bluuebunny/crossref_metadata_2025_split huggingface dataset:
Inheritance of DDT dehydrochlorination and of a mechanism restricting uptake of DDT in the mosquito Aedes aegypti
Authors: Rathor H. R. , Wood R. J. 
Published: April 2011

Crosses and backcrosses were made between the T8 dichlorodiphenyltrichloroethane (DDT) resistant strain and NS susceptible strain. Each generation was tested for resistance, for internal levels of DDT and dichlorodiphenyldichloroethylene (DDE) (thus "DDT uptake" (DDT + DDE) and percentage DDT dehydrochlorination in vivo), and for DDT dehydrochlorination in vitro, both at the larval and adult stages. The patterns of inheritance of uptake and dehydrochlorination were different. At both life stages, dehydrochlorination (both in vivo and in vitro) was intermediate in the F1, reverting to or exceeding the parental strains in the backcrosses except in adult tests on the backcrosses to the susceptible strain where it remained intermediate. Uptake increased very substantially in the F1 compared with either parental strain and was also high in the backcrosses. This was interpreted as being due to the disruption of an uptake-restricting mechanism in T8 brought about by outcrossing. Larval resistance in the various generations was correlated significantly with dehydrochlorination, both in vivo and in vitro but bore no clear relation to uptake. Resistance in adults was found not to be correlated significantly with either. Key words: DDT dehydrochlorination, pesticide resistance, DDT uptake, DDT resistance, dehydrochlorination in vivo and in vitro assays.
Polyploid polymorphism in Andropogon gerardii
Authors: Keeler K. H. , Kwankin B. , Barnes P. W. , Galbraith D. W. 
Published: April 2011

The relationship between nuclear DNA content and chromosome number was investigated in Andropogon gerardii. The distribution of cytotypes in a natural population of this grass was also examined. Nuclear DNA content was determined using flow cytometry rather than the traditional method of Feulgen microphotometry. Our results demonstrate the increased accuracy and speed of this new method in the detection and study of polyploidy. Nuclear DNA content is strongly correlated to chromosome number in Andropogon gerardii (r = 0.971, P <0.01). The natural population of this grass was found to consist of plants with 2N = 60 chromosomes (hexaploid cytotype) and 2N = 80 chromosomes (octoploid cytotype), in equal proportions. Intermediate cytotypes were lacking in the natural population, although three progeny plants grown in the greenhouse from wild-collected seed show intermediate values of nuclear DNA content and have 2N = 70 chromosomes. The two coexisting cytotypes are intermingled and show no difference in microhabitats. The absence of septaploids in the natural population suggests that the two cytotypes are probably reproductively isolated. Key words: polyploidy, DNA contents, flow cytometry, polymorphism.
Use of 4x–2x crosses to determine gene–centromere map distances of isozyme loci in Solanum species
Authors: Douches David S. , Quiros Carlos F. 
Published: April 2011

With the meiotic abnormality described as the parallel spindles mechanism operating during anaphase II, first division type restitution 2n gametes (FDR) were identified in selected diploid Solanum clones. Generating 4x–2x FDR testcrosses of the general form aaaa × Aa with these diploid parents provided a means of estimating gene–centromere linkages with the application of half-tetrad analysis to the segregating tetraploid progenies. In this study, gene–centromere map distances were obtained for 10 isozyme loci and the yellow tuber flesh locus (Y). Electrophoretic assay of the tetraploid progenies yielded pooled gene–centromere linkage estimates for Got-1 (0.9 map units, mu), Pgm-2 (2.0 mu), Sdh-1 (8.3 mu), Aps-1 (13.5 mu), Adh-1 (15.8 mu), Prx-3 (18.0 mu), Idh-1 (18.4 mu), Pgi-1 (26.0 mu), 6-Pgdh-3 (30.1 mu), Mdh-1 (33.5 mu), and y (16.8 mu). These linkage data were combined with previously reported diploid testcross linkage data to show that these 11 markers are distributed over at least 8 of the 24 chromosome arms in the potato genome. In addition, gene order for the Idh-1/Sdh-1 linkage block (36.8 mu) was predicted to be of the sequence Id1-1 –centromere–Sdh-1, which is similarly found in Lycopersicon. Because of the codominant nature of these enzyme-coding loci, the theoretical expectations for 4x–2x FDR segregation were tested in this crop. Tests for reciprocity of exchange products of pooled data for 6-Pgdh-3, Mdh-1, Pgi-1, Adh-1, and Sdh-1 families yielded good fits to the expected 1:1 ratio. With these defined electrophoretic markers available, more critical genetic analyses can be extended to a number of genetic and breeding problems concerning the potato. Key words: half-tetrad analysis, 4x–2x, isozymes, Solanum, linkages.
Polytene chromosome mapping in Ceratitis capitata (Diptera: Tephritidae)
Authors: Bedo D. G. 
Published: April 2011

Polytene chromosome reference maps of the five autosomes of Ceratitis capitata from male pupal orbital bristle trichogen cells are presented and a correlation is established between two of them and the two largest of the five autosomes in the haploid mitotic complement. Characteristic features of each chromosome are described identifying areas that are difficult to analyze and noting the existence of common alternative band expression. A quantitative analysis of the mitotic karyotype of C. capitata indicates that the two smallest autosome pairs cannot be reliably distinguished. This may present problems with future attempts to establish homologies between the remaining mitotic and polytene chromosomes. A comparison of polytene chromosome banding patterns from salivary gland and trichogen cells failed to find any homologous regions, or even to identify homologous chromosomes. The banding differences are not explained by variation in puffing patterns, heterochromatin expression, or polyteny levels, but appear to reflect fundamental differences in banding patterns of the chromosomes in each tissue. Key words: Ceratitis capitata, polytene chromosome map, mitotic chromosome measurements.
Genetic control of environmentally induced DNA variation in flax genotrophs
Authors: Al-Saheal Y. A. , Larik A. S. 
Published: April 2011

Heritable changes can be induced in the amount of nuclear DNA of the Stormont Cirrus variety (PL) of flax when grown in the specific environments of nitrogen and phosphorus, but such changes did not occur in variety Royal (R). Changes occurred in the amount of nuclear DNA of R when the PL nuclear and cytoplasmic factors were introduced by crossing. In the experiments reported here, tests were made on the plasticity of the F1's of their reciprocal crosses to PL and R to understand why L and S genotrophs are stable. The results suggest that there may be a feedback from nucleus to cytoplasm in L0, which inactivates the cytoplasmic factor. Possibly a paramutation-like mechanism adjusts the different amount of DNA, or heterochromatin, between the homologous chromosomes in heterozygotes. L3 and S3 DNA has reverted to the same amount as in PL. This reversion in DNA appears to be accompanied by an increase in stability rather than in any gain in plasticity. Key words: environment, flax, genotrophs, DNA variation.
Development of a PCR marker for rapid identification of the Bt-10 gene for common bunt resistance in wheat
Authors: Laroche André , Demeke Tigst , Gaudet Denis A , Puchalski Byron , Frick Michelle , McKenzie R 
Published: April 2011

In western Canada, the Bt-10 resistance gene in wheat (Triticum aestivum) is effective against all the known races of common bunt caused by Tilletia tritici and T. laevis. The genotypes of 199 F2 plants, originated from a cross between BW553 containing Bt-10 and the susceptible spring wheat cultivar 'Neepawa,' were established in greenhouse and field inoculation studies. A ratio of 1:2:1 resistant : heterozygous : susceptible was observed for bunt reaction, indicating that Bt-10 was expressed in a partially dominant fashion. A polymorphic DNA fragment, amplified using RAPD, and previously shown to be linked to Bt-10 was sequenced and SCAR (sequence characterized amplified region) primers devised. However, SCAR primers failed to amplify the polymorphic fragment. Restriction of PCR products with DraI revealed a polymorphic fragment of 490 bp resulting from a single base pair difference between lines possessing Bt-10 and those lacking the gene. As per the base pair difference, FSD and RSA primers were designed to generate a 275-bp polymorphic DNA fragment. Both 275- and 490-bp polymorphic fragments were present in all of the 22 cultivars known to carry Bt-10, and absent in all 16 cultivars lacking Bt-10. A 3:1 ratio was observed for presence: absence of the 275-bp marker in the F2 population. Using Southern analysis, the 490-bp fragment was effective in differentiating homozygous resistant plants from those heterozygous for Bt-10, based on its presence and the hybridization signal strength. A 1:2:1 resistant : heterozygous : susceptible ratio was also observed for the molecular marker and corresponded to 88% of the phenotypes deduced from the original F2 population. The molecular marker was estimated to be between 1.1 cM and 6.5 cM away from the Bt-10 resistance gene, based on the segregation analysis. Segregation analyses of Bt-10 and the 275-bp marker, evaluated in three different Canada Prairie Spring (CPS) wheat populations, demonstrated a segregation ratio of 3:1 for the molecular marker in two of the populations. These results demonstrated that the PCR marker system using the FSD and RSA primer pair permitted a rapid and reliable identification of individual lines carrying the Bt-10 gene for resistance to common bunt. Key words: resistance gene, genetic segregation, molecular marker, RAPD analysis.
Chromosomal location of AFLP markers in common wheat utilizing nulli-tetrasomic stocks
Authors: Huang Xiuqiang , Zeller Friedrich J , Hsam Sai LK , Wenzel Gerhard , Mohler Volker 
Published: April 2011

Amplified fragment length polymorphism (AFLP) markers with a total of 256 EcoRI + ANN- MseI + CNN primer combinations were investigated employing the common wheat cultivar Triticum aestivum 'Chinese Spring.' On average, 103 fragments per primer combination were amplified, ranging from a maximum of 226 fragments to a minimum of 18 fragments. The primer combinations E + AAA - M + CNN and E + ATT - M + CNN produced very few distinct fragments. By using 15 randomly chosen EcoRI + ANN - MseI + CNN primer combinations, 928 AFLP markers were allocated to wheat chromosomes, of which 131 were assigned to specific chromosome arms. These AFLP markers were locus-specific and randomly distributed on the different chromosomes. In addition, 6 and 41 AFLP markers were simultaneously absent in two nulli-tetrasomics (NTs) of both homoeologous and non-homoeologous groups, respectively, whereas additional fragments were detected in N1BT1A, N5AT5D, and N6BT6A lines.Key words: aneuploid, chromosome assignment, Triticum aestivum.
TAS49a dispersed repetitive sequence isolated from subtelomeric regions ofNicotianatomentosiformischromosomes
Authors: Horáková Mirka , Fajkus Jirí 
Published: April 2011

We have isolated and characterized a new repetitive sequence, TAS49, from terminal restriction fragments of Nicotiana tomentosiformis genomic DNA by means of a modified vectorette approach. The TAS49 was found directly attached to telomeres of N. tabacum and one of its ancestors, N. tomentosiformis, and also at inner chromosome locations. No association with telomeres was detected neither in N. otophora nor in the second tobacco ancestor, N. sylvestris. PCR and Southern hybridization reveal similarities in the arrangement of TAS49 on the chromosomes of 9 species of the genus Nicotiana, implying its occurrence as a subunit of a conserved complex DNA repeat. TAS49 belongs to the family of dispersed repetitive sequences without features of transposons. The copy number of TAS49 varies widely in the genomes of 8 species analyzed being lowest in N. sylvestris, with 3300 copies per diploid genome. In N. tomentosiformis, TAS49 forms about 0.56% of the diploid genome, corresponding to 17 400 copies. TAS49 units are about 460 bp long and show about 90% of mutual homology, but no significant homology to DNA sequences deposited in GenBank and EMBL. Although genomic clones of TAS49 contain an open reading frame encoding a proline-rich protein similar to plant extensins, no mRNA transcript was detected. TAS49 is extensively methylated at CpG and CpNpG sites and its chromatin forms nucleosomes phased with a 170 ± 8 bp periodicity.Key words: repetitive DNA sequence, subtelomere, plant, Nicotiana.
Cloning of two glutamate dehydrogenase cDNAs fromAsparagus officinalis: Sequence analysis and evolutionary implications
Authors: Pavesi Angelo , Ficarelli Antonella , Tassi Francesca , Restivo Francesco Maria 
Published: April 2011

Two different amplification products, termed c1 and c2, showing a high similarity to glutamate dehydrogenase sequences from plants, were obtained from Asparagus officinalis using two degenerated primers and RT-PCR (reverse transcriptase polymerase chain reaction). The genes corresponding to these cDNA clones were designated aspGDHA and aspGDHB. Screening of a cDNA library resulted in the isolation of cDNA clones for aspGDHB only. Analysis of the deduced amino acid (aa) sequence from the full-length cDNA suggests that the gene product contains all regions associated with metabolic function of NAD glutamate dehydrogenase (NAD-GDH). A first phylogenetic analysis including only GDHs from plants suggested that the two GDH genes of A. officinalis arose by an ancient duplication event, pre-dating the divergence of monocots and dicots. Codon usage analysis showed a bias towards A/T ending codons. This tendency is likely due to the biased nucleotide composition of the asparagus genome, rather than to the translational selection for specific codons. Using principal coordinate analysis, the evolutionary relatedness of plant GDHs with homologous sequences from a large spectrum of organisms was investigated. The results showed a closer affinity of plant GDHs to GDHs of thermophilic archaebacterial and eubacterial species, when compared to those of unicellular eukaryotic fungi. Sequence analysis at specific amino acid signatures, known to affect the thermal stability of GDH, and assays of enzyme activity at non-physiological temperatures, showed a greater adaptation to heat-stress conditions for the asparagus and tobacco enzymes compared with the Saccharomyces cerevisiae enzyme.Key words: Asparagus officinalis, glutamate dehydrogenase, complementary DNA, enzyme thermostability, principal coordinate analysis, evolution.
Cloning and characterization ofVine-1, a LTR-retrotransposon-like element inVitis viniferaL., and otherVitisspecies
Authors: Verriès C , Bès C , This P , Tesnière C 
Published: April 2011

We report the organization of a grapevine chimeric gene Adhr-Vine-1, composed by an Adhr gene, into which a retroelement, Vine-1, was inserted. Sequence analysis revealed that Adhr is a member of the Adh multigene family, but does not correspond to any other grapevineAdh described to date. Vine-1, albeit defective, is the most complete LTR (long terminal repeat)-retrotransposon-like element described in Vitis vinifera L. It is 2392 bp long, with two almost identical LTRs (287 bp) in the same orientation, and flanked by direct repeats of a 5 bp host DNA. This element presents other features, characteristic of retroviruses and retrotransposons including inverted repeats, a primer binding site, and a polypurine tract. It has a single open reading frame (ORF) of 581 amino acids, potentially encoding for a gag protein and parts of the protease and integrase proteins. Vine-1 is most likely related to the copia-like type family, but with no significant similarity to any previously described plant retrotransposon or inserted element, nor to any eukaryotic element described to date. Vine-1 element has been found in Adhr at the same location in different V. vinifera cultivars, but not in some other analyzed Vitis species. These data suggest that Vine-1 insertion in Adhr is specific to V. vinifera, and has occurred after the Adh isogene separation, but prior to cultivar development. Sequences related to Vine-1 were revealed in multiple copies in the V. vinifera genome and, to a lesser extent, in other analyzed Vitis species. The polymorphism observed prompts us to question the role played by transposition in the evolution of the Vitis genus.Key words: alcohol dehydrogenase, LTR, polymorphism, retrotransposon, Vitis vinifera L.
Chromosomal location of a Triticum timopheevii - derived powdery mildew resistance gene transferred to common wheat
Authors: Järve K , Peusha H O , Tsymbalova J , Tamm S , Devos K M , Enno T M 
Published: April 2011

A dominant powdery mildew resistance gene introduced from Triticum timopheevii in line 146-155-T of common wheat, Triticum aestivum, was located on chromosome 6B by monosomic analysis. Restriction fragment length polymorphism (RFLP) and microsatellite analyses detected the presence of a T. timopheevii segment, translocated to chromosome 6B, with breakpoints between the loci Xpsr8/Xpsr964 on 6BS and Xpsr154/Xpsr546 on 6BL. The novel powdery mildew resistance gene, which has been designated Pm27, was shown to cosegregate with the microsatellite locus Xpsp3131, which is located on the introgressed T. timopheevii segment. The molecular data confirm the location of Pm27 on the translocated 6B chromosome. Key words: monosomic analysis, RFLP, microsatellites, Pm27.
Comparison of changes evoked by GABA (γ-aminobutyric acid) and anoxia in [K+]o, [Cl-]o, and [Na+]o in stratum pyramidale and stratum radiatum of the guinea pig hippocampus
Authors: Obrocea G V , Morris M E 
Published: April 2011

Ion-selective microelectrode recordings were made to assess a possible contribution of extracellular γ-aminobutyric acid (GABA) accumulation to early responses evoked in the brain by anoxia and ischemia. Changes evoked by GABA or N2 in [K+]o, [Cl-]o, [Na+]o, and [TMA+]o were recorded in the cell body and dendritic regions of the stratum pyramidale (SP) and stratum radiatum (SR), respectively, of pyramidal neurons in CA1 of guinea pig hippocampal slices. Bath application of GABA (1-10 mM) for approximately 5 min evoked changes in [K+]o and [Cl-]o with respective EC50 levels of 3.8 and 4.1 mM in SP, and 4.7 and 5.6 mM in SR. In SP 5 mM GABA reversibly increased [K+]o and [Cl-]o and decreased [Na+]o; replacement of 95% O2 -5% CO2 by 95% N2 -5% CO2 for a similar period of time evoked changes which were for each ion in the same direction as those with GABA. In SR both GABA and N2 caused increases in [K+]o and decreases in [Cl-]o and [Na+]o. The reduction of extracellular space, estimated from levels of [TMA+]o during exposures to GABA and N2, was 5-6% and insufficient to cause the observed changes in ion concentration. Ion changes induced by GABA and N2 were reversibly attenuated by the GABAA receptor antagonist bicuculline methiodide (BMI, 100 µM). GABA-evoked changes in [K+]o in SP and SR and [Cl-]o in SP were depressed by >=90%, and of [Cl-]o in SR by 50%; N2-evoked changes in [K+]o in SP and SR were decreased by 70% and those of [Cl-]o by 50%. BMI blocked Δ [Na+]o with both GABA and N2 by 20-30%. It is concluded that during early anoxia: (i) accumulation of GABA and activation of GABAA receptors may contribute to the ion changes and play a significant role, and (ii) responses in the dendritic (SR) regions are greater than and (or) differ from those in the somal (SP) layers. A large component of the [K+]o increase may involve a GABA-evoked Ca2+-activated gk, secondary to [Ca2+]i increase. A major part of [Cl-]o changes may arise from GABA-induced gCl and glial efflux, with strong stimulation of active outward transport and anion exchange at SP, and inward Na+/K+/2Cl- co-transport at SR. Na+ influx is attributable mainly to Na+-dependent transmitter uptake, with only a small amount related to GABAA receptor activation. Although the release and (or) accumulation of GABA during anoxia might be viewed as potentially protectant, the ultimate role may more likely be an important contribution to toxicity and delayed neuronal death. Key words: brain slices, ion-selective microelectrodes, stratum pyramidale, stratum radiatum, bicuculline methiodide, extracellular space shrinkage.
Renal adenosine A3 receptors in the rat: assessment of functional role
Authors: Mozaffari Mahmood S , Abebe Worku , Warren Brett K 
Published: April 2011

The functional roles of adenosine A3 receptors in the rat kidney were assessed for the first time with respect to A1 receptor-mediated responses. Utilizing a chronically instrumented conscious rat preparation, we tested renal excretory responses to acute administration of the A3 receptor antagonists 3-ethyl - 5-benzyl-2-methyl-6-phenyl- 4-phenylethynyl-1,4-(+)-dihydropridine-3,5-dicarboxylate (MRS-1191) and 9-chloro-2-(2-furyl)-5-phenylacetylamino- [1,2,4]-triazolo[1,5-c]quinazoline (MRS-1220) with reference to the effects of the A1 receptor antagonist 1,3-dipropyl-8-cyclopentylxanthine (DPCPX). The intravenous administration of DPCPX resulted in significant increases in fluid and sodium excretions without affecting glomerular filtration rate (GFR). This suggests that DPCPX-induced diuretic and natriuretic responses are related to decreased tubular reabsorption. However, neither MRS-1191 nor MRS-1220 alone affected fluid or sodium excretions, or GFR, indicating lack of an effect of either compound on renal function. On the other hand, the co-administration of MRS-1220 with DPCPX abolished both the diuretic and natriuretic responses to DPCPX, being suggestive of antagonism between these two compounds. MRS-1191, however, did not affect the DPCPX-induced fluid and sodium excretions. Neither the A1 nor the A3 receptor antagonists altered potassium excretion individually or in combination. The data suggest that while adenosine A1 receptors are involved in the regulation of renal fluid and sodium transport, A3 receptors do not appear to have a major role in regulation of renal excretory function under baseline physiological conditions. Key words: adenosine A3 receptor, adenosine antagonist, diuresis, natriuresis, rat.
Time course in calpain activity and autolysis in slow and fast skeletal muscle during clenbuterol treatment
Authors: Douillard Aymeric , Galbes Olivier , Rossano Bernadette , Vernus Barbara , Bonnieu Anne , Candau Robin , Py Guillaume 
Published: April 2011

Calpains are Ca2+cysteine proteases that have been proposed to be involved in the cytoskeletal remodeling and wasting of skeletal muscle. Cumulative evidence also suggests that β2-agonists can lead to skeletal muscle hypertrophy through a mechanism probably related to calcium-dependent proteolytic enzyme. The aim of our study was to monitor calpain activity as a function of clenbuterol treatment in both slow and fast phenotype rat muscles. For this purpose, for 21 days we followed the time course of the calpain activity and of the ubiquitous calpain 1 and 2 autolysis, as well as muscle remodeling in the extensor digitorum longus (EDL) and soleus muscles of male Wistar rats treated daily with clenbuterol (4 mg·kg–1). A slow to fast fiber shift was observed in both the EDL and soleus muscles after 9 days of treatment, while hypertrophy was observed only in EDL after 9 days of treatment. Soleus muscle but not EDL muscle underwent an early apoptonecrosis phase characterized by hematoxylin and eosin staining. Total calpain activity was increased in both the EDL and soleus muscles of rats treated with clenbuterol. Moreover, calpain 1 autolysis increased significantly after 14 days in the EDL, but not in the soleus. Calpain 2 autolysis increased significantly in both muscles 6 hours after the first clenbuterol injection, indicating that clenbuterol-induced calpain 2 autolysis occurred earlier than calpain 1 autolysis. Together, these data suggest a preferential involvement of calpain 2 autolysis compared with calpain 1 autolysis in the mechanisms underlying the clenbuterol-induced skeletal muscle remodeling.