The Existence of Chlorophyll c in the Chl b-Containing,Light-Harvesting Complex of the Green Alga Mantoniella squamata (Prasinophyceae)

The prasinophycean alga Mantoniella contains, in addition to Chl a and b, at least a third green pigment which is functionally active in the light-harvesting antenna. This third Chl was isolated in order to elucidate its chemical structure. The absorption and fluorescence spectra were measured not only from the purified pigment but also from its pheophytin and its methylpheophorbide. The spectra were compared with those of authentic Chl c-1 and c-2, which were isolated from the diatom Nitzschia sp. and with Mg-DVPP (purified from Rhodobacter). The results show that the pigment from Mantoniella compares best with Chl c-1. In order to clarify the spectral data, Chl c-1 and c-2, Mg-DVPP, and the pigment from Mantoniella were subjected to a chromatographic system that is able to separate these porphyrins. The chromatographic analysis clearly shows that the pigment from Mantoniella co-migrates with Chl c-1 and not with the bacterial pigment. Mantoniella is the first organism which has been demonstrated to contain Chl a, b, and authentic c.     

The Proterozoic History and Present State of Cyanobacteria

The paper delves into the main regularities of the distribution of fossil microorganisms in Precambrian rocks, beginning from the Archean Eon about 3.5 billion years ago and ending in the Cambrian Period about 0.5 billion years ago. The paper analyzes facial peculiarities in the lateral differentiation of microfossils in Proterozoic basins and the main stages of temporal changes in fossil cyanobacterial communities, which are based on the irreversible succession of physicochemical conditions on the Earth and the evolution of eukaryotic microorganisms and their incorporation into prokaryotic ecosystems. To gain insight into Proterozoic fossil record, modern stratified cyanobacterial mats built up from layers of prokaryotes are considered. The analysis of phosphatization, carbonatization, and silification processes in modern algal–bacterial communities suggests that analogous processes took place in Proterozoic microbiotas. A comparison of modern and Precambrian living forms confirms the inference that cyanobacterial communities are very conservative and have changed insignificantly both morphologically and physiologically during the past two billion years.     

Phylogeny and Molecular Evolution of the Green Algae

The green lineage (Viridiplantae) comprises the green algae and their descendants the land plants, and is one of the major groups of oxygenic photosynthetic eukaryotes. Current hypotheses posit the early divergence of two discrete clades from an ancestral green flagellate. One clade, the Chlorophyta, comprises the early diverging prasinophytes, which gave rise to the core chlorophytes. The other clade, the Streptophyta, includes the charophyte green algae from which the land plants evolved. Multi-marker and genome scale phylogenetic studies have greatly improved our understanding of broad-scale relationships of the green lineage, yet many questions persist, including the branching orders of the prasinophyte lineages, the relationships among core chlorophyte clades (Chlorodendrophyceae, Ulvophyceae, Trebouxiophyceae and Chlorophyceae), and the relationships among the streptophytes. Current phylogenetic hypotheses provide an evolutionary framework for molecular evolutionary studies and comparative genomics. This review summarizes our current understanding of organelle genome evolution in the green algae, genomic insights into the ecology of oceanic picoplanktonic prasinophytes, molecular mechanisms underlying the evolution of complexity in volvocine green algae, and the evolution of genetic codes and the translational apparatus in green seaweeds. Finally, we discuss molecular evolution in the streptophyte lineage, emphasizing the genetic facilitation of land plant origins.     

Physical map and gene organization of the mitochondrial genome from the unicellular green alga Platymonas (Tetraselmis) subcordiformis (Prasinophyceae)

the entire mitochondrial genome (mt genome) of the unicellular green alga Platymonas subcordiformis (synonym Tetraselmis subcordiformis; Prasinophyceae) was cloned and a physical map for the four restriction enzymes Hind III, Eco RI, Bgl II and Xba I was constructed. The mt genome of P. subcordiformis is a 42.8 kb circular molecule, coding for at least 23 genes. Hybridization and sequence analysis revealed the presence of a ca. 1.5 kb inverted repeat on the mt genome of P. subcordiformis. Phylogenetic analyses based on sequences of several coxI genes were carried out. Our data indicate that mitochondria from P. subcordiformis and from land plants form a natural, monophyletic group.     

Studies on the ultrastructure and taxonomy of the genusTetraselmis (Prasinophyceae)

Ultrastructural investigations on many isolates ofTetraselmis have revealed that the species have characteristic fine structural features of the pyrenoid and it was proposed (Horiet al., 1982) that the genus be subdivided into four subgenera. In the present study of this series, species of the subgenusPrasinocladia, includingTetraselmis marina, T. verrucosa andT. verrucosa f.rubens, are described in detail.     

Petsamomyces, a new genus of organic-walled microfossils from the coal-bearing deposits of the Early Proterozoic, Kola Peninsula

A new genus of organic-walled microfossils of supposed fungal origin, Petsamomyces Belova gen. nov., is described from the black shales of the Pechenga complex of the Early Proterozoic (Kola Peninsula). The find testifies to the development of eukaryotic heterotrophic microorganisms as early as 2 Ga ago.     

Isolation,purification, and characterization of flagellar scales from the green flagellateTetraselmis striata (Prasinophyceae)

Summary Flagellar scales from the green flagellateTetraselmis striata (Prasinophyceae) were isolated, purified by isopycnic cesium chloride-gradient and zonal sucrose gradient centrifugation and their structure and biochemical composition investigated. Three types of flagellar scales were purified to more than 90% purity, a fourth type up to 75% purity. In addition to the previously known types of flagellar scales (pentagonal scales, rod-shaped scales, hair-scales), a novel scale type (i.e., the knotted scales) was discovered. New information about the asymmetric structure of the rod-shaped scales is presented and consequently they are renamed man scales. Flagellar scales consist mainly of carbohydrate (50–70%), significant amounts of protein (11% of dry weight) were found only in pentagonal scales. The main sugars (90%) of the pentagonal and man scales are the unusual 2-keto-sugar acids 3-deoxy-5-O-methyl-2-octulosonic acid (5 OMeKDO), 3-deoxy-2-heptulosaric acid (DHA), and 3-deoxy-2-octulosonic acid (KDO), the knotted scales contain as major sugars galactose and arabinose in addition to KDO and 5 OMeKDO but lack DHA. 13 major polypeptides were identified in flagellar scales by one-dimensional SDS-PAGE, 11 of these are of high molecular mass (>116 kDa). While the majority of polypeptides was found associated with pentagonal scales, at least 4 polypeptides were tentatively assigned to the hair-scales and knotted scales.Abbreviations CSF crude scale fraction - PS pentagonal scales - MS man scales - HS hair-scales - KS knotted scales - SDS-PAGE sodium dodecyl sulfate polyacrylamide gel electrophoresis - DHA 3-deoxylyxo-2-heptulosaric acid - 5 OMeKDO 3-deoxy-5-O-methyl-manno-2-octulosonic acid - KDO 3-deoxy-manno-2-octulosonic acid - GA Golgi apparatus     

Phylogeny of genera of Prasinophyceae and Pedinophyceae (Chlorophyta) deduced from molecular analysis of the rbcL gene

A molecular approach was used to study the phylogeny of 12 genera of Prasinophyceae and two genera of Pedinophyceae (Chlorophyta). The study was based on maximum likelihood and LogDet transformation analyses of a 1094-basepair fragment of the large subunit of ribulose-l,5-bisphosphate carboxylase/oxygenase (rbcL), a chloroplast-encoded gene. With the inclusion of homologous sequences from two cyanobacteria (Anabaena PCC 7120 and Anacystis nidulans (Richter) Drout et Daily) and a prochlorophyte(Prochlorothrix hollandica Burger-Wiersma, Stal et Mur), the maximum likelihood reconstructions suggested that species referred to the family Mamiellaceae are secondarily reduced forms rather than the most ancestral eukaryotic green plants. The systematic position of Micromonas pusilla (Butcher) Manton et Parke based on morphology is ambiguous, but the rbcL-based inferences indicated that it is related to the Mamiellaceae. In spite of being morphologically very different, Pycnococcus and Pseudoscourfieldia appear to be closely related, and it is suggested that Pseudoscourfieldia be included in the family Pycnococcaceae. The phylogenetic framework when based on first and second codon positions identifies the Mamiellaceae, Pycnococcaceae, Halosphaer-aceae, and Mesostigmataceae as monophyletic families, whereas the Chlorodendraceae appears to be of polyphyletic origin. However, this branching pattern was not confirmed by bootstrap analyses. The analysts based on a LogDet transformation matrix also supported the close relationship among species belonging to the Mamiellaceae (including Micromonas pusiila) and that the pedinophytes form a separate group. The branching pattern among most of the prasinophyte genera was not resolved giving a tree topology similar to those obtained in the bootstrap analyses. A relative rate test showed that the rbcL gene in the Pedinophyceae has evolved at a slower speed relative to that in the Prasinophyceae.     

Springtails (Hexapoda,Collembola) of Tundra Landscapes of the Kola Peninsula

A quantitative study of collembolan assemblages on the Barents Sea coast of the Kola Peninsula was performed. Altogether, 104 collembolan species of 55 genera and 16 families were found. Analysis of the faunal composition revealed its high similarity to that of the faunas of the neighboring regions of Norway as well as a marked decline in species richness as compared to the Siberian analogues. A high share of littoral forms with increased vagility and the predominance of species with “southern” (= boreal) and “western” distribution patterns are the main characteristics of the fauna studied; only a few true arctic forms were found, always with low abundance and occurrence levels. Most of the studied collembolan assemblages are characterized by the dominance of a few species which inhabit a part of or the entire range of plant communities. As a result, collembolan assemblages under various types of vegetation cover in different landscape elements often show only insignificant differences.     

Ecological-faunistical review of fish parasites in the Umbozero Lake (the Kola Peninsula)

Data on fish infestation by parasites in the Umbozero Lake are given. 90 species of parasites were identified including 16 species of Myxosporea, 2 Suctoria, 18 Peritricha, 12 Monogenea, 13 Cestoda, 18 Trematoda, 5 Nematoda, 2 Acanthocephala, 2 Hirudinea, and 2 species of Crustacea. Character of parasites' distribution in fishes of this lake and ecological peculiarities in the host-parasite system are demonstrated.     

Brachiopods from the family Ambocoeliidae George (Order Spiriferida) from the Emsian (Lower Devonian) of northeastern Russia

Brachiopods from the family Ambocoeliidae George from the Emsian (Lower Devonian) of northeastern Russia are described: Bisinocoelia despecta sp. nov.; Yakutospirifer gen. nov. with the type species Y. krivensis sp. nov.; Micospirifer gen. nov. with the type species M. simplex sp. nov.; Kolymospirifer gen. nov. with the type species K. optatus sp. nov. (subfamily Ambocoeliinae); Datnospirifer gen. nov. with the type species D. alius sp. nov.; Khalimospirifer gen. nov. with the type species Kh. microscopicus sp. nov.; Gerospirifer gen. nov. with the type species G. normalis sp. nov., and G. gerensis sp. nov.; Dogdospirifer gen. nov. with the type species D. yolkini sp. nov. (subfamily Rhynchospiriferinae).     

Representatives of the family Bochianitidae (Ammonoidea) from the Lower Cretaceous of the Crimean Mountains

The heteromorph ammonites of the family Bochianitidae from the Lower Cretaceous of the Crimean Mountains are revised. The validity of the genus Janenschites, separated from the genus Bochianites is confirmed. The species Bochianites neocomiensis (d’Orbigny), B. goubechensis Mandov, B. levis sp. nov. and B. crymensis sp. nov. are described from the Berriasian and the species Janenschites oosteri (Sarasin et Schöndelmayer) and J. incisus sp. nov. are described from the Lower Barremian. The family Bochianitidae first appeared at the beginning of the Berriasian in the southern regions (Africa and the Crimea), and spread to the northern regions of western Europe in the Valanginian-Hauterivian.     

哈萨克斯坦中部(Kaydagul Formation) 欧洲水松的角质层结构分析

研究了哈萨克斯坦中部上渐新统/下中新统的欧洲水松(Glyptostrobus europaeus (Brongn.) Ung.)的枝叶微形态结构,并利用扫描电子显微镜和光学显微镜与"现存最近亲缘种"--水松(G. pensilis C. Koch)的表皮特征进行了比较.     

Assessment of the Reproduction Efficiency of the Atlantic salmon Salmo salar (Salmonidae) in the Kola River (Kola Peninsula) Based on Data on the Density of Juveniles

Journal of Ichthyology - In the Kola River (Kola Peninsula), on the basis of cluster analysis of long-term density data in the nursery areas of underyearlings, wild and wild + hatchery parr of...     

Proterozoic microfossils from the Mara Dolomite Member, Emmerugga Dolomite, McArthur Group, from the Northern Territory, Australia

An assemblage of microfossils from the mid-Proterozoic Mara Dolomite Member of the Emmerugga Dolomite, McArthur Group, Northern Territory, Australia, has been studied. The assemblage contains 10 species, of which one is new. The classification of Proterozoic microfossils is reviewed and a morphographic scheme adopted. The new assemblage is compared with other McArthur Group assemblages, and the differences between the assemblages are explained in terms of environmental differences. Comparison with other microfossil assemblages world-wide, suggests that these assemblages have stratigraphic potential.