Two New Genera of Marine Tubificidae (Oligochaeta) from Australia's Great Barrier Reef

Macquaridriloides gen.n. is established for M. heronae from Heron Reef in Queensland, Australia. The species is characterized principally by its lack of spermathecae, and its elaborate male efferent ducts, each of which consists of (1) a ciliated vas deferens, (2) a ciliated and muscular atrium with diffuse prostates, and (3) a stout muscular, non-ciliar ejaculatory duct opening into a large copulatory sac surrounded by posterior prostates. The genus appears closely related to Macquaridrilus Jamieson, 1968, the habitat and zoogeography of which are briefly discussed. Heronidrilus gen.n. is established for H. fastigatus sp.n. and H. bihamis sp.n. both from Heron Reef. This genus is closely related to Macquaridriloides , but the two species differ from M. heronae in that they possess spermathecae and lack ejaculatory ducts.     

Identification of sequence mutations affecting hemagglutinin specificity to sialic acid receptor in influenza A virus subtypes

The attachment of the hemagglutinin protein of the H1N1 subtype of the pandemic influenza A virus to the sialic acid receptor Sia(α2-6)Gal has contributed to the ability of the virus to replicate in the human body and transmit among humans. In view of the pandemic caused by the replication and transmission of the H1N1 virus, more studies on the specificity of hemagglutinin towards sialic acid and how it affects the replication and transmission ability of this virus among humans are needed. In this study, we have applied sequence, structural and functional analyses to the hemagglutinin protein of the pandemic H1N1 virus, with the aim of identifying amino acid mutation patterns that affect its specificity to sialic acid. We have also employed a molecular docking method to evaluate the complex formed between hemagglutinin protein and the sialic acid receptor. Based on our results, we suggest two possible mutation patterns, namely (1) positions 190 and 225 from glutamic acid and glycine to aspartic acid (E190D in A/Brevig Mission/1/18 (H1N1), A/New York/1/18(H1N1) and A/South Carolina/1/1918(H1N1) and G225D in A/South Carolina/1/1918(H1N1), A/South Carolina/1/1918(H1N1), and A/Puerto Rico/8/34(H1N1)), and (2) positions 226 and 228 from glutamine and glycine to leucine and serine, respectively (Q226L and G228S in A/Guiyang/1/1957(H2N2), A/Kayano/57(H2N2), A/Aichi/2/1968(H3N2), A/Hong Kong/1/1968(H3N2) and A/Memphis/1/68(H3N2)) that can potentially contribute to the specificity of hemagglutinin to Sia(α2-6)Gal, thereby enabling the replication and transmission of virus within and among humans.     

Genetic and chaetal variation in Nais worms (Annelida,Clitellata, Naididae)

The genus Nais is a group of oligochaetous clitellates, common in eutrophic freshwater habitats. About 30 species are described. Species identification is based primarily on chaetal characters, which are often subtle, inconsistent, and even overlapping between nominal species. We investigated the correlation between genetic variation and chaetal morphology in this genus. Eighty‐one individuals from Europe, North America, and China were included in the study. Seventy‐five of these were preserved as vouchers. They were scrutinized with regard to chaetal morphology, and ten different morphotypes were identified. Three molecular markers, two mitochondrial (the COI gene and 16S rDNA) and one nuclear (the ITS region), were used to establish the genetic lineages in the material. Genetic variation was found to be largely congruent with chaetal character patterns. However, at least nine separately evolving lineages (all supported by mitochondrial as well as nuclear data) correspond to at most six nominal species. Four morphotypes/lineages are recognized as Nais barbata, Nais christinae, Nais elinguis, and Nais stolci, respectively, whereas five, or possibly more, lineages represent a morphological continuum covering the variation of the Nais communis/variabilis complex. Thus, cryptic speciation is revealed. Our results indicate that a taxonomic revision of the genus will be needed in the future.     

The Appearance and Development of Photosynthetic Activity in Etiolated Barley Leaves and Isolated Etio-chloroplasts

The appearance and development of the oxygen exchanging capacity of greening barley leaves were measured using a manometric technique and an oxygen race electrode. An oxygen evolution could first be detected after one hour of greening. During the first hour of greening a light-dependent oxygen uptake was observed. The oxygen evolving capacity, calculated on a chlorophyll weight basis, showed a fast rise in activity during the first hours of greening. A maximal activity was reached after 5 to 10 hours of greening; the oxygen evolution then declined. Using oxygen electrodes different aspects of the electron transport in etio-chloroplasts prepared from the greening barley leaves were also investigated. The activity in photosystem I and II, as well as the cooperation between the two photosystems, were studied by measuring the oxygen exchange from the etio-chloroplasts in the absence and presence of added oxidants and reductants. An activity in photosystem I could be detected already after 5 minutes of greening. The activity of photosystem I, when calculated on a chlorophyll basis, had the same appearance as the oxygen evolution from the intact plant material. An activity in photosystem II and a cooperation between the two photosystems were first detected after 3 hours of greening. After about 15 hours of greening a cooperation corresponding to that from chloroplasts prepared from normal green leaves was observed.     

Redescription of Grania monochaeta (Michaelsen), a Marine Enchytraeid (Oligochaeta) from South Georgia (SW Atlantic)

Enchytraeus monochaetus Michaelsen is redescribed as Grania monochaeta. It is distinguished from other Grania species by two main characters: its morphology of spermathecae, and its setal distribution, the latter being unique within the genus owing to the presence of dorsal setae in preclitellar segments.     

Exome Sequencing and Functional Validation in Zebrafish Identify GTDC2 Mutations as a Cause of Walker-Warburg Syndrome

Whole-exome sequencing (WES), which analyzes the coding sequence of most annotated genes in the human genome, is an ideal approach to studying fully penetrant autosomal-recessive diseases, and it has been very powerful in identifying disease-causing mutations even when enrollment of affected individuals is limited by reduced survival. In this study, we combined WES with homozygosity analysis of consanguineous pedigrees, which are informative even when a single affected individual is available, to identify genetic mutations responsible for Walker-Warburg syndrome (WWS), a genetically heterogeneous autosomal-recessive disorder that severely affects the development of the brain, eyes, and muscle. Mutations in seven genes are known to cause WWS and explain 50%-60% of cases, but multiple additional genes are expected to be mutated because unexplained cases show suggestive linkage to diverse loci. Using WES in consanguineous WWS-affected families, we found multiple deleterious mutations in GTDC2 (also known as AGO61). GTDC2's predicted role as an uncharacterized glycosyltransferase is consistent with the function of other genes that are known to be mutated in WWS and that are involved in the glycosylation of the transmembrane receptor dystroglycan. Therefore, to explore the role of GTDC2 loss of function during development, we used morpholino-mediated knockdown of its zebrafish ortholog, gtdc2. We found that gtdc2 knockdown in zebrafish replicates all WWS features (hydrocephalus, ocular defects, and muscular dystrophy), strongly suggesting that GTDC2 mutations cause WWS.     

Redescriptions of Phallodrilus parthenopaeus Pierantoni and P. obscurus Cook (Oligochaeta, Tubificidae)

The type species of Phallodrilus Pierantoni, 1902, P. parthenopaeus Pierantoni, 1902; is redescribed on the basis of new material from W Scotland. The species is characterized by its specific spermathecal and penial setae, its very slender atria, and its long spermathecal ducts. Sexually fully mature specimens of P. obscurus Cook, 1969 are described for the first time, on the basis of material from New Jersey (E USA). The new material shows that this species possesses 5 to 9 penial setae in each ventral bundle of segment XI, and that its atria are coated with a relatively thick musculature.     

Designing cyclopentapeptide inhibitor as potential antiviral drug for dengue virus ns5 methyltransferase

NS5 methyltransferase (Mtase) has a crucial role in the replication of dengue virus. There are two active sites on NS5 Mtase i.e., SAM and RNA-cap binding sites. Inhibition of the NS5 Mtase activity is expected to prevent the propagation of dengue virus. This study was conducted to design cyclic peptide ligands as enzyme inhibitors of dengue virus NS5 Mtase through computational approach. Cyclopentapeptides were designed as ligand of SAM binding site as much as 1635 and 736 cyclopentpeptides were designed as ligand of RNA-cap binding site. Interaction between ligand and NS5 Mtase has been conducted on the Docking simulation. The result shows that cyclopentapeptide CTWYC was the best peptide candidate on SAM binding site, with estimated free binding energy -30.72 kca/mol. Cyclopentapeptide CYEFC was the best peptide on RNA-cap binding site with estimated free binding energy -22.89 kcal/mol. Both peptides did not have tendency toward toxicity properties. So it is expected that both CTWYC and CYEFC ligands could be used as a potential antiviral drug candidates, which can inhibit the SAM and RNA-cap binding sites of dengue virus NS5 Mtase.