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Morphological Evidence (morphological + evidence)
Selected AbstractsSYSTEMATICS OF GRACILARIOPSIS (GRACILARIALES, RHODOPHYTA) BASED ON rbcL SEQUENCE ANALYSES AND MORPHOLOGICAL EVIDENCE,JOURNAL OF PHYCOLOGY, Issue 1 2003Carlos Frederico D. Gurgel A phylogeny has been inferred from parsimony and likelihood analyses of plastid rbcL DNA sequences for seven recognized and six undescribed species of Gracilariopsis (Gp.) (Gracilariales, Rhodophyta). New descriptions and illustrations of cystocarp morphology are provided for four Gracilariopsis species from North and South America. The generitype, Gp. sjoestedtii (Kylin) Dawson, is reinstated to include plants distributed from British Columbia to Pacific Baja California, and the name is corrected to Gp. andersonii (Grunow) Dawson. Gracilariopsis lemaneiformis (Bory) Dawson, Acleto et Foldvik is shown not to have a worldwide distribution but to be restricted to the vicinity of Peru. Gracilariopsis costaricensis is recognized with the provision that it may prove to be conspecific with Gp. lemaneiformis. Gracilariopsis "lemaneiformis" from North and South Carolina is described as a new species, Gp. carolinensis Liao et Hommersand sp. nov. Gracilariopsis longissima (Gmelin) Steentoft, Irvine et Farnham from Western Europe and the Mediterranean Sea and Gp. tenuifrons (Bird et Oliveira) Fredericq et Hommersand from the Ca-ribbean Sea and Brazil are recognized. Entities that have been referred to Gp. "lemaneiformis" from China and Japan constitute an undescribed species that is related to Gp. heteroclada Zhang et Xia. An invasive species from the Gulf of California, Mexico, and South Australia that has been assigned to Gp. "lemaneiformis" is resolved in a clade that includes Gp. longissima. Four undescribed species are included in the molecular analyses. The systematics of Gracilariopsis is discussed in the light of the morphological and molecular evidence. [source] A SYSTEMATIC STUDY OF GIGAR-TINACEAE FROM PACIFIC NORTH AMERICA BASED ON MOLECULAR AND MORPHOLOGICAL EVIDENCEJOURNAL OF PHYCOLOGY, Issue 2000J.R. Hughey Greater than 50 species of Gigartinaceae have been described from Pacific North America, about half of which are currently recognized. Although the family is treated extensively in the taxonomic literature, many of the species are still confused and a comprehensive revision is required. We sequenced the rbcL (RuBisCO) gene and ITS (Internal Transcribed Spacer) 1, 2, and 5.8S regions from a large number of recent collections and identified a discrete of number data sets. These were analysed in comparison with the morphological evidence for each of the taxa. Uncertain of the possibility that our operational taxonomic units may not correspond to the types, we developed a protocol for isolating PCR-friendly DNA from herbarium specimens, some reaching back as far as 1670. The DNA profiles of types and historically important specimens were compared to those for recently collected silica gel-dried and formalin-fixed material and assigned correct names. Species studied ranged from Alaska to Mexico and the Gulf of California and were compared to outgroup taxa from Pacific South America and the Southern Ocean. Particular attention was paid to variations in morphology as they relate to habitat with emphasis on the presence or absence of different morphological forms among sympatric and allopatric populations. We recognize 10 species in Chondracanthus (including one new combination and one new species) and 16 species in Mazzaella (including two new combinations and two new species). Finally, we tested a phylogenetic hypothesis inferred for the Gigartinaceae from rbcL sequences for congruence with one generated from ITS sequences. [source] Morphological Evidence for Direct Interaction Between Gonadotrophin-Releasing Hormone Neurones and Astroglial Cells in the Human HypothalamusJOURNAL OF NEUROENDOCRINOLOGY, Issue 9 2007M. Baroncini In rodents, there is compelling evidence indicating that dynamic cell-to-cell communications involving cross talk between astroglial cells (such as astrocytes and specialised ependymoglial cells known as tanycytes) and neurones are important in regulating the secretion of gonadotrophin-releasing hormone (GnRH), the neurohormone that controls both sexual maturation and adult reproductive function. However, whether such astroglial cell,GnRH neurone interactions occur in the human brain is not known. In the present study, we used immunofluorescence to examine the anatomical relationship between GnRH neurones and glial cells within the hypothalamus of five women. Double-staining experiments demonstrated the ensheathment of GnRH neurone perikarya by glial fibrillary acidic protein (GFAP)-immunoreactive astrocyte processes in the periventricular zone of the tuberal region of the hypothalamus. GFAP immunoreactivity did not overlap that of GnRH at the GnRH neurone's projection site (i.e. the median eminence of the hypothalamus). Rather, human GnRH neuroendocrine fibres were found to be closely associated with vimentin or nestin-immunopositive radial gial processes likely belonging to tanycytes. In line with these light microscopy data, ultrastructural examination of GnRH-immunoreactive neurones showed numerous glial cells in direct apposition to pre-embedding-labelled GnRH cell bodies and/or dendrites in the infundibular nucleus, whereas postembedding immunogold-labelled GnRH nerve terminals were often seen to be enwrapped by glial cell processes in the median eminence. GnRH nerve button were sometimes visualised in close proximity to fenestrated pituitary portal blood capillaries and/or evaginations of the basal lamina that delineate the pericapillary space. In summary, these data demonstrate that GnRH neurones morphologically interact with astrocytes and tanycytes in the human brain and provide evidence that glial cells may contribute physiologically to the process by which the neuroendocrine brain controls the function of GnRH neurones in humans. [source] Intermediary Spleen Microvasculature in Canis familiaris, Morphological Evidences of a Closed and Open TypeANATOMIA, HISTOLOGIA, EMBRYOLOGIA, Issue 5 2003G. Alexandre-Pires Summary Numerous studies have been made regarding circulation via the red pulp of the spleen, and intense controversy surrounds the question as to whether or not endothelial continuity exists between arterial and venous vessels. Aware of this intense controversy, and in order to perform investigation over the spleen of dogs infected with a parasitic disease (future reports shall be done), the authors studied the vascularization of the normal dog spleen in order to define its normal pattern and evaluate the eventual changes of the circulation pattern under the parasitic condition. These studies led us to report, unequivocally, using complementary vascular replective techniques, that the normal dog's intermediary circulation is morphologically closed and of the open kind also. These findings are contrary to the thesis that defends the existence of a physiologically closed and morphologically open circulation in the dog spleen. Lymphatic vessels in the spleen of the dog are also demonstrated. [source] The wing vestiture of the non-ditrysian Lepidoptera (Insecta).ACTA ZOOLOGICA, Issue 4 2001Comparative morphology, phylogenetic implications Abstract The ultrastructure of the dorsal forewing vestiture in exemplars of all family group taxa of non-ditrysian Lepidoptera is examined, and the evolutionary implications at family level and above are discussed. Wing-scale terminology is reviewed. Three different types of bilayer wing-scale covering are recognized; only a few groups have a single-layer wing-scale covering. The general scale arrangement is random, but a few taxa have clustered scale arrangements and scattered heteroneurans have scales arranged in transverse rows. Cross ribs are present in all taxa, but only as vestiges in eriocraniid cover scales. Ridge dimorphism is widespread in Neolepidoptera. Surprisingly, ridges and cross ribs on the adwing scale surface are of general occurrence in Neopseustidae and Hepialidae, and are even found on parts of the ground scales of many other Neolepidoptera. Morphological evidence strongly indicates that the fused wing-scale types found in non-Coelolepidan Lepidoptera and Neolepidoptera are independently evolved, as evidenced from the presence of vestigial perforations. Absence of perforations is not infallible evidence that a scale is solid. Microtrichia are independently reduced in a number of taxa and probably re-evolved in at least higher nepticulids. Wing vestiture and scale characters indicate that Tischerioidea may be the sister group of Ditrysia. [source] Three-genome mosses: complex double allopolyploid origins for triploid gametophytes in SphagnumMOLECULAR ECOLOGY, Issue 7 2009ERIC F. KARLIN Abstract This paper documents the occurrence of allotriploidy (having three differentiated genomes) in gametophytes of two Southern Hemisphere Sphagnum species (S. australe, S. falcatulum). The pattern of microsatellite alleles indicates that both species are composed of a complex of allodiploid and allotriploid gametophytes, with the latter resulting from two allopolyploidization events. No haploid (n = x) gametophytes were found for either species. The ploidal levels suggested by the pattern of microsatellite alleles were confirmed by flow cytometry and Feulgen DNA image densitometry. For both S. australe and S. falcatulum, the respective allodiploid plants (or their ancestors) are one of the parent species of the allotriploid plants. This is the first report of triploidy in Sphagnum gametophytes occurring in nature and also the first report of the presence of three differentiated genomes in any bryophyte. It is also the first report of intersectional allopolyploidy in Sphagnum, with S. australe appearing to have parental species from Sphagnum sections Rigida and Sphagnum, and S. falcatulum having parental species from Sphagnum sections Cuspidata and Subsecunda. In both species, the allotriploid cytotypes were the most prevalent cytotype on the South Island of New Zealand. The pattern of microsatellite alleles shows the presence of two genetically distinct populations of allodiploid S. australe, possibly indicating multiple origins of polyploidy for that allodiploid cytotype. Morphological evidence is also highly indicative of recurrent polyploidy in the allotriploid cytotype of S. falcatulum. Allopolyploidy has clearly played a major evolutionary role in these two Southern Hemisphere taxa. This study, in conjunction with other recent research, indicates that allopolyploidy is a common, if not the predominant, form of polyploidy in Sphagnum. [source] Craniodental mechanics and diet in Asian colobines: Morphological evidence of mature seed predation and sclerocarpyAMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY, Issue 1 2010Daisuke B. Koyabu Abstract Folivory has been accepted as the general dietary pattern for colobines. However, recent ecological studies have revealed that extensive seed eating is found in some colobine species. The ripeness of foraged seeds is also reported to differ between seed eaters. As seeds are generally stress-limited and may pose greater mechanical demands, seed-eating species are predicted to exhibit morphological features adaptive for seed predation. In addition, species that feeds on seeds from unripe fruits with hard pericarp is predicted to exhibit increased leverage for anterior dentition. To test these hypotheses, we compared the craniodental morphology of seed-eating Asian colobines (Presbytis rubicunda and Trachypithecus phayrei) with those of species that rarely exploit seeds (Presbytis comata, Trachypithecus obscurus, and Semnopithecus vetulus). The results show that the seed-eating colobines possess a masticatory system with enhanced leverage at postcanine bite points. The sclerocarpic forager P. rubicunda also exhibits markedly greater masticatory leverage at anterior dental bite points, while the mature-seed-eating T. phayrei shows no such advantage for canine and incisor use. These observations suggest that P. rubicunda is well adapted to husking the resistant pericarps of unripe fruits, using the anterior dentition and to gain access to the immature seeds, whereas such sclerocarpic feeding behavior may be less important for T. phayrei. Our findings indicate that the distinctive craniodental variations of colobines may be linked to mature and/or immature seed eating and suggest the significance of seed predation for the evolution of colobine monkeys. Am J Phys Anthropol, 2010. © 2010 Wiley-Liss, Inc. [source] In vivo imaging of microglial cell traffickingACTA OPHTHALMOLOGICA, Issue 2009M PAQUES Purpose Microglial cells (MCs) are active sensors of neural tissues that are rapidly mobilized upon disruption of homeostasis. OUr goal was to observe in vivo the migration of MCs, which has not been done yet. Methods Following acute laser damage, the behavior of MCs in the retina of adult Cx3cr1gfp/+ and gfp/gfp mice was observed noninvasively using time-lapse confocal scanning laser ophthalmoscopy. Observation were done at various time-points up to 8 days after laser damage. Results Focal damage elicite prompt migratory response of MCs within 200 to 400 µm around laser burns. This migratory response was preceded in all case by dendritic reorientation. Convergent and nonconvergent migration were observed. Such migratory activity persisted several days after laser damage. At day 8, the microglia network was restored and microglial locomotion had ceased. Conclusion To our knowledge, this is the first observation of microglial locomotion in vivo. A Morphological evidence of microglial activation starts with dendritic reorganization. Migrating cells were only of the dendritic type (i.e. not ameboid). There appears to be a notable heterogeneity in the locomotor response of MCs. MCs within and around scars remain highly motile and mobile several days after laser damage. [source] The Palaeoptera Problem: Basal Pterygote Phylogeny Inferred from 18S and 28S rDNA SequencesCLADISTICS, Issue 3 2002Rasmus Hovmöller Monophyly of the pterygote insects is generally accepted, but the relationships among the three basal branches (Odonata, Ephemeroptera and Neoptera) remain controversial. The traditional view, to separate the pterygote insects in Palaeoptera (Odonata + Ephemeroptera) and Neoptera, based on the ability or inability to fold the wings over the abdomen, has been questioned. Various authors have used different sets of morphological characters in support of all three possible arrangements of the basal pterygote branches. We sequenced 18S and 28S rDNA from 18 species of Odonata, 8 species of Ephemeroptera, 2 species of Neoptera, and 1 species of Archaeognatha in our study. The new sequences, in combination with sequences from GenBank, have been used in a parsimony jackknife analysis resulting in strong support for a monophyletic Palaeoptera. Morphological evidence and the phylogenetic implications for understanding the origin of insect flight are discussed. [source] Comparative histology of the vaginal,cloacal region in Squamata and its phylogenetic implicationsACTA ZOOLOGICA, Issue 4 2007Paola María Sánchez-Martínez Abstract We described the histology and morphology of the vaginal,cloacal region in 18 species from 12 Squamata families. This comparative study revealed a wide variation in the cloacal morphology. Fifteen morphological characters were considered to be primary homology hypotheses and were optimized over the topology derived from the parsimony analysis of the available soft morphological evidence, including the characters described in this study. The synapomorphies optimized for Squamata are bifid urodaeum, common urodaeal cavity with similar histological features of the urodaeal horns, and presence of glands in the anterior urodaeum; for Scleroglossa the synapomorphy is the lateral position of the vaginal intrusion into the anterior urodaeal chamber, for Nyctisaura + Scincomorpha the synapomorphy is the presence of a bifid posterior urodaeum; and for Xantusidae + Annulata it is the presence of simple glands in the anterior urodaeum. The central position of the vaginal intrusion into the urodaeal chamber and the intraepithelial position of the glandular unit in the anterior urodaeum behave as autapomorphies for Iguanidae. This study contributes evidence that defines the relationships within Scleroglossa. Cloacal features provide interesting information that is useful as a source of morphological characters for phylogenetic studies in Squamata. [source] PRECLINICAL STUDY: FULL ARTICLE: Altered architecture and functional consequences of the mesolimbic dopamine system in cannabis dependenceADDICTION BIOLOGY, Issue 3 2010Saturnino Spiga ABSTRACT Cannabinoid withdrawal produces a hypofunction of mesencephalic dopamine neurons that impinge upon medium spiny neurons (MSN) of the forebrain. After chronic treatment with two structurally different cannabinoid agonists, ,9 -tetrahydrocannabinol and CP55 940 (CP) rats were withdrawn spontaneously and pharmacologically with the CB1 antagonist SR141716A (SR). In these two conditions, evaluation of tyrosine hydroxylase (TH)-positive neurons revealed significant morphometrical reductions in the ventrotegmental area but not substantia nigra pars compacta of withdrawn rats. Similarly, confocal analysis of Golgi,Cox-stained sections of the nucleus accumbens revealed a decrease in the shell, but not the core, of the spines' density of withdrawn rats. Administration of the CB1 antagonist SR to control rats, provoked structural abnormalities reminiscent of those observed in withdrawal conditions and support the regulatory role of cannabinoids in neurogenesis, axonal growth and synaptogenesis by acting as eu-proliferative signals through the CB1 receptors. Further, these measures were incorporated into a realistic computational model that predicts a strong reduction in the excitability of morphologically altered MSN, yielding a significant reduction in action potential output. These pieces of evidence support the tenet that withdrawal from addictive compounds alters functioning of the mesolimbic system and provide direct morphological evidence for functional abnormalities associated with cannabinoid dependence at the level of dopaminergic neurons and their postsynaptic counterpart and are coherent with recent hypothesis underscoring a hypodopaminergic state as a distinctive feature of the ,addicted brain'. [source] Cell autonomous sorting and surface positioning in the formation of primitive endoderm in embryoid bodies,GENESIS: THE JOURNAL OF GENETICS AND DEVELOPMENT, Issue 6 2007Malgorzata E. Rula Abstract The differentiation and formation of the primitive endoderm in early embryos can be mimicked in vitro by the aggregation of embryonic stem cells to form embryoid bodies. We present morphological evidence that primitive endoderm cells often first locate in the interior of embryoid bodies and subsequently migrate to the surface. Cell mixing experiments indicate that surface positioning is an intrinsic property of endoderm epithelial cells. Moreover, Disabled-2 (Dab2) is required for surface sorting and positioning of the endoderm cells: when Dab2 expression was eliminated, the differentiated endoderm epithelial cells distributed throughout the interior of the embryoid bodies. Surprisingly, E-cadherin is dispensable for primitive endoderm differentiation and surface sorting in embryoid bodies. These results support the model that primitive endoderm cells first emerge in the interior of the inner cell mass and are subsequently sorted to the surface to form the primitive endoderm. genesis 45: 327,338, 2007. Published 2007 Wiley-Liss, Inc. [source] Confocal imaging and tracking of the exocytotic routes for D -serine-mediated gliotransmissionGLIA, Issue 12 2008Magalie Martineau Abstract D -Serine is an astrocyte-derived regulator for N -methyl- D -aspartate receptors, but the intracellular routes of its trafficking are still largely unknown. Here, we combined confocal microscopy with colocalization quantification to track the astrocytic organelles that store D -serine. We report that D -serine colocalizes with the transfected eGFP-synaptobrevin/VAMP2 and eGFP-cellubrevin/VAMP3, two v-SNAREs of the regulated secretory pathway. No significant colocalization was found with markers of the endosomal sorting and recycling system: EEA1, eGFP-endobrevin/VAMP8, eGFP-TI-VAMP/VAMP7, LAMP1, and CD63. Blockade of vesicular budding with colchicine shows that secretory vesicles import D -serine downstream to the Golgi apparatus. Finally, treatment of astrocytes with the Ca2+ -ionophore A23187, glutamate agonists, or bradykinin trigger translocation of synaptobrevin/VAMP2 to the plasma membrane with a concomitant disappearance of D -serine from the regulated secretory pathway. Our results provide morphological evidence for a vesicular storage of D -serine in the regulated secretory pathway and the possible recruitment of these stores by Ca2+ mobilization to release D -serine. © 2008 Wiley-Liss, Inc. [source] Gallbladder cancer: a morphological and molecular updateHISTOPATHOLOGY, Issue 2 2009Robert David Goldin Gallbladder cancer (GBC) shows a marked geographical variation in its incidence, with the highest figures being seen in India and Chile and relatively low levels in many Western countries. Risk factors for its development include the presence of gallstones, infection and the presence of an anomalous pancreatobiliary ductal junction. It can arise from either a pathway involving metaplasia or dysplasia or one in which there is a pre-existing adenoma. The former is the more common and, because it is often not associated with a macroscopically recognizable lesion, leads to the recommendation that all gallbladders need to be examined microscopically. Accurate staging of invasive cancers is essential to determine prognosis and treatment, and this requires extensive tumour sampling. A number of genetic alterations have been identified in the preinvasive and invasive stages of GBC and they support the morphological evidence of there being two pathways by which tumours develop. Some of these genetic changes are associated with particular risk factors. For example, cases with anomalous pancreatobiliary ductal junction show a higher frequency of K-ras mutations. Some changes are associated with differences in prognosis. For example, cancers without expression of p21 but with expression for p27 have a better prognosis, whereas those that express c-erb-B2 have a worse one. Work has also been done on identifying clinical, imaging and other factors that indicate that patients have a higher risk of having GBC. This is particularly important in high-incidence areas in which GBC is a significant public health problem. [source] Subcellular distribution of key enzymes of lipid metabolism during the euthermia-hibernation-arousal cycleJOURNAL OF ANATOMY, Issue 6 2009Anna Suozzi Abstract Mammalian hibernation is a natural, fully reversible hypometabolic state characterized by a drastic reduction of body temperature and metabolic activity, which ensures survival to many species under adverse environmental conditions. During hibernation, many hibernators rely for energy supply almost exclusively on lipid reserves; the shift from carbohydrate to lipid metabolism implies profound rearrangement of the anabolic and catabolic pathways of energetic substrates. However, the structural counterpart of such adaptation is not known. In this study we investigated, by using immunoelectron microscopy, the fine intracellular distribution of two key enzymes involved in lipid metabolism, namely, the fatty acid synthase (FAS) and the long-chain fatty acyl-CoA synthetase (ACSL), in hepatocytes of euthermic, hibernating and arousing hazel dormice. Our results show that the two enzymes are differentially distributed in cellular compartments (cytoplasm, mitochondria and cell nuclei) of hepatocytes during euthermia. Quantitative redistribution of both enzymes among cellular compartments takes place during hibernation and arousal, in accordance with the physiological changes. Interestingly, this redistribution follows different seasonal patterns in cytoplasm, mitochondria and nuclei. In conclusion, our data represent the first quantitative morphological evidence of lipid enzyme distribution in a true hibernator throughout the year cycle, thus providing a structural framework to biochemical changes associated with the hypometabolism of hibernation. [source] A SYSTEMATIC STUDY OF GIGAR-TINACEAE FROM PACIFIC NORTH AMERICA BASED ON MOLECULAR AND MORPHOLOGICAL EVIDENCEJOURNAL OF PHYCOLOGY, Issue 2000J.R. Hughey Greater than 50 species of Gigartinaceae have been described from Pacific North America, about half of which are currently recognized. Although the family is treated extensively in the taxonomic literature, many of the species are still confused and a comprehensive revision is required. We sequenced the rbcL (RuBisCO) gene and ITS (Internal Transcribed Spacer) 1, 2, and 5.8S regions from a large number of recent collections and identified a discrete of number data sets. These were analysed in comparison with the morphological evidence for each of the taxa. Uncertain of the possibility that our operational taxonomic units may not correspond to the types, we developed a protocol for isolating PCR-friendly DNA from herbarium specimens, some reaching back as far as 1670. The DNA profiles of types and historically important specimens were compared to those for recently collected silica gel-dried and formalin-fixed material and assigned correct names. Species studied ranged from Alaska to Mexico and the Gulf of California and were compared to outgroup taxa from Pacific South America and the Southern Ocean. Particular attention was paid to variations in morphology as they relate to habitat with emphasis on the presence or absence of different morphological forms among sympatric and allopatric populations. We recognize 10 species in Chondracanthus (including one new combination and one new species) and 16 species in Mazzaella (including two new combinations and two new species). Finally, we tested a phylogenetic hypothesis inferred for the Gigartinaceae from rbcL sequences for congruence with one generated from ITS sequences. [source] Phrenic nerve diabetic neuropathy in rats: unmyelinated fibers morphometryJOURNAL OF THE PERIPHERAL NERVOUS SYSTEM, Issue 2 2009Valéria Paula S. Fazan Abstract We have demonstrated that phrenic nerves' large myelinated fibers in streptozotocin (STZ)-induced diabetic rats show axonal atrophy, which is reversed by insulin treatment. However, studies on structural abnormalities of the small myelinated and the unmyelinated fibers in the STZ-model of neuropathy are limited. Also, structural changes in the endoneural vasculature are not clearly described in this model and require detailed study. We have undertaken morphometric studies of the phrenic nerve in insulin-treated and untreated STZ-diabetic rats and non-diabetic control animals over a 12-week period. The presence of neuropathy was assessed by means of transmission electron microscopy, and morphometry of the unmyelinated fibers was performed. The most striking finding was the morphological evidence of small myelinated fiber neuropathy due to the STZ injection, which was not protected or reversed by conventional insulin treatment. This neuropathy was clearly associated with severe damage of the endoneural vessels present on both STZ groups, besides the insulin treatment. The STZ-diabetes model is widely used to investigate experimental diabetic neuropathies, but few studies have performed a detailed assessment of either unmyelinated fibers or capillary morphology in this animal model. The present study adds useful information for further investigations on the ultrastructural basis of nerve function in diabetes. [source] SCHWANN CELL APOPTOSIS IN TISSUE CULTURE FOLLOWING THE ADMINISTRATION OF PRO-INFLAMMATORY CYTOKINESJOURNAL OF THE PERIPHERAL NERVOUS SYSTEM, Issue 1 2000E. Scarpini In immune-mediated demyelination of the nervous system, glial cell apoptosis has been observed recently; however, the relevance of the phenomenon and the characterization of the involved molecules are still controversial. Cytokines are secreted by many cells, including inflammatory and glial cells, and appear to play a relevant role in the peripheral nervous system (PNS) immuno-mediated demyelination, being active in promoting the damage to Schwann cells, myelin, and axons. Even though the exact role of the different cytokines is at present uncertain, they have a sequential different expression in PNS immune-mediated demyelination and could induce apoptotic death of Schwann cells in the vicinity of the inflammatory reaction via the expression of CD95 (Apo1/Fas). This study has been designed to detect in rat primary Schwann cell tissue cultures whether the administration of IL-1B and IFN-y can induce cell death. Identification of apoptotic Schwann cell was performed by morphological, immunohistochemical, and electron-microscopy analysis. Our results show that Schwann cells stimulated by proinflammatory cytokines IL-1B and IFN-y show morphological evidence of nuclear chromatin condesation at the DAPI staining and are TUNEL positive. The same features of apoptotic cell death were observed by electron microscopy. These findings provide evidence to support the hypothesis that cytokines can directly damage Schwann cells in disorders of the PNS. [source] Chordate phylogeny and evolution: a not so simple three-taxon problemJOURNAL OF ZOOLOGY, Issue 2 2008T. Stach Abstract Traditional concepts of chordate phylogeny have recently been in turmoil: in a large-scale molecular study, the traditional hypothesis that cephalochordates are sister taxon to craniates was replaced by the hypothesis of a sister group relationship between tunicates and craniates. It was claimed that the morphological evidence that supported traditional phylogeny was weak and that morphological characters at least equally strong could be mustered in support of the ,new phylogeny.' In the present review, it is shown that the uncritical use of published codings of morphological characters in recent phylogenetic analyses is responsible for this perception. To ameliorate this situation, the main focus of the present publication is a review of the morphological evidence that has been deemed relevant in chordate phylogeny. Characters are presented in enough detail to allow readers to make self-reliant informed decisions on character coding. I then analyze these characters cladistically, and it is demonstrated that support of the traditional hypothesis is substantial. I briefly evaluate molecular systematic studies and criticize ,evo-devo' studies for lack of cladistic rigor in the evolutionary interpretations of their data by (1) failing to formally code their characters (2) failing to subject their data to the congruence test with other characters, the crucial test in phylogenetic analyses. Finally, a short and by necessity eclectic discussion of suggested evolutionary scenarios is presented. [source] Forest elephant (Loxodonta africana cyclotis) stature in the Réserve de Faune du Petit Loango, GabonJOURNAL OF ZOOLOGY, Issue 4 2003Bethan J. Morgan Abstract The stature of forest elephants Loxodonta africana cyclotis was determined at the Petit Loango Reserve over 14 months from January to December 1998 and May to June 1999 using three measures: shoulder height, hind footprint length and boli diameter. The shoulder height of 53 identified elephants was measured using photogrammetric methods. The minimum estimated shoulder height was 69 cm from a young calf, and the tallest animal was 216 cm. Hind footprint length and boli diameter data were collected from unidentified individuals. The minimum footprint size was 12.5 cm and the largest 35.3 cm. Boli diameter ranged from 4.0 to 16.0 cm. A comparison of the size categories with those of savanna elephants in Amboseli National Park, Kenya, suggested a similar distribution of size, age and population structure, despite a marked difference in overall stature. These are the first data for measures of African forest elephant size compared to African savanna elephant size. Such data may add morphological evidence supporting recent genetic work suggesting that African forest elephants be re-classified as a distinct species from the African savanna elephant. [source] World-wide genetic differentiation of Eubalaena: questioning the number of right whale speciesMOLECULAR ECOLOGY, Issue 11 2000H. C. Rosenbaum Abstract Few studies have examined systematic relationships of right whales (Eubalaena spp.) since the original species descriptions, even though they are one of the most endangered large whales. Little morphological evidence exists to support the current species designations for Eubalaena glacialis in the northern hemisphere and E. australis in the southern hemisphere. Differences in migratory behaviour or antitropical distribution between right whales in each hemisphere are considered a barrier to gene flow and maintain the current species distinctions and geographical populations. However, these distinctions between populations have remained controversial and no study has included an analysis of all right whales from the three major ocean basins. To address issues of genetic differentiation and relationships among right whales, we have compiled a database of mitochondrial DNA control region sequences from right whales representing populations in all three ocean basins that consist of: western North Atlantic E. glacialis, multiple geographically distributed populations of E. australis and the first molecular analysis of historical and recent samples of E. glacialis from the western and eastern North Pacific Ocean. Diagnostic characters, as well as phylogenetic and phylogeographic analyses, support the possibility that three distinct maternal lineages exist in right whales, with North Pacific E. glacialis being more closely related to E. australis than to North Atlantic E. glacialis. Our genetic results provide unequivocal character support for the two usually recognized species and a third distinct genetic lineage in the North Pacific under the Phylogenetic Species Concept, as well as levels of genetic diversity among right whales world-wide. [source] The colonization history of Olea europaea L. in Macaronesia based on internal transcribed spacer 1 (ITS-1) sequences, randomly amplified polymorphic DNAs (RAPD), and intersimple sequence repeats (ISSR)MOLECULAR ECOLOGY, Issue 7 2000J. Hess Abstract Phylogenetic relationships in the Olea europaea complex and the phylogeography of 24 populations of the Macaronesian olive (O. europaea ssp. cerasiformis) were assessed by using three molecular markers: nuclear ribosomal internal transcribed spacer 1 (ITS-1) sequences, randomly amplified polymorphic DNAs (RAPD), and intersimple sequence repeats (ISSR). Parsimony analysis of the ITS-1 sequences and Neighbour-joining (NJ) analyses of RAPD and ISSR banding variation revealed four major lineages in the O. europaea complex: (1) ssp. cuspidata; (2) ssp. cerasiformis from Madeira; (3) ssp. laperrinei; and (4) ssp. cerasiformis from the Canary Islands plus ssp. europaea. These results provide unequivocal support for two independent dispersal events of Olea to the Madeira and Canary Islands. Molecular and morphological evidence led to recognition of two separate olive taxa in Macaronesia, to date included in ssp. cerasiformis. NJ analyses of the combined RAPD and ISSR data suggest that the colonization of the Canaries by O. europaea may have followed an east to west stepping-stone model. An interisland dispersal sequence can be recognized, starting from the continent to Fuerteventura, Gran Canaria, Tenerife, La Gomera, and finally La Palma. High dispersal activity of the lipid-rich Olea fruits by birds in the Mediterranean region is congruent with multiple dispersal of olives to Macaronesia and successive colonization of the archipelagos. The observation of strong genetic isolation between populations of different islands of the Canary Islands suggests, however, that subsequent interisland dispersal and establishment has been very rare or may not have occurred at all. [source] Lack of apoptosis in patients with progressive external ophthalmoplegia and mutated adenine nucleotide translocator-1 geneMUSCLE AND NERVE, Issue 2 2002Gigliola Fagiolari PhD Abstract Adenine nucleotide translocator-1 (ANT-1), encoded by chromosome 4 (4q34-35 locus), is a component of the mitochondrial permeability transition pores that are involved in apoptotic mechanisms. We studied muscle biopsies from seven individuals with autosomal dominant progressive external ophthalmoplegia caused by ANT-1 mutations. We found no instance of terminal deoxynucleotidyltransferase-mediated dUTP nick end labeling (TUNEL) positivity nor significant expression of apoptosis-related proteins. Furthermore, there was no morphological evidence of apoptosis at the ultrastructural level. Thus, degeneration of muscle in this disorder is nonapoptotic. © 2002 Wiley Periodicals, Inc. Muscle Nerve 26: 265,269, 2002 [source] Correlation of single photon emission computed tomography with pathology and seizure outcome in children undergoing epilepsy surgeryNEUROPATHOLOGY & APPLIED NEUROBIOLOGY, Issue 2 2002J. H. Cross Introduction:, Single photon emission computed tomography (SPECT) imaging regional cerebral blood flow (rCBF) can help localize the seizure focus in partial epilepsies during presurgical evaluation. Few studies have explored the possible relationship between preoperative SPECT and underlying pathology, or any relationship to postsurgical outcome. Study group:, Thirty-five children with medically intractable epilepsy undergoing resective surgery between the ages of 11 months and 18 years had presurgical ictal and interictal rCBF and post surgery follow up of 3,6 years. Results:, Pathological examination revealed 13 to have hippocampal sclerosis (HS): of these 11 had relatively low interictal rCBF perfusion on the side of seizure onset, and eight had hyperfusion ictally. Eight children had morphological evidence of cortical dysplasia: all had a localizing ictal rCBF concordant with the area resected whereas only six demonstrated localized reduction in perfusion on interictal rCBF. All three patients with Rasmussens encephalitis had informative rCBF scans, concordant with the seizure focus. However, infarct, tumours and nonspecific pathology demonstrated poor localization of the seizure focus. No SPECT parameter correlated independently with outcome, although overall the HS group had the best outcome, particularly those with localizing ictal SPECT. Comment:, Ictal SPECT appears predictive of underlying cortical dysplasia. Although in this small group of HS in children, ictal SPECT added little to interictal SPECT for seizure localization, it may be useful in the prediction of outcome. SPECT adds little to the evaluation of children being considered for hemispherectomy over and above the abnormalities detectable on MRI scan. [source] Secondary clonal cytogenetic abnormalities following successful treatment of acute promyelocytic leukemia,AMERICAN JOURNAL OF HEMATOLOGY, Issue 11 2009Crisoula Batzios To identify patients who developed secondary clonal cytogenetic aberrations (CCA) following therapy for acute promyelocytic leukemia (APL), we retrospectively analyzed cytogenetic results from 123 patients diagnosed with APL between 1995 and 2007, who had ongoing cytogenetic analysis undertaken in our laboratory. During follow-up for APL we identified 12 patients (9.8%) who developed CCA, not detected at diagnosis of APL and unrelated to their original APL karyotype. All patients had received all-trans retinoic acid (ATRA) and chemotherapy and were in complete remission for APL when secondary CCA were identified. The median latency period between diagnosis of APL and emergence of secondary CCA was 27.5 months (range: 2,54 months). To date, four patients with CCA have been diagnosed with therapy-related myelodysplastic syndrome (t-MDS)/acute myeloid leukemia (t-AML), giving a median t-MDS/AML free survival of 78 months, with follow-up ranging between 20 and 136 months from APL diagnosis. Three patients have died: two patients died of t-AML and another developed relapsed APL with persistence of his secondary clone but no diagnosis of t-MDS/AML and died from transplant-related complications. Two patients are alive with t-MDS. Seven patients with CCA are alive with no morphological evidence of MDS at the time of their last known follow-up; thus median survival has not been reached. The appearance of these abnormalities in the absence of morphological evidence of MDS in the majority of patients is unusual, and highlights the importance of continued cytogenetic follow-up in these patients. Am. J. Hematol., 2009. © 2009 Wiley-Liss, Inc. [source] Variation and causal factors of craniofacial robusticity in Patagonian hunter-gatherers from the late HoloceneAMERICAN JOURNAL OF HUMAN BIOLOGY, Issue 6 2006Valeria Bernal Fueguian-Patagonian skulls have been characterized as some of the most robust of any modern crania. However, the causal factors of such robusticity remain unsettled. We assess within- and among-sample cranial robusticity of seven samples from continental Patagonia and Tierra del Fuego, using geometric morphometric techniques. In addition, the biomechanical, phylogenetic, and climatic hypotheses proposed to account for robusticity in such samples are discussed. Two Amerindian samples of farmers and two early middle Holocene samples from South America were included. The results show: 1) large variation in craniofacial robusticity among Patagonian samples, with the highest robusticity in samples from south continental Patagonia and Isla Grande of Tierra del Fuego, whereas central and north Patagonian samples display the same degree of robusticity as farmer samples; 2) that early middle Holocene samples display lower levels of robusticity than South Patagonian samples; and 3) strong association between latitude and craniofacial robusticity, with the most robust craniofacial morphologies occurring at the highest latitudes. In consequence, neither masticatory stress nor retention of ancestral features is supported by the morphological evidence analyzed. Hence it is hypothesized that endocrine changes related to cold climate may be a plausible explanation for several craniofacial features found in Fueguian and south continental Patagonian samples, such as their large masticatory component, and pronounced supraorbital ridge and glabellar region. Am. J. Hum. Biol. 18:748,765, 2006. © 2006 Wiley-Liss, Inc. [source] New strepsirrhine primate from the late Eocene of Peninsular Thailand (Krabi Basin)AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY, Issue 4 2006Laurent Marivaux Abstract In this paper, we describe the newly discovered lower jaw of a primate from the late Eocene Krabi coal mine (Bang Mark pit) of Peninsular Thailand. We performed microtomographic examinations at the European Synchrotron Radiation Facility (ESRF, Grenoble, France) to analyze different morphological aspects of the jaw and teeth. Although partially preserved, this fossil mandible reveals a set of distinctive dental traits (e.g., double-rooted P2 and molarized P4) that allow us to describe a new stepsirrhine adapiform: Muangthanhinius siami, new genus and species. This taxon is somewhat atypical among Paleogene adapiforms, and more specialized than the sivaladapid adapiforms (hoanghoniines) that existed in Asia in the same epoch. In fact, Muangthanhinius shows a degree of dental specialization approximating that of some modern strepsirrhine lemuriforms, although it lacks the highly specialized anterior dentition characterizing this living primate group (canine + incisors forming a very procumbent toothcomb). In contrast, Muangthanhinius exhibits a large canine deeply anchored within the dentary that probably protruded high above the toothrow. Finally, despite the development of a molarized P4 as in Miocene sivaladapid sivaladapines, Muangthanhinius differs in molar morphology from this group, and the position of this new taxon within the Adapiformes remains indeterminate. Clarification of its phylogenetic position will require more morphological evidence than is currently available. Am J Phys Anthropol, 2006. © 2006 Wiley-Liss, Inc. [source] Transfer of Nosema locustae (Microsporidia) to Antonospora locustae n. comb.THE JOURNAL OF EUKARYOTIC MICROBIOLOGY, Issue 2 2004Based on Molecular, Ultrastructural Data ABSTRACT. Nosema locustae is a microsporidian parasite of grasshopper pesthd that is used as a biological control agent, and is one of the emerging model systems for microsporidia. Due largely to its diplokaryotic nuclei, N. locustae has been classified in the genus Nosema, a large genus with members that infect a wide variety of insects. However, some molecular studies have cast doubt on the validity of certain Nosema species, and on the taxonomic position of N. locustae. To clarify the affinities of this important insect parasite we sequenced part of the rRNA operon of N. locustae and conducted a phylogenetic analysis using the complete small subunit rRNA gene. Nosema locustae is only distantly related to the nominotypic N. bombycis, and is instead closely related to Antonospora scoticae, a recently described parasite of bees. We examined the ultrastructure of mature N. locustae spores, and found the spore wall to differ from true Nosema species in having a multi-layered exospore resembling that of Antonospora (one of the distinguishing features of that genus). Based on both molecular and morphological evidence, therefore, we propose transferring N. locustae to the genus Antonospora, as Antonospora locustae n. comb. [source] Genetic and morphological evidence for reproductive isolation between sympatric populations of Galaxias (Teleostei: Galaxiidae) in South Island, New ZealandBIOLOGICAL JOURNAL OF THE LINNEAN SOCIETY, Issue 3 2001JONATHAN M. WATERS New Zealand's South Island houses a flock of closely related stream-resident fish taxa (Galaxias vulgaris sensu lato), including a number of species recently described on the basis of subtle morphological differences. The taxonomic status of some members of the species complex remains uncertain. This study examines the degree of reproductive isolation between recently recognized morphotypes from Southland (G. ,southern', flatheads; G. gollumoides, roundheads) which co-occur in Bushy Creek, a tributary of the Mataura R. Although these morphotypes are broadly sympatric in Southland and Stewart Island, Bushy Creek is their only documented zone of contact. Molecular (microsatellite, isozyme and mtDNA markers) and morphological analyses of 139 fish samples across a 500-m transect (seven stations) reveal a cline from predominantly G. ,southern' (N=85) to predominantly G. gollumoides (JV=54), corresponding with a gradual increase in stream gradient. Multivariate analyses of genotypic and morphological data independently reveal distinct clusters that are completely congruent with mtDNA type, suggesting an absence of mtDNA introgression. Our data support the separate species status of G. ,southern' and G. gollumoides under both biological and phylogenetic species concepts. We suggest that the speciation of these taxa occurred in allopatry through independent losses of diadromy, with sympatry resulting from secondary contact. [source] Cockroach as the Earliest Eusocial AnimalACTA GEOLOGICA SINICA (ENGLISH EDITION), Issue 4 2010ANSKÝ, Peter VR Abstract: A completely preserved cockroach Sociala perlucida gen. et sp. nov. (Blattida: Socialidae fam. nov.) is described from the Mesozoic (Albian Early Cretaceous) amber of Archingeay in France. It is categorized within the new family Socialidae, originating from the Mesozoic cockroach family Liberiblattinidae, and representing the sister group to the most basal known eutermite families. Numerous direct and indirect morphological evidence (such as a unique narrow body and pronotum with reduced coloration, legs without carination and with numerous sensillar pitts (forelegs) as adaptations to life in nests analogical to the living termitophillous species; enlarged head, long palps for communication, a general venation modified in a direction towards termites (subcosta and radial vein [R] approximated, R branches approximated, simplified, cross-veins reduced), and possibly also the development of the breaking forewing sutura for detaching wings after marriage flight), suggest its eusocial mode of life. Thus, the first eusociality originated within cockroaches, prior to giving birth to termites; termites and Cryptocercus are not directly related. The group of eusocial cockroaches makes termite morphotaxon polyphyletic, but also in this case, the erection of a new order for mastotermites (including Cratomastotermitidae) and/or the inclusion of eusocial, morphological cockroaches within termites appears counterproductive, thus an example of such a general exception to the taxonomical procedure is provided. [source] | |||||||||||||||||||||||||||||||