bluuebunny/crossref_metadata_2025_split huggingface dataset:
Genetic diversity among parental lines of Indica hybrid rice (Oryza sativa L.) in China based on coefficient of parentage
Authors: Wang S. , Lu Z. 
Published: November 2006

AbstractGenetic diversity constitutes the raw material for plant improvement, and provides protection against genetic vulnerability to biotic and abiotic stresses. Diversity of parental lines of indica hybrid rice in China is not well‐characterized. The major objective of this study was to quantify genetic diversity of Chinese parental lines of hybrid rice via coefficient of parentage (COP). All 100 parental lines of hybrid rice widely used in hybrid breeding and commercial production during 1976–2003 were studied by COP analysis. The mean COP for the 100 parental lines was low (0.056), indicating a potentially high degree of diversity in Chinese hybrid rice breeding. Forty‐nine percent of all pairs of parental lines were completely unrelated by pedigree data. The low mean COP for the parental lines was attributed to a continual incorporation of exotic germplasm (wild rice, japonica and javanica etc.) into the genetic base over time, to the introduction of foreign germplasm from the Philippines (International Rice Research Institute), Korea, the United States, Thailand, and Guyana as breeding stock. The mean COP from 1976 to 1990 was twice as much as that from 1990 to 2003. Cluster analysis was an effective method to discriminate diversity, ten clusters were identified, and maintainer lines, restorer lines and other parental lines with special genetic background were clearly grouped. In addition, restorer lines were further divided into 11 sub‐clusters, which basically was in agreement with hybrid rice breeding. Among ten provinces, Hunan, Sichuan and Fujian were outstanding for breeding 54 of 100 parental lines in hybrid rice production, and the genetic diversity of parental lines in Fujian, Sichuan,Guangxi, Hunan and Jiangsu were all narrower than that in Hubei, Guangdong, Zhejiang and Jiangxi. The result of coefficient of parentage analysis for 100 parental lines may promote the management of parental diversity and hybrid rice breeding in China.
Inheritance of cellular thermotolerance in bread wheat
Authors: Dhanda S. S. , Munjal R. 
Published: November 2006

AbstractLeaf membrane stability (LMS) and the tetrazolium triphenyl chloride (TTC) test, heat susceptibility index (HSI), heat response index (HRI) and grain yield were used to evaluate 20 diverse wheat genotypes under normal and heat stress conditions for 2 years. The varieties ‘Seri’ and ‘Raj 3765’ had a desirable combination of cellular thermotolerance (TTC and LMS), heat tolerance (HRI) and high grain yield potential under heat stress, while ‘WH 730’ and ‘WH 533’ were better in cellular thermotolerance and heat tolerance. The varieties ‘PBW 373’ and ‘Kauz’ also performed better under heat stress in terms of grain yield and HSI/HRI. The varieties ‘Kanchan’, ‘PBW 373’, ‘NIAW 34’ and ‘GW 173’ were avoiders/escapers, ‘Seri’ and ‘HUW 234’ were tolerant to heat stress, while ‘WH 730’, ‘WH 533’, ‘Nesser’, ‘Raj 3765’ and ‘Kauz’ showed a combination of both. Correlation coefficients revealed that HRI was the most important trait, followed by TTC because the genotype having high HRI also had high grain yield and was better in mitochondrial viability and membrane stability under heat stress. Significance of GCA and SCA variances indicated the presence of both additive and dominant types of gene action. The use of the parents with high GCA effects, namely, ‘Raj 3765’ and ‘WH 730’ in a crossing programme for thermotolerance may provide desirable segregants through selection.
Characterization of a novel form of fertile great headed garlic (Allium sp.)
Authors: Hirschegger P. , Galmarini C. , Bohanec B. 
Published: November 2006

AbstractA new form of great headed garlic (GHG), was collected, grown and utilized as garlic in the province of Mendoza, Argentina. It was found in contrast to other known forms of GHG that this novel form is fertile, while other characteristics remained unknown. Studies revealed that all accessions investigated formed large bulbs and produced fertile seeds, with a germination rate of around 30%. Genome size analysis and chromosome counting of the GHG accessions, made in comparison with hexaploid forms of GHG, revealed that the accessions were octoploid, with a genome size ranging from 119.5 to 122.4 pg. Preliminary karyotype analysis indicates a possible allopolyploid origin. It is suggested that this fertile accession deserves further attention as a novel source of genetic variation in ‘garlic‐like’ plants.
Organization and expression of the mitochondrial genome in CMS (Moricandia) Brassica juncea: nuclear‐mitochondrial incompatibility results in differential expression of the mitochondrial atpα gene
Authors: Gaikwad K. , Baldev A. , Kirti P. B. , Mohapatra T. , Bhat S. R. , Chopra V. , Prakash S. 
Published: November 2006

AbstractThe mitochondrial genome of CMS (Moricandia) Brassica juncea has been characterized. Southern analysis using nine different mt‐specific gene probes revealed differences between B. juncea and M. arvensis and the CMS line. A northern profile of flower bud and leaf mt RNA blots was found conserved for six genes tested. However, tissue‐specific expression was observed for atpα. A longer transcript was present in the bud tissue of the CMS line, which reverted to normal in the presence of the fertility restorer gene, while its expression was normal in the leaf tissues. The atpα gene was cloned from B. juncea, M. arvensis and the CMS line. Restriction mapping shows a high degree of restriction site conservation between the CMS and B. juncea lines with minor alterations at the 5′ and the 3′ ends, indicating the presence of an almost intact M. arvensisatpα gene in the CMS line harbouring a B. juncea nucleus. The results are discussed with respect to the potential role of atpα in generating male sterility in CMS (Mori) B. juncea.
Androgenetic plants of Anemone coronaria derived through anther culture
Authors: Laura M. , Safaverdi G. , Allavena A. 
Published: November 2006

AbstractThe genus Anemone (Ranunculaceae) includes many species cultivated for ornamental purposes. Most cut flower cultivars belong to A. coronaria L. and are multiplied by seed and sold for cultivation as 1‐year‐old tubers. As cultivars represent a population of hybrid individuals derived from crosses between heterozygous parents, the use of a true F1 hybrid would improve the uniformity and quality of the product. As a first step towards the development of pure‐breeding lines, anther cultures were established from elite cultivars of A. coronaria. Somatic embryos and plantlets were regenerated from five elite cultivars, and up to 16.9 regenerants per 100 cultured anthers were obtained. Cytological analysis identified that 11 of 19 regenerants had either a 2x = 16 karyotype, or were mixoploids. RAPD‐based DNA fingerprinting showed that all the regenerants tested differed genetically from their anther donor, confirming their androgenetic origin. The shortening to 15 months for the time required to produce homozygous lines may convince seed companies to invest in F1 hybrid breeding.
A major QTL effect controlling resistance to powdery mildew in winter wheat at the adult plant stage
Authors: Bougot Y. , Lemoine J. , Pavoine M.T. , Guyomar'ch H. , Gautier V. , Muranty H. , Barloy D. 
Published: November 2006

AbstractPowdery mildew is one of the major diseases of wheat in regions with a maritime or semi‐continental climate which can strongly affect grain yield. The objective of the study was to identify and compare quantitative resistance to powdery mildew of line RE9001 at the adult plant and vernalized seedling stages. RE9001 has no known Pm gene and shows a high level of adult plant resistance in the field. Using 104 recombinant inbred lines (RILs) of an RE9001 × ‘Courtot’ F8 population, a genetic map was developed with 363 markers distributed over 26 linkage groups and covering 3825 cM. The global map density was 1 locus/10.3 cM. RILs were assessed under field and tunnel greenhouse conditions for 2 years in two locations. Eleven quantitative trait loci (QTL) were detected at the adult stage and they explained 63% of the variation, depending on the environment. Three QTLs were found, at least, in the two environments. One QTL from RE9001, mapped on chromosome 2B, was stable in each environment. This QTL, QPm.inra.2B, explained 10.3–36.6% of the variation and could be mapped in the vicinity of the Pm6 gene. At the vernalized seedling stage, one QTL detected by the isolate 93‐27 could be an allele of the Pm3g gene present in ‘Courtot’. No residual effect of the Pm3g gene was detected at either stage. Markers flanking the QTL 2B could be useful tools to combine resistance to powdery mildew in wheat cultivars.
An extension of the Smith model for quantitative genetic analysis of selection response under recurrent selection
Authors: Melchinger A. E. , Flachenecker C. 
Published: November 2006

AbstractSelection and random genetic drift are the main forces affecting selection response in recurrent selection (RS) programmes. The correct assessment of both forces allows a better comparison of the efficiency of different RS schemes. The objective of this study was to extend the population diallel analysis proposed by Hammond and Gardner in 1974 and the model proposed by Smith in 1979 with full consideration of inbreeding depression due to random genetic drift. The effect of random genetic drift is expected to be large, particularly in studies with many selection cycles and/or high rates of inbreeding. Therefore, the extension of the population diallel allows a better assessment of the selection response in RS programmes.
Extending lifetime of plastic changes in the human brain
Authors: Nyffeler Thomas , Wurtz Pascal , Lüscher Hans‐Rudolf , Hess Christian W. , Senn Walter , Pflugshaupt Tobias , Von Wartburg Roman , Lüthi Mathias , Müri René M. 
Published: November 2006

AbstractThe ability of the brain to adjust to changing environments and to recover from damage rests on its remarkable capacity to adapt through plastic changes of underlying neural networks. We show here with an eye movement paradigm that a lifetime of plastic changes can be extended to several hours by repeated applications of theta burst transcranial magnetic stimulation to the frontal eye field of the human cortex. The results suggest that repeated application of the same stimulation protocol consolidates short‐lived plasticity into long‐lasting changes.
Hypothalamic proopiomelanocortin (POMC) neurons have a cholinergic phenotype
Authors: Meister Björn , Gömüç Burçak , Suarez Elisabet , Ishii Yuko , Dürr Katrin , Gillberg Linda 
Published: November 2006

AbstractNeuronal networks originating in the hypothalamic arcuate nucleus play fundamental roles in the control of energy balance. Neuropeptide Y (NPY)‐producing neurons in the arcuate nucleus stimulate food intake, whereas arcuate nucleus neurons that release the proopiomelanocortin (POMC)‐derived peptide α‐melanocyte‐stimulating hormone (α‐MSH) potently reduce food intake. Relatively little attention has been focused on classical neurotransmitters in regulation of food intake. Here, we have investigated the potential presence of acetylcholine (ACh) in NPY‐ and POMC‐containing neuronal populations of the arcuate nucleus. Antisera to proteins required for cholinergic neurotransmission, including choline acetyltransferase (ChAT) and the vesicular acetylcholine transporter (VAChT), were employed in double‐labeling immunohistochemical experiments. In colchicine‐treated rats, ChAT‐ and VAChT‐immunopositive cell bodies were located in the ventral aspect of the arcuate nucleus. ChAT and VAChT immunoreactivities were demonstrated in α‐MSH‐ and cocaine‐ and amphetamine‐regulated transcript (CART)‐containing cell bodies of the arcuate nucleus, whereas cell bodies containing NPY or agouti‐related peptide (AGRP) were distinct from VAChT‐immunoreactive neuronal perikarya. VAChT immunoreactivity was also present in a large number of α‐MSH‐containing nerve fiber varicosities throughout the central nervous system. In the commissural part of the nucleus tractus solitarius, no α‐MSH‐containing cell bodies were found to have ChAT or VAChT immunoreactivity. The presence of markers for cholinergic neurotransmission in a subpopulation of hypothalamic POMC/CART neurons suggests co‐release of ACh with peptides derived from the POMC precursor and CART. The results indicate a role for ACh in control of energy balance, mediating the effects of peripheral hormones such as leptin and insulin.
Early deprivation leads to altered behavioural, autonomic and endocrine responses to environmental challenge in adult Fischer rats
Authors: Rüedi‐Bettschen Daniela , Zhang Weining , Russig Holger , Ferger Boris , Weston Anna , Pedersen Else‐Marie , Feldon Joram , Pryce Christopher R. 
Published: November 2006

AbstractDepression is diagnosed on the basis of abnormal positive affects (anhedonia) and negative affects (low mood, helplessness, coping deficit, fatigue), and associated physiological abnormalities include hyperactivity of the HPA endocrine system and autonomic nervous system. Adverse early life environments, including parent–offspring emotional and physical neglect, are associated with traits of altered physiological and neurobiological function and long‐term predisposition to depression. Animal studies based on early life adversity can potentially yield environmental models of the developmental behavioural neurobiology of depression. In Wistar rats, we demonstrated that isolation of pups from dam and littermates at room temperature for 4 h per day on P1–14 (early deprivation, ED) led to adulthood anhedonia‐like traits of reduced motivation to obtain gustatory reward and reduced social motivation, relative to subjects left undisturbed during infancy (non‐handling, NH). We hypothesized that the depression‐like effects of ED would be even more pronounced and multiple in the stress hyper‐responsive Fischer rat strain. The effects of ED were studied relative to NH and 15 min of daily isolation (early handling, EH). Relative to NH and EH, which exhibited remarkably similar phenotypes, ED led, principally in males, to chronic traits of: reduced motivation for and consumption of gustatory reward; increased activity in the pre‐test and test phases of the forced swim test; reduced coping behaviour in an aversive environment; attenuated plasma corticosterone stress response to a normal plasma ACTH stress response; increased hypertensive response to a novel environment; and increased prefrontal cortical serotonin. High sensitivity to an aversive early environment in male Fischer rats therefore constitutes an important model for the study of affective development and its neurobiology.
Nicotine withdrawal suppresses nicotinic modulation of long‐term potentiation induction in the hippocampal CA1 region
Authors: Yamazaki Yoshihiko , Fujii Satoshi , Jia Yousheng , Sumikawa Katumi 
Published: November 2006

AbstractWe have previously reported that acute and chronic nicotine exposure lower the threshold for long‐term potentiation (LTP) induction in the rat hippocampal CA1 region, and acute application of nicotine in the chronic‐nicotine‐treated hippocampus further reduces the threshold. However, it is unknown how withdrawal from chronic nicotine exposure affects the induction of LTP. Here, we show that, following nicotine withdrawal, the threshold for LTP induction fluctuates before returning to the basal level and acute nicotine is no longer effective in lowering the threshold at 4 days after withdrawal. Chronic nicotine‐induced enhancement of N‐methyl‐d‐aspartate receptor responses slowly diminishes and returns to the control level by 8 days of withdrawal. In 4‐day‐withdrawn hippocampi, there is functional up‐regulation of postsynaptic α7 nicotinic acetylcholine receptors (nAChRs) on interneurons in the stratum radiatum, whereas the release of γ‐aminobutyric acid from their terminals is reduced. In both control and chronic nicotine‐exposed hippocampi, acute nicotine depresses monosynaptic inhibitory postsynaptic currents recorded in pyramidal cells but has almost no effect at 4 days of withdrawal. The lack of effect is due, at least in part, to the loss of a presynaptic nicotine effect. These withdrawal‐induced changes are accompanied by decreases in normal nicotine‐induced enhancement of N‐methyl‐d‐aspartate receptor responses, which may be responsible for the lack of acute nicotine‐mediated facilitation of LTP induction in 4‐day‐withdrawn hippocampi. These withdrawal‐induced changes may contribute to the cellular basis of unpleasant withdrawal symptoms and, thus, nicotine dependence.
Stress reverses plasticity in the pathway projecting from the ventromedial prefrontal cortex to the basolateral amygdala
Authors: Maroun Mouna 
Published: November 2006

AbstractWe have previously shown that high‐frequency stimulation to the basolateral amygdala (BLA) induces long‐term potentiation (LTP) in the ventromedial prefrontal cortex (vmPFC) and that prior exposure to inescapable stress inhibits the induction of LTP in this pathway [Maroun & Richter‐Levin (2003)J. Neurosci., 23, 4406–4409]. Here, we show that the reciprocal pathway projecting from the vmPFC to the BLA is resistant to the induction of LTP. Conversely, long‐term depression (LTD) is robustly induced in the BLA in response to low‐frequency stimulation to the vmPFC. Furthermore, prior exposure to inescapable stress reverses plasticity in this pathway, resulting in the promotion of LTP and the inhibition of LTD. Our findings suggest that, under normal and safe conditions, the vmPFC is unable to exert excitatory synaptic plasticity over the BLA; rather, LTD, which encodes memory of safety in the BLA, is favoured. Following stressful experiences, LTP in the BLA is promoted to encode memory of fear.
Coordination of presynaptic and postsynaptic maturation in a zebra finch forebrain motor control nucleus during song learning
Authors: Wang Jian , Hessler Neal A. 
Published: November 2006

AbstractWhile some species of birds retain the ability to learn new songs as adults, many species can only learn during a restricted period when young. Previous studies have suggested that one potential mechanism of such a limited learning period, an alteration in the composition of postsynaptic NMDA receptors, does not competely block further song learning. Here, we examined whether presynaptic function could play a role in the regulation of learning capacity. We first showed that the participation of NMDA receptor NR2B subunits in synaptic currents in the robust nucleus of the arcopallium (RA), a critical location for integration of signals during song learning by young birds, decreases from young birds to adults. Using release‐dependent block of postsynaptic NMDA receptors by an open‐channel antagonist to assay presynaptic function, we showed that transmitter release at RA synapses from both HVC and the lateral magnocellular nucleus of the anterior nidopallium systematically decreases during the period of song learning, and in adults is about half that of juveniles. Further, activation of postsynaptic NMDA receptors could induce an acute depression of transmitter release, while lack of exposure to a normal learning environment could delay the developmental reduction in transmitter release. These results suggest that regulation of learning capacity may occur in part by coordination of presynaptic and postsynaptic function.
N‐ethylmaleimide increases release probability at GABAergic synapses in layer I of the mouse visual cortex
Authors: Kirmse Knut , Kirischuk Sergei 
Published: November 2006

AbstractThe sulphydryl alkylating agent N‐ethylmaleimide (NEM) has been often used as an uncoupler of pertussis toxin‐sensitive G‐proteins. However, the effects of NEM on γ‐aminobutyric acid (GABA)ergic synaptic transmission remain controversial. Using the whole‐cell patch‐clamp technique, GABAA receptor‐mediated postsynaptic currents (IPSCs) have been recorded from Cajal‐Retzius (CR) cells in layer I of the neonatal mouse visual cortex. NEM increased the frequencies of both spontaneous and miniature IPSCs (mIPSCs) without an effect on the median mIPSC amplitudes or mIPSC kinetics. The NEM actions on mIPSCs did not depend on the extracellular Ca2+, Ca2+ release from intracellular stores, adenylyl cyclase and protein kinase A activities. NEM increased the mean amplitudes of evoked IPSCs and strongly decreased the paired‐pulse ratio. The size of the readily releasable pool of presynaptic vesicles (RRP) was estimated using a high‐frequency stimulation protocol. The RRP size was not affected by NEM. In addition, NEM significantly decreased the latency between the stimulus and the onset of GABA release. These results suggest that NEM selectively increases GABA release probability. At postnatal day 2, mIPSCs were observed only in about 30% of CR cells. NEM application revealed, however, that more than 90% of CR cells receive GABAergic inputs. Therefore, NEM seems to be a useful tool to verify the existence of ‘silent’ GABAergic synapses.
Lipo‐prostaglandin E1 in combination with steroid therapy is effective for treatment of sudden sensorineural hearing loss in Korean patients with Type 2 diabetes
Authors: Ahn J. H. , Kim T. Y. , Kim Y.‐J. , Han M. W. , Yoon T. H. , Chung J. W. 
Published: November 2006

AbstractBackground  Diabetes mellitus is a risk factor for sudden sensorineural hearing loss (SSNHL), possibly as a result of microvascular damage, increased blood viscosity and embolic and thrombotic episodes.Aim  To perform a prospective, randomized clinical trial to determine the therapeutic effect of lipo‐prostaglandin E1 (lipo‐PGE1) on SSNHL in Korean patients with Type 2 diabetes.Methods  The study group consisted of 270 consecutive Korean patients (130 male, 140 female) in whom SSNHL was diagnosed. Patients were classified as diabetic or non‐diabetic by the new American Diabetes Association criteria. With the approval of the institute ethics committee, patients were randomly assigned to treatment with of 10 µg lipo‐PGE1 (lipo‐PGE1 group) given as a continuous infusion over 5 days, or saline (placebo group). In addition, all patients studied were treated with 48 mg methylprednisolone for 5 days.Results  The overall recovery rates after treatment were 51.5% in diabetic and 64.2% in non‐diabetic patients. In diabetic patients, there was a significantly higher rate of hearing improvement in the lipo‐PGE1 group (64.7%) compared with the placebo group (37.5%), whereas, in non‐diabetic patients, there was no significant difference in rate of hearing improvement between the lipo‐PGE1 group (70.3%) and the placebo group (58.3%).Conclusion  Lipo‐PGE1 may have beneficial effects in the treatment of SSNHL in Korean patients with Type 2 diabetes.