Characterization of ferric-anguibactin transport in Vibrio anguillarum

The fish pathogen Vibrio anguillarum is the causative agent of a fatal hemorrhagic septicemia in salmonid fish. Many serotype O1 strains harbors a 65 Kbp plasmid (pJM1 encoding an iron sequestering system essential for virulence. The genes involved in the biosynthesis of the indigenous siderophore anguibactin are encoded by both the pJM1 plasmid and the chromosome, while those involved in the transport of the ferric-siderophore complex, including the outer membrane receptor, are plasmid-encoded. This work describes the role of specific amino acid residues of the outer membrane receptor FatA in the mechanism of transport of ferric-anguibactin. FatA modeling indicated that this protein has a 22 stranded ß-barrel blocked by the plug domain, the latter being formed by residues 51–54. Deletion of the plug domain resulted in a receptor unable to act as an open channel for the transport of the ferric anguibactin complex.     

Reaching a Consensus: Terminology and Concepts Used in Coordination and Decision-Making Research

Research on coordination and decision-making in humans and nonhuman primates has increased considerably throughout the last decade. However, terminology has been used inconsistently, hampering the broader integration of results from different studies. In this short article, we provide a glossary containing the central terms of coordination and decision-making research. The glossary is based on previous definitions that have been critically revised and annotated by the participants of the symposium “Where next? Coordination and decision-making in primate groups” at the XXIIIth Congress of the International Primatological Society (IPS) in Kyoto, Japan. We discuss a number of conceptual and methodological issues and highlight consequences for their implementation. In summary, we recommend that future studies on coordination and decision-making in animal groups do not use the terms “combined decision” and “democratic/despotic decision-making.” This will avoid ambiguity as well as anthropocentric connotations. Further, we demonstrate the importance of 1) taxon-specific definitions of coordination parameters (initiation, leadership, followership, termination), 2) differentiation between coordination research on individual-level process and group-level outcome, 3) analyses of collective action processes including initiation and termination, and 4) operationalization of successful group movements in the field to collect meaningful and comparable data across different species.     

Mosaic genome architecture of the Anopheles gambiae species complex

Background

Attempts over the last three decades to reconstruct the phylogenetic history of the Anopheles gambiae species complex have been important for developing better strategies to control malaria transmission.

Methodology

We used fingerprint genotyping data from 414 field-collected female mosquitoes at 42 microsatellite loci to infer the evolutionary relationships of four species in the A. gambiae complex, the two major malaria vectors A. gambiae sensu stricto (A. gambiae s.s.) and A. arabiensis, as well as two minor vectors, A. merus and A. melas.

Principal Findings

We identify six taxonomic units, including a clear separation of West and East Africa A. gambiae s.s. S molecular forms. We show that the phylogenetic relationships vary widely between different genomic regions, thus demonstrating the mosaic nature of the genome of these species. The two major malaria vectors are closely related and closer to A. merus than to A. melas at the genome-wide level, which is also true if only autosomes are considered. However, within the Xag inversion region of the X chromosome, the M and two S molecular forms are most similar to A. merus. Near the X centromere, outside the Xag region, the two S forms are highly dissimilar to the other taxa. Furthermore, our data suggest that the centromeric region of chromosome 3 is a strong discriminator between the major and minor malaria vectors.

Conclusions

Although further studies are needed to elucidate the basis of the phylogenetic variation among the different regions of the genome, the preponderance of sympatric admixtures among taxa strongly favor introgression of different genomic regions between species, rather than lineage sorting of ancestral polymorphism, as a possible mechanism.     

Cadinane sesquiterpenoids of Phomopsis cassiae, an endophytic fungus associated with Cassia spectabilis (Leguminosae)

Five cadinane sesquiterpenes derivatives were isolated by bioassay-guided fractionation from Phomopis cassiae, an endophytic fungus isolated from Cassia spectabilis. The structures of the two diastereoisomeric 3,9,12-trihydroxycalamenenes (1, 2); 3,12-dihydroxycalamenene (3); 3,12-dihydroxycadalene (4) and 3,11,12-trihydroxycadalene (5) were established on the basis of analyses of 1D and 2D NMR and HRTOFMS experiments. Antifungal activity of the isolates was evaluated against Cladosporium sphaerospermum and Cladosporium cladosporioides, revealing 5 as the most active compound.     

Phytochrome-mediated control of grana and stroma thylakoid formation in plastids of mustard cotyledons

The etioplast»chloroplast transition in the cotyledons of mustard seedlings (Sinapis alba L.) has been studied by electron microscopy. It was found that the active form of phytochrome, established by a red light pulse pretreatment, increases the initial rate and eliminates the lag of grana and stroma thylakoid formation after the onset of white light 60 h after sowing. The effect of a pretreatment with 15 s red light pulses is fully reversible by 756 nm light pulses. This reversibility is lost within 5 min. Evidence is presented which suggests that the time course of grana and stroma thylakoid formation is not correlated with the time course of the dispersal of the prolamellar body. The different functions of phytochrome and chlorophyll in controlling thylakoid formation are discussed.     

High Resolution X Chromosome-Specific Array-CGH Detects New CNVs in Infertile Males

Context

The role of CNVs in male infertility is poorly defined, and only those linked to the Y chromosome have been the object of extensive research. Although it has been predicted that the X chromosome is also enriched in spermatogenesis genes, no clinically relevant gene mutations have been identified so far.

Objectives

In order to advance our understanding of the role of X-linked genetic factors in male infertility, we applied high resolution X chromosome specific array-CGH in 199 men with different sperm count followed by the analysis of selected, patient-specific deletions in large groups of cases and normozoospermic controls.

Results

We identified 73 CNVs, among which 55 are novel, providing the largest collection of X-linked CNVs in relation to spermatogenesis. We found 12 patient-specific deletions with potential clinical implication. Cancer Testis Antigen gene family members were the most frequently affected genes, and represent new genetic targets in relationship with altered spermatogenesis. One of the most relevant findings of our study is the significantly higher global burden of deletions in patients compared to controls due to an excessive rate of deletions/person (0.57 versus 0.21, respectively; p = 8.785×10⁻⁶) and to a higher mean sequence loss/person (11.79 Kb and 8.13 Kb, respectively; p = 3.435×10⁻⁴).

Conclusions

By the analysis of the X chromosome at the highest resolution available to date, in a large group of subjects with known sperm count we observed a deletion burden in relation to spermatogenic impairment and the lack of highly recurrent deletions on the X chromosome. We identified a number of potentially important patient-specific CNVs and candidate spermatogenesis genes, which represent novel targets for future investigations.     

The spirocyclopropyl moiety as a methyl surrogate in the structure of l-fucosidase and l-rhamnosidase inhibitors

Nitrogen-in-the-ring analogues of l-fucose and l-rhamnose were prepared, which feature a spirocyclopropyl moiety in place of the methyl group of the natural sugar. The synthetic route involved a titanium-mediated aminocyclopropanation of a glycononitrile as the key step. Four new spirocyclopropyl iminosugar analogues were generated, which displayed some activity towards l-fucosidase and l-rhamnosidase.     

Internal ethnicity in the ethnic economy

Internal ethnicity refers to ethnic subgroups within an immigrant group. An ‘ethnic economy’ includes the self‐employed and their co‐ethnic workers. Although most research treats the boundaries of ‘ethnic economy’ and its variant, the ‘ethnic enclave economy’, as though they were coterminous with those of national‐origin immigrant groups, this assumption is unreliable. Ethnic boundaries need not coincide with those of nationality origin when internal ethnicity exists. To test this hypothesis, we utilize survey data collected from a sample of Iranians in Los Angeles. Because this national‐origin immigrant group contains four ethno‐religious subgroups (Armenians, Bahais, Jews and Muslims), the Iranians in Los Angeles operated four distinctive ethnic economies, not one. Each ethno‐religious subgroup had its own ethnic economy, and these separate economies were only weakly tied to an encompassing Iranian ethnic economy.