Morphofunctional organization of reserve stem cells providing for asexual and sexual reproduction of invertebrates

Published and original data indicating evolutionary conservation of the morphofunctional organization of reserve stem cells providing for asexual and sexual reproduction of invertebrates are reviewed. Stem cells were studied in representatives of five animal types: archeocytes in sponge Oscarella malakhovi (Porifera), large interstitial cells in colonial hydroid Obelia longissima (Cnidaria), neoblasts in an asexual race of planarian Girardia tigrina (Platyhelmintes), stem cells in colonial rhizocephalans Peltogasterella gracilis, Polyascus polygenea, and Thylacoplethus isaevae (Arthropoda), and colonial ascidian Botryllus tuberatus (Chordata). Stem cells in animals of such diverse taxa feature the presence of germinal granules, are positive for proliferating cell nuclear antigen, demonstrate alkaline phosphatase activity (a marker of embryonic stem cells and primary germ cells in vertebrates), and rhizocephalan stem cells express the vasa-like gene (such genes are expressed in germline cells of different metazoans). The self-renewing pool of stem cells is the cellular basis of the reproductive strategy including sexual and asexual reproduction.     

Gamet Ultrastructure in Some Species of the Genus <Emphasis Type="Italic">Icelus</Emphasis> (Pisces: Cottidae)

With the help of scanning and transmission electron microscopy, the morphology of spermatozoa of Icelus spiniger and egg envelopes of I. spiniger and I. spatula has been studied. Spermatozoa have an elongated head flattened on one side, an insignificant centriolar fossa, and numerous mitochondria in the middle section. The axoneme has a structure described by the formula 9 + 2. The envelopes of oocytes of both species have a follicular membrane, chorion, and zona radiata.     

New <Emphasis Type="Italic">slbo</Emphasis>-Gal4 driver lines for the analysis of border cell migration during <Emphasis Type="Italic">Drosophila</Emphasis> oogenesis

Border cell (BC) migration during Drosophila oogenesis is an excellent model for the analysis of the migratory and invasive cell behavior. Most studies on BC migration have exploited a slbo-Gal4 driver to regulate gene expression in these cells or to mark them. Here, we report that the slbo-Gal4 transgene present in the line #6458 from the Bloomington Stock Center is inserted within chickadee (chic), a gene encoding the actin-binding protein Profilin, which promotes actin polymerization and is known to be involved in cell migration. The chic⁶⁴⁵⁸ mutation caused by the transgene insertion behaves as a null chic allele and is homozygous lethal. To evaluate possible effects of chic⁶⁴⁵⁸ on the assessment of BC behavior, we generated new lines bearing the slbo-Gal4 transgene inserted into different second chromosome loci that do not appear to be involved in cell migration. Using these new lines and the slbo-Gal4-chic⁶⁴⁵⁸ line, we defined the functional relationships between the twinfilin (twf) and chic in BC migration. Migration of BCs is substantially reduced by mutations in twf, which encodes an actin-binding protein that inhibits actin filament assembly. The defects caused by twf mutations are significantly suppressed when the slbo-Gal4-chic⁶⁴⁵⁸, but not the new slbo-Gal4 drivers were used. These findings indicate twf and chic interact and function antagonistically during BC migration in Drosophila oogenesis.     

Clavicipitaceous entomopathogens: new species in <Emphasis Type="Italic">Metarhizium</Emphasis> and a new genus <Emphasis Type="Italic">Nigelia</Emphasis>

In several surveys in the tropical forests in Thailand, specimens that looked morphologically similar to Metarhizium martiale and Cordyceps variegata, as well as other Metarhizium species were collected and cultured in vitro. A combined phylogeny of several genes including the small (18S) and large (28S) subunits of the ribosomal DNA, elongation factor 1-α (TEF), RNA polymerase II subunits 1 and 2 (RPB1, RPB2) genes has shown these to be new taxa in the Clavicipitaceae. Nigelia is described as a new genus closely related to Metarhizium, to the scale insect pathogens Aschersonia (Hypocrella), Samuelsia and Moelleriella, and to plant pathogens in Claviceps and Balansia, and other relatives. Nigelia comprises M. martiale and a new species Nigelia aurantiaca, which has been found infecting lepidopteran larvae and which produces pseudoimmersed, obliquely arranged, obpyriform perithecia with curved or bent ostioles and with whole (non-separating) cylindric ascospores. Metarhizium chaiyaphumense, M. kalasinense, M. prachinense, M. samlanense, and M. takense are described as new species of Metarhizium. Metarhizium martiale is transferred to Nigelia, and Paecilomyces reniformis is transferred to Metarhizium.     

New records of the Late Carboniferous ammonoid genus <Emphasis Type="Italic">Eoshumardites</Emphasis> in the Kolyma–Omolon Region,and notes on the evolution of Eoshumarditidae

A new species, Eoshumardites popowi Kutygin sp. nov., is described from the Upper Carboniferous of the upper reaches of the Paren’ River in the Gizhiga Province of the Kolyma–Omolon Region. The ontogeny of the sutural and shell morphology of the new species is described. In the level of sutural organization, E. popowi occupies an intermediate position between E. lenensis (Popow) and E. sublenensis Klets. It has been suggested that Eoshumardites evolved from the genus Syngastrioceras rather than Aktubites and, on this basis, a new monotypic endemic family, Eoshumarditidae, has been proposed. This family existed in the Kasimovian synchronously with members of the family Parashumarditidae.     

<Emphasis Type="Italic">Batrachochytrium salamandrivorans</Emphasis> and the Risk of a Second Amphibian Pandemic

Amphibians are experiencing devastating population declines globally. A major driver is chytridiomycosis, an emerging infectious disease caused by the fungal pathogens Batrachochytrium dendrobatidis (Bd) and Batrachochytrium salamandrivorans (Bsal). Bd was described in 1999 and has been linked with declines since the 1970s, while Bsal is a more recently discovered pathogen that was described in 2013. It is hypothesized that Bsal originated in Asia and spread via international trade to Europe, where it has been linked to salamander die-offs. Trade in live amphibians thus represents a significant threat to global biodiversity in amphibians. We review the current state of knowledge regarding Bsal and describe the risk of Bsal spread. We discuss regional responses to Bsal and barriers that impede a rapid, coordinated global effort. The discovery of a second deadly emerging chytrid fungal pathogen in amphibians poses an opportunity for scientists, conservationists, and governments to improve global biosecurity and further protect humans and wildlife from a growing number of emerging infectious diseases.     

On Two Little Known Species of Leaf Beetles (Coleoptera,Chrysomelidae) from the South Urals

120 years ago G.G. Jacobson described two species of leaf beetles from the South Urals that have remained poorly studied until recently. Chrysolina roddi, previously known only from the foothills and low mountains of the South Urals, the low Zhiguli Mountains, and the limestone cliffs on the Don River, is recorded here for the first time from the alpine tundra of the Iremel massif; its host plant in the alpine zone is the small alpine lovage Pachypleurum simplex (= Ligusticum mutellinoides), family Apiaceae. Two species of the subgenus Crositops, Ch. roddi and Ch. kabaki, are presently treated as foothill-alpine disjunct taxa. The distribution of Ch. poretzkyi, described from the low-montane part of Bashkortostan, also shows a foothill-alpine disjunction. Alpine populations of Ch. poretzkyi are described here as a new subspecies Ch. (Arctolina) poretzkyi olschwangi Mikhailov subsp. n. Revision of the type of Ch. poretzkyi that has long been considered lost confirms that this species belongs to the subgenus Arctolina, in disagreement with its previous placement in the subgenus Pleurosticha. Within Arctolina, the identity of Ch. tundralis and its differences from Ch. poretzkyi are discussed.     

A new soybean rust resistance allele from PI 423972 at the <Emphasis Type="Italic">Rpp4</Emphasis> locus

Phakopsora pachyrhizi is a fungal pathogen and the cause of Asian soybean rust. P. pachyrhizi was first detected in the continental USA in 2004 and has since been a threat to the soybean industry. There are six described loci that harbor resistance to P. pachyrhizi (Rpp) genes. The resistance of PI 423972 was previously shown to be within 5 cM of the Rpp4 locus of PI 459025B, yet had differential reactions when challenged with P. pachyrhizi isolates India 1973 and Taiwan 1972. In this study, the resistance of PI 423972 was mapped to a 187.5 kb interval between the SNP markers GSM0543 and GSM0387 on chromosome 18 (51,397,064 to 51,584,617 bp, Glyma.Wm82.a2) that overlaps the interval for Rpp4 and is designated as Rpp4-b. A unique haplotype is described for PI 423972 that separates it from PI 459025B, 32 North American soybean ancestors, and all described sources of Rpp gene resistance.     

Identification of a second <Emphasis Type="Italic">PAD1</Emphasis> in <Emphasis Type="Italic">Brettanomyces bruxellensis</Emphasis> LAMAP2480

Volatile phenols are aromatic compounds produced by some yeasts of the genus Brettanomyces as defense against the toxicity of hydroxycinnamic acids (p-coumaric acid, ferulic acid and caffeic acid). The origin of these compounds in winemaking involves the sequential action of two enzymes: coumarate decarboxylase and vinylphenol reductase. The first one converts hydroxycinnamic acids into hydroxystyrenes, which are then reduced to ethyl derivatives by vinylphenol reductase. Volatile phenols derived from p-coumaric acid (4-vinylphenol and 4-ethylphenol) have been described as the major contributors to self-defeating aromas associated with stable, gouache, wet mouse, etc., which generates large economic losses in the wine industry. The gene responsible for the production of 4-vinylphenol from p-coumaric acid has been identified as PAD1, which encodes a phenylacrylic acid decarboxylase. PAD1 has been described for many species, among them Candida albicans, Candida dubliniensis, Debaryomyces hansenii and Pichia anomala. In Brettanomyces bruxellensis LAMAP2480, a 666 bp reading frame (DbPAD) encodes a coumarate decarboxylase. Recent studies have reported the existence of a new reading frame belonging to DbPAD called DbPAD2 of 531 bp, which could encode a protein with similar enzymatic activity to PAD1. The present study confirmed that the transformation of Saccharomyces cerevisiae strain BY4722 with reading frame DbPAD2 under the control of the B. bruxellensis ACT1 promoter, encodes an enzyme with coumarate decarboxylase activity. This work has provided deeper insight into the origin of aroma defects in wine due to contamination by Brettanomyces spp.     

The high diversity of <Emphasis Type="Italic">Lotus corniculatus</Emphasis> endosymbionts in soils of northwest Spain

The diversity of rhizobia that establish symbiosis with Lotus corniculatus has scarcely been studied. Several species of Mesorhizobium are endosymbionts of this legume, including Mesorhizobium loti, the type species of this genus. We analysed the genetic diversity of strains nodulating Lotus corniculatus in Northwest Spain and ten different RAPD patterns were identified among 22 isolates. The phylogenetic analysis of the 16S rRNA gene showed that the isolated strains belong to four divergent phylogenetic groups within the genus Mesorhizobium. These phylogenetic groups are widely distributed worldwide and the strains nodulate L. corniculatus in several countries of Europe, America and Asia. Three of the groups include the currently described Mesorhizobium species M. loti, M. erdmanii and M. jarvisii which are L. corniculatus endosymbionts. An analysis of the recA and atpD genes showed that our strains belong to several clusters, one of them very closely related to M. jarvisii and the remanining ones phylogenetically divergent from all currently described Mesorhizobium species. Some of these clusters include L. corniculatus nodulating strains isolated in Europe, America and Asia, although the recA and atpD genes have been sequenced in only a few L. corniculatus endosymbionts. The results of this study revealed great phylogenetic diversity of strains nodulating L. corniculatus, allowing us to predict that even more diversity will be discovered as further ecosystems are investigated.     

An overlooked hybrid between the two diploid <Emphasis Type="Italic">Chenopodium</Emphasis> species in Central Europe determined by microsatellite and morphological analysis

The presence and extent of hybridization within the Chenopodium album aggregate (Amaranthaceae) is still unclear. Although many hybrid combinations have been described, their existence in the field has never been systematically studied and verified. The main aim of this study was to ascertain the extent of interspecific hybridization between the diploid species C. ficifolium and C. suecicum using highly variable nuclear microsatellite markers. Due to the absence of such kind of molecular markers for the whole C. album group, we divided the analysis into two steps: (1) Eleven microsatellite loci designed for the closely related species C. quinoa were cross-amplified in five Eurasian species of the C. album diploid–polyploid complex, i.e. C. album s.s. (6x), C. striatiforme (4x), C. strictum (4x), C. ficifolium (2x) and C. suecicum (2x); (2) For the detection of interspecific hybridization between C. ficifolium and C. suecicum, we sampled 480 individuals from five localities in Central Europe. We also investigated morphological differences between the parental taxa and their hybrid and devised a key for their determination. Analysis of variation in microsatellite loci using Bayesian methods, PCoA and Neighbour-joining tree identified 32 F1 hybrids. These F1 hybrids, described here as C. paradoxum Mandák, formed a cluster between well-differentiated parental species, combining the morphological characters of both their parents. Moreover, genetic analyses also recognized several F2 or backcross hybrids, whose delimitation, mainly from C. suecicum and F1 hybrids, based on morphological characters, is problematic.     

The pleiotropic nature of <Emphasis Type="Italic">rib80, hit1</Emphasis>, and <Emphasis Type="Italic">red6</Emphasis> mutations affecting riboflavin biosynthesis in the yeast <Emphasis Type="Italic">Pichia guilliermondii</Emphasis>

The yeast Pichia guilliermondii is capable of riboflavin overproduction under iron deficiency. The rib80, hit1, and red6 mutants of this species, which exhibit impaired riboflavin regulation, are also distinguished by increased iron concentrations in the cells and mitochondria, morphological changes in the mitochondria, as well as decreased growth rates (except for red6) and respiratory activity. With sufficient iron supply, the rib80 and red6 mutations cause a 1.5–1.8-fold decrease in the activity of such Fe-S cluster proteins as aconitase and flavocytochrome b ₂, whereas the hit1 mutation causes a six-fold decrease. Under iron deficiency, the activity of these enzymes was equally low in all of the studied strains.     

Diversity and enzymatic potentialities of <Emphasis Type="Italic">Bacillus</Emphasis> sp. strains isolated from a polluted freshwater ecosystem in Cuba

Genotypic and phenotypic characterization of Bacillus spp. from polluted freshwater has been poorly addressed. The objective of this research was to determine the diversity and enzymatic potentialities of Bacillus spp. strains isolated from the Almendares River. Bacilli strains from a polluted river were characterized by considering the production of extracellular enzymes using API ZYM. 14 strains were selected and identified using 16S rRNA, gyrB and aroE genes. Genotypic diversity of the Bacillus spp. strains was evaluated using pulsed field gel electrophoresis. Furthermore, the presence of genetic determinants of potential virulence toxins of the Bacillus cereus group and proteinaceous crystal inclusions of Bacillus thuringiensis was determined. 10 strains were identified as B. thuringiensis, two as Bacillus megaterium, one as Bacillus pumilus and one as Bacillus subtilis. Most strains produced proteases, amylases, phosphatases, esterases, aminopeptidases and glucanases, which reflect the abundance of biopolymeric matter in Almendares River. Comparison of the typing results revealed a spatio-temporal distribution among B. thuringiensis strains along the river. The results of the present study highlight the genotypic and phenotypic diversity of Bacillus spp. strains from a polluted river, which contributes to the knowledge of genetic diversity of Bacilli from tropical polluted freshwater ecosystems.     

A new species ofScopulariopsis from soil

A new species ofScopularoipsis described from soil is characterized by the conidiophores, branches, and sporogenous cells being distinctly swollen. The conidia have a well-marked germ slit running more or less longitudinally down the spore. TheScopulariopsis state ofMicroascus doguetii is re-examined and evidence is presented which indicates that the striations on the walls of the spores are germ slits.     

Mealybugs of the genus <Emphasis Type="Italic">Fonscolombia</Emphasis> Licht. (Homoptera,Pseudococcidae) of the fauna of Russia and adjacent countries

The genus name Euripersia Borchs. is considered a junior synonym of Fonscolombia Licht. based on the absence of essential differences between type species of these genera. The key to Fonscolombia includes, in addition to the type species, nine species from Russia and adjacent countries. Eight of these species are redescribed and illustrated, F. butorinae Danzig et Gavrilov, 2005 has been recently described as new. Two species originally described in Euripersia do not belong to this genus. One is transferred to Trionymus Berg, and thus a new combination is established: Trionymus mongolicus (Danzig), comb. n. Synonymy of Euripersia caulicola with Phenacoccus incertus Kir. has been established recently (Danzig, 2005). Other species presently placed in Euripersia (Ben-Dov, 1994) need a revision. Lectotypes are designated for 4 nominal species. Fonscolombia is related to Phenacoccus Sign., the separation of these two genera is not clear. Fonscolombia is characterized by broad-oval and convex body, poorly developed anal lobes, short, 6-8-segmented (F. edentata and F. herbacea with 7–9-segmented) antennae, and cerarii present on the last abdominal segments only (C ₃ sometimes present). Most species live on roots of grasses (F. butorinae between leaves near soil, F. herbacea, on dicotyledonous herbs) and are characterized by ovoviviparity.