3D-microanatomy and histology of the hydrothermal vent gastropod Lurifax vitreus Warén & Bouchet, 2001 (Heterobranchia: Orbitestellidae) and comparisons with Ectobranchia

Up to now, the internal anatomy of representatives of only two of three recent genera of the Orbitestellidae have been described. Herein, a species of the third genus, Lurifax vitreus from hydrothermal vent sites of the North Atlantic, is examined on the basis of semi-thin sections. Data on three-dimensional (3D)-anatomy and histology are provided in order to increase knowledge of the family. In addition, the original serial sections of Orbitestella wareni and Microdiscula cf. subcanaliculata of the original paper by Ponder (Journal of Molluscan Studies 56:515–532, 1990a) were reinvestigated and compared with Lurifax vitreus. Although Lurifax vitreus is significantly larger than the two former genera, it is again devoid of a gill but shows opponent ciliary stripes and a pallial tentacle. Most orbitestellid characters reflect plesiomorphic conditions among the Heterobranchia; autapomorphies of the family include an orthostrophic protoconch, massive jaws, a diagnostic radula type, paired posterior pedal glands with a common opening, and a pedally innervated copulatory organ. In agreement with actual molecular trees, our data suggest a placement of Orbitestellidae as basic Heterobranchia outside of Ectobranchia (Valvatoidea).     

Anatomy and systematics of bathyphytophilid limpets (Mollusca, Archaeogastropoda) from the northeastern Pacific

Bathyphytophilus diegensis sp. n. is described on basis of shell and radula characters. The radula of another species of Bathyphytophilus is illustrated, but the species is not described since the shell is unknown. Both species feed on detached blades of the surfgrass Phyllospadix carried by turbidity currents into continental slope depths in the San Diego Trough. The anatomy of B. diegensis was investigated by means of semithin serial sectioning and graphic reconstruction. ‘The shell is limpet-like; the protoconch resembles that of pseudococculinids and other lepetclloids. The radula is a distinctive, highly modified rhipidoglossate type with close similarities to the lepetellid radula. The anatomy falls well into the lepetelloid bauplan and is in general similar to that of Pseudococculinidae and Pyropcltidae. Apomorphic features are the presence of gill-leaflets at both sides of the pallial roof (shared with certain pseudococculinids), the lack of jaws, and in particular many enigmatic pouches (bacterial chambers?) which open into the postcrior oesophagus. Autapomorphic characters of shell, radula and anatomy confirm the placement of Bathyphytophilus (with Aenigmabonus) in a distinct family, Bathyphytophilidac Moskalev, 1978. As revealed by a cladistic study, the Bathyphytophilidae should be classified within the Lepetelloidea close to the Lepetellidae, Pyropeltidae, and Pseudococculinidae.     

Towards a sound definition of Skeneidae (Mollusca,Vetigastropoda): 3D interactive anatomy of the type species, <Emphasis Type="Italic">Skenea serpuloides</Emphasis> (Montagu, 1808) and comments on related taxa

The family Skeneidae, originally characterized by their minute size, lack of nacre and a rhipidoglossate radula, is an example of a polyphyletic assemblage. Most ‘skeneimorph’ species are based on the shell, sometimes the radula and rarely features of the external body. Data on internal anatomy are almost entirely lacking. In order to provide a complete anatomical data set with histological information, we applied serial semithin sectioning and 3D reconstructions to describe and visualize the anatomy of the type species of Skeneidae, Skenea serpuloides (Montagu, 1808). In addition, comparative data are provided for three other Skeneidae, Skenea profunda Friele, 1879; Dillwynella lignicola Marshall, 1988 and Dillwynella voightae Kunze, 2011 as well as for a tiny turbinid-like species, Lodderena minima (Tenison-Woods, 1887). We diagnose Skeneidae as trochoidean vetigastropods with combined epipodial sense organs (ESOs), neck lobes, eyes with a closed vesicle and the diagnostic propodial penis. Other features include simultaneous hermaphroditism with distinct testis/vas deferens and ovary/oviduct, a urogenital opening with the right kidney and a distinct seminal receptacle. Several features of Skeneidae are explained by dwarfing through progenesis, and accordingly, we interpret paedomorphosis of various characters. In contrast, L. minima has a true hermaphroditic gland, but lacks of propodial penis and a receptaculum. Also, molecular data support an exclusion of Lodderena from the Skeneidae.     

The Anatomy of Melanodrymia aurantiaca Hickman,a Coiled Archaeogastropod from the East Pacific Hydrothermal Vents (Mollusca,Gastropoda)

The anatomy of Melanodrymia aurantiaca Hickman, 1984, a coiled archaeogastropod from the East Pacific hydrothermal vents, is described based on reconstructions of paraffin and semi-thin section series. Whereas the large protoconch with net-like sculpture and the lack of a secondary larval shell, the bipectinate gill lacking skeletal rods, the rhipidoglossate rasdula and in particular the hypoathroid nervous system with pedal cords reflect an archaeogastropod level of organization, the single set of pallial organs, the monotocard heart, the single left kidney, the glandular gonoduct and internal fertilization indicated by penis (males) and receptaculum (females) resemble conditions of higher streptoneurans. The latter similarities are regarded as convergences, however. The unique combination of primitive and advanced features as well as specific peculiarities (e.g. neural sexual dimorphism) prevents an inclusion of Melanodrymia aurantiaca in any of the known archaeogastropod groups. Based on similarity of snout formation and similar radula type several other recently described archaeogastropods (Peltospiroidea) are possibly related to M. aurantiaca.     

Parity-Violating Energy Shifts of Murchison L-Amino Acids are Consistent with an Electroweak Origin of Meteorite L-Enantiomeric Excesses

In 1996, four α-methyl amino acids in the Murchison meteorite—L-isovaline, L-α-methylnorvaline, L-α-methyl-allo-isoleucine and L-α-methyl-isoleucine—were found to show significant enantiomeric excesses of the L form, ranging from 2% to 9%. Their deuterium to hydrogen isotope ratios suggest they formed in the pre-solar interstellar gas cloud rather than during a later aqueous processing phase on the asteroid parent body. In this paper we apply the techniques of the preceding two papers to compute the parity-violating energy shifts of these amino acids. We find that, in the gas phase, the PVESs of the neutral L forms of all four Murchison α-methyl amino acids are decisively negative, and there is even some correlation between the magnitudes of the L-excesses and the magnitudes of the PVESs—all of which is at least consistent with an electroweak origin of the Murchison enantiomeric excesses.     

Anatomy and systematic affinity of Stanleya neritinoides (Smith, 1880), an enigmatic member of the thalassoid gastropod species flock in Lake Tanganyika, East Africa (Cerithioidea, Paludomidae)

The radiation of gastropods in Lake Tanganyika is an ideal system for testing competing hypotheses of species flock formation. Yet, much of the basic biology of these species remains unknown. In an ongoing effort to understand the evolution of Tanganyikan gastropods, we here describe Stanleya neritinoides. Alcohol‐preserved material of the soft parts is rare, consequently, the systematic position of the species, and a repeated suggested affinity to Tanganyicia rufofilosa, have been based primarily on features of the shell. However, features of the radula and operculum are unique and do not suggest an affinity to any other Tanganyikan species. Thus, S. neritinoides has remained a particularly poorly known and enigmatic member of the species flock. This investigation confirmed that several aspects of internal and external anatomy are shared between S. neritinoides, T. rufofilosa, and other Tanganyikan gastropods, but that S. neritinoides is unique in features of the radula and seminal receptacle. Moreover, S. neritinoides differs from T. rufofilosa in features of the foregut, midgut, hindgut, kidney, nervous system, reproductive system and reproductive strategy. These new data are inconsistent with an interpretation of identity of Stanleya and Tanganyicia. In addition, given the pervasive differences between the two, a sister‐group relationship between the two is unlikely. More precise systematic placement of S. neritinoides awaits the establishment of a phylogenetic framework for all Tanganyikan gastropods.     

Faunistic similarity and endemism of earthworms in east mediterranean region

The analysis presents earthworm distribution in eight designated tectonic units (C—Cyprus, EP—East Pondites, ET—East Taurus block, Sc—Sakarya continent, Kb—Kırşehir block, L—the Levant, TM—Taurus–Menderes block, WP—West Pondites) in the East Mediterranean region (EM). It represents a full list of earthworm species (N = 81) of the region and reveals significant faunal similarities between Sc + WP, and between Kb + TM. The new Sc + WP unit is characterized by the presence of archaic (Spermophorodrilus) as well as modern earthworm fauna. In contrast, the second newly established Kb + TM unit is characterized by poorly presented earthworm autochthonous fauna and by a lack of endemic species. The analysis done on the species list (N = 73) representing the autochthonous family Lumbricidae showed statistically supported separation of L and EP between themselves and from other designated units. The Levant, part of the Arabian tectonic plate, is characterized by a high level of endemism in ancient (Healyella) and modern (Dendrobaena, Perelia) genera, and by the lack of archaic genera. The EP harbors unique species representing archaic (Eophila), ancient (Healyella), and modern (Allolobophora, Aporrectodea, Dendrobaena and Eisenia) earthworm genera in the EM. The analysis also indicates origin of earthworm fauna in TM and faunistic relationships among the designated units. Clearly, the present-day division of the EM earthworm fauna shows recognizable influences of tectonic history.     

Shortage of Lipid-radical Cycles in Membranes as a Possible Prime Cause of Energetic Failure in Aging and Alzheimer Disease

Polyunsaturated fatty acids (PUFA) and α-tocopherol (α-TOH) are the most oxygen-sensitive constituents of cells. α-TOH is a member of the vitamin E family that is considered the most important lipophilic antioxidant in cell membranes. Its importance is emphasized by the involvement of oxidative stress in injury to the central nervous system and neurodegenerative diseases. Currently, α-TOH transfer protein (TTP), is believed to play a significant role in maintaining the vitamin status but the presence of α-TOH in membranes is required but not sufficient to protect the membranes against lipid hydroperoxides (LOOH) formation. The lipid-radical theory presented in this review considers the role of two membrane factors—α-tocopherol and cytochrome b5; these factors secure the functioning of lipid-radical cycles and the participation of lipid-radical reactions in the key membrane processes. The prominent intermembrane reaction realized via a protein–lipid interaction, during which electron transport from cytochrome b5—located in the outer membrane—to peroxyl radical (LOO^·)—located in inner membrane—causes reduction of the peroxyl radical: cyt.b5red + LOO^· → cyt.b5ox + LOO⁻. This secures an interaction of α-TOH with other intermediate, LOO⁻ excepting the LOOH formation. The discussion will be focused on the consequences of ineffective electron transfer to LOO^· and excessive oxidative pathway of metabolism of the PUFA (LOO^· → LOOH). Assuming the operation of cytochrome b5/α-tocopherol-controlled lipid-radical cycles and considering the role of the cycles in membrane bioenergetics we arrive at a model for effective function of adenine nucleotide translocator and ATP synthesis in mitochondria. This paper summarizes our experimental evidence that the oxidative and non-oxidative pathways of metabolism of PUFA via their respective intermediates occur in the cells. While this fact is not widely appreciated it may be relevant to elucidation of new mechanisms of neurodegenerative diseases.     

Expression in promoter variant of the ERα gene in bos taurus liver

Due to the variant functions that estrogens play in the regulation of reproduction, development of the mammary gland, growth and differentiation of cells, estrogen receptors and their genes are considered as a candidates for the markers of production and functional traits in farm animals, including cattle. In the earliest study, a 2853-bp bovine ER gene 5′-region was PCR amplified and sequenced. Moreover, for the first time, a polymorphism was described within 5′ region of the bovine ERα gene—A/G transition lying upstream at position 2591 from acceptor splice site +85, possibly within its promoter—which could be recognized with RFLP-BglI. In other study we are found second polymorphism—A/G transition at position 1213 from acceptor splice site +85, located in promoter for exon B. We have examined the specific mRNA expression of ERα in various genotypes using real-time RT-PCR. We used four animals from each genotype group—AG, GG for BglI and AA, AG for SnaBI—to analyse liver ERα expression at the level of Real-time PCR. Liver samples were taken from the 16 young Friesian bulls of the different ERα genotypes, slaughtered at the local abattoir. As shown by Real-Time PCR, on the livers of animals with different genotype ERα mRNA for BglI polymorphism we didn’t found variability, but for SnaBI we have found variability between AG and AA genotypes.     

Molecular phylogenetic studies of Lachnum and its allies based on the Japanese material

Molecular phylogenetic studies were carried out based on ITS-5.8S rDNA, the D1–D2 region of the large subunit rRNA gene, RPB2, and combined data of D1–D2 and RPB2 as well as these three genes on 36 species among 7 genera for Lachnum and allied genera in the family Hyaloscyphaceae. In the combined data of all three regions, seven strongly supported clades were obtained. The same clades were also recognized in most of the trees based on each gene, and the combined data of D1–D2 and RPB2, although some of them were not strongly supported. Four clades represented Albotricha, Brunnipila, Incrucipulum, and Lachnellula, respectively, whereas Lachnum was distributed to the remaining three clades. The molecular phylogenies strongly supported a group of species with granulate hairs, and we suggest the concept of Lachnaceae should be restricted to these species. Based on the molecular phylogenetic analysis, three new combinations—Incrucipulum longispineum, I. radiatum, and Lachnellula pulverulentum from Lachnum—are proposed.     

Morphology and anatomy of palm seedlings

A historical survey of studies of seedling morphology and anatomy in the palm family is given. The traditional three germination types—adjacent ligular, remote ligular, and remote tubular—that have been commonly recognized are reevaluated. The study includes seedlings of 63 species, representing the six subfamilies of palms. Morphological characteristics of germination patterns and the anatomy of the eophyll are described. The results of this survey show that germination types determined by the length of the hyperphyll (cotyledonary petiole) are not completely valid. Instead, a combination of characters such as primary root orientation, coleoptile length, number of cataphylls, and eophyll plication correspond to the most recent classification of the family, and represent a better way of describing germination.     

Redox-dependent conformational changes in eukaryotic cytochromes revealed by paramagnetic NMR spectroscopy

Cytochrome c (Cc) is a soluble electron carrier protein, transferring reducing equivalents between Cc reductase and Cc oxidase in eukaryotes. In this work, we assessed the structural differences between reduced and oxidized Cc in solution by paramagnetic NMR spectroscopy. First, we have obtained nearly-complete backbone NMR resonance assignments for iso-1-yeast Cc and horse Cc in both oxidation states. These were further used to derive pseudocontact shifts (PCSs) arising from the paramagnetic haem group. Then, an extensive dataset comprising over 450 measured PCSs and high-resolution X-ray and solution NMR structures of both proteins were used to define the anisotropic magnetic susceptibility tensor, Δχ. For most nuclei, the PCSs back-calculated from the Δχ tensor are in excellent agreement with the experimental PCS values. However, several contiguous stretches—clustered around G41, N52, and A81—exhibit large deviations both in yeast and horse Cc. This behaviour is indicative of redox-dependent structural changes, the extent of which is likely conserved in the protein family. We propose that the observed discrepancies arise from the changes in protein dynamics and discuss possible functional implications.     

A catshark (Neoselachii, Carcharhiniformes, Scyliorhinidae) from the Late Jurassic of Germany

A new genus and species of catshark (Neoselachii, Carcharhiniformes, Scyliorhinidae) —Bavariscyllium tischlingeri n. gen. n. sp. — is described from the Late Jurassic (Tithonian) Plattenkalke of South Germany. The new taxon is known from a single articulated skeleton having the skull, the trunk and all of the fins preserved. The position of the first dorsal fin in relation to the pelvic fins and the dental morphology shows that the specimen belongs into the neoselachian family Scyliorhinidae. Two isolated tooth crowns from the Kimmeridgian of North Germany are identified asBavariscyllium sp. and represent the oldest unambigious fossil record of the Scyliorhinidae known so far.     

Gastropod fauna of the Cameroonian coasts

 Eighteen species of gastropods were encountered living near and within the large coastal swamps, mangrove forests, intertidal flats and the rocky shore of the Cameroonian coast of the Atlantic Ocean. These represent members of the subclasses Neritimorpha, Caenogastropoda, and Heterostropha. Within the Neritimorpha, representatives of the genera Nerita, Neritina, and Neritilia could be distinguished by their radula anatomy and ecology. Within the Caenogastropoda, representatives of the families Potamididae with Tympano-tonos and Planaxidae with Angiola are characterized by their early ontogeny and ecology. The Pachymelaniidae are recognized as an independent group and are introduced as a new family within the Cerithioidea. Littorinimorpha with Littorina, Assiminea and Potamopyrgus as well as Neogastropoda (Thais) and Heterostropha (Melampus and Onchidium) are described and compared with representatives of the Caribbean and Indo-Pacific province. Received: 15 January 1999 / Accepted: 26 July 1999     

Spawning and early ontogenesis of the littoral polychaete <Emphasis Type="Italic">Namanereis littoralis</Emphasis> (Grube, 1876) (Nereididae,Namanereidinae)

For the first time, under laboratory conditions, development of the polychaete Namanereis littoralis (Grube, 1876) is investigated. Under conditions of the Sea of Japan, its reproduction occurs in July and is confined to the season of monsoon rains. Fertilization is external. Spawning manifests no epitocous transformations. Fecundity is low, ovicells are rich in yolk, and development is nonpelagic, lecithotrophic, embryonized, characterized by a high rate—5–8 days—and occurs in mucous clutches up to hatching of benthic juveniles. Temperature and salinity optima of development are 22–27°C and 16–21‰, respectively, characterizing the species as subtropical brackish-water by its origin. Archaic and specialized traits are noted in the early ontogenesis of N. littoralis.     

Diversity and biogeography of testate amoebae

Testate amoebae are amoeboid protists inhabiting a test (shell). They occur globally in soils, wetlands and freshwater, especially peats and mosses. They are of ancient origin, dating from at least the Mesozoic, with possible ancestors as old as the Neoproterozoic. Approximately 2,000 taxa have been described—a number which could easily rise to 4,000 with comprehensive recording. Whilst many protists appear to be cosmopolitan as morphospecies, some of the larger testate species (exceeding 100 μm) have long been considered, controversially, to be geographically restricted. Definitive conclusions have often been confounded by gaps in distributional data and misidentification. Recent increases in recording from previously little known regions, and the rise of molecular taxonomy, have started to resolve outstanding issues—processes still far from complete. Accordingly, biogeographical studies have concentrated on “flagship” species—those which can be identified with certainty and are sufficiently recorded to determine their ecological ranges. Apodera vas (Certes) has been proved to be largely restricted to the Gondwanaland continents and sub-Antarctic islands, but absent from the Holartic despite the availability of much suitable habitat. An early analysis postulated a Mesozoic origin of the species and a distribution influenced by continental drift. Recent molecular evidence could imply a later origin. Either way, its current distribution is clearly influenced by the pattern of global wind currents and lack of lowland tropical habitat. By contrast a “Gondwana-tropical” group of species appears to be restricted to latitudes unaffected by glaciation. Instances of local endemism, such as restriction to a single island, are also known, which await molecular evidence for substantiation. Special Issue: Protist diversity and geographic distribution. Guest editor: W. Foissner.     

Comparative buccal anatomy in Helisoma (mollusca,pulmonata, basommatophora)

Dissections were performed to document buccal anatomy in three species of the pulmonate genus Helisoma Swainson, 1840. The 28 muscles which are responsible for radular feeding in these animals are organized in three concentric and integrated envelopes. The deepest of these includes muscles which manipulate the radula about the odontophoral cartilage. Elements of the middle envelope direct movements of the cartilage within the buccal cavity, and muscles of the outer envelope control movements of the buccal mass within the cephalic haemocoel. Motion analysis by videomicrography showed that muscles of the middle and outer envelopes contribute to the action of radular feeding by acting as antagonists to other muscles and to hydrostatic elements of the buccal apparatus. Observations of radular dentition showed that although each of the three species examined has a unique radula, especially with regard to the specific details of tooth shape, all resemble a radula characteristic of the Planorbidae with regard to other, more general, aspects of ribbon architecture.