New hand bones of Hadropithecus stenognathus: implications for the paleobiology of the Archaeolemuridae

A partial, associated skeleton of Hadropithecus stenognathus (AHA-I) was discovered in 2003 at Andrahomana Cave in southeastern Madagascar. Among the postcranial elements found were the first hand bones (right scaphoid, right hamate, left first metacarpal, and right and left fifth metacarpals) attributed to this rare subfossil lemur. These hand bones were compared to those of extant strepsirrhines and catarrhines in order to infer the positional adaptations of Hadropithecus, and they were compared to those of Archaeolemur in order to assess variation in hand morphology among archaeolemurids. The scaphoid tubercle does not project palmarly as in suspensory and climbing taxa, and the hamate has no hook at all (just a small tubercle), which also points to a poorly developed carpal tunnel. There is a distinctive, radioulnarly directed "spiral" facet for articulation with the triquetrum that is most similar in orientation to that of more terrestrial primates (i.e., Lemur catta, Papio, and Gorilla). The first metacarpal is very reduced and represents only 48% of the length of metacarpal V, as in Archaeolemur, which suggests that pollical grasping of arboreal supports was not important. Compared to Archaeolemur, the shaft of metacarpal V is gracile, and the head has no dorsal ridge and lacks characteristics functionally associated with digitigrade, extended metacarpophalangeal joint postures. Proximally, the articular facet for the hamate is oriented more dorsally. Thus, the carpometacarpal joint V appears to have a distinctive hyperextended set, which has no analog among living or extinct primates. The carpals of Hadropithecus are diagnostic of a pronograde, arboreal and terrestrial (although not digitigrade) locomotor repertoire that typifies Lemur catta and some Old World monkeys. No clinging, suspensory, or climbing specializations that characterize indriids or lorises can be found in the hand of this subfossil lemur. The hand of Hadropithecus likely had similar ranges of movement at the radiocarpal and midcarpal joints as of those of pronograde primates, such as lemurids, for which the hand is held in a more extended, pronated, and neutral (i.e., showing less ulnar deviation) position during locomotion in comparison to that of vertical clingers or slow climbers. Although highly autapomorphic, the hand of Hadropithecus resembles that of its sister taxon, Archaeolemur, in having a very reduced pollex and an articular facet on the scaphoid for a sizeable prepollex. These unusual hand features reinforce the monophyly of the Archaeolemuridae.     

Ecological implications of the relative rarity of fossil hominins at Laetoli

Hominins are a very rare component of the large-mammal fauna at Laetoli. Although no equivalent data are available for Hadar, the much higher count and relative abundance of hominins suggests that they may have been more common at the latter site. The apparent relative rarity of hominins at Laetoli may have significant implications for understanding the ecology of Australopithecus afarensis. However, it is essential to first assess the extent to which taphonomic variables might have been a contributing factor. Using data from fossil ruminants, we show that the survivability of skeletal elements at Laetoli relates to the extent to which they can resist carnivore scavenging and their likelihood of being entirely buried by volcanic ashes and tuffaceous sediments. The rarity of hominins at Laetoli is probably due in part to the influence of these two taphonomic factors. However, these factors cannot account entirely for the difference in hominin relative abundance between these two sites, and ecological differences were probably a contributing factor. The highest population densities of chimpanzees today occur in forest and closed woodland, with reduced densities in open woodland. If similar levels of population-density variation characterized A. afarensis, the differences between Hadar and Laetoli may relate to the quality/optimality of the habitats. Hadar was, in general, much more densely wooded and mesic than Laetoli, with permanent and substantial bodies of water. In contrast, Laetoli was predominantly a woodland-shrubland-grassland mosaic supported only by ephemeral streams and ponds. The apparent greater relative abundance of hominins at Hadar compared with Laetoli suggests that, like chimpanzees, A. afarensis may have been more successful in more densely wooded habitats. Compared with Hadar, Laetoli probably represented a less optimal habitat for the foraging and dietary behavior of A. afarensis, and this is reflected in their inferred lower abundance, density, and biomass.     

Primates follow the 'island rule': implications for interpreting Homo floresiensis

When the diminutive skeleton of Homo floresiensis was found on the Indonesian island of Flores, it was interpreted as an island dwarf, conforming to the 'island rule' that large animals evolve smaller size on islands, but small animals tend to get larger. However, previous studies of the island rule have not included primates, so the extent to which insular primate populations undergo size change was unknown. We use a comparative database of 39 independently derived island endemic primate species and subspecies to demonstrate that primates do conform to the island rule: small-bodied primates tend to get larger on islands, and large-bodied primates get smaller. Furthermore, larger species undergo a proportionally greater reduction in size on islands.     

Genotype patterns at CLU,CR1, PICALM and APOE,cognition and Mediterranean diet: the PREDIMED-NAVARRA trial

The traditional Mediterranean diet (MedDiet) has shown beneficial effects on cognitive decline. Nevertheless, diet–gene interactions have been poorly evaluated. We aimed to investigate diet–gene interaction in the PREDIMED-NAVARRA randomized trial. A total of 522 participants (67 ± 6 years at baseline) enrolled in the PREDIMED-NAVARRA trial were randomly allocated to one of three diets: two MedDiets (supplemented with either extra-virgin olive oil or nuts) or a low-fat diet. They were evaluated with the Mini-Mental State Examination (MMSE) and the Clock Drawing Test (CDT) after 6.5 years of intervention. Subjects were genotyped for CR1-rs3818361, CLU-rs11136000, PICALM-rs3851179 and Apolipoprotein E (ApoE) genes. We studied MedDiet–gene interactions for cognition and assessed the effect of the MedDiet on cognition across different genetic profiles. A significant interaction (p = 0.041) between CLU-rs11136000 and the MedDiet intervention on the MMSE was found with a beneficial effect of MedDiet among carriers of the T minor allele (B = 0.97, 95 % CI 0.45–1.49). Similar effect was observed for CR1-rs3818361, but no significant interaction was observed (p = 0.335). For PICALM-rs3851179, the MedDiet intervention showed a beneficial effect in both genotype groups. No apparent interaction was found for the CDT between intervention and gene variants. Similarly, participants randomly allocated to MedDiet groups, with favorable profiles of CR1, CLU and PICALM genes, significantly improved CDT scores compared to controls with the same genetic profile. Cognitive performance was better for non-ApoE4 and for ApoE4 carriers of MedDiet groups compared to controls, but for CDT performance, we only found statistical significant differences for non-ApoE4 carriers. A MedDiet intervention modulates the effect of genetic factors on cognition. The effect of MedDiet might be greater for subjects with a more favorable genetic profile.     

Three-dimensional computer simulations of feeding behaviour in red and giant pandas relate skull biomechanics with dietary niche partitioning

The red (Ailurus fulgens) and giant (Ailuropoda melanoleuca) pandas are mammalian carnivores convergently adapted to a bamboo feeding diet. However, whereas Ailurus forages almost entirely on younger leaves, fruits and tender trunks, Ailuropoda relies more on trunks and stems. Such difference in foraging mode is considered a strategy for resource partitioning where they are sympatric. Here, we use finite-element analysis to test for mechanical differences and similarities in skull performance between Ailurus and Ailuropoda related to diet. Feeding simulations suggest that the two panda species have similar ranges of mechanical efficiency and strain energy profiles across the dentition, reflecting their durophagous diet. However, the stress distributions and peaks in the skulls of Ailurus and Ailuropoda are remarkably different for biting at all tooth locations. Although the skull of Ailuropoda is capable of resisting higher stresses than the skull of Ailurus, the latter is able to distribute stresses more evenly throughout the skull. These differences in skull biomechanics reflect their distinct bamboo feeding preferences. Ailurus uses repetitive chewing in an extended mastication to feed on soft leaves, and Ailuropoda exhibits shorter and more discrete periods of chomp-and-swallow feeding to break down hard bamboo trunks.     

A new tarkadectine primate from the Eocene of Inner Mongolia,China: phylogenetic and biogeographic implications

Tarka and Tarkadectes are Middle Eocene mammals known only from the Rocky Mountains region of North America. Previous work has suggested that they are members of the Plagiomenidae, an extinct family often included in the order Dermoptera. Here we describe a new primate, Tarkops mckennai gen. et sp. nov., from the early Middle Eocene Irdinmanha Formation of Inner Mongolia, China. The new taxon is particularly similar to Tarka and Tarkadectes, but it also displays many features observed in omomyids. A phylogenetic analysis based on a data matrix including 59 taxa and 444 dental characters suggests that Tarkops, Tarka and Tarkadectes form a monophyletic group—the Tarkadectinae—that is nested within the omomyid clade. Within Omomyidae, tarkadectines appear to be closely related to Macrotarsius. Dermoptera, including extant and extinct flying lemurs and plagiomenids, is recognized as a clade nesting within the polyphyletic group of plesiadapiforms, therefore supporting the previous suggestion that the relationship between dermopterans and primates is as close as that between plesiadapiforms and primates. The distribution of tarkadectine primates on both sides of the Pacific Ocean basin suggests that palaeoenvironmental conditions appropriate to sustain primates occurred across a vast expanse of Asia and North America during the Middle Eocene.     

The species of Thalerosphyrus Eaton, 1881 (Insecta,Ephemeroptera, Heptageniidae,Ecdyonurinae) in Java and Sumatra,with some comments on the diversity of the genus in the Oriental Realm

Three species belonging to the genus Thalerosphyrus Eaton, 1881 are reported from Java and Sumatra. The nymphs of Th. determinatus (Walker, 1853) from Java, Th. sinuosus (Navás, 1933) from Java and Sumatra and Th. lamuriensis Sartori, 2014 from Sumatra are redescribed. The egg morphology of the three species is also presented for the first time. A key to the nymphs is proposed. General considerations on the composition of the genus Thalerosphyrus in the Oriental Realm are given. The distribution of the genus is greatly expended, and currently ranges over the Himalaya and Sumbawa in the Sunda Islands.     

Major trends in stem anatomy and growth forms in the perianth-bearing Piperales,with special focus on Aristolochia

Background and Aims

The order Piperales has the highest diversity of growth forms among the earliest angiosperm lineages, including trees, shrubs, climbers and herbs. However, within the perianth-bearing Piperales (Asarum, Saruma, Lactoris, Hydnora, Prosopanche, Thottea and Aristolochia), climbing species only occur in the most species-rich genus Aristolochia. This study traces anatomical and morphological traits among these lineages, to detect trends in growth form evolution and developmental processes.

Methods

Transverse stem sections of different developmental stages of representatives of Asarum, Saruma, Lactoris, Hydnora, Thottea and Aristolochia were compared and anatomical traits were linked to growth form evolution. Biomechanical properties of representative climbers were determined in three-point bending tests and are discussed based on the anatomical observations. Growth form evolution of the perianth-bearing Piperales was reconstructed by ancestral character state reconstruction using Mesquite.

Key Results

While species of Asarum and Saruma are exclusively herbaceous, species of the remaining genera show a higher diversity of growth habit and anatomy. This growth form diversity is accompanied by a more complex stem anatomy and appropriate biomechanical properties. The ancestral growth form of the perianth-bearing Piperales is reconstructed with either a shrub-like or herbaceous character state, while the following three backbone nodes in the reconstruction show a shrub-like character state. Accordingly, the climbing habit most probably evolved in the ancestor of Aristolochia.

Conclusions

Since the ancestor of the perianth-bearing Piperales has been reconstructed with a herb- or shrub-like habit, it is proposed that the climbing habit is a derived growth form, which evolved with the diversification of Aristolochia, and might have been a key feature for its diversification. Observed anatomical synapomorphies, such as the perivascular fibres in Lactoris, Thottea and Aristolochia, support the phylogenetic relationship of several lineages within the perianth-bearing Piperales. In addition, the hypothesis that the vegetative organs of the holoparasitic Hydnoraceae are most probably rhizomes is confirmed.     

Annotated checklist of the recent and extinct pythons (Serpentes, Pythonidae), with notes on nomenclature, taxonomy, and distribution

McDiarmid et al. (1999) published the first part of their planned taxonomic catalog of the snakes of the world. Since then, several new python taxa have been described in both the scientific literature and non-peer-reviewed publications. This checklist evaluates the nomenclatural status of the names and discusses the taxonomic status of the new taxa, and aims to continue the work of McDiarmid et al. (1999) for the family Pythonidae, covering the period 1999 to 2010. Numerous new taxa are listed, and where appropriate recent synonymies are included and annotations are made. A checklist and a taxonomic identification key of valid taxa are provided.     

Infection Status of Estuarine Fish and Oysters with Intestinal Fluke Metacercariae in Muan-gun, Jeollanam-do, Korea

The source of human infection with intestinal flukes was surveyed in estuarine fishes, including the dotted gizzard shad, common sea bass, common blackish goby, redlip mullet, black sea bream, and oyster collected from Muan-gun, Jeollanam-do, Korea during August and September 2007. Collected fishes and oysters were artificially digested in pepsin-HCl solution and examined under a stereomicroscope. In 36 shads (Konosirus punctatus) and 20 basses (Lateolabrax japonicus) examined, Heterophyopsis continua metacercariae were found in 58.3% and 100%, and their average numbers were 12.0 and 6.3 per infected fish, respectively. In 34 gobies (Acanthogobius flavimanus) examined, metacercariae of H. continua were detected in 79.4%, Stictodora lari in 97.1%, and Acanthotrema felis in 92.1%, and their average numbers were 45.8, 189.3, and 235.3 per infected fish, respectively. In 37 redlip mullets (Chelon haematocheilus), Heterophyes nocens metacercariae were found in 56.8%, Pygidiopsis summa in 94.6%, and Stictodora fuscata in 45.9%, and the average metacercarial densities were 17.4, 31.3, and 35.1 per infected fish, respectively. In 30 black sea breams (Acanthopagrus schlegeli) and 45 oysters (Crassostrea gigas) examined, no metacercariae were detected. From the above results, it has been confirmed that the dotted gizzard shad, common sea bass, common blackish goby, and redlip mullet from Muan-gun, Jeollanam-do, Korea are infected with the metacercariae of heterophyid flukes.     

Systematics of Australian Thrasorinae (Hymenoptera, Cynipoidea, Figitidae) with descriptions of Mikeiinae, new subfamily, two new genera, and three new species

The Australian Thrasorinae are revised and Mikeius is transferred to Mikeiinae Paretas-Martínez & Pujade-Villar, subfam. n., and Mikeius clavatus Pujade-Villar & Restrepo-Ortiz, sp. n., is described. Two new genera of Thrasorinae are erected: Cicatrix Paretas-Martínez, gen. n., including Cicatrix pilosiscutum(Girault), comb. n. from Amblynotus, Cicatrix schauffi (Buffington), comb. n. from Mikeius, and Cicatrix neumannoides Paretas-Martínez & Restrepo-Ortiz, sp. n.; and Palmiriella Pujade-Villar & Paretas-Martínez, gen. n., including Palmiriella neumanni (Buffington), comb. n. from Mikeius, Thrasorus rieki Paretas-Martínez & Pujade-Villar, sp. n., is also described. A phylogenetic analysis of 176 morphological and biological characters, including all these new taxa and all genera previously included in Thrasorinae, was conducted. All subfamilies were recovered as monophyletic, with the following relationships: Parnipinae (Euceroptrinae (Mikeiinae (Plectocynipinae (Thrasorinae)))). A worldwide key to the subfamilies of Figitidae is provided that includes the new subfamily, as well as a key to genera Thrasorinae.     

The genus Galumna in Nepalese oribatid mite fauna,with notes on systematic placement of some species (Acari,Oribatida, Galumnidae)

The oribatid mite genus Galumna (Oribatida, Galumnidae) is recorded for the first time in Nepal. A new species, Galumna tetraporosasp. n., is described from soil of secondary mixed broadleaved forest. It is most similar morphologically to G. tokyoensis Aoki, 1966 and G. valida Aoki, 1994, however, it differs from both by the absence of interlamellar setae and the presence of two pairs of notogastral porose areas Aa. Galumna granalata Aoki, 1984 is redescribed on the basis of specimens from Nepal. Galumna floridae (Jacot, 1929) and G. hexagona Balogh, 1960 are transferred to the genus Notogalumna; G. mauritii Mahunka, 1978 is transferred to the genus Dimidiogalumna.     

Strip-tilled Cover Cropping for Managing Nematodes, Soil Mesoarthropods, and Weeds in a Bitter Melon Agroecosystem

A field trial was conducted to examine whether strip-tilled cover cropping followed by living mulch practice could suppress root-knot nematode (Meloidogyne incognita) and enhance beneficial nematodes and other soil mesofauna, while suppressing weeds throughout two vegetable cropping seasons. Sunn hemp (SH), Crotalaria juncea, and French marigold (MG), Tagetes patula, were grown for three months, strip-tilled, and bitter melon (Momordica charantia) seedlings were transplanted into the tilled strips; the experiment was conducted twice (Season I and II). Strip-tilled cover cropping with SH prolonged M. incognita suppression in Season I but not in Season II where suppression was counteracted with enhanced crop growth. Sunn hemp also consistently enhanced bacterivorous and fungivorous nematode population densities prior to cash crop planting, prolonged enhancement of the Enrichment Index towards the end of both cash crop cycles, and increased numbers of soil mesoarthropods. Strip-tilled cover cropping of SH followed by clipping of the living mulch as surface mulch also reduced broadleaf weed populations up to 3 to 4 weeks after cash crop planting. However, SH failed to reduce soil disturbance as indicated by the Structure Index. Marigold suppressed M. incognita efficiently when planted immediately following a M. incognita-susceptible crop, but did not enhance beneficial soil mesofauna including free-living nematodes and soil mesoarthropods. Strip-tilled cover cropping of MG reduced broadleaf weed populations prior to cash crop planting in Season II, but this weed suppression did not last beyond the initial cash crop cycle.     

Dehydrogenases,Acid and Alkaline Phosphatases,and Esterases for Chemotaxonomy of Selected Meloidogyne,Ditylenchus, Heterodera and Aphelenchus spp.

Various taxonomically useful profiles of four dehydrogenases (lactate, malate, glucose-6-phosphate, and a-glycerophosphate) and three hydrolases (acid and alkaline phosphatase and esterase) were detected in whole nematode homogenates of Meloidogyne javanica, M. hapla, M. incognita, M. arenaria, Ditylenchus dipsaci, D. triformis, Heterodera glycines, and Aphelenchus avenae. The enzyme profiles were stable in populations cultured on several different hosts. A tentative enzymically-determined phylogeny of Meloidogyne is given.     

The application of multiplex fluorimetric sensor for the analysis of flavonoids content in the medicinal herbs family Asteraceae,Lamiaceae, Rosaceae

Background

The aim of our research work was to quantify total flavonoid contents in the leaves of 13 plant species family Asteraceae, 8 representatives of family Lamiaceae and 9 plant species belonging to family Rosaceae, using the multiplex fluorimetric sensor. Fluorescence was measured using optical fluorescence apparatus Multiplex(R) 3 (Force-A, France) for non-destructive flavonoids estimation. The content of total flavonoids was estimated by FLAV index (expressed in relative units), that is deduced from flavonoids UV absorbing properties.

Results

Among observed plant species, the highest amount of total flavonoids has been found in leaves of Helianthus multiflorus (1.65 RU) and Echinops ritro (1.27 RU), Rudbeckia fulgida (1.13 RU) belonging to the family Asteraceae. Lowest flavonoid content has been observed in the leaves of marigold (Calendula officinalis) (0.14 RU) also belonging to family Asteraceae. The highest content of flavonoids among experimental plants of family Rosaceae has been estimated in the leaves of Rosa canina (1.18 RU) and among plant species of family Lamiaceae in the leaves of Coleus blumei (0.90 RU).

Conclusions

This research work was done as pre-screening of flavonoids content in the leaves of plant species belonging to family Asteraceae, Lamiaceae and Rosaceae. Results indicated that statistically significant differences (P > 0.05) in flavonoids content were observed not only between families, but also among individual plant species within one family.     

The spider family Selenopidae (Arachnida, Araneae) in Australasia and the Oriental Region

We relimit and revise the family Selenopidae to include four new genera and 27 new species from Australia and the Oriental Region. The family is redefined, as are the genera Anyphops Benoit, Garcorops Corronca, Hovops Benoit, Selenops Latreille, and Siamspinops Dankittipakul & Corronca, to accommodate the new genera and to correct previous inconsistencies in the diagnoses and definitions of the aforementioned genera. The species of Selenops that occur throughout India and China are also reviewed. Three species occur in China: Selenops bursarius Karsch 1879, also known from Japan, Korea and Taiwan, Selenops ollarius Zhu, Sha, & Chen 1990, and Selenops radiatus Latreille 1819, the type of the genus and most widespread selenopid. Selenops cordatus Zhu, Sha & Chen syn. n. is recognized as a junior synonym of Selenops radiatus. Amamanganopsgen. n. is monotypic, with Amamanganops baginawasp. n. (♀; from the Philippines). Godumopsgen. n. is monotypic, with Godumops caritussp. n. (♂; from Papua New Guinea). Karaopsgen. n. occurs throughout Australia and includes 24 species. A new combination is proposed for Karaops australiensis (L. Koch 1875) comb. n. (ex. Selenops), and the new species: Karaops gangariesp. n. (♀, ♂), Karaops monteithisp. n. (♀), Karaops alanlongbottomisp. n. (♂), Karaops keithlongbottomisp. n. (♂), Karaops larryoosp. n. (♂), Karaops jarritsp. n. (♂,♀), Karaops marrayagongsp. n. (♀), Karaops ravenisp. n. (♂,♀), Karaops badgeraddasp. n. (♀), Karaops burbidgeisp. n. (♂,♀), Karaops karrawarlasp. n. (♂,♀), Karaops julianneaesp. n. (♀), Karaops martamartasp. n. (♀), Karaops manaaynsp. n. (♀, ♂), Karaops vadlaadambarasp. n. (♀, ♂), Karaops pilkingtonisp. n. (♀, ♂), Karaops deserticolasp. n. (♀), Karaops ngarutjaranyasp. n. (♂,♀), Karaops francesaesp. n. (♂,♀), Karaops toolbrunupsp. n. (♀, ♂), the type species Karaops ellenaesp. n. (♂,♀), Karaops jenniferaesp. n. (♀), and Karaops dawarasp. n. (♀).The genus Makdiopsgen. n. contains five species from India and Nepal. A new combination is proposed for Makdiops agumbensis (Tikader 1969), comb. n., Makdiops montigenus (Simon 1889), comb. n., Makdiops nilgirensis (Reimoser 1934) comb. n.,(ex. Selenops). Also, there are two new species the type of the genus Makdiops mahishasurasp. n. (♀; from India), and Makdiops shivasp. n. (♀). The genus Pakawopsgen. n. is monotypic. A new combination is proposed for Pakawops formosanus (Kayashima 1943) comb. n. (ex. Selenops), known only from Taiwan. A new combination is proposed for Siamspinops aculeatus (Simon)comb. n. (ex. Selenops). The distribution and diversity of the studied selenopid fauna is discussed. Finally, keys are provided to all of the selenopid genera and to the species of Karaopsgen. n.and Makdiopsgen. n.     

Oviposition behaviour of four ant parasitoids (Hymenoptera, Braconidae, Euphorinae, Neoneurini and Ichneumonidae, Hybrizontinae), with the description of three new European species

The oviposition behaviour of four ant parasitoids was observed and filmed for the first time. The movies are available from YouTube (search for Elasmosoma, Hybrizon, Kollasmosoma and Neoneurus). Two of the observed species (Neoneurus vesculussp. n. and Kollasmosoma sentumsp. n.) are new to science. A third species (Neoneurus recticalcarsp. n.) is described from Slovakia and Norway. Keys to the Palaearctic species of the genera Neoneurus and Kollasmosoma are added.     

The karyotype of three Brazilian Terrarana frogs (Amphibia, Anura) with evidence of a new Barycholos species

A recent substantial rearrangement of the 882 described eleutherodactyline frog species has considerably improved the understanding of their systematics. Nevertheless, many taxonomic aspects of the South American eleutherodactyline species remain unknown and require further investigation using morphological, cytogenetic and molecular approaches. In this work, the karyotypes of the Brazilian species Ischnocnema juipoca (Atibaia and Campos do Jordão, SP), Barycholos cf. ternetzi (Uberlândia, MG, and Porto Nacional, TO), and Pristimantis crepitans (Chapada dos Guimarães and São Vicente, MT) were analyzed using Giemsa staining, Ag-NOR labeling, and C-banding techniques. All individuals had a diploid number of 22 chromosomes, but the Fundamental Numbers were different among species. The herein described low chromosome number of Pristimantis crepitans is unique within this genus, suggesting that cytogenetically this species is not closely related either to its congeneric species or to Ischnocnema. In addition, karyotype differences, mainly in the NOR position, clearly distinguished the two Barycholos populations, besides indicating the existence of a so far undescribed species in this genus. A taxonomic review could clarify the systematic position of P. crepitans and verify the hypothetic new Barycholos species.     

The asymmetric trimeric architecture of [2Fe-2S] IscU: implications for its scaffolding during iron-sulfur cluster biosynthesis

IscU is a key component of the ISC machinery and is involved in the biogenesis of iron-sulfur (Fe-S) proteins. IscU serves as a scaffold for assembly of a nascent Fe-S cluster prior to its delivery to an apo protein. Here, we report the first crystal structure of IscU with a bound [2Fe-2S] cluster from the hyperthermophilic bacterium Aquifex aeolicus, determined at a resolution of 2.3 Å, using multiwavelength anomalous diffraction of the cluster. The holo IscU formed a novel asymmetric trimer that harbored only one [2Fe-2S] cluster. One iron atom of the cluster was coordinated by the S^γ atom of Cys36 and the N^ε atom of His106, and the other was coordinated by the S^γ atoms of Cys63 and Cys107 on the surface of just one of the protomers. However, the cluster was buried inside the trimer between the neighboring protomers. The three protomers were conformationally distinct from one another and associated around a noncrystallographic pseudo-3-fold axis. The three flexible loop regions carrying the ligand-binding residues (Cys36, Cys63, His106 and Cys107) and the N-terminal α1 helices were positioned at the interfaces and underwent substantial conformational rearrangement, which stabilized the association of the asymmetric trimer. This unique trimeric A. aeolicus holo-IscU architecture was clearly distinct from other known monomeric apo-IscU/SufU structures, indicating that asymmetric trimer organization, as well as its association/dissociation, would be involved in the scaffolding function of IscU.     

Redefinition of the genus Allonychiurus Yoshii, 1995 (Collembola, Onychiuridae) with description of a new species from China

In this paper, we describe a new species of the genus Allonychiurus Yoshii, 1995, characterized by the presence of an apical swelling on the fourth antennal segment as well as a combination of chaetotaxic and pseudocellar characters. The genus Allonychiurus is redefined. Four of its species are considered as incertae sedis: Allonychiurus michelbacheri (Bagnall, 1948), Allonychiurus spinosus (Bagnall, 1949), Allonychiurus caprariae (Dallai, 1969) and Allonychiurus sensitivus (Handschin, 1928). The three species Allonychiurus borensis (Beruete, Arbea & Jordana, 1994), Allonychiurus sensilatus (Thibaud & Massoud, 1979) and Allonychiurus vandeli (Cassagnau, 1960) are removed from Allonychiurus and placed in Micronychiurus Bagnall, 1949, Thalassaphorura Bagnall, 1949 and Spinonychiurus Weiner, 1996 respectively. The synonymy of Thibaudichiurus Weiner, 1996 with Allonychiurus is rejected and Allonychiurus foliatus (Rusek, 1967) and Allonychiurus mariangeae (Thibaud & Lee, 1994) are re-allocated to Thibaudichiurus. List and identification key to the world species of the genus are given.