Iron Enhancement of Ascorbate Toxicity

Iron has been shown to enhance ascorbate-induced damage to both acetylcholine esterase and E. coli B in a manner analogous to previous studies with ascorbate and copper ions. It is suggested that the mechanism of damage entails interaction of iron with biological macromolecules, followed by its reduction by ascorbate. Subsequently, the iron (11) could participate in generating hydroxyl radicals from hydrogen peroxide via the Fenton reaction, which in turn, could damage biomolecules in a site-specific and multiple hit fashion. The high abundance of iron in biological systems, especially in certain storage disorders, may indicate an important toxicological role of the combination of iron and ascorbate.     

Methyloligella halotolerans gen. nov., sp. nov. and Methyloligella solikamskensis sp. nov., two non-pigmented halotolerant obligately methylotrophic bacteria isolated from the Ural saline environments

Two newly isolated halotolerant obligately methylotrophic bacteria (strains C2^T and SK12^T) with the serine pathway of C₁ assimilation are described. The isolates are strictly aerobic, Gram negative, asporogenous, non-motile rods, forming rosettes, multiplying by binary fission. Mesophilic and neutrophilic, accumulate intracellularly compatible solute ectoine and poly-β-hydroxybutyrate. The novel strains are able to grow at 0 up to 16% NaCl (w/v), optimally at 3–5% NaCl. The major cellular fatty acids are C_18:1ω7c and C_19:0cyc and the prevailing quinone is Q-10. The predominant phospholipids are phosphatidylcholine, phosphatidylglycerol, phosphatidyldimethylethanolamine and phosphatidylethanolamine. Assimilate NH₄⁺ by glutamate dehydrogenase and via the glutamate cycle (glutamine synthetase and glutamate synthase). The DNA G + C contents of strains C2^T and SK12^T are 60.9 and 60.5 mol% (Tm), respectively. 16S rRNA gene sequence similarity between the two new isolates are 99% but below 94% with other members of the Alphaproteobacteria thus indicating that they can be assigned to a novel genus Methyloligella. Rather low level of DNA–DNA relatedness (53%) between the strains C2^T and SK12^T indicates that they represent two separate species of the new genus, for which the names Methyloligella halotolerans gen. nov., sp. nov. and Methyloligella solikamskensis sp. nov. are proposed. The type strain of Methyloligella halotolerans is C2^T (=VKM B-2706^T = CCUG 61687^T = DSM 25045^T) and the type strain of Methyloligella solikamskensis is SK12^T (=VKM B-2707^T = CCUG 61697^T = DSM 25212^T).     

Comparative Genome Analysis Reveals Cyanidiococcus gen. nov., A New Extremophilic Red Algal Genus Sister to Cyanidioschyzon (Cyanidioschyzonaceae,Rhodophyta)

The taxonomic placement of strains belonging to the extremophilic red alga Galdieria maxima has been controversial due to the inconsistent phylogenetic position inferred from molecular phylogenetic analyses. Galdieria maxima nom. inval. was classified in this genus based on morphology and molecular data in the early work, but some subsequent molecular phylogenetic analyses have inferred strains of G. maxima to be closely related to the genus Cyanidioschyzon. To address this controversy, an isolated strain identified as G. maxima using the rbcL gene sequence as the genetic barcode was examined using a comprehensive analysis across morphological, physiological, and genomic traits. Herein are reported the chloroplast-, mitochondrion-, and chromosome-level nuclear genome assemblies. Comparative analysis of orthologous gene clusters and genome arrangements suggested that the genome structure of this strain was more similar to that of the generitype of Cyanidioschyzon, C. merolae than to the generitype of Galdieria, G. sulphuraria. While the ability to uptake various forms of organic carbon for growth is an important physiological trait of Galdieria, this strain was identified as an ecologically obligate photoautotroph (i.e., the inability to utilize the natural concentrations of organic carbons) and lacked various gene models predicted as sugar transporters. Based on the genomic, morphological, and physiological traits, we propose this strain to be a new genus and species, Cyanidiococcus yangmingshanensis. Re-evaluation of the 18S rRNA and rbcL gene sequences of the authentic strain of G. maxima, IPPAS-P507, with those of C. yangmingshanensis suggests that the rbcL sequences of “G. maxima” deposited in GenBank correspond to misidentified isolates.     

Neoleptonema yongpilii E.-Y. Lee & I.K. Lee,gen. et sp. nov. (Phaeophyceae), based on morphological characters and RuBisCO spacer sequences

An elachistacean epiphyte, Neoleptonema yongpilii E.-Y. Lee & I.K. Lee, gen. et sp. nov., is reported from Korean coasts. The plants are distinguished by having unbranched assimilatory filaments with intercalary plurilocular sporangia as well as lateral plurilocular sporangia from the cortex. The new genus differs from the genera Leptonematella P. Silva and Halothrix Reinke by having pod-shaped plurilocular sporangia on the medulla, and from Elachista Duby and Proselachista Y.P. Lee & Garbary by having intercalary plurilocular sporangia and a poorly developed medulla. The phylogenetic relationships of Neoleptonema yongpilii were inferred from the spacer sequences between the genes coding for the large and small subunits of the RuBisCO gene. The new genus is a member of a poorly resolved clade consisting of several genera within the Elachistaceae, within which it is more closely related to Halothrix and Elachista nipponica than to Leptonematella.     

A critical survey of the evidence for the occurrence of Helminthocladia agardhiana Dixon [H. hudsoni J. Ag. pro parte] in Europe

An examination of cystocarps from the rarely collected southern Australian alga currently known as Lomentaria corynephora (J. Agardh) Kylin has shown it to be a member of the Rhodymeniales but incorrectly placed in Lomentaria. As it is not referable to any of the genera presently ascribed to the order, the new genus Semnocarpa is proposed to accommodate its suite of unique features. Semnocarpa closely resembles Lomentaria in habit and in having basally septate branches, a peripheral network of widely separated medullary filaments around the cell-free (but mucilage-filled) centres of the main and lateral axes, gland cells directed inwardly on scattered medullary cells, and tetrasporangia produced laterally from surface cortical cells that line deep cavities in the branch surfaces. Features of the mature cystocarp, however, strongly differentiate Semnocarpa from Lomentaria. The carposporophyte has a fusion cell in which outlines of the component cells remain discernible, as opposed to having a fully consolidated fusion cell, and is laxly enclosed in a system of filaments derived from surrounding inner cortical cells. The cystocarp is entirely submerged within the bearing branch, there being no protuberant pericarp derived from the outer cortex of the sort previously thought to be a uniform feature of the family Lomentariaceae and virtually all Rhodymeniales. These features suggest that Semnocarpa is likely to be a highly derived member of the Lomentariaceae. A second species is newly described from material collected in Western Australia. Semnocarpa minuta sp. nov. differs from S. corynephora in its exclusively epiphytic habit, two-layered medulla, smaller stature and extensive crustose holdfast.     

An ultrastructural study of Marsupiomonas pelliculata gen. et sp. nov., a new member of the Pedinophyceae

A new species, Marsupiomonas pelliculata gen. et sp. nov. (Pedinophyceae), is described. A single flagellum emerges from a deep pit with a distinctive thickened margin. The flagellum has rigid fibrillar hairs which are probably formed in the perinuclear space. A short second flagellar basal body lies within the cell close to the basal body of the emergent flagellum and the flagellar root system consists of striated and microtubular roots. There is a distinctive theca covering all but the anterior end of the cell and also a single large bright green chloroplast with an immersed pyrenoid surrounded by a starch shell. The wide salinity tolerance of the species is discussed in relation to its distribution in estuarine and salt marsh habitats. The salient features of the new species—the insertion of the emergent flagellum into a deep pit and the possession of a theca—are also seen in Pedinomonas tenuis, and it is suggested that P. tenuis could be transferred to the new genus Marsupiomonas. The class Pedinophyceae now includes three genera (Pedinomonas, Resultor and Marsupiomonas) and the distinguishing features are discussed.     

Multivariate geometry as an approach to algal community analysis

Multivariate analyses are put in the context of more usual approaches to phycological investigations. The intuitive common-sense involved in methods of ordination, classification and discrimination are emphasised by simple geometric accounts which avoid jargon and matrix algebra. Warnings are given that artifacts result from technique abuses by the naive or over-enthusiastic. An analysis of a simple periphyton data set is presented as an example of the approach. Suggestions are made as to situations in phycological investigations, where the techniques could be appropriate. The discipline is reprimanded for its neglect of the multivariate approach.     

A new,three‐dimensionally preserved enantiornithine bird (Aves: Ornithothoraces) from Gansu Province,north‐western China

In recent years, the Lower Cretaceous (Aptian) Xiagou Formation has yielded approximately 100 avian partial skeletons, many with soft‐tissue traces, from sites in the Changma Basin of Gansu Province, north‐western China. The most abundant taxon amongst these is the ornithuromorph Gansus yumenensis, but enantiornithines have also been identified in the sample. Here we describe two incomplete, semi‐articulated appendicular skeletons, the first consisting of a partial left pelvic girdle and complete pelvic limb, and the second comprised of a nearly complete right pelvic limb. Both specimens bear characteristics diagnostic of Enantiornithes, and are referred to a new taxon, Qiliania graffini gen. et sp. nov. The exceptional, three‐dimensional preservation of these specimens (compared to the crushed, nearly two‐dimensional condition of most other Early Cretaceous avian fossils) reveals new information regarding enantiornithine anatomy, evolution, and diversity. © 2011 The Linnean Society of London, Zoological Journal of the Linnean Society, 2011, 162 , 201–219.     

A new genus of miniaturized and pug-nosed gecko from South America (Sphaerodactylidae: Gekkota)

Sphaerodactyl geckos comprise five genera distributed across Central and South America and the Caribbean. We estimated phylogenetic relationships among sphaerodactyl genera using both separate and combined analyses of seven nuclear genes. Relationships among genera were incongruent at different loci and phylogenies were characterized by short, in some cases zero length, internal branches and poor phylogenetic support at most nodes. We recovered a polyphyletic Coleodactylus, with Coleodactylus amazonicus being deeply divergent from the remaining Coleodactylus species sampled. The C. amazonicus lineage possessed unique codon deletions in the genes PTPN12 and RBMX while the remaining Coleodactylus species had unique codon deletions in RAG1. Topology tests could not reject a monophyletic Coleodactylus, but we show that short internal branch lengths decreased the accuracy of topology tests because there were not enough data along short branches to support one phylogenetic hypothesis over another. Morphological data corroborated results of the molecular phylogeny, with Coleodactylus exhibiting substantial morphological heterogeneity. We identified a suite of unique craniofacial features that differentiate C. amazonicus not only from other Coleodactylus species, but also from all other geckos. We describe this novel sphaerodactyl lineage as a new genus, Chatogekko gen. nov. We present a detailed osteology of Chatogekko, characterizing osteological correlates of miniaturization that provide a framework for future studies in sphaerodactyl systematics and biology.     

Middle Eocene Pelagornithidae and Gaviiformes (Aves) from the Ukrainian Paratethys

Abstract: We describe avian remains from Novopskov, a new middle Eocene marine locality in Ukraine. The fossils constitute the most substantial collection of Palaeogene bird bones from Eastern Europe and contribute to a better knowledge of the Paratethyan seabird fauna. Most of the specimens belong to Pelagornithidae (bony‐toothed birds), and two species of very different size can be distinguished. The larger of these is tentatively referred to Dasornis sp., the smaller to Odontopteryx toliapica. The specimens include skeletal elements that were not described for Palaeogene bony‐toothed birds and document previously unknown morphological differences between Palaeogene and Neogene Pelagornithidae. It is argued that the purported crane Eobalearica tugarinovi, from the middle Eocene of Kyrgyzstan, is probably also a bony‐toothed bird. A new genus and species of small Gaviiformes, Colymbiculus udovinchenkoi, is described, which is the earliest fossil record of a loon from Europe, preceding the next oldest specimens by more than 10 myr. The Ukrainian fossils document profound differences between middle Eocene and extant marine avifaunas of Europe, and whereas the middle Eocene Paratethyan avifauna appears to have been similar to that of the North Sea with regard to pelagornithid diversity, the absence of prophaethontids and relative abundance of Gaviiformes may indicate faunistic differences concerning the remaining seabirds.