bluuebunny/crossref_metadata_2025 huggingface dataset:
Glial–Gonadotrophin Hormone (GnRH) Neurone Interactions in the Median Eminence and the Control of GnRH Secretion
Authors: Ojeda S. R. , Lomniczi A. , Sandau U. S.
Published: June 2008

A wealth of information now exists showing that glial cells are actively involved in the cell–cell communication process generating and disseminating information within the central nervous system. In the hypothalamus, two types of glial cells, astrocytes and ependymal cells lining the latero‐ventral portion of the third ventricle (known as tanycytes), regulate the secretory activity of neuroendocrine neurones. This function, initially described for astrocytes apposing magnocellular neurones, has been more recently characterised for neurones secreting gonadotrophin hormone‐releasing hormone (GnRH). The available evidence suggests that glial cells of the median eminence regulate GnRH secretion via two related mechanisms. One involves the production of growth factors acting via receptors with tyrosine kinase activity. The other involves plastic rearrangements of glia–GnRH neurone adhesiveness. GnRH axons reach the median eminence, at least in part, directed by basic fibroblast growth factor. Their secretory activity is facilitated by insulin‐like growth factor 1 and members of the epidermal growth factor family. A structural complement to these soluble molecules is provided by at least three cell–cell adhesion systems endowed with signalling capabilities. One of them uses the neuronal cell adhesion molecule (NCAM), another employs the synaptic cell adhesion molecule (SynCAM), and the third one consists of neuronal contactin interacting with glial receptor‐like protein tyrosine phosphatase‐β. It is envisioned that, within the median eminence, soluble factors and adhesion molecules work coordinately to control delivery of GnRH to the portal vasculature.
Aromatase in the Brain: Not Just for Reproduction Anymore
Authors: Garcia‐Segura L. M.
Published: June 2008

Aromatase, the enzyme that synthesises oestrogens from androgen precursors, is expressed in the brain, where it has been classically associated with the regulation of neuroendocrine events and behaviours linked with reproduction. Recent findings, however, have revealed new unexpected roles for brain aromatase, indicating that the enzyme regulates synaptic activity, synaptic plasticity, neurogenesis and the response of neural tissue to injury, and may contribute to control nonreproductive behaviours, mood and cognition. Therefore, the function of brain aromatase is not restricted to the regulation of reproduction as previously thought.
Two Decades of Circadian Time
Authors: Hastings M. H. , Maywood E. S. , Reddy A. B.
Published: June 2008

Circadian rhythms coordinate our physiology at a fundamental level. Over the last 20 years, we have witnessed a paradigm shift in our perception of what the clocks driving such rhythms actually are, moving from ‘black boxes’ to talking about autoregulatory transcriptional/post‐translational feedback loops with identified molecular components. We also now know that the pacemaker of the suprachiasmatic nuclei (SCN) is not our only clock but quite the opposite because circadian clocks abound in our bodies, driving local rhythms of cellular metabolism, and synchronised to each other and to solar time, by cues from the SCN. This discovery of dispersed local clocks has far‐reaching implications for understanding our physiology and the pathological consequences of clock dysfunction, revealing that clocks are critical in a variety of metabolic and neurological conditions, all of which have long‐term morbidity attributable to them. Without the currently available molecular framework, these insights would have not have been possible. In the circadian future, a growing appreciation of the systems‐level functioning of these clocks and their various cerebral and visceral outputs, will likely stimulate the development of novel therapies for major illnesses.
An Insight to Pituitary Folliculo‐Stellate Cells
Authors: Devnath S. , Inoue K.
Published: June 2008

Folliculo‐stellate cells (FS‐cells) are star‐shaped and follicle‐forming cells in the anterior pituitary gland that were first identified by electron microscopy as non‐endocrine agranular cells. Light microscopy has revealed many of their cytophysiological features and the FS‐cell is known to be positive for S‐100 protein, a marker for FS‐cells. So far, functions ascribed to FS‐cells include the formation of an extensive and complex tridimentional network, scavenger activity by engulfing degenerated cells, paracrine regulation of endocrine cells by producing various growth factors and cytokines, such as interleukin‐6, leukemia inhibitory factor, basic fibroblastic growth factor, vascular endothelial cell growth factor and follistatin, and large‐scale inter‐cellular communication by means of their long cytoplasmic processes and gap junctions. Moreover, their multi‐potential characteristics and other cytological features support the possibility of them becoming organ‐specific stem cells. This concept is yet to be resolved, however. In this review, we focus on these features of FS‐cells along with some futuristic approaches.
Hypothalamic Control of Anterior Pituitary Function: A History
Authors: Charlton H.
Published: June 2008

The concept of neurohumoral control of anterior pituitary function championed by Geoffrey Harris was based upon clinical and biological observation backed by rigorous experimental testing. The areas of the brain involved in the control of gonadotrophic hormone synthesis and release were identified by electrical stimulation, lesioning and fibre tract cutting. The medial preoptic area (MPOA) proved to be a major integrating centre, with axon terminals from this region terminating at the median eminence releasing factors into the portal vessels to give a direct route from brain to pituitary. It took over a decade before the gonadotrophic hormone‐releasing hormone (GnRH) was isolated, sequenced and synthesised. With antibodies raised against this peptide, the MPOA was identified as a site rich in GnRH neurones and the hormone was detected at high levels in portal blood extracts. A natural knockout of the GnRH gene was discovered in a hypogonadal (hpg) mouse. Hormone injections, gene replacement methods and neural grafting in these mutants all confirmed the central role of GnRH in reproduction. The modern techniques of molecular biology have allowed us to extend our knowledge base. In the last few years the role of kisspeptin and its receptor (GPR54) in the control of the GnRH neurone has added a further level of hypothalamic involvement in the modulation of reproduction.
Neuroendocrinology and Aging
Authors: Epelbaum J.
Published: June 2008

This short review goes back to early discoveries concerning the neuroendocrinology of aging, discussing the Brown‐Sequard experiment on rejuvenation at the end of the 19th century and Steinach’s subsequent experiments in the early 20th century. It also considers the seminal experiments of Pierre Ascheim, Ming Tsung Peng and Joseph Meites in the 1960s on the aging of the gonadotrophic axis. Major age‐associated changes in neuroendocrine regulatory processes involved in the menopausal transition, andropause, somatopause and adrenopause are also reviewed. Finally, some views on future directions of research into the neuroendocrinology of aging are proposed, based on the pleiotropy of neuroendocrine messengers and functions.
The Regulation of Seasonal Changes in Food Intake and Body Weight
Authors: Ebling F. J. P. , Barrett P.
Published: June 2008

Seasonal rhythms of body weight, reflecting altered food intake, energy storage and expenditure, are a common feature of mammals inhabiting temperate and arctic latitudes. They have evolved so that predictable annual changes in the external environment can be anticipated and animals can adjust their physiology and behaviour in preparation for the changing demands of the seasons. These long‐term changes in energy balance are not simply effected by the brain centres and peptidergic pathways known to underlie short‐term homeostatic regulation. Screens of altered gene expression in Siberian hamsters comparing the anabolic summer state in long photoperiods and the catabolic ‘winter’ state in short photoperiods have identified differential gene expression in the hypothalamus. The majority of gene expression changes are confined to two restricted areas: the dorsomedial posterior arcuate nucleus, and the ventral ependymal layer of the third ventricle. Functions encoded by these ‘seasonal’ genes include thyroid hormone metabolism, retinoic acid and histaminergic signalling, and VGF and secretogranin production. The changes in thyroid hormone availability that are brought about by differential activity of deiodinase enzymes are of particular importance because experimental manipulation of central thyroid levels can prevent seasonal cyclicity. Given the importance of thyroid hormone in the initial development of the brain, we hypothesise that thyroid hormone‐dependent plasticity of hypothalamic connections and neurogenesis underlie seasonal cycles of food intake and body weight.
Steroid Receptor Signalling in the Brain – Lessons Learned from Molecular Imaging
Authors: Kawata M. , Nishi M. , Matsuda K. , Sakamoto H. , Kaku N. , Masugi‐Tokita M. , Fujikawa K. , Hirahara‐Wada Y. , Takanami K. , Mori H.
Published: June 2008

Studies with green fluorescent protein (GFP) have revealed the subcellular distribution of many steroid hormone receptors to be much more dynamic than previously thought. Fluorescence resonance energy transfer (FRET) and fluorescence recovery after photobleaching (FRAP) are powerful techniques with which to examine protein–protein interaction and the mobility of tagged proteins, respectively. FRET analysis revealed that steroid treatment (with corticosterone or testosterone) induces direct interaction of the glucocorticoid receptor (GR) and importin α in the cytoplasm and that, shortly after nuclear entry, the GR detaches from importin α. The mineralocorticoid receptor (MR) and androgen receptor (AR) show the same trafficking. Upon oestradiol treatment, ERα and ERβ in the same cell are relocalised to form a discrete pattern and are localised in the same discrete cluster (subnuclear foci). FRAP analysis showed that nuclear ERα and ERβ are most dynamic and mobile in the absence of the ligand, and that mobility decreases slightly after ligand treatment. Genomic as well as non‐genomic actions of steroid hormones influence the cellular function of target tissues spacio‐temporally.
The Endocannabinoid System and Energy Metabolism
Authors: Bellocchio L. , Cervino C. , Pasquali R. , Pagotto U.
Published: June 2008

Many different regulatory actions have been attributed to endocannabinoids, and their involvement in several pathophysiological conditions is under intense scrutiny. Cannabinoid receptors [cannabinoid receptor type 1 (CB1) and CB2] participate in the physiological modulation of many central and peripheral functions. The ability of the endocannabinoid system to control appetite, food intake and energy balance has recently received considerable attention, particularly in the light of the different modes of action underlying these functions. The endocannabinoid system modulates rewarding properties of food by acting at specific mesolimbic areas in the brain. In the hypothalamus, CB1 receptors and endocannabinoids are integrated components of the networks controlling appetite and food intake. Interestingly, the endocannabinoid system was recently shown to control several metabolic functions by acting on peripheral tissues such as adipocytes, hepatocytes, the gastrointestinal tract, the skeletal muscles and the endocrine pancreas. The relevance of the system is further strengthened by the notion that visceral obesity seems to be a condition in which an overactivation of the endocannabinoid system occurs, and therefore drugs interfering with this overactivation by blocking CB1 receptors are considered as potentially valuable candidates for the treatment of obesity and related cardiometabolic risk factors.
Kisspeptin and GPR54: Discovery of a Novel Pathway in Reproduction
Authors: Seminara S. B. , Crowley Jr W. F.
Published: June 2008

In order to find novel modulators of gonadotrophin‐releasing hormone (GnRH) secretion, genetic tools were employed in patients with idiopathic hypogonadotrophic hypogonadism (IHH). Mutations in a G‐protein coupled receptor, GPR54, were identified, making this receptor a genetic determinant and indisputable gatekeeper of normal reproductive function. This article places these investigations into historical context and reviews some of the new findings relevant to this pathway.
Central Control of Bone Remodelling
Authors: Takeda S.
Published: June 2008

The discovery that the brain controls bone remodelling has provided a new paradigm for our understanding of bone biology. This review summarises the genetic, molecular and physiological bases for the central control of bone remodelling and discusses the future directions of this new research field of neuroskeletal biology.
Neurodevelopmental and Neurophysiological Actions of Thyroid Hormone
Authors: Williams G. R.
Published: June 2008

For over 100 years, thyroid hormones have been known to be essential for neonatal neurodevelopment but whether they are required by the foetal brain remains a matter of controversy. For decades, the prevailing view was that thyroid hormones are not necessary until after birth because circulating levels in the foetus are very low and the placenta forms an efficient barrier to their transfer from the mother. Clinical observations of good neurological outcome following early treatment of congenital hypothyroidism were used to support the view that thyroid hormones are not required early in neurodevelopment. Nevertheless, the issue remained contentious because of findings that the severity of foetal neurological deficit due to maternal iodine deficiency correlated with the degree of maternal thyroxine (T4) deficiency. Furthermore, neurological damage in these cases could be prevented by correction of maternal T4 deficiency before mid‐gestation. This observation led to the opposing view, supported by epidemiological studies of neurological cretinism, that maternal thyroid hormones are important and necessary for early foetal neurodevelopment. It is now clear that thyroid hormones are essential for both foetal and post‐natal neurodevelopment and for the regulation of neuropsychological function in children and adults. In recent years, this controversial subject has progressed very rapidly following remarkable progress in understanding of the molecular mechanisms of thyroid hormone action. This article reviews the contributions of molecular biology and genetics to our new understanding of the physiological effects of thyroid hormones on neurodevelopment and in the adult brain.
Measurement of Immediate‐Early Gene Activation‐ c‐fos and Beyond
Authors: Kovács K. J.
Published: June 2008

Immediate‐early genes (IEG) are powerful tools for identifying activated neurosecretory neurones and extended circuits that affect neuroendocrine functions. The generally acknowledged scenario is when cells became activated, IEGs expressed and IEG‐encoded transcription factors affect target gene expression. However, there are several examples in which: (i) neuronal activation occurs without induction of IEGs; (ii) IEG induction is not related to challenge‐induced neuropeptide expression; and (iii) markers of neuronal activation are not expressed in chronically activated neurones. In spite of these limitations, the use of c‐Fos and other regulatory‐ or effector transcription factors as markers of neuronal activation will continue to be an extremely powerful technique. Recently‐developed models, including transgenic mice expressing different marker genes under the regulation of IEG promoters, will help to monitor neuronal activity in vivo or ex vivo and to reveal connection between activated neurones. Furthermore, combinations between novel imaging techniques, such as magnetic resonance and IEG‐based mapping strategies, will open new means with which to study functional activity in the neurosecretory systems.
Adaptive Responses of the Maternal Hypothalamic‐Pituitary‐Adrenal Axis during Pregnancy and Lactation
Authors: Brunton P. J. , Russell J. A. , Douglas A. J.
Published: June 2008

Over the past 40 years, it has been recognised that the maternal hypothalamic‐pituitary‐adrenal (HPA) axis undergoes adaptations through pregnancy and lactation that might contribute to avoidance of adverse effects of stress on the mother and offspring. The extent of the global adaptations in the HPA axis has been revealed and the underlying mechanisms investigated within the last 20 years. Both basal, including the circadian rhythm, and stress‐induced adrenocorticotrophic hormone and glucocorticoid secretory patterns are altered. Throughout most of pregnancy, and in lactation, these changes predominantly reflect reduced drive by the corticotropin‐releasing factor (CRF) neurones in the parvocellular paraventricular nucleus (pPVN). An accompanying profound attenuation of HPA axis responses to a wide variety of psychological and physical stressors emerges after mid‐pregnancy and persists until the end of lactation. Central to this suppression of stress responsiveness is reduced activation of the pPVN CRF neurones. This is consequent on the reduced effectiveness of the stimulation of brainstem afferents to these CRF neurones (for physical stressors) and of altered processing by limbic structures (for emotional stressors). The mechanism of reduced CRF neurone responses to physical stressors in pregnancy is the suppression of noradrenaline release in the PVN by an up‐regulated endogenous opioid mechanism, which is induced by neuroactive steroid produced from progesterone. By contrast, in lactation suckling the young provides a neural stimulus that dampens the HPA axis circadian rhythm and reduces stress responses. Reduced noradrenergic input activity is involved in reduced stress responses in lactation, although central prolactin action also appears important. Such adaptations limit the adverse effects of excess glucocorticoid exposure on the foetus(es) and facilitate appropriate metabolic and immune responses.
Prolactin: A Pleiotropic Neuroendocrine Hormone
Authors: Grattan D. R. , Kokay I. C.
Published: June 2008

The neuroendocrine control of prolactin secretion is unlike that of any other pituitary hormone. It is predominantly inhibited by the hypothalamus and, in the absence of a regulatory feedback hormone, it acts directly in the brain to suppress its own secretion. In addition to this short‐loop feedback action in the brain, prolactin has been reported to influence a wide range of other brain functions. There have been few attempts to rationalise why a single hormone might exert such a range of distinct and seemingly unrelated neuroendocrine functions. In this review, we highlight some of the original studies that first characterised the unusual features of prolactin neuroendocrinology, and then attempt to identify areas of new progress and/or controversy. Finally, we discuss a hypothesis that provides a unifying explanation for the pleiotrophic actions of prolactin in the brain.
The Placenta is Simply a Neuroendocrine Parasite
Authors: Lowry P. J.
Published: June 2008

This paper will document the early scientific observations that kindled my neuroendocrinological interest in pre‐eclampsia, a life‐threatening disease that affects both mother and baby. My interest in this subject started with the placental origin of melanotrophin activity, moving on, through corticotrophin‐releasing factor and its binding protein, to a tachykinin modified specifically in the placenta by phosphocholine, a post‐translational moiety normally used by parasites to avoid immune surveillance and rejection. This work may finally have led to an understanding of the identity of the elusive placental factor that, whilst attempting to compensate for the poor implantation of the placenta, causes the many symptoms seen in the mother during pre‐eclampsia.
Roles of Oestrogen Receptors α and β in Behavioural Neuroendocrinology: Beyond Yin/Yang
Authors: Rissman E. F.
Published: June 2008

Oestrogen receptor β (ERβ) was discovered more than 10 years ago. It is widely distributed in the brain. In some areas, such as the entorhinal cortex, it is present as the only ER, whereas in other regions, such as the bed nucleus of the stria terminalis and preoptic area, it can be found co‐expressed with ERα, often within the same neurones. These ERs share ligands, and there are several complex relationships between the two receptors. Initially, the relationship between them was labelled as ‘yin/yang’, meaning that the actions of each complemented those of the other, but now, years later, other relationships have been described. Based on evidence from neuroendocrine and behavioural studies, three types of interactions between the two oestrogen receptors are described in this review. The first relationship is antagonistic; this is evident from studies on the role of oestrogen in spatial learning. When oestradiol is given in a high, chronic dose, spatial learning is impaired. This action of oestradiol requires ERα, and when ERβ is not functional, lower doses of oestradiol have this negative effect on behaviour. The second relationship between the two receptors is one that is synergistic, and this is illustrated in the combined effects of the two receptors on the production of the neuropeptide oxytocin and its receptor. The third relationship is sequential; separate actions of the two receptors are postulated in activation and organisation of sexually dimorphic reproductive behaviours. Future studies on all of these topics will inform us about how ER selective ligands might affect oestrogen functions at the organismal level.
Sleep during the Antarctic winter: preliminary observations on changing the spectral composition of artificial light
Authors: FRANCIS GAVIN , BISHOP LYNDSEY , LUKE CLAIRE , MIDDLETON BENITA , WILLIAMS PETER , ARENDT JOSEPHINE
Published: June 2008

Antarctic Base personnel live for 3 months in winter with no natural sunlight. This project compared sleep, by actigraphy, during periods of increased exposure to white light or blue enriched light in 2003. The primary aim was to help define the optimum spectral composition and intensity of artificial environmental light. Nine men and one woman (33 ± 7 years, mean ± SD), wore activity and light monitors continuously from 28.2 to 9.10, and kept sleep diaries. Extra light was provided by light boxes (standard white, 5300 K, or prototype blue enriched, 10 000K, Philips Lighting), which were turned on in bedrooms and in communal/work areas approximately 08.00–18.00 hours. After a no‐treatment control period, 28.2–20.3, sequential 4–5 week periods of first white, then blue light, were imposed with a further control period 19.9–9.10. A limited baseline study in 2002 (no interventions) similarly measured light and activity in seven men and one woman (30 ± 7 years). Daily light exposure in winter (lux, mean ± SD) was doubled in 2003 (maximum 1039 ± 281, average 64 ± 21), compared to 2002 (572 ± 276 and 30 ± 11), P < 0.05 and P < 0.01, with no differences between white and blue light. There were no major differences in sleep between light conditions in 2003. A delay in sleep timing was found in midwinter compared to control (2003, bedtime, P < 0.05, sleep start, P < 0.05, sleep end, P < 0.01) and sleep fragmentation increased (P < 0.05). Sleep efficiency was slightly higher during all blue light periods compared to all white periods (P < 0.05). The use of higher intensity light of suitable spectral composition is proposed.
Serpentine and non‐serpentine ecotypes of Collinsia sparsiflora associate with distinct arbuscular mycorrhizal fungal assemblages
Authors: SCHECHTER S. P. , BRUNS T. D.
Published: June 2008

Although plant adaptation to serpentine soils has been studied for several decades, the mechanisms of plant adaptation to edaphic extremes are still poorly understood. Arbuscular mycorrhizal fungi (AMF) are common root symbionts that can increase the plant hosts’ establishment and growth in stressful environments. However, little is known about the role plant–AMF interactions play in plant adaptation to serpentine. As a first step towards understanding this role, we examined the AMF assemblages associated with field populations of serpentine and non‐serpentine ecotypes of California native plant Collinsia sparsiflora. We sampled roots of C. sparsiflora from three serpentine and three non‐serpentine sites in close proximity (110 m to 1.94 km between sites) and analysed the small subunit ribosomal DNA gene amplified from root DNA extracts using AMF‐specific primers. A total of 1952 clones from 24 root samples (four from each site) were sequenced. We used sequence similarity and phylogenetic analysis to determine operational taxonomic units (OTU) resulting in 19 OTUs representing taxa from six AMF genera, including one serpentine‐specific OTU. We used Bray–Curtis similarity, multidimensional scaling and analysis of similarity to compare root sample AMF assemblages. These analyses clearly showed that plant ecotypes associated with distinct AMF assemblages; an Acaulospora OTU‐dominated serpentine, and a Glomus OTU‐dominated non‐serpentine assemblages. Species diversity and evenness were significantly higher in serpentine assemblages. Finally, relate analysis showed a relationship between ecotype AMF assemblages and soil nutrients. This study reveals a strong relationship between AMF associates and plant adaptation to edaphic extremes.
Phylogeny of the Helicophidae (Trichoptera), with emphasis on the New Caledonian species of Helicopha
Authors: JOHANSON KJELL A. , KEIJSNER MARLENE
Published: June 2008

Abstract A phylogenetic analysis is presented for Helicophidae genera based on fragments of the three genes COI, 16S and EF‐1a (total 1705 bp) and morphology (70 characters). Molecular data show that both the family Helicophidae + Alloecentrella Wise and the New Caledonian species form monophyletic groups. Monophyly of the New Caledonian Helicophidae based on morphology alone is not supported. Nine new species of Helicopha (Trichoptera, Helicophidae) from New Caledonia are described: H. neocaledonia sp.n., H. loripes sp.n., H. angulata sp.n., H. stellata sp.n., H. bifurcata sp.n., H. mouirangensis sp.n., H. acuta sp.n., H. taoensis sp.n., and H. aoupiniensis sp.n. The Helicophidae now include 42 known species of which 18 are New Caledonian endemics. New Caledonian Helicophidae form a monophyletic group, whose species diversity is the greatest amongst the world’s Helicophidae. Descriptions of the females of Helicopha dognyensis and H. ramea, previously known only from males, are the first for females from New Caledonia. Briama Johanson & Ward (syn.n.) is phylogenetically most closely related to New Caledonian Helicopha and is considered as synonymous. Alloecentrella Wise from New Zealand, previously classified within Calocidae, is more closely related to Austrocentrus Schmid from Chile and is to be classified as Helicophidae.
Insights into the phylogenetic relationships within Cixiidae (Hemiptera: Fulgoromorpha): cladistic analysis of a morphological dataset
Authors: CEOTTO PAULA , BOURGOIN THIERRY
Published: June 2008

Abstract According to the most recent classifications proposed, the planthopper family Cixiidae comprises three subfamilies, namely Borystheninae, Bothriocerinae and Cixiinae, the latter with 16 tribes. Here we examine morphological characters to present the first phylogenetic reconstructions within Cixiidae derived from a cladistic analysis. We scored 85 characters of the head, thorax, and male and female genitalia for 50 taxa representative of all cixiid subfamilies and tribes and for six outgroup taxa. Analyses were based on maximum parsimony – using both equally weighted and successive weighting procedures – and Bayesian inferences. The monophyly of most currently accepted tribes and subfamilies was investigated through Templeton statistical tests of alternative phylogenetic hypotheses. The cladistic analyses recover the monophyly of Cixiidae, the subfamily Bothriocerinae, and the tribes Pentastirini, Mnemosynini, and Eucarpiini. Successive weighting and Bayesian inference recover the monophyly of the tribe Gelastocephalini, but only Bayesian inference supports the monophyly of Semoniini. The relationships recovered support the groups [Stenophlepsini (Borystheninae + Bothriocerinae)] arising from the tribe Oecleini, and [Andini + Brixiidini + Brixiini (polyphyletic) + Bennini]. Templeton tests reject the alternative hypothesis of a monophyletic condition for the tribe Pintaliini as presently defined.
Systematics and biogeography of the fishfly genus Parachauliodes (Megaloptera: Corydalidae) endemic to the east Asian islands
Authors: LIU XINGYUE , HAYASHI FUMIO , YANG DING
Published: June 2008

Abstract The fishfly genus Parachauliodes van der Weele, 1909 comprises six species from Taiwan, Japan, and South Korea, ranging along the east Asian islands. Herein, all the Parachauliodes species are described, including two new species, namely P. asahinai sp.n. and P. niger sp.n. A cladistic analysis based on adult and larval morphological characters was conducted to reconstruct the interspecific phylogeny of the Parachauliodes species. Two main clades within Parachauliodes were obtained from the cladistic analysis, namely ‘P. asahinai +P. continentalis’ and ‘(P. japonicus + P. yanbaru) + (P. nebulosus + P. niger)’. Based on the present interspecific phylogeny and distribution patterns of Parachauliodes, its ancestor might have invaded the east Asian islands by a land bridge from Taiwan via Ryukyu to the Japanese archipelago about 10−5 million years ago.
A carbon‐isotopic study of an end‐Permian mass‐extinction horizon, Bulla, northern Italy: a negative δ13C shift prior to the marine extinction
Authors: Gorjan P. , Kaiho K. , Chen Z. Q.
Published: June 2008

Palaeontological data from the Permian‐Triassic Bulla section, northern Italy, demonstrate a rapid extinction at this site. This occurs after a negative carbonate carbon‐isotope (δ13Ccarb) shift, consistent with two other northern Italian sites (Val Badia and Tesero). However, conclusion goes against recent reporting that the extinction occurs before the δ13Ccarb shift. We agree that the shift occurs after the extinction at Jameson Land, east Greenland (a high latitude palaeolocation). However, all other sections show the shift before, or coincident with, the extinction. We suggest that the simplest explanation is a coeval shift in carbonate carbon‐isotope shifts, and it follows that the extinction was not. This suggests that the end‐Permian extinction crept from region to region. It also suggests that the marine extinction occurred first in high northern latitudes.
Laboratory experiments of slab break‐off and slab dip reversal: insight into the Alpine Oligocene reorganization
Authors: Regard Vincent , Faccenna Claudio , Bellier Olivier , Martinod Joseph
Published: June 2008

We present laboratory experiments to study the consequence of the rupture of a subducting slab on the deep geometry of the subduction zone. In our experiments, slab break‐off occurs after the entrance of buoyant material at trench causing a slowing down of the subduction and producing an increase of the shortening rate and a transient episode of subduction dip reversal. We discuss the potential application of these processes to the recent collisional evolution of the Alps proposing that the rupture of the slab produced a reorganization of the belt with a transition from one sided to a doubly vergent orogen.
Ordovician metagranitoid from the Anatolide‐Tauride Block, northwest Turkey: geodynamic implications
Authors: Okay Aral I. , Satır Muharrem , Shang Cosmas K.
Published: June 2008

We report a Middle Ordovician metagranitoid from the northern margin of the Anatolide‐Tauride Block, the basement of which is generally characterized by voluminous Latest Proterozoic to Early Cambrian granitoids. The Ordovician metagranitoid forms an ∼400‐m‐thick body in the marbles and micaschists of the Tavşanlı Zone. The whole sequence was metamorphosed in the blueschist facies during the Late Cretaceous (c. 80 Ma). Zircons from the metagranitoid give a Middle Ordovician Pb‐Pb evaporation age of 467.0 ± 4.5 Ma interpreted as the age of crystallization of the parent granitic magma. The micaschists underlying the metagranitoid yield Cambro‐Ordovician (530–450 Ma) and Carboniferous (c. 310 Ma) detrital zircon ages indicating that the granitoid is a pre‐ or syn‐metamorphic tectonic slice. The Ordovician metagranitoid represents a remnant of the crystalline basement of the Anatolide‐Tauride Block and provides evidence for Ordovician magmatism at the northern margin of Gondwana. Prismatic Carboniferous detrital zircons in the micaschists indicate that during the Triassic, the northern margin of the Anatolide‐Tauride Block was close to Variscan terranes.
The age of the Nantuo Formation and Nantuo glaciation in South China
Authors: Zhang Shihong , Jiang Ganqing , Han Yigui
Published: June 2008

A U–Pb sensitive high‐resolution ion microprobe (SHRIMP) age of 654.5 ± 3.8 Ma from an ash bed immediately below the Nantuo Formation in South China provides the lowest age constraint for the Nantuo glaciation, which has been correlated with the global ‘Marinoan’ glaciation. A U–Pb SHRIMP age of 636.3 ± 4.9 Ma from a fallout tuff within the basal layer of the Nantuo Formation, along with the existing age of 635.2 ± 0.6 Ma from its overlying Doushantuo cap carbonate, suggests that the traditionally defined Nantuo Formation may have been deposited in a short time period at the end of the Nantuo glaciation. In combination with available ages globally, the data support a relatively short duration and rapid termination of ‘Marinoan’ glaciations.
Raman confirmation of microdiamond in the Svartberget Fe‐Ti type garnet peridotite, Western Gneiss Region, Western Norway
Authors: Vrijmoed J. C. , Smith D. C. , Van Roermund H. L. M.
Published: June 2008

Ultra‐high pressure metamorphic rocks have been found worldwide. The volume and areal extent of an exhumed UHPM domain are important for understanding the geodynamic mechanisms responsible for the high pressure and relatively medium temperature conditions needed for their creation. We report here Raman microspectroscopical data that prove the existence of microdiamonds at the Svartberget Fe‐Ti type peridotite locality in the Western Gneiss Region of Norway. Raman microscopy of two carbon microinclusions belonging to polyphase inclusion assemblages included in garnets from a garnet‐phlogopite websterite vein yielded a sharp, narrow, intense peak at 1332 cm−1, characteristic of diamond. The diamond is associated with polyphase solid inclusions possibly originating from supercritical, dense, H‐C‐N‐O‐F‐P‐S‐Cl fluids. Lithological, textural and geochronological evidence points towards a Caledonian origin of the trapped fluid and subsequent diamond formation.
First report of eclogites from central Tibet, China: evidence for ultradeep continental subduction prior to the Cenozoic India‐Asian collision
Authors: Zhang Kai‐Jun , Zhang Yu‐Xiu , Tang Xian‐Chun , Xie Yao‐Wu , Sha Shao‐Li , Peng Xing‐Jie
Published: June 2008

Eclogites characterized by a garnet + clinopyroxene + orthopyroxene + sanidine + rutile assemblage are reported for the first time in the eastern Bangong suture, central Tibet (China). Garnet and sanidine are exsolved from clinopyroxene. Al‐exchange barometer for orthopyroxene and garnet and K concentrations in clinopyroxene indicate a peak pressure of ∼4 GPa. The occurrence of these ultrahigh‐pressure rocks implies the subduction of continental crust to a depth of >130 km along the eastern Bangong suture zone during the Early Jurassic. The denudation of these ultrahigh‐pressure metamorphic rocks could have provided a significant source for the Jurassic turbidites in the western Bangong ocean basin.
Phospholipase C5 (NPC5) is involved in galactolipid accumulation during phosphate limitation in leaves of Arabidopsis
Authors: Gaude Nicole , Nakamura Yuki , Scheible Wolf‐Rüdiger , Ohta Hiroyuki , Dörmann Peter
Published: June 2008

The replacement of phospholipids by galacto‐ and sulfolipids in plant membranes represents an important adaptive process for growth on phosphate‐limiting soils. Gene expression and lipid analyses revealed that the MYB transcription factor PHR1 that has been previously shown to regulate phosphate responses is not a major factor controlling membrane lipid changes. Candidate genes for phospholipid degradation were selected based on induction of expression during phosphate deprivation. Lipid measurements in the corresponding Arabidopsis mutants revealed that the non‐specific phospholipase C5 (NPC5) is required for normal accumulation of digalactosyldiacylglycerol (DGDG) during phosphate limitation in leaves. The growth and DGDG content of a double mutant npc5 pho1 (between npc5 and the phosphate‐deficient pho1 mutant) are reduced compared to parental lines. The amount of DGDG increases from approximately 15 mol% to 22 mol% in npc5, compared to 28 mol% in wild‐type, indicating that NPC5 is responsible for approximately 50% of the DGDG synthesized during phosphate limitation in leaves. Expression in Escherichia coli revealed that NPC5 shows phospholipase C activity on phosphatidylcholine and phosphatidylethanolamine. A double mutant of npc5 and pldζ2 (carrying a mutation in the phospholipase Dζ2 gene) was generated. Lipid measurements in npc5 pldζ2 indicated that the contribution of PLDζ2 to DGDG production in leaves is negligible. In contrast to the chloroplast envelope localization of galactolipid synthesis enzymes, NPC5 localizes to the cytosol, suggesting that, during phosphate limitation, soluble NPC5 associates with membranes where it contributes to the conversion of phospholipids to diacylglycerol, the substrate for galactolipid synthesis.
The S locus‐linked Primula homeotic mutant sepaloid shows characteristics of a B‐function mutant but does not result from mutation in a B‐function gene
Authors: Li Jinhong , Webster Margaret , Dudas Brigitta , Cook Holly , Manfield Iain , Davies Brendan , Gilmartin Philip M.
Published: June 2008

Floral homeotic and flower development mutants of Primula, including double, Hose in Hose, Jack in the Green and Split Perianth, have been cultivated since the late 1500s as ornamental plants but until recently have attracted limited scientific attention. Here we describe the characterization of a new mutant phenotype, sepaloid, that produces flowers comprising only sepals and carpels. The sepaloid mutation is recessive, and is linked to the S locus that controls floral heteromorphy. The phenotype shows developmental variability, with flowers containing three whorls of sepals surrounding fertile carpels, two whorls of sepals with a diminished third whorl of sepals surrounding a fourth whorl of carpels, or three whorls of sepals surrounding abnormal carpels. In some respects, these phenotypes resemble the Arabidopsis and Antirrhinum homeotic B‐function mutants apetala3/deficiens (ap3/def) and pistillata/globosa (pi/glo). We have isolated the Primula vulgaris B‐function genes PvDEFICIENS (PvDEF) and PvGLOBOSA (PvGLO), expression of both of which is affected in the sepaloid mutant. PvGLO, like sepaloid, is linked to the S locus, whereas PvDEF is not. However, our analyses reveal that sepaloid and PvGLO represent different genes. We conclude that SEPALOID is an S‐linked independent regulator of floral organ identity genes including PvDEF and PvGLO.
Variation for homoeologous gene silencing in hexaploid wheat
Authors: Bottley Andrew , Koebner Robert M.D.
Published: June 2008

The absence of expression of individual members of a homoeologous set of genes in a polyploid is a well‐established phenomenon. However, the extent to which such ‘homoeologous silencing’ can vary between individual genotypes within a species is unexplored. We have used the single‐strand conformation polymorphism assay to identify homoeologue non‐expression at 15 single‐copy genes across a panel of 16 wheat varieties, representative of the genetic diversity present in modern northern European winter wheat (Triticum aestivum). There was no evidence for any homoeologous silencing at seven of the fifteen genes, but in the remaining eight, at least one of the three homoeologues varied qualitatively for expression in either the root or the seedling leaf. The identity of the non‐expressed homoeologue was generally consistent, but when the expression profiles of eight informative genes were compared, only two varieties shared the same pattern of silencing. A small‐scale study suggested that silencing patterns were largely inherited across self‐pollinated generations, and some evidence is presented for the epigenetic segregation of these patterns in a population bred from parents having contrasting silencing profiles. Epigenetic variation exerts a significant effect on phenotype, so given the ubiquity and variability in homoeologous silencing observed in wheat, we suggest that it is likely to play a considerable role in generating phenotypic variation. Thus epigenetic profiling may need to be incorporated as part of the analytical tool kit for predictive wheat breeding.
A novel HLA‐A*3315 allele identified by haplotype‐specific extraction and sequence‐based typing
Authors: Lim J. , Kim Y. , Han K. , Kim H.‐J. , Min W.‐S.
Published: June 2008

A novel HLA‐A*33 variant allele, A*3315, was identified in three Korean siblings. This allele shows only one nucleotide difference from A*330301 in exon 4 at nucleotide position 727 (codon 219 CGG→TGG), resulting in an amino acid change from arginine (R) to tryptophan (W).
Prevalence and specificity of immunoglobulin G and immunoglobulin A non‐complement‐binding anti‐HLA alloantibodies in retransplant candidates
Authors: Arnold M.‐L. , Dechant M. , Doxiadis I. I. N. , Spriewald B. M.
Published: June 2008

The role of complement‐binding donor‐directed anti‐human leukocyte antigen (HLA) antibodies in graft rejection is well established, whereas the prevalence and relevance of non‐complement‐binding (NCB) anti‐HLA antibodies are less well defined. The aim of our study was to establish a sensitive and reliable test system for the detection and the specification of these NCB anti‐HLA antibodies. Sera from 60 patients awaiting retransplantation were analysed for the presence of anti‐HLA class I alloantibodies with complement‐dependent cytotoxicity (CDC) tests. Immunoglobulin (Ig)Gall anti‐HLA class I and class II alloantibodies were differentiated on generic level by plate‐based solid phase enzyme‐linked immunosorbent assay. Subsequently, a modified bead‐based (Luminex) assay was applied, allowing the investigation of IgG2/4 NCB isotypes as well as IgA1/2. The anti‐HLA specificities of the NCB alloantibodies were determined and compared with known mismatches from previous transplants. Seventeen of the 60 sera (28%) were positive in the CDC increasing to 26 of 60 (43%) in the class I and 33 of 60 (55%) in the class II plate‐based assay. Using the modified bead‐based system 24 of 60 sera (40%) contained NCB IgG2/4, which were mostly donor specific. In addition, a high prevalence of NCB IgA antibodies was detected (26 of 60 sera), which occurred independently of IgG2/4 NCB, and half of which were donor specific. NCB anti‐HLA alloantibodies, including the IgA isotype, can reliably be detected using the modified bead‐based test system. These NCB alloantibodies had a high prevalence in retransplant candidates and were mostly donor specific.
A new HLA‐A*24 variant, A*2485, identified by sequence‐based typing in a Chinese individual
Authors: Li Z. , Zou H.‐Y. , Cheng L.‐H. , Jin S.‐Z. , Wang D.‐M. , Deng Z.‐H.
Published: June 2008

We report the identification of the novel allele HLA‐A*2485 that was found during routine high‐resolution sequence‐based typing of a Chinese bone marrow donor. The A*2485 allele has 1nt change from A*240201 at nt525 where T>A, codon 151 H>Q (CAT→CAA).
New insights into the functions of B cells
Authors: Balin Samuel J. , Platt Jeffrey L. , Cascalho Marilia
Published: June 2008

Abstract:  Organ transplants between genetically different individuals elicit powerful immune responses that invariably cause rejection in the absence of immune suppression. Among the immune responses elicited by organ allografts, B‐cell responses causing antibody‐mediated rejection are one of the most vexing. However, recent advances in the field indicate that B cells and antibodies’ contribution to immunity extends well beyond the traditional functions ascribed to antibodies. Here we review “non‐humoral” functions of B cells and the implications of these functions to transplantation.
Increased Ig‐null B lymphocytes in the peripheral blood of pediatric solid organ transplant recipients with elevated Epstein‐Barr viral loads
Authors: Schauer Elizabeth , Webber Steven , Kingsley Laurence , Green Michael , Rowe David
Published: June 2008

Abstract:  In this study, the characteristics of Ig‐null B cells in high viral load carriers were examined by four‐color flow cytometry. The frequency of Ig‐null B cells in patients with high, low or undetectable virus loads was found that while patients with a high load had more Ig‐null cells, these cells were also present in the low and undetectable load groups. As Ig‐null cells from patients with no viral load were EBV‐negative, EBV infection was not absolutely required for the generation or survival of Ig‐null cells. Ig‐null cells were CD19+, sIg‐, CD5−, CD10−, CD27−, CD23−, CD38−, and CD69− with variable surface expression of CD20 and CD40. Ig‐null cells did not have a proliferating cell phenotype (Ki67‐) and a high proportion were HLA class I‐ and class II‐. Virus copy number in CD19+ Ig‐null cell populations may be much higher than in CD19+ Ig+ cell populations. EBV infected Ig‐null cells were common in blood specimens from pediatric solid organ transplant recipients and infected Ig‐null cells may pose potential problems for immunotherapies that target infected B cells directly.
Long‐term follow‐up of portal hypertension after liver transplantation in children
Authors: Ling S. C. , Pfeiffer A. , Avitzur Y. , Fecteau A. , Grant D. , Ng V. L.
Published: June 2008

Abstract:  We aimed to describe the long‐term changes in the imaging and clinical features of PHALT in children. A retrospective review was undertaken of consecutive children undergoing their first liver transplant between 1993 and 2003. Details of clinical progress and ultrasound imaging were recorded at one‐yr post‐transplantation and at last follow‐up. Data were extracted on 83 children (median age at transplant 1.7 yr, range one month to 17.5 yr, 44 girls) who underwent 89 transplants. Four of these children died at a mean 5.6 yr (range 3.8–6.9 yr) after transplantation. Of the survivors, follow‐up at one yr (n = 83) and at last follow‐up (n = 71, median 4.3 yr post‐transplant) revealed imaging evidence of splenomegaly in 46% and 44%, ascites in 6% and 4%, and portal systemic collaterals in 12% and 14%, respectively. Gastrointestinal hemorrhage associated with portal hypertension had occurred in no children at one yr and in four (6%) at latest follow‐up. Features of portal hypertension on ultrasound scan are common in children before liver transplantation. An important minority of children will suffer clinically significant complications of PHALT during long‐term follow‐up, caused by both vascular and parenchymal disease.