Lineage-specific molecular probing reveals novel diversity and ecological partitioning of haplosporidians

Haplosporidians are rhizarian parasites of mostly marine invertebrates. They include the causative agents of diseases of commercially important molluscs, including MSX disease in oysters. Despite their importance for food security, their diversity and distributions are poorly known. We used a combination of group-specific PCR primers to probe environmental DNA samples from planktonic and benthic environments in Europe, South Africa and Panama. This revealed several highly distinct novel clades, novel lineages within known clades and seasonal (spring vs autumn) and habitat-related (brackish vs littoral) variation in assemblage composition. High frequencies of haplosporidian lineages in the water column provide the first evidence for life cycles involving planktonic hosts, host-free stages or both. The general absence of haplosporidian lineages from all large online sequence data sets emphasises the importance of lineage-specific approaches for studying these highly divergent and diverse lineages. Combined with host-based field surveys, environmental sampling for pathogens will enhance future detection of known and novel pathogens and the assessment of disease risk.     

Labdane diterpenes from Marrubium velutinum and Marrubium cylleneum

From the aerial parts of Marrubium velutinum and Marrubium cylleneum, seven labdane diterpenes, velutine A, 15-epi-velutine A, velutine B, 15-epi-velutine B, velutine C, cyllenine A and 15-epi-cyllenine A, have been isolated together with five known diterpenes and four known flavones. The structures of the isolated compounds were established by means of NMR [(1)H-(1)H-COSY, (1)H-(13)C-HMQC, HMBC, HMQC-TOCSY, NOESY] and MS spectral analyses. Complete NMR assignments are reported for known compounds.     

Semicircular canal system in early primates

Mammals with more rapid and agile locomotion have larger semicircular canals relative to body mass than species that move more slowly. Measurements of semicircular canals in extant mammals with known locomotor behaviours can provide a basis for testing hypotheses about locomotion in fossil primates that is independent of postcranial remains, and a means of reconstructing locomotor behaviour in species known only from cranial material. Semicircular canal radii were measured using ultra high resolution X-ray CT data for 9 stem primates (“plesiadapiforms”; n = 11), 7 adapoids (n = 12), 4 omomyoids (n = 5), and the possible omomyoid Rooneyia viejaensis (n = 1). These were compared with a modern sample (210 species including 91 primates) with known locomotor behaviours. The predicted locomotor agilities for extinct primates generally follow expectations based on known postcrania for those taxa. “Plesiadapiforms” and adapids have relatively small semicircular canals, suggesting they practiced less agile locomotion than other fossil primates in the sample, which is consistent with reconstructions of them as less specialized for leaping. The derived notharctid adapoids (excluding Cantius) and all omomyoids sampled have relatively larger semicircular canals, suggesting that they were more agile, with Microchoerus in particular being reconstructed as having had very jerky locomotion with relatively high magnitude accelerations of the head. Rooneyia viejaensis is reconstructed as having been similarly agile to omomyids and derived notharctid adapoids, which suggests that when postcranial material is found for this species it will exhibit features for some leaping behaviour, or for a locomotor mode requiring a similar degree of agility.     

Osmia species (Hymenoptera, Megachilidae) from the southeastern United States with modified facial hairs: taxonomy, host plants, and conservation status

We describe females and males of Osmia (Melanosmia) calaminthaesp. n., an apparent floral specialist on Calamintha ashei (Lamiaceae), and provide observations on the behavior of female bees on flowers of this plant. We also provide diagnostic information for Osmia (Diceratosmia) conjunctoides Robertson, stat. n., and synonymize Osmia (Diceratosmia) subfasciata miamiensis Mitchell with Osmia conjunctoidessyn. n. Females of both Osmia calaminthae and Osmia conjunctoides are unique among North American Osmia for having short, erect, simple facial hairs, which are apparent adaptations for collecting pollen from nototribic flowers. Osmia calaminthae is currently only known from sandy scrub at four nearby sites in the southern Lake Wales Ridge in Highlands County, Florida, USA, while Osmia conjunctoides is known from limited but widespread sites in the southeastern USA. We discuss the conservation status of both species based on known or speculated floral associates and distributions.     

Transforming growth factor-beta and insulin-like signalling pathways in parasitic helminths

The signal transduction pathways involved in regulating developmental arrest in the free-living nematode, Caenorhabditis elegans, are fairly well characterised. However, much less is known about how these processes may influence the developmental timing and maturation in helminth parasites. Here, we provide an overview of two signalling pathways implicated in the regulation of dauer larva formation in C. elegans, the insulin-like signalling pathway and the transforming growth factor-beta pathway, and explore what is known about these signalling pathways in a variety of parasitic helminths. Understanding the differences about how these pathways are affected by environmental cues in free-living versus parasitic species of helminths may provide insights into novel mechanisms for the control or prevention of helminth-induced disease.     

Degraded limonoids from Melia azedarach and biogenetic implications

The unique series of C-2'-acylated C-glycosylflavones is extended by the discovery of the C-8-glucosyl derivatives 2'-O-galloylvitexin and 2'-O-galloylorientin and their C-6 analogues 2'-O-galloylisovitexin and 2'-O-galloylisoorientin, representing the first described O-galloyl-C-glycosylflavones. They are accompanied in the aerial parts of Pelargonium reniforme by the known non-galloylated parent analogues vitexin, orientin, isovitexin and isoorientin, as well as several known flavonoid-O-glycosides. The structures of these compounds were established from spectroscopic studies. Differentiation between C-glycosylation at C-6 and C-8 is discussed on the basis of the effects of dynamic rotational isomerism.     

Ent-3,4-seco-labdane and ent-labdane diterpenoids from Croton stipuliformis (Euphorbiaceae)

From a methanolic extract of the leaves of Croton stipuliformis, three ent-3,4-seco-labdanes (1-3) and an ent-labdane (4) together with the known compounds 6-hydroxynidorellol (5), maravuic acid, and sitosterol were isolated and identified from their spectroscopic data. The absolute stereochemistry of compound 4 was determined by application of Mosher's method in the NMR tube.     

A newly-identified lineage of Schistosoma

Because of their role in causing schistosomiasis, flukes of the genus Schistosoma are the best known of all digeneans. The genus has traditionally been divided into four familiar species groups. Here we report on three poorly known species of Schistosoma, one of which, Schistosoma hippopotami, is known from the hippopotamus, one of which is provisionally identified as Schistosoma edwardiense, another hippo parasite, and a third that has not previously been described. All were collected from freshwater snails obtained from Lake Edward, western Uganda, the type locality for both known hippo schistosomes. The three different kinds of schistosome cercariae differ from one another in size, and all are readily differentiated by their long tail stems from the cercariae of human-infecting species. Furthermore, each was recovered from a different genus of snail host, Biomphalaria sudanica, Bulinus truncatus or Ceratophallus natalensis. Molecular analysis, based on 8350 bases of combined nuclear and mitochondrial DNA, groups these three long tail-stem cercariae into a well supported clade that does not associate with any of the recognised species groups. The placement of this clade, basal to all African species plus several Asian species, suggests that there has been an ancient association between Schistosoma and hippos. This new African Schistosoma clade advocates the need for further modification of the traditional species group-based classification. Two of the four species groups are paraphyletic. It also suggests that Schistosoma has been remarkably plastic with respect to adapting to snail hosts-three distantly related genera of planorbid snails have been exploited by worms within a single clade. Finally, it adds a new layer of complexity to deciphering the origins of Schistosoma, often considered to be African but recently challenged as being Asian. In the late Cenozoic the distribution of hippo species straddled both Africa and Asia and they may have provided a means for the introduction of blood flukes to Africa.     

Terpenoids from Guarea guidonia

The volatile oil and the methanol extract from the leaves of Guarea guidonia, Meliaceae, were individually submitted to chromatographic separation. A sesquiterpene (2S*)-eudesma-5,7-dien-2-ol, together with six known ones, were isolated from the volatile oil. The methanolic extract afforded two known and two new triterpenes (23S*)-cycloart-24-ene-3 beta,23-diol and (23R*)-cycloart-24-ene-3 beta,23-diol, besides three known sesquiterpenes, one known diterpene and two steroids. Their structures were established on the basis of spectrocopic data, mainly by 1H and 13C NMR spectroscopic analyses.     

Constituents of two Flourensia species

The MeOH extract of aerial parts of Flourensia riparia Grisebach (Asteraceae) afforded a sesquiterpene lactone, 4beta-hydroxy-4,10alpha-dimethyl-7alphaH,8alphaH-eudesman-11-ene-8,12-olide, together with septuplinolide, its isomer at positions C-5 and C-10. In addition, known flavonoids, p-hydroxyacetophenone derivatives, carabrone and isoalantolactone were identified. Three known flavonoids and a benzofuran were isolated from Flourensia campestris Wedd.     

Description of two new species of Clivina Latreille (Coleoptera, Carabidae, Clivinini) from southeastern United States

Two new species of the genus Clivina Latreille are described. One, Clivina choatei Bousquet & Skelley, belongs to the nominotypical subgenus and is known from six specimens collected in northern Florida. The species is structurally similar to Clivina myops Bousquet, known only from the holotype found in North Carolina, but differs among others by its smaller size and wider elytral striae. The second species, Clivina alabama Bousquet, belongs to the subgenus Antroforceps Barr and is known from two specimens collected in north-central Alabama. The species is structurally most similar to Clivina sasajii Ball, known only from Latimer County in Oklahoma, but differs among others in the absence of eyes and in having the pronotum and elytra proportionally wider.     

Trap diversity and evolution in the family Droseraceae

We review trapping mechanisms in the carnivorous flowering plant family Droseraceae (order Caryophyllales). Its members are generally known to attract, capture, retain and digest prey animals (mainly arthropods) with active snap-traps (Aldrovanda, Dionaea) or with active sticky flypaper traps (Drosera) and to absorb the resulting nutrients. Recent investigations revealed how the snap-traps of Aldrovanda vesiculosa (waterwheel plant) and Dionaea muscipula (Venus’ flytrap) work mechanically and how these apparently similar devices differ as to their functional morphology and shutting mechanics. The Sundews (Drosera spp.) are generally known to possess leaves covered with glue-tentacles that both can bend toward and around stuck prey. Recently, it was shown that there exists in this genus a higher diversity of different tentacle types and trap configurations than previously known which presumably reflect adaptations to different prey spectra. Based on these recent findings, we finally comment on possible ways for intrafamiliar trap evolution.     

Ingenane diterpenoids from Euphorbia esula

An extensive study of metabolites present in Euphorbia esula led to isolation of 16 ingenane diterpenoids 1-16 together with the known ingenane derivative 17 and four known cycloartane triterpenoids. Their structures were elucidated on the basis of spectroscopic studies and comparison with known related compounds. All the compounds were assayed for their inhibitory activity against human HeLa cervical cancer cell line.     

Diketopiperazines from two strains of South China Sea sponge-associated microorganisms

The paper reports the isolation and structural elucidation of seven diketopiperazines from the title microorganisms. Although all isolates are known, three of which were isolated from the actinomycetes for the first time. And this is also the first report to isolate four DKPs from the D. avara-associated microorganism.     

Pterocarpans from Bituminaria morisiana and Bituminaria bituminosa

The aerial parts of Mediterranean papilionaceous plants Bituminaria morisiana and B. bituminosa afforded, along with known phenolics, the prenylated pterocarpans bitucarpin A and B, whose structure was elucidated by spectroscopic techniques. A known isoflavonoid (8-prenyldaidzein) was also obtained for the first time as a genuine plant constituent. The accumulation of pterocarpans at the expense of biogenetically more primitive shikimate metabolites like furanocoumarins or isoflavonoids supports the inclusion of this plant, once part of the genus Psoralea, into the distinct genus Bituminaria.     

Charminarone,a seco-pseudoguaianolide from Parthenium hysterophorus

A novel sesquiterpenoid, charminarone, the first seco-pseudoguaianolide, has been isolated along with several known compounds from the whole plant of Parthenium hysterophorus. The structure of the new compound has been settled as 1,10-seco-dihydroisoparthenin 1,10-dione from its spectral data as well as from its conversion by reductive coupling reaction with Zn/TiCl(4) reagent to the known compound, anhydrodihydroisoparthenin. The reagent Zn/TiCl(4) has been used here for the first time to construct the seven membered ring of a pseudoguaianolide sesquiterpenoid.     

The effects of the slug biological control agent, Phasmarhabditis hermaphrodita (Nematoda), on non-target aquatic molluscs

The nematode Phasmarhabditis hermaphrodita is used as a commercial biological control agent of slugs in the UK. Although it is known to affect other terrestrial mollusc species, its effects on freshwater molluscs are not known. The present study investigated the effects of P. hermaphrodita on the survival of juvenile Lymnaea stagnalis and Physa fontinalis, two common freshwater snails, at 'spray tank' concentration and a 50% diluted 'spray tank' concentration over a 14-day period. Survival of L. stagnalis was significantly reduced at both application levels but P. fontinalis suffered no mortalities over the experimental period. The possible differential mechanisms of pathology between the two host species are discussed.     

Fossil frogs (Anura) from Shanwang (Middle Miocene; Shandong Province, China)

The early middle Miocene biota from the Shanwang locality in eastern China is one of the most diverse and well preserved in the world. This overall richness contrasts with its low diversity of anuran amphibians. The most abundant anurans are representatives of the family Ranidae, which remains the dominant group in the extant anuran fauna of China. Besides Rana basaltica Young, some other ranids can be recognised at the locality, and are clearly distinguishable from R. basaltica based on their larger size and different proportions. Ranids are also represented by a developmental series of tadpoles, ranging from approximately Nieuwkoop-Faber (NF) stage 43 to a metamorphosing tadpole of NF stage 57. This is the first known developmental series of fossil non-pipoid Anura outside the Pelobatidae. In addition to the ranids, Bufo shandongensis nov. sp. (replacement name for B. linquensis), represented by one of the earliest known articulated bufonid skeletons, is described and illustrated. Another large toad, Macropelobates linquensis (Yang) nov. comb., is re-described; it can be assigned to the Pelobatoidea, with a possible relationship to the Scaphiopodidae, and can be considered, based on the presence of a large spade, a tibiofibula shorter than the femur, and a short astragalus and calcaneus, to be the earliest known anuran burrower.     

Vampires in the oceans: predatory cercozoan amoebae in marine habitats

Vampire amoebae (vampyrellids) are predators of algae, fungi, protozoa and small metazoans known primarily from soils and in freshwater habitats. They are among the very few heterotrophic naked, filose and reticulose protists that have received some attention from a morphological and ecological point of view over the last few decades, because of the peculiar mode of feeding of known species. Yet, the true extent of their biodiversity remains largely unknown. Here we use a complementary approach of culturing and sequence database mining to address this issue, focusing our efforts on marine environments, where vampyrellids are very poorly known. We present 10 new vampyrellid isolates, 8 from marine or brackish sediments, and 2 from soil or freshwater sediment. Two of the former correspond to the genera Thalassomyxa Grell and Penardia Cash for which sequence data were previously unavailable. Small-subunit ribosomal DNA analysis confirms they are all related to previously sequenced vampyrellids. An exhaustive screening of the NCBI GenBank database and of 454 sequence data generated by the European BioMarKs consortium revealed hundreds of distinct environmental vampyrellid sequences. We show that vampyrellids are much more diverse than previously thought, especially in marine habitats. Our new isolates, which cover almost the full phylogenetic range of vampyrellid sequences revealed in this study, offer a rare opportunity to integrate data from environmental DNA surveys with phenotypic information. However, the very large genetic diversity we highlight within vampyrellids (especially in marine sediments and soils) contrasts with the paradoxically low morphological distinctiveness we observed across our isolates.