇实验中的2个基本操作。介绍2种果蝇实验中实用的小制作：培养瓶用的海绵塞,以及在海绵塞的基础上改进的用于转移果蝇进行麻醉的＂移蝇塞＂,使用移蝇塞可以使麻醉果蝇的操作变得容易控制,同时还可以有效地控制进入麻醉瓶中果蝇的数量。这2种小制作材料易得,制作简单,非常实用。     

Cossidae of the socotra archipelago (yemen)

The faunistic composition of the family Cossidae (Lepidoptera) of the Socotra Archipelago is revised. Five species are recognized, including two new species (Mormogystia brandstetteri and Meharia hackeri), and dubious identifications and records are discussed. Adults and genitalia are illustrated and bionomic details, DNA barcodes and a synonymic checklist for Socotran cossids are provided. A review of their distribution reveals that at least 80 percent of Socotra's cossids are unique to the archipelago, which is renowned for its endemism. A checklist listing all the species from generas Meharia, Mormogystia, Aethalopteryx, Azygophleps, as well as the synonymy and distribution is provided.     

Holoparasitic Rafflesiaceae possess the most reduced endophytes and yet give rise to the world's largest flowers

Background and Aims

Species in the holoparasitic plant family Rafflesiaceae exhibit one of the most highly modified vegetative bodies in flowering plants. Apart from the flower shoot and associated bracts, the parasite is a mycelium-like endophyte living inside their grapevine hosts. This study provides a comprehensive treatment of the endophytic vegetative body for all three genera of Rafflesiaceae (Rafflesia, Rhizanthes and Sapria), and reports on the cytology and development of the endophyte, including its structural connection to the host, shedding light on the poorly understood nature of this symbiosis.

Methods

Serial sectioning and staining with non-specific dyes, periodic–Schiff''s reagent and aniline blue were employed in order to characterize the structure of the endophyte across a phylogenetically diverse sampling.

Key Results

A previously identified difference in the nuclear size between Rafflesiaceae endophytes and their hosts was used to investigate the morphology and development of the endophytic body. The endophytes generally comprise uniseriate filaments oriented radially within the host root. The emergence of the parasite from the host during floral development is arrested in some cases by an apparent host response, but otherwise vegetative growth does not appear to elicit suppression by the host.

Conclusions

Rafflesiaceae produce greatly reduced and modified vegetative bodies even when compared with the other holoparasitic angiosperms once grouped with Rafflesiaceae, which possess some vegetative differentiation. Based on previous studies of seeds together with these findings, it is concluded that the endophyte probably develops directly from a proembryo, and not from an embryo proper. Similarly, the flowering shoot arises directly from the undifferentiated endophyte. These filaments produce a protocorm in which a shoot apex originates endogenously by formation of a secondary morphological surface. This degree of modification to the vegetative body is exceptional within angiosperms and warrants additional investigation. Furthermore, the study highlights a mechanical isolation mechanism by which the host may defend itself from the parasite.     

Genome sequence of the Wenxinia marina type strain (DSM 24838T), a representative of the Roseobacter group isolated from oilfield sediments

Wenxinia marina Ying et al. 2007 is the type species of the genus Wenxinia, a representative of the Roseobacter group within the alphaproteobacterial family Rhodobacteraceae, isolated from oilfield sediments of the South China Sea. This family was shown to harbor the most abundant bacteria especially from coastal and polar waters, but was also found in microbial mats, sediments and attached to different kind of surfaces.Here we describe the features of W. marina strain HY34^T together with the genome sequence and annotation of strain DSM 24838^T and novel aspects of its phenotype. The 4,181,754 bp containing genome sequence encodes 4,047 protein-coding genes and 59 RNA genes. The genome of W. marina DSM 24838^T was sequenced as part of the activities of the Genomic Encyclopedia of Type Strains, Phase I: the one thousand microbial genomes (KMG) project funded by the DoE and the Transregional Collaborative Research Centre 51 (TRR51) funded by the German Research Foundation (DFG).     

Retrograde Traffic Out of the Yeast Vacuole to the TGN Occurs via the Prevacuolar/Endosomal Compartment

A large number of trafficking steps occur between the last compartment of the Golgi apparatus (TGN) and the vacuole of the yeast Saccharomyces cerevisiae. To date, two intracellular routes from the TGN to the vacuole have been identified. Carboxypeptidase Y (CPY) travels through a prevacuolar/endosomal compartment (PVC), and subsequently on to the vacuole, while alkaline phosphatase (ALP) bypasses this compartment to reach the same organelle. Proteins resident to the TGN achieve their localization despite a continuous flux of traffic by continually being retrieved from the distal PVC by virtue of an aromatic amino acid–containing sorting motif. In this study we report that a hybrid protein based on ALP and containing this retrieval motif reaches the PVC not by following the CPY sorting pathway, but instead by signal-dependent retrograde transport from the vacuole, an organelle previously thought of as a terminal compartment. In addition, we show that a mutation in VAC7, a gene previously identified as being required for vacuolar inheritance, blocks this trafficking step. Finally we show that Vti1p, a v-SNARE required for the delivery of both CPY and ALP to the vacuole, uses retrograde transport out of the vacuole as part of its normal cellular itinerary.     

Biodegradation of Phenanthrene by Pseudomonas putida and a Bacterial Consortium in the Presence and in the Absence of a Surfactant

This study describes the biodegradation of phenanthrene in aqueous media in the presence and in the absence of a surfactant, Brij 30. Biodegradations were performed using either Pseudomonas putida DSMZ 8368 or a bacterial consortium Pyr01 isolated from one PAHs-polluted site. P. putida degraded phenanthrene to form 1-hydroxy-2-naphthoic acid (1H2Na) as the major metabolite. LC–MS analysis revealed the production of complementary intermediates in the presence of Brij 30, showing intense ions at mass-to-charge ratios (m/z) 97 and 195. Higher phenanthrene biodegradation rate was obtained in the presence of Brij 30. Conversely, in the case of Pyr01consortium, the addition of Brij 30 (0.5 g L⁻¹) had a negative effect on biodegradation: no phenanthrene biodegradation products were detected in the medium, whereas a production of several intermediates (m/z 97, 195 and 293) was obtained without surfactant. New results on phenanthrene metabolism by P. putida DSMZ 8368 and Pyr01 consortium in the presence and in the absence of Brij 30 we obtained. They confirm that the knowledge of the effect of a surfactant on bacterial cultures is crucial for the optimization of surfactant-enhanced PAHs biodegradation.

Electronic supplementary material

The online version of this article (doi:10.1007/s12088-012-0265-z) contains supplementary material, which is available to authorized users.