bluuebunny/crossref_metadata_2025_split huggingface dataset:
On the verge of extinction: genetics of the critically endangered Iberian plant species,Borderea chouardii(Dioscoreaceae) and implications for conservation management
Authors: SEGARRA‐MORAGUES J. G. , PALOP‐ESTEBAN M. , GONZÁLEZ‐CANDELAS F. , CATALÁN P. 
Published: March 2005

AbstractBorderea chouardiiis a relictual and dioecious, strictly sexually reproducing, long‐living geophyte of the Dioscoreaceae family. Previous biological and demographic studies have indicated the existence of a uniformly distributed panmictic population of this taxon at the southernmost Spanish pre‐Pyrenean mountain ranges where it occurs in rather inaccessible crevices of a single limestone cliff. However, individuals ofB. chouardiiare spatially subdivided into two subpopulations located, respectively, on the upper and lower parts of the cliff, and vertically separated 150 m. Because of its extreme rarity,B. chouardiiwas the first Iberian taxon to have a specific conservation plan and has been included in several red lists under the category of critically endangered (CR). However, no previous attempts have been conducted to analyse the fine scale evolutionary mechanisms involved in its present microspatial distribution. Genetic diversity and population structure have been investigated through the analysis of neutral hypervariable markers such as simple sequence repeats (SSRs) and randomly amplified polymorphic DNAs (RAPDs) to unravel the impact of life history traits in the differentiation of the two subpopulations. Both types of molecular markers were unequivocal in distinguishing two genetically distinct groups of individuals corresponding to their spatial separation. However, SSRs detected a higher level of subpopulation differentiation (FST = 0.35,RST = 0.32) than RAPDs (FST = 0.21). SSR data indicated significant deviation from random dispersal of genes and genotypes between the two groups, suggesting that mating occurs mainly among individuals within subpopulations, thus, favouring the divergence between the two groups. This microevolutionary differentiation scenario might have been caused by a coupled effect of past genetic drift and reproductive isolation, as a result of strong glacial age bottlenecks and inefficient dispersal system of pollen and seeds, respectively. The identification of such genetic structure in this narrow endemic prompts a modification of the management strategies of its single extant population.
Complex mating system and dispersal patterns in a social lizard,Egernia whitii
Authors: CHAPPLE DAVID G. , KEOGH J. SCOTT 
Published: March 2005

AbstractIn contrast to the polygynous mating systems typically displayed by most reptilian taxa, long‐term genetic monogamy appears to be widespread within a lineage of group‐living Australian scincid lizards, theEgerniagroup. We have recently shown that White's skink,Egernia whitii, lives in small but temporally stable social aggregations. Here, we examine the mating system, spatial organization, and dispersal patterns ofE. whitiiusing behavioural field studies and data from four microsatellite loci. Parentage analysis ofE. whitiilitters revealed that its mating system is characterized by both polygyny and monogamy. Polygyny was the predominant mating system but within‐season social and genetic monogamy was common (36–45% of breeding pairs). The incidence of between‐season monogamy inE. whitiiwas rare compared to that reported for its congeners. Low levels of multiple paternity (12% of litters) and extra‐group paternity (16%) were detected. Social groups are generally comprised of closely related individuals, but breeding pairs were not more closely related compared to other potential mates. Spatial autocorrelation analyses revealed significant positive local genetic structure over 50 m, which was consistent for all age–sex classes. There was no clear and consistent evidence for sex‐biased dispersal, with assignment tests (mean assignment index) and relatedness analyses suggesting female‐biased dispersal, but spatial autocorrelation analyses indicating a trend for male‐biased dispersal. We discuss the implication of our results in regard to the factors promoting the evolution of monogamy within theEgerniagroup.
Molecular phylogenetics of the Macaronesian‐endemic genus Bystropogon (Lamiaceae): palaeo‐islands, ecological shifts and interisland colonizations
Authors: TRUSTY JENNIFER L. , OLMSTEAD RICHARD G. , SANTOS‐GUERRA ARNOLDO , SÁ‐FONTINHA SUSANA , FRANCISCO‐ORTEGA JAVIER 
Published: March 2005

AbstractA molecular phylogenetic study of Bystropogon L’Hèr. (Lamiaceae) is presented. We performed a cladistic analysis of nucleotide sequences of the internal transcribed spacers (ITS), of the nuclear ribosomal DNA, and of the trnL gene and trnL‐trnF intergenic spacer of the chloroplast DNA. Bystropogon odoratissimus is the only species endemic to the Canary Islands that occurs in the three palaeo‐islands of Tenerife. This species is not part of an early diverging lineage of Bystropogon and we suggest that it has a recent origin. This phylogenetic pattern is followed by most of the species endemic to the palaeo‐islands of Tenerife. The two sections currently recognized in Bystropogon form two monophyletic groups. Taxa belonging to the section Bystropogon clade show interisland colonization limited to the Canary Islands with ecological shifts among three ecological zones. Taxa from the section Canariense clade show interisland colonization both within the Canary Islands and between the Canary Islands and Madeira. Speciation events within this clade are mostly limited to the laurel forest. The genus has followed a colonization route from the Canaries towards Madeira. This route has also been followed by at least five other plant genera with species endemic to Macaronesia. Major incongruences were found between the current infrasectional classification and the molecular phylogeny, because the varieties of Bystropogon origanifolius and Bystropogon canariensis do not form two monophyletic groups. The widespread B. origanifolius appears as progenitor of the other species in section Bystropogon with a more restricted distribution.
Genetic and epigenetic consequences of recent hybridization and polyploidy in Spartina (Poaceae)
Authors: SALMON ARMEL , AINOUCHE MALIKA L. , WENDEL JONATHAN F. 
Published: March 2005

AbstractTo study the consequences of hybridization and genome duplication on polyploid genome evolution and adaptation, we used independently formed hybrids (Spartina × townsendii and Spartina × neyrautii) that originated from natural crosses between Spartina alterniflora, an American introduced species, and the European native Spartina maritima. The hybrid from England, S. × townsendii, gave rise to the invasive allopolyploid, salt‐marsh species, Spartina anglica. Recent studies indicated that allopolyploid speciation may be associated with rapid genetic and epigenetic changes. To assess this in Spartina, we performed AFLP (amplified fragment length polymorphism) and MSAP (methylation sensitive amplification polymorphism) on young hybrids and the allopolyploid. By comparing the subgenomes in the hybrids and the allopolyploid to the parental species, we inferred structural changes that arose repeatedly in the two independently formed hybrids. Surprisingly, 30% of the parental methylation patterns are altered in the hybrids and the allopolyploid. This high level of epigenetic regulation might explain the morphological plasticity of Spartina anglica and its larger ecological amplitude. Hybridization rather than genome doubling seems to have triggered most of the methylation changes observed in Spartina anglica.
Positional cues for the starch/lipid balance in maize kernels and resource partitioning to the embryo
Authors: Rolletschek Hardy , Koch Karen , Wobus Ulrich , Borisjuk Ljudmilla 
Published: March 2005

SummaryThis study tests the hypotheses that in vivo oxygen levels inside developing maize grains locally affect assimilate partitioning and ATP distribution within the kernel. These questions were addressed through combined topographical analysis (O2‐ and ATP‐mapping), metabolite profiling, and isotope flux analysis. Internal and external oxygen levels were also experimentally altered. Under ambient conditions, mean O2 concentration immediately inside starchy endosperm dropped to only 1.4% of atmospheric saturation (approximately 3.8 μm), but was 10‐fold higher in the oil‐storing embryo. Increasing the O2 supply to intact kernels stimulated their O2 demand, shifted ATP localization within the kernel, and elevated their ATP/ADP ratio. Enhanced O2 availability also increased steady‐state levels of glycolytic intermediates and those of the citric acid cycle, as well as some related pools of free amino acids. Subsequent analyses indicated that starch formation within endosperm, but not lipid biosynthesis within embryo, was adapted to the endogenous low oxygen. Increasing the O2 supply did not change ADP‐glucose levels, activity of ADP‐glucose pyrophosphorylase, 13C‐labeling of ADP‐glucose, or flux of 14C‐sucrose into starch. In contrast, enhanced O2 availability increased 14C‐label uptake into the embryo, 13C‐labeling of acetyl‐coenzyme A, and finally 14C‐incorporation into lipids. Lipid accumulation in embryo appeared highest in regions with higher ATP. Consistent with labeling data, a decrease in O2 supply most strongly affected the embryo, whereas rising O2 levels expanded ATP‐rich zones toward the starch‐storing endosperm and the scutellar part of embryo. The latter might be responsible for higher 14C‐label uptake into the embryo and flux toward lipid. Collectively, data indicate that the in vivo oxygen distribution in maize kernels markedly affects ATP gradients, metabolite levels, and favors assimilate partitioning toward starch within the O2‐depleted endosperm. Clear advantages are thus evident for peripheral localization of the protein and lipid storing structures in maize kernels.
A role of Toc33 in the protochlorophyllide‐dependent plastid import pathway of NADPH:protochlorophyllide oxidoreductase (POR) A†
Authors: Reinbothe Steffen , Pollmann Stephan , Springer Armin , James Richard Johari , Tichtinsky Gabrielle , Reinbothe Christiane 
Published: March 2005

SummaryNADPH:protochlorophyllide oxidoreductase (POR) A is a key enzyme of chlorophyll biosynthesis in angiosperms. It is nucleus‐encoded, synthesized as a larger precursor in the cytosol and imported into the plastids in a substrate‐dependent manner. Plastid envelope membrane proteins, called protochlorophyllide‐dependent translocon proteins, Ptcs, have been identified that interact with pPORA during import. Among them are a 16‐kDa ortholog of the previously characterized outer envelope protein Oep16 (named Ptc16) and a 33‐kDa protein (Ptc33) related to the GTP‐binding proteins Toc33 and Toc34 of Arabidopsis. In the present work, we studied the interactions and roles of Ptc16 and Ptc33 during pPORA import. Radiolabeled Ptc16/Oep16 was synthesized from a corresponding cDNA and imported into isolated Arabidopsis plastids. Crosslinking experiments revealed that import of 35S‐Oep16/Ptc16 is stimulated by GTP. 35S‐Oep16/Ptc16 forms larger complexes with Toc33 but not Toc34. Plastids of the ppi1 mutant of Arabidopsis lacking Toc33, were unable to import pPORA in darkness but imported the small subunit precursor of ribulose‐1,5‐bisphosphate carboxylase/oxygenase (pSSU), precursor ferredoxin (pFd) as well as pPORB which is a close relative of pPORA. In white light, partial suppressions of pSSU, pFd and pPORB import were observed. Our results unveil a hitherto unrecognized role of Toc33 in pPORA import and suggest photooxidative membrane damage, induced by excess Pchlide accumulating in ppi1 chloroplasts because of the lack of pPORA import, to be the cause of the general drop of protein import.
microRNA‐directed cleavage of ATHB15 mRNA regulates vascular development in Arabidopsis inflorescence stems
Authors: Kim Joonki , Jung Jae‐Hoon , Reyes Jose L. , Kim Youn‐Sung , Kim Sun‐Young , Chung Kyung‐Sook , Kim Jin A. , Lee Minsun , Lee Yoontae , Narry Kim V. , Chua Nam‐Hai , Park Chung‐Mo 
Published: March 2005

SummaryClass III homeodomain‐leucine zipper proteins regulate critical aspects of plant development, including lateral organ polarity, apical and lateral meristem formation, and vascular development. ATHB15, a member of this transcription factor family, is exclusively expressed in vascular tissues. Recently, a microRNA (miRNA) binding sequence has been identified in ATHB15 mRNA, suggesting that a molecular mechanism governed by miRNA binding may direct vascular development through ATHB15. Here, we show that miR166‐mediated ATHB15 mRNA cleavage is a principal mechanism for the regulation of vascular development. In a gain‐of‐function MIR166a mutant, the decreased transcript level of ATHB15 was accompanied by an altered vascular system with expanded xylem tissue and interfascicular region, indicative of accelerated vascular cell differentiation from cambial/procambial cells. A similar phenotype was observed in Arabidopsis plants with reduced ATHB15 expression but reversed in transgenic plants overexpressing an miR166‐resistant ATHB15. ATHB15 mRNA cleavage occurred in standard wheat germ extracts and in Arabidopsis and was mediated by miR166 in Nicotiana benthamiana cells. miR166‐assisted ATHB15 repression is likely to be a conserved mechanism that regulates vascular development in all vascular plants.
The atypical resistance gene, RPW8, recruits components of basal defence for powdery mildew resistance in Arabidopsis
Authors: Xiao Shunyuan , Calis Ozer , Patrick Elaine , Zhang Guangmin , Charoenwattana Piyavadee , Muskett Paul , Parker Jane E. , Turner John G. 
Published: March 2005

SummaryGenetic studies have identified a number of components of signal transduction pathways leading to plant disease resistance and the accompanying hypersensitive response (HR) following detection of pathogens by plant resistance (R) genes. In Arabidopsis, the majority of R proteins so far characterized belong to a plant superfamily that have a central nucleotide‐binding site and C‐terminal leucine‐rich‐repeats (NB‐LRRs). Another much less prevalent class comprises RPW8.1 and RPW8.2, two related proteins that possess a putative N‐terminal transmembrane domain and a coiled‐coil motif, and confer broad‐spectrum resistance to powdery mildew. Here we investigated whether RPW8.1 and RPW8.2 engage known pathway(s) for defence signalling. We show that RPW8.1 and RPW8.2 recruit, in addition to salicylic acid and EDS1, the other NB‐LRR gene‐signalling components PAD4, EDS5, NPR1 and SGT1b for activation of powdery mildew resistance and HR. In contrast, NDR1, RAR1 and PBS3 that are required for function of certain NB‐LRR R genes, and COI1 and EIN2 that operate, respectively, in the jasmonic acid and ethylene signalling pathways, do not contribute to RPW8.1 and RPW8.2‐mediated resistance. We further demonstrate that EDR1, a gene encoding a conserved MAPKK kinase, exerts negative regulation on HR cell death and powdery mildew resistance by limiting the transcriptional amplification of RPW8.1 and RPW8.2. Our results suggest that RPW8.1 and RPW8.2 stimulate a conserved basal defence pathway that is negatively regulated by EDR1.
Morphoquantitative Aspects of Nitrergic Myoenteric Neurons from the Stomach of Diabetic Rats Supplemented with Acetyl‐L‐Carnitine
Authors: Fregonesi C. E. P. T. , Molinari S. L. , Alves Â. M. P. , Defani M. A. , Zanoni J. N. , Bazotte R. B. , De Miranda Neto M. H. 
Published: March 2005

SummaryThe NADPH‐diaphorase (NADPH‐d) positive myoenteric neurons from the body of the stomach of rats with streptozotocin‐induced diabetes with or without supplementation with acetyl‐L‐carnitine (ALC) were evaluated. At the age of 105 days the animals were divided into four groups: normoglycaemic (C), normoglycaemic supplemented with ALC (CC), diabetic (D) and diabetic supplemented with ALC (DC). The supplementation with ALC (200 mg/kg body weight/day) to groups CC and DC was made during 105 days. After this period the animals were killed and the stomach removed and subjected to the histochemical technique of NADPH‐d for the staining of the neurons of the myoenteric plexus. The area of 500 neurons of each group was investigated, as well as the neuronal density in an area of 23.84 mm2 in each stomach. ALC promoted reduction (P < 0.05) of fasting glycaemia, water ingestion and areas of the profiles of the cell bodies of the NADPH‐d neurons in the diabetic animals. The density of these neurons was not statistically different in the groups studied. It is suggested, therefore, a moderate neuroprotective effect of ALC, because the diminishment of the areas of the neuronal profiles in the supplemented diabetic animals, although being statistically significant relative to the non‐supplemented diabetics, was not sufficient to equal the values from the non‐diabetic controls.
Histological Basis of the Porcine Femoral Artery for Vascular Research
Authors: Solanes N. , Rigol M. , Ramírez J. , Segalés J. , Roqué M. , Marimon J.M. , Pérez‐Villa F. , Roig E. , Sanz G. , Heras M. 
Published: March 2005

SummaryThe similarities between the porcine and human cardiovascular systems make the pig a useful animal model for the study of vascular biology. However, a standardized method is needed to describe the normal histological properties of porcine arteries in order to evaluate pathologic lesions in future studies. Descriptive and morphometric analyses were done on 16 porcine femoral arteries. For these purposes, three histological stains (haematoxylin eosin, Masson's trichrome, and orcein), four immunohistochemical methods (using antibodies anti‐α‐actin, anti‐CD3, anti‐L1 and anti‐lysozyme), and a glycohistochemical method (usingDolichos bifloruslectin) were performed. The porcine femoral arteries evaluated had a mean total area of 6.25 ± 1.99 mm2and a diameter of 2.79 ± 0.41 mm. The majority of the total area was occupied by the medial layer (42.97 ± 5.38%) and was mainly constituted by smooth muscle cells (94.58 ± 2.65%). All the cell markers used reacted with porcine paraffin‐embedded tissue. However, the anti‐lysozyme antibody was excluded from this histological analysis because of cytoplasmatic reactivity in smooth muscle cells. In summary, this study proposes histological methods to describe the normal characteristics of the porcine femoral artery and raises the possibility of applying this methodology in future studies on porcine vascular research.
Ultrastructure and Histochemical Study of Glycoconjugates in the Gills of the White Croaker (Micropogonias furnieri)
Authors: Díaz A. O. , García A. M. , Devincenti C. V. , Goldemberg A. L. 
Published: March 2005

SummaryThe ultrastructure of the primary and secondary lamellae of gills was investigated in a marine teleost, the white croaker. The following cells were identified and briefly described: pavement cells, mucous cells, mitochondria‐rich cells and rodlet cells. These cell types are present throughout the length of the lamellae. They are studied by means of a series of carbohydrate histochemical methods, including lectin procedures. Neutral sugars and substituted sialic acid were detected by means of periodic acid–borohydride reduction–saponification–periodic acid Schiff reaction (PA/Bh/KOH/PAS), saponification–selective periodic acid Schiff reaction (KOH/PA*S) and saponification–selective periodic acid–borohydride reduction–periodic acid Schiff reaction (KOH/PA*/Bh/PAS) histochemical techniques. A battery of seven lectins was used to study binding on tissue sections at the light microscopic level to characterize glycoconjugates in gills. The reaction to Canavalia ensiformis agglutinin (Con‐A), Triticum vulgaris agglutinin (WGA), and Ricinus cummunis agglutinin‐1 (RCA‐1) was weak in pavement cells; unlike Con‐A, the reaction to WGA and RCA‐1 was more intense in mucous cells. Arachis hypogaea agglutinin (PNA) lectin showed a strong reaction in mucous cells. Ulex europaens agglutinin‐1 (UEA‐1) lectin was negative in all cell types. The lectin pattern was similar for both primary and secondary lamellae, except for PNA reaction, which was weak in the pavement cells of the secondary lamella and negative in the pavement cells of the primary lamella.
Immune response to a laminin‐binding protein (Lmb) in group A streptococcal infection
Authors: Wahid Rezwanul M. , Yoshinaga Masao , Nishi Junichiro , Maeno Nobuaki , Sarantuya Jav , Ohkawa Toshiya , Jalil Abdul M. , Kobayashi Keiko , Miyata Koichiro 
Published: March 2005

Abstract
Background
: A laminin‐binding protein (Lmb) similar to that of group B streptococcus is conserved in group A streptococcus (GAS) and has a role in adhesion of GAS to epithelial cells. The role of this protein is yet to be clarified in disease process and thus, it is important to know its role in binding of GAS to laminin and the immunogenic response against it in patients related with GAS infection.
Methods
: A recombinant protein (rGAS‐Lmb) was purified using the lmb gene from M1 GAS and tested for its role in binding of GAS with laminin. The antibody response against rGAS‐Lmb in patient sera related with GAS infection was measured by ELISA.
Results
: The rGAS‐Lmb bound with laminin directly and inhibited the binding of GAS to laminin. The antibody response against rGAS‐Lmb in patients with uncomplicated streptococcal infection (U. Strep) and those with rheumatic fever (RF) were significantly higher than those in the control group (P < 0.0001 and P < 0.001, respectively). No difference of anti‐rGAS‐Lmb antibody titer could be found between these two disease groups.
Conclusion
: The higher antibody response in patients with GAS infection implies that the protein is well expressed during the period of infection and may be related with the colonization and infection of GAS in pharyngeal mucosa.
Neutrophil‐mediated inflammation in respiratory syncytial viral bronchiolitis
Authors: Yasui Kozo , Baba Atsushi , Iwasaki Yasushi , Kubo Tetsuo , Aoyama Kohki , Mori Tetsuo , Yamazaki Takashi , Kobayashi Norimoto , Ishiguro Akira 
Published: March 2005

Abstract
Background
: The involvement of neutrophil‐mediated inflammation may play an important role in the pathogenesis of acute respitory syncytial virus bronchiolitis. However, no measurable marker is sensitive enough to assess neutrophil‐mediated inflammation in the airways. Released neutrophil elastase (NE) in intraluminal airways has been reported to induce pulmonary inflammation. The aim of this study was to determine whether the amount of urinary trypsin inhibitor (UTI) in serum, a degenerate induced by NE, reflects the degree of airway inflammation in children with respiratory syncytial viral (RSV) bronchiolitis and whether the severity of inflammation is evaluated. The pre‐α‐/inter‐α‐trypsin inhibitor is assumed to be precursors of the UTI. When NE degrades these inhibitors, UTI is liberated.
Methods
: Serum UTI concentrations in infants admitted with RSV bronchiolitis, other viral infections, bacterial pneumonia and control subjects were measured by means of one‐step sandwich‐type enzyme immunoassay.
Results
: Serum UTI concentrations in 25 patients on admission were significantly higher than the 15 infantile control values (mean ± SEM, 22.126 ± 2.317 and 6.701 ± 0.719 U/mL, respectively; P < 0.0001). The elevated levels returned to baseline values with improvement in the respiratory symptoms. Higher levels of serum UTI with RSV infection were consistently associated with clinical symptoms and artificial ventilation. Serum NE concentrations of patients were elevated in some patients but not significantly different from controls in the patients who showed only upper respiratory symptoms with RSV infections.
Conclusion
: The findings strongly suggested that neutrophil‐mediated events are involved in the pathogenesis of RSV bronchiolitis, and the monitoring of UTI concentrations might be useful for evaluating the neutrophil‐mediated airway inflammation.