bluuebunny/crossref_metadata_2025_split huggingface dataset:
Improved doubled haploid production protocol for Brassica napus using microspore colchicine treatment in vitro and ploidy determination by flow cytometry
Authors: Weber S. , ÜNker F. , Friedt W. 
Published: October 2005

AbstractA rapid and efficient microspore culture protocol was applied to produce homozygous progeny of crosses between low erucic canola and high erucic resynthesized rapeseed (Brassica napus L.). Microspores of Canadian cultivars ‘Excel’ and ‘Profit’ as well as three F1 hybrids with the resynthetic line ‘RS239’ were treated with colchicine immediately after isolation. Flow cytometry was applied for early identification of doubled haploid (DH) regenerants. The diploidization rate was subsequently verified by scoring flower morphology. In vitro colchicine treatment had a positive effect on induced diploidization, and was associated with the frequency of preliminary spontaneous diploidization which was, however, determined by the genotype. In addition, the effects of colchicine treatment on embryoid formation and regeneration have been evaluated. The method presented is feasible for commercial large‐scale production of DHs in rapeseed as the genotype‐specific diploidization can be efficiently balanced by in vitro colchicine treatment. In addition, the use of flow cytometry immediately after in vitro culture allows efficient selection for DHs, thus saving labour and cost and in the laboratory and subsequent greenhouse phase.
Screening for resistance to Kyuri green mottle mosaic virus in various melons
Authors: Daryono B. S. , Somowiyarjo S. , Natsuaki K. T. 
Published: October 2005

AbstractAmong many species in the genus Tobamovirus, Kyuri green mottle mosaic virus (KGMMV) is known as a major seed‐borne virus infecting cucurbit plants, including melon, which possesses no known resistance. The identification of genetic resistance to KGMMV in Indonesia (KGMMV‐YM) in melons is of economic importance. Thus, 45 melon cultigens collected from 17 Asian countries were screened by manual virus inoculation and resistance to KGMMV‐YM was examined by visual observation, enzyme‐linked immunosorbent assay and reverse transcription‐polymerase chain reaction (RT‐PCR). The results show that resistance to KGMMV‐YM was found in ‘Mawatauri’, ‘Kohimeuri’, PI 161375 and PI 371795, and analysis by RT‐PCR showed the presence of KGMMV‐YM in susceptible cultigens as early as 3 days after leaf inoculation.
AFLP–SSR maps of maize × teosinte and maize × maize: comparison of map length and segregation distortion
Authors: Mano Y. , Muraki M. , Fujimori M. , Takamizo T. , Kindiger B. 
Published: October 2005

AbstractTwo genetic linkage maps of Zea mays were constructed: one population comprised 94 F2 individuals of a dent ‘B64’ × teosinte (Z. mays ssp. huehuetenangensis) cross while the second consisted of 94 F2 individuals of a ‘B64’ × Caribbean flint ‘Na4’ cross. The level of polymorphism was higher in the ‘B64’ × teosinte combination than the ‘B64’ × ‘Na4’ combination. In the ‘B64’ × teosinte cross, a total of 338 amplified fragment length polymorphism (AFLP) and 75 simple sequence repeat (SSR) markers were mapped to 10 chromosomes, which covered 1402.4 cM. In the ‘B64’ × ‘Na4’ cross, a total of 340 AFLP and 97 SSR markers were mapped to 10 chromosomes, covering 1662.8 cM. Segregation distortion regions were found on chromosomes 4, 5 and 8 in the ‘B64’ × teosinte cross and on chromosome 9 in the ‘B64’ × ‘Na4’ cross. Comparison of the two maps revealed that the maize × teosinte map was 11.5% shorter than the maize × maize map. The maps generated in this study may be useful to identify genes controlling flooding tolerance.
Genetic diversity in camelina germplasm as revealed by seed quality characteristics and RAPD polymorphism
Authors: Vollmann J. , Grausgruber H. , Stift G. , Dryzhyruk V. , Lelley T. 
Published: October 2005

AbstractCamelina is an alternative oilseed crop species with limited information about the origin and diversity of available germplasm. Therefore, a set of 130 camelina accessions from a world collection was evaluated for oil content, protein content and 1000‐seed weight in field experiments grown in three macro‐environments in Austria. Based on phenotypic data, accessions were categorized into four groups with different seed characteristics using k‐means cluster analysis or principal component extraction. Subsequently, a representative set of 41 accessions was subjected to random amplified polymorphic DNA (RAPD) analysis. Of 24 primers, 15 were polymorphic producing a total of 30 marker loci. Genetic distance estimates between the 41 accessions were calculated, based both on RAPD polymorphism and on seed quality characteristics, and dendrograms were generated for comparison. Similarities were found between the two different clustering approaches, and grouping was partly in agreement with pedigree information or geographic origin. However, as the two estimates of diversity sampled different segments of the genome, i.e. regions coding for seed characteristics or phenotypically neutral genomic regions highlighted by discrete markers, the correlation between the two distance matrices was low.
Genetic basis of seedling‐resistance to leaf rust in bread wheat ‘Thatcher’
Authors: Mishra A. N. , Kaushal K. , Shirsekar G. S. , Yadav S. R. , Brahma R. N. , Pandey H. N. 
Published: October 2005

AbstractThe bread wheat cultivar ‘Thatcher’ is documented to carry the gene Lr22b for adult‐plant resistance to leaf rust. Seedling‐resistance to leaf rust caused by Puccinia triticina in the bread wheat cultivar ‘Thatcher’, the background parent of the near‐isogenic lines for leaf rust resistance genes in wheat, is rare and no published information could be found on its genetic basis. The F2 and F3 analysis of the cross ‘Agra Local’ (susceptible) × ‘Thatcher’ showed that an apparently incompletely dominant gene conditioned seedling‐resistance in ‘Thatcher’ to the three ‘Thatcher’‐avirulent Indian leaf rust pathotypes – 0R8, 0R8‐1 and 0R9. Test of allelism revealed that this gene (temporarily designated LrKr1) was derived from ‘Kanred’, one of the parents of ‘Thatcher’. Absence of any susceptible F2 segregants in a ‘Thatcher’ × ‘Marquis’ cross confirmed that an additional gene (temporarily designated LrMq1) derived from ‘Marquis’, another parent of ‘Thatcher’, was effective against pathotype 0R9 alone. These two genes as well as a second gene in ‘Kanred’ (temporarily designated LrKr2), which was effective against all the three pathotypes, but has not been inherited by ‘Thatcher’, seem to be novel, undocumented leaf rust resistance genes.
Detection of RAPD markers linked to the everbearing gene in Japanese cultivated strawberry
Authors: Sugimoto T. , Tamaki K. , Matsumoto J. , Yamamoto Y. , Shiwaku K. , Watanabe K. 
Published: October 2005

AbstractTo identify markers for the everbearing gene in strawberries, 199 F1 progeny plants were produced from a cross between ‘Ever Berry’ (a Japanese everbearing strawberry) and ‘Toyonoka’ (a Japanese Junebearing strawberry) as the experimental population. The results of flowering tests produced 97 everbears and 102 Junebears. The chi‐square test gave a goodness of fit for the expected ratio of 1 : 1 for everbears to Junebears, suggesting the inheritance of the everbearing trait is controlled by a monogenic dominant gene. RAPD analyses on this trait were carried out using ‘Ever Berry’ and ‘Toyonoka’. Seventy‐one primers, which produced 89 polymorphic fragments between the two parents, were identified from a total of 175 primers. Five markers relating to the everbearing trait were selected from 26 of the 199 progeny plants. The remaining 173 seedlings were analysed with these five markers and a linkage map was constructed using all of the 199 F1 progeny plants. The length of this linkage group is 39.7 cM. The closest markers found, OPE07‐1 and OPB05‐1, are respectively mapped at 11.8 and 15.8 cM on each side of the everbearing gene.
Identification and genetic characterization of a safflower mutant with a modified tocopherol profile
Authors: Velasco L. , Pérez‐Vich B. , Fernández‐Martínez J. M. 
Published: October 2005

AbstractSafflower (Carthamus tinctorius L.) seeds have a tocopherol fraction dominated by α‐tocopherol, which accounts for more than 95% of the tocopherols. α‐Tocopherol exerts a high vitamin E activity, but a low in vitro antioxidant action. For non‐food applications, replacement of high α‐tocopherol by γ‐tocopherol is preferred. Because of the limited variability found in germplasm of cultivated safflower, the objective of the present research was to search for variability for tocopherol profile in germplasm of wild safflower species. Bulk seed samples of 77 accessions from six species were analysed for total tocopherol content and profile. One accession of C. oxyacanthus showed increased γ‐tocopherol content (36%). Single‐seed analysis showed the existence of a bimodal distribution, which included high α‐tocopherol (>90%) and high γ‐tocopherol (HGT) seeds (>85%). Plants from the HGT seeds bred true for the trait and showed introgression of cultivated safflower, which allowed a rapid selection for cultivated safflower traits. Genetic analysis revealed that the HGT trait was controlled by partially recessive alleles at a single locus Tph1, which will facilitate the transference of the novel trait to diverse safflower germplasms.
Influence of high molecular weight glutenin subunit substitution on rheological behaviour and bread‐baking quality of near‐isogenic lines developed from Chinese wheats
Authors: Deng Z.‐Y. , Tian J.‐C. , Sun G.‐X. 
Published: October 2005

AbstractThree near‐isogenic lines (NILs) of wheat involving Glu‐B1 and Glu‐D1 alleles were used to study the genetic contribution of high molecular weight glutenin subunits (HMW‐GS) to gluten strength. The HMW‐GS composition of each NILs was determined by SDS‐PAGE. No significant differences were found in grain protein contents among the NILs. Gluten strength and dough‐mixing properties were measured by the Farinograph, the Extensograph, and SDS‐sedimentation (SDS‐SE). Results indicated that line 2, containing the Glu‐1B 14 + 15 and Glu‐1D 5 + 10 combination of subunits, had higher values for flour quality, dough rheological parameters, and bread‐baking quality when compared with lines 8 and 13. Line 8, containing Glu‐1B 7 + 9 and Glu‐1D 5 + 10, was better than line 13 with the Glu‐1B 14 + 15 and Glu‐1D 10 combination. Some major parameters appeared significantly different. The presence of Glu‐1B 14 + 15 was associated with higher dough strength based on SDS‐SE volume and several rheological parameters when compared with Glu‐1B 7 + 9. Lines with subunit 10 at Glu‐D1 performed significantly worse than those with 5 + 10 in gluten index, SDS‐SE volume, Farinograph stability time, Extensograph area and bread‐baking quality.
Induction of long‐term depression and phosphorylation of the δ2 glutamate receptor by protein kinase C in cerebellar slices
Authors: Kondo Tetsuro , Kakegawa Wataru , Yuzaki Michisuke 
Published: October 2005

AbstractThe phosphorylation of ionotropic glutamate receptors (iGluRs) by protein kinases plays a crucial role in synaptic plasticity. In the cerebellum, protein kinase C (PKC) activation is required for the induction of long‐term depression (LTD) at parallel fibre–Purkinje cell synapses. Although δ2 glutamate receptors (GluRδ2), expressed predominantly in Purkinje cells, are essential for cerebellar LTD, little is known about the mechanism by which GluRδ2 participates in LTD or its relationship with PKC activation pathways. We found that a PKC activator, phorbol ester, induced postsynaptic LTD in Purkinje cells in mouse cerebellar slice preparations without significantly changing the presynaptic properties. Under this condition, the GluRδ2 prepared from the cerebellar slices was significantly phosphorylated. Indeed, the C‐terminus of the GluRδ2 fused with glutathione‐S‐transferase (GST) was directly phosphorylated by purified PKC at a specific serine residue. In addition, two‐dimensional phosphopeptide mapping analysis indicated that the major phosphorylation site of the GST‐fusion protein containing the C‐terminus of GluRδ2 was identical to that of GluRδ2 prepared from cerebellar slices. Therefore, GluRδ2 is phosphorylated by PKC in vitro and by an LTD‐inducing stimulus in slice preparations. Because this region of GluRδ2 is known to associate with certain intracellular molecules, the PKC phosphorylation status of the C‐terminus of GluRδ2 may be involved in new signaling pathways during LTD.
Improvement of memory for context by inhibition of caspase‐1 in aged rats
Authors: Gemma Carmelina , Fister Matthew , Hudson Charles , Bickford Paula C. 
Published: October 2005

AbstractImpaired learning and memory is a common pathologic feature associated with numerous neurologic disorders. There is strong evidence that central inflammation contributes significantly to the progression of several neurodegenerative diseases as well as to the ageing process. For example, in aged rats an increase in interleukin‐1β (IL‐1β) is implicated in the decline of synaptic plasticity in the hippocampus and impaired performance on cognitive tasks such as contextual fear conditioning. IL‐1β is a proinflammatory cytokine initially synthesized in an inactive precursor form that is cleaved by caspase‐1 to generate the biologically mature form. In the present study, cleavage of IL‐1β was chronically inhibited using a specific caspase‐1 inhibitor (Ac‐YVAD‐CMK; 10 pmol) in both aged (22 month) and young (4 month) rats. Both groups received Ac‐YVAD‐CMK for 28 days intracerebroventricularly through a brain infusion cannula connected to an osmotic minipump. On day 20 the animals were trained in contextual fear conditioning, and memory for context was tested on day 22. Chronic infusion of a specific caspase‐1 inhibitor in aged rats ameliorated age‐related increases in hippocampal IL‐1β and improved memory for context.
Dynamic distribution of endoplasmic reticulum in hippocampal neuron dendritic spines
Authors: Toresson Håkan , Grant Seth G. N. 
Published: October 2005

AbstractThe role of the endoplasmic reticulum (ER) localized in dendritic spines has become a subject of intense interest because of its potential functions in local protein synthesis and signal transduction. Although it is recognized from electron microscopic studies that not all spines contain ER, little is know of its dynamic regulation or turnover. Here, we report a surprising degree of turnover of ER within spines. Using confocal microscopy imaging we observed continuity of spine‐ER with dendritic ER in hippocampal primary neurons. Over 24 h, less than 50% of spine ER was stable. Despite this high degree of turn over, we identified a significant subset of spines that maintained ER for at least 4 days. These results indicate that within a single neuron, the organelle composition of a spine is unexpectedly dynamic and may explain aspects of the spine‐to‐spine variation in calcium spike magnitude and localized protein synthesis and trafficking.
Decreased metabolic response to visual stimulation in the superior colliculus of mice lacking the glial glutamate transporter GLT‐1
Authors: Herard Anne‐Sophie , Dubois Albertine , Escartin Carole , Tanaka Kohichi , Delzescaux Thierry , Hantraye Philippe , Bonvento Gilles 
Published: October 2005

AbstractDuring a specific task, an increase in glucose utilization anatomically restricted to the functionally activated region(s) is a landmark of brain physiology. While this response represents the biological bases for functional brain imaging, the underlying signalling pathway(s) are still not fully characterized. Recent evidence suggests that glial glutamate (re)uptake plays a key role. We provide evidence that the metabolic response to synaptic activation (i.e. enhancement of glucose uptake) is decreased in the superior colliculus during visual stimulation in young adult mice deficient in the glial glutamate transporter GLT‐1. A similar reduction was not observed in the glial glutamate transporter GLAST‐knockout mice. Consistent with our previous observation obtained in the somatosensory cortex, our data suggest that a metabolic crosstalk takes place between neurons and astrocytes in the adult brain which would be regulated by synaptic activity and mediated by GLT‐1.
Isolation and characterization of neural precursor cells from the Sox1–GFP reporter mouse
Authors: Barraud Perrine , Thompson Lachlan , Kirik Deniz , Björklund Anders , Parmar Malin 
Published: October 2005

AbstractWe have made use of a reporter mouse line in which enhanced green fluorescence protein (GFP) is inserted into the Sox1 locus. We show that the GFP reporter is coexpressed with the Sox1 protein as well as with other known markers for neural stem and progenitor cells, and can be used to identify and isolate these cells by fluorescence‐activated cell sorting (FACS) from the developing or adult brain and from neurosphere cultures. All neurosphere‐forming cells with the capacity for multipotency and self‐renewal reside in the Sox1–GFP‐expressing population. Thus, the Sox1–GFP reporter system is highly useful for identification, isolation and characterization of neural stem and progenitor cells, as well as for the validation of alternative means for isolating neural stem and progenitor cells. Further, transplantation experiments show that Sox1–GFP cells isolated from the foetal brain give rise to neurons and glia in vivo, and that many of the neurons display phenotypic characteristics appropriate for the developing brain region from which the Sox1–GFP precursors were derived. On the other hand, Sox1–GFP cells isolated from the adult subventricular zone or expanded neurosphere cultures gave rise almost exclusively to glial cells following transplantation. Thus, not all Sox1–GFP cells possess the same capacity for neuronal differentiation in vivo.
Immediate–early gene induction in hippocampus and cortex as a result of novel experience is not directly related to the stressfulness of that experience
Authors: Pace Thaddeus W. W. , Gaylord Reginald , Topczewski Farran , Girotti Milena , Rubin Benjamin , Spencer Robert L. 
Published: October 2005

AbstractThe stressful quality of an experience, as perceived by rats, is believed to be largely represented by the magnitude of a hypothalamic–pituitary–adrenal (HPA) axis response. The hippocampus may be especially important for assessing the stressfulness of psychological stressors such as novel experience. If such is the case then experience‐dependent immediate–early gene expression levels within the hippocampus may parallel relative levels of HPA axis activity. We examined this prospect in rats that were placed in four different novel environments (empty housing tub, circular arena, elevated pedestal or restraint tube). Restraint and pedestal produced the largest magnitude of increased ACTH and corticosterone secretion, arena an intermediate level (Experiment 2) and tub the least magnitude of increase. We saw a very similar experience‐dependent pattern of relative Fos protein, c‐fos mRNA and zif268 mRNA expression in the paraventricular nucleus of the hypothalamus. However, in hippocampus (and select regions of cortex), immediate–early gene expression was associated with the exploratory potential of the novel experience rather than level of HPA axis activity; pedestal and arena elicited the greatest immediate–early gene expression, tub an intermediate level and restraint the least amount of expression. We conclude that the stressfulness of psychological stressors is not represented by the amount of immediate–early gene induction elicited in hippocampus and cortex, nor does there appear to be a general enhancing or depressive influence of acute stress on immediate–early gene induction in those brain regions.
Regulation of adult olfactory neurogenesis by insulin‐like growth factor‐I
Authors: McCurdy Richard D. , Féron François , McGrath John J. , Mackay‐Sim Alan 
Published: October 2005

AbstractInsulin‐like growth factor‐I (IGF‐I) has multiple effects within the developing nervous system but its role in neurogenesis in the adult nervous system is less clear. The adult olfactory mucosa is a site of continuing neurogenesis that expresses IGF‐I, its receptor and its binding proteins. The aim of the present study was to investigate the roles of IGF‐I in regulating proliferation and differentiation in the olfactory mucosa. The action of IGF‐I was assayed in serum‐free culture combined with bromodeoxyuridine‐labelling of proliferating cells and immunochemistry for specific cell types. IGF‐I and its receptor were expressed by globose basal cells (the neuronal precursor) and by olfactory neurons. IGF‐I reduced the numbers of proliferating neuronal precursors, induced their differentiation into neurons and promoted morphological differentiation of neurons. The evidence suggests that IGF‐I is an autocrine and/or paracrine signal that induces neuronal precursors to differentiate into olfactory sensory neurons. These effects appear to be similar to the cellular effects of IGF‐I in the developing nervous system.
Critical role of amygdala in flavor but not taste preference learning in rats
Authors: Touzani Khalid , Sclafani Anthony 
Published: October 2005

AbstractThe role of the amygdala (AMY) in learning to associate complex flavor (taste + odor cues) with the oral and post‐oral properties of nutrients was examined. Rats with excitotoxic lesions of the basolateral AMY learned to prefer flavors paired with intragastric (IG) infusions of maltodextrin or corn oil (Experiment 1), although the preference was slightly attenuated. However, rats with large AMY lesions failed to develop a preference for flavors paired with IG infusions of the same nutrients (Experiments 2 and 4) but were able to learn a preference for a taste mixture paired with IG maltodextrin infusions (Experiment 3). The rats with large AMY lesions also did not acquire a preference for a flavor cue paired with the sweet taste of fructose (Experiment 5). Collectively, these data provide evidence that AMY is essential for flavor‐ but not taste‐nutrient preference learning.
Optic chiasm formation in humans is independent of foveal development
Authors: Neveu Magella M. , Holder Graham E. , Sloper John J. , Jeffery Glen 
Published: October 2005

AbstractA failure of human foveal development only occurs in two genetically determined conditions; aniridia (Pax6 mutation) and albinism (tyrosinase mutation). The chiasmatic pathways from this region are disrupted in albinism and central retinal blood vessel patterns are abnormal. It is assumed that these three abnormalities have a common mechanism. Here we investigate whether similar abnormalities are present in subjects with aniridia. Using fundus photographs it is shown that abnormal blood vessel patterns are present in aniridia, but these significantly differ from those in albinos. Using electrophysiological techniques, abnormal hemispheric projections through the chiasm are demonstrated in albinos, but aniridics do not differ from normal subjects. These results demonstrate that although mutations in Pax6 and tyrosinase both affect central retinal development, they have a fundamentally different impact on the formation of the retinal vasculature and the projections from this region. This strongly suggests that separate mechanisms regulate the development of the central retina and decussation patterns at the optic chiasm.