bluuebunny/crossref_metadata_2025_split huggingface dataset:
Chromosome instability in wheat plants regenerated from suspension culture
Authors: Fedak George , Armstrong K. C. , Handyside R. J. 
Published: April 2011

Plants of Triticum aestivum cv. Chinese Spring were regenerated from 30 calli obtained from suspension cultures. All four plants showed abnormal meiotic chromosome behaviour relative to the control. The average meiotic configuration over all plants was 1.55 I + 18.16 II + 0.30 III + 0.82 IV. In addition, an isochromosome was frequently observed in cells of all plants, which was indicative of centromeric breaks. Key words: culture (suspension), wheat, chromosome instability.
Phylogenetic relationships in the evolution of Solanum scabrum
Authors: Ganapathi A. , Rao G. R. 
Published: April 2011

Several cross-pollinations were made between Solanum scabrum (2n = 6x = 72) and S. nigrum (2n = 6x = 72), S. americanum (2n = 2x = 24), and a C3 amphiploid of the cross S. villosum (2n = 4x = 48) × S. americanum (2n = 2x = 24) with a view to determine their phyletic relationship. It was found that the crosses between S. nigrum and S. scabrum, and S. scabrum and a "big-fruited form" were accomplished easily, whereas the cross S. scabrum × S. americanum was successful only when S. scabrum, the higher chromosomal form, was used as the maternal parent. The hybrids (F1) exhibited moderate pollen fertility and vigorous growth, and set fruits and seeds abundantly, even though meiotic abnormalities were encountered in most of the pollen mother cells. From the chromosome pairing behaviour in the hybrids, it is concluded that S. americanum is the diploid ancestor of hexaploid S. scabrum and S. nigrum. The latter two species might have evolved from the sterile triploid hybrids of S. villosum × S. americanum by spontaneous amphiploidy. Key words: Solanum, phylogenetics. polyploidy.
Genetics and cytogenetics of resistance to Puccinia graminis tritici in three South African wheats
Authors: Singh R. P. , McIntosh R. A. 
Published: April 2011

Resistance to Puccinia graminis tritici pathotype 34-1, 2, 3, 4, 5, 6, 7 in a South African wheat, W3757, was attributed to a dominant gene located in an alien (possibly Agropyron elongatum) chromosome that had substituted with wheat chromosome 6D. This gene, designated SrB, and present in two additional South African wheats, W3758 and W3759, conferred a high level of adult plant resistance to pathotypes used for field assessments. Because SrB is apparently different from other genes transferred from A. elongatum to wheat, its possible exploitation following translocation to a wheat chromosome seems warranted. Key words: Puccinia graminis tritici, Triticum aestivum, wheat cytogenetics, rust resistance, alien substitution line.
Idiograms of horse chromosomes at prometaphase, early metaphase, and midmetaphase after R-banding by BrdU incorporation followed by the fluorochrome–photolysis–Giemsa technique
Authors: Romagnano April , Drouin Régen , Richer Claude-Lise 
Published: April 2011

We present three idiograms of equine chromosomes, R-banded after BrdU incorporation and stained by the fluorochrome–photolysis–Giemsa technique. The haploid set of prometaphasic chromosomes shows 591 bands (range 7–38 per chromosome), the early metaphasic set 404 (range 5–26), and the midmetaphasic set 272 (range 3–18). Following cell synchronization with thymidine, more than twice as many R-bands were revealed on the resulting prometaphasic chromosomes, making possible the establishment of a very accurate and characteristic representation of this banding pattern in the domestic horse. Key words: chromosome banding, horse, R-bands, prometaphase.
RAPD analysis of seed purity in a commercial hybrid cabbage (Brassica oleracea var. capitata) cultivar
Authors: Crockett Phillip A , Bhalla Prem L , Lee C K , Singh Mohan B 
Published: April 2011

The use of random amplified polymorphic DNA (RAPD) markers for evaluating seed purity in a commercial F1-hybrid cabbage (Brassica oleracea var. capitata) cultivar is demonstrated. Genomic DNA isolated from single ungerminated seed was found to be suitable for RAPD analysis. DNA from F1-hybrid and its parental lines was subjected to RAPD screening with 36 random decamer arbitrary primers. A total of 241 scorable products were observed with 54 (22%) being polymorphic. The RAPD data showed that the parental lines of this commercial cabbage cultivar were not very closely related. Two primers were chosen for purity testing of the F1-hybrid seeds. The sib (inbred seed; seed from self-pollination of parental lines) contamination results obtained by RAPD analysis were comparable to the commonly used grow-out trial and isozyme analysis, hence showing that RAPD analysis can be used for seed purity testing of commercial hybrid cabbage seeds. Key words: Brassica, cabbage, RAPD, seed purity test, F1-hybrid seed.
Relationship between pachytene synapsis, metaphase I associations, and transmission of 2B and 4B chromosomes in rye
Authors: Jiménez Guillermo , Manzanero Silvia , Puertas María J 
Published: April 2011

2B rye plants selected for high (H) or low (L) B transmission rate were studied at pachytene and metaphase I of meiosis to determine the relationship between synapsis, bivalents at metaphase I, and B transmission rate. The results show that the 2 B chromosomes (Bs) form bivalents at pachytene in both the H and L lines, whereas the frequency of bivalents at metaphase I is much higher in the H than in the L line. This demonstrates that B transmission is mainly related to the proper association of Bs at metaphase I, as well as that synapsis of the 2 Bs in the L line is normal, but the bivalent is not consolidated by a chiasma in most cases. Crosses were made between 2B plants of the H and L lines in all combinations (H × H, H × L, L × H, and L × L) to obtain 4B plants. Similarly, bivalent formation at pachytene and metaphase I was studied. The results show that 4B plants of the H × H and L × L classes differ significantly at pachytene and metaphase I since the former forms more bivalents. The heterozygous 4 Bs of the H × L and L × H classes show intermediate values. The relation H × H > H × L > L × H > L × L was consistently found for the variables transmission rate, bivalents at pachytene, bivalents at metaphase I, and B mean chiasma frequency. A maternal effect was also found. Our data suggest that there are two separate mechanisms acting upon synapsis and chiasma formation in H and L B chromosomes: (i) there is variable efficiency of the control of synapsis at early stages of meiosis; and (ii) there is variable efficiency of the control of the number of chiasmata.Key words: B chromosomes, synaptonemal complex, Secale cereale.
The genes encoding granule-bound starch synthases at the waxy loci of the A, B, and D progenitors of common wheat
Authors: Yan Liuling , Bhave Mrinal , Fairclough Robert , Konik Christine , Rahman Sadequr , Appels Rudi 
Published: April 2011

Three genes encoding granule-bound starch synthase (wx-TmA, wx-TsB, and wx-TtD) have been isolated from Triticum monococcum (AA), and Triticum speltoides (BB), by the polymerase chain reaction (PCR) approach, and from Triticum tauschii (DD), by screening a genomic DNA library. Multiple sequence alignment indicated that the wx-TmA, wx-TsB, and wx-TtD genes had the same extron and (or) intron structure as the previously reported waxy gene from barley. The lengths of the three wx-TmA, wx-TsB, and wx-TtD genes were 2834 bp, 2826 bp, and 2893 bp, respectively, each covering 31 bp in the untranslated leader and the entire coding region consisting of 11 exons and 10 introns. The three genes had identical lengths of exons, except exon1, and shared over 95% identity with each other within the exon regions. The majority of introns were significantly variable in length and sequence, differing mainly in length (1-57 bp) as a result of insertion and (or) deletion events. The deduced amino acid sequence from these three genes indicated that the mature WX-TMA, -TSB, and -TTD proteins contained the same number of amino acids, but differed in predicted molecular weight and isoelectric point (pI) due to amino acid substitutions (13-18). The predicted physical characteristics of the WX proteins matched the respective proteins in wheat very closely, but the match was not perfect. Furthermore the exon5 sequences of the wx-TmA, wx-TsB, and wx-TtD genes were different from a cDNA encoding a waxy gene of common wheat previously reported. The striking difference was that an insertion of 11 amino acids occurred in the cDNA sequence that could not be observed in the exons of the A, B, and D genes. It was noted, however, that the 3prime end of intron4 of these genes could account for the additional 11 amino acids. The sequence information from the available waxy genes identified the intron4-exon5-intron5 region as being diagnostic for sequence variation in waxy. The sequence variation in the waxy genes provides the basis for primer design to distinguish the respective genes in common wheat, and its progenitors, using PCR. Key words: Angiosperms, Poaceae, Triticeae, Triticum monococcum, Triticium speltoides, Triticum tauschii, granule-bound starch synthase, polymerase chain reaction (PCR), molecular evolution.
Biodiversity of Asian rice gall midge (Orseolia oryzae Wood Mason) from five countries examined by AFLP analysis
Authors: Katiyar S K , Chandel G , Tan Y , Zhang Y , Huang B , Nugaliyadde L , Fernando K , Bentur J S , Inthavong S , Constantino S , Bennett J 
Published: April 2011

Amplified fragment length polymorphism (AFLP) analysis was used to assess the biodiversity of one of the most important dipteran pests of cereals, the Asian rice gall midge (Orseolia oryzae Wood Mason). Larvae and pupae were collected at 15 locations in five Asian countries and preserved in 95% ethanol for storage, shipment, and DNA extraction using cetyltrimethylammonium bromide (CTAB). Although only ~1 µg of DNA was extracted from a single pupa or larva, the use of several AFLP primers in various combinations meant that this amount of DNA was sufficient to allow many DNA fingerprints to be made per individual. Fingerprints were sufficiently reproducible, especially during selective amplification, to allow the genetic diversity within a field population to be characterized. Extraction of DNA from a pool of 20 insects yielded AFLP fingerprints in which variation among individuals was sacrificed in favor of detecting differences among populations. For each location, pooled DNA was amplified with three primer pairs. A total of 261 distinct AFLP bands were identified for the 45 fingerprints. Cluster analysis, performed by the unweighted pair-group method (UPGMA), separated the populations into two distinct groups. Group I included two populations from Guangdong province of southern China and one each from Laos and Imphal in northeastern India, while group II was comprised of eleven populations from elsewhere in India (Assam, Orissa, Madhya Pradesh, Andhra Pradesh, and Kerala) and from Nepal and Sri Lanka. AFLP analysis provided insight into the origins of gall midge biotypes. In 1992, the prevailing biotype in Imphal changed from Indian biotype 3 to a new biotype 3M. Our data show that biotype 3M belongs to group I and did not arise by a recent mutation from biotype 3, which belongs to group II. By contrast, Indian biotypes 2 and 4 are likely to have diverged through recent mutation and selection, as are Chinese biotypes 1 and 4. The almost simultaneous emergence of new biotypes in Kerala and Sri Lanka during 1985-1988 was most probably coincidental, because these biotypes are not closely related. AFLP fingerprints were also able to detect sexual dimorphism in the DNA of adult gall midges and to distinguish gall midge from its major parasite Platygaster oryzae. Key words: biotypes, Cecidomyiidae, insect, Oryza sativa, Platygaster oryzae, population, sexual dimorphism.
Varied expression of a Y-linked P[w+] insert due to imprinting inDrosophila melanogaster
Authors: Haller Bethany S , Woodruff R C 
Published: April 2011

During gametogenesis, a gene can become imprinted affecting its expression in progeny. We have used the expression of a Y-linked P[w+]YAL transposable DNA element as a reporter system to investigate the effect of parental origination on the expression of the w+insert. Expression of w+was greater in male progeny when the Y chromosome, harboring the insert, was inherited from the parental male rather than from the parental female. Imprinting was not due to a genetic background influence in the males, since the only difference among the males was the parental origin of the Y chromosome. It was also observed that the genetic background can affect imprinting, since w+expression was also higher in males when the Y was derived from C(1)DX attached-X parental females rather than from C(1)RM attached-X parental females. Though the heterochromatic imprinting mechanism is unknown, a mutated Heterochromatin Protein 1 (HP1) gene, which is associated with suppression of position-effect variegation, increases expression of the w+locus in the P[w+]YAL insert, indicating that HP1 may play a role in Y chromosome packaging.Key words: Drosophila melanogaster, heterochromatin, HP1, imprinting, P-element, Y chromosome.
Microsatellite DNA markers in Populus tremuloides
Authors: Rahman Muhammad H , Dayanandan S , Rajora Om P 
Published: April 2011

Markers for eight new microsatellite DNA or simple sequence repeat (SSR) loci were developed and characterized in trembling aspen (Populus tremuloides) from a partial genomic library. Informativeness of these microsatellite DNA markers was examined by determining polymorphisms in 38 P. tremuloides individuals. Inheritance of selected markers was tested in progenies of controlled crosses. Six characterized SSR loci were of dinucleotide repeats (two perfect and four imperfect), and one each of trinucleotide and tetranucleotide repeats. The monomorphic SSR locus (PTR15) was of a compound imperfect dinucleotide repeat. The primers of one highly polymorphic SSR locus (PTR7) amplified two loci, and alleles could not be assigned to a specific locus. At the other six polymorphic loci, 25 alleles were detected in 38 P. tremuloides individuals; the number of alleles ranged from 2 to 7, with an average of 4.2 alleles per locus, and the observed heterozygosity ranged from 0.05 to 0.61, with an average of 0.36 per locus. The two perfect dinucleotide and one trinucleotide microsatellite DNA loci were the most informative. Microsatellite DNA variants of four SSR loci characterized previously followed a single-locus Mendelian inheritance pattern, whereas those of PTR7 from the present study showed a two-locus Mendelian inheritance pattern in controlled crosses. The microsatellite DNA markers developed and reported here could be used for assisting various genetic, breeding, biotechnology, genome mapping, conservation, and sustainable forest management programs in poplars. Key words: poplar, microsatellites, genetic mapping, simple sequence repeat (SSR) markers, DNA fingerprinting.
A gene controlling sex in grapevines placed on a molecular marker-based genetic map
Authors: Dalbó M A , Ye G N , Weeden N F , Steinkellner H , Sefc K M , Reisch B I 
Published: April 2011

Genetic maps of Vitis (2n = 38) have been constructed from an interspecific hybrid population of 58 seedlings of the cross 'Horizon' ('Seyval' × 'Schuyler') × Illinois 547-1 (V. cinerea B9 × V. rupestris B38). The maps were initially constructed based on 277 RAPD (random amplified polymorphic DNA) markers using a double-pseudotestcross strategy. Subsequently, 25 microsatellites, 4 CAPS (cleaved amplified polymorphic sequence), and 12 AFLP (amplified fragment length polymorphism) markers were added to the maps. Another 120 markers, mostly those segregating 3:1, were also assigned but not positioned on the linkage groups in the two maps. The 'Horizon' map consisted of 153 markers covering 1199 cM, with an average map distance of 7.6 cM between markers. The Illinois 547-1 map had 179 markers covering 1470 cM, with an average map distance of 8.1 cM. There were 20 linkage groups in each map, one more than the basic number of chromosomes in grapes. Ten linkage groups in each map were identified as homologous using 16 microsatellite and 2 CAPS markers polymorphic in both parents. A single locus controlling sex in grapes mapped close to a microsatellite marker. These maps provide enough coverage of the genome for QTL (quantitative trait loci) analysis and as a starting point for positional gene cloning in grapes. Key words: Vitis, RAPD, microsatellite, SSR, CAPS.
Sequence analysis of trinucleotide repeat microsatellites from an enrichment library of the equine genome
Authors: Tozaki T , Inoue S , Mashima S , Ohta M , Miura N , Tomita M 
Published: April 2011

Microsatellites are useful tools for the construction of a linkage map and parentage testing of equines, but only a limited number of equine microsatellites have been elucidated. Thus, we constructed the equine genomic library enriched for DNA fragments containing (CAG)n repeats. The enriched method includes hybridization-capture of repeat regions using biotin-conjugated oligonucleotides, nucleotide substrate-biased polymerase reaction with the oligonucleotides and subsequent PCR amplification, because these procedures are useful for the cloning of less abundant trinucleotide microsatellites. Microsatellites containing (CAG)n repeats were obtained at the ratio of one per 3-4 clones, indicating an enrichment value about 104-fold, resulting in less time consumption and less cost for cloning. In this study, 66 different microsatellites, (CAG)n repeats, were identified. The number of complete simple CAG repeats in our clones ranged 4-33, with an average repeat length of 8.8 units. The microsatellites were useful as sequence-tagged site (STS) markers. In addition, some clones containing (CAG)n repeats showed homology to human (CAG)n-containing genes, which have been previously mapped. These results indicate that the clones might be a useful tool for chromosome comparison between equines and humans. Key words: microsatellites, (CAG)n repeats, equine.
Enhancement of hippocampal cholinergic neurotransmission through 5-HT1A receptor-mediated pathways by repeated lithium treatment in rats
Authors: Fujii Takeshi , Nakai Katsuhiko , Nakajima Yasuo , Kawashima Koichiro 
Published: April 2011

Hippocampal cholinergic neuronal activity is reported to be regulated, at least partly, through serotonin1A (5-HT1A) receptors. Chronic lithium treatment has been shown to alter both behavioral and neurochemical responses mediated by postsynaptic 5-HT1A receptors. We investigated whether long-term lithium treatment affects central cholinergic neurotransmission through 5-HT1A receptor-mediated pathways. Changes in acetylcholine (ACh) release induced by 8-hydroxy-2-(di-n-propylamino)tetralin (8-OH-DPAT), a 5-HT1A receptor agonist, in the rat hippocampus were measured using a microdialysis technique and a radioimmunoassay for ACh. Administration of lithium for 21 days resulted in a serum lithium concentration of 1.03 mM and caused little change in density or affinity of [3H]8-OH-DPAT binding sites in the hippocampus. The local application of 8-OH-DPAT into the hippocampus of lithium treated rats increased the ACh efflux in both the absence and the presence of physostigmine, a cholinesterase (ChE) inhibitor, in the perfusion fluid. The basal ACh efflux of lithium treated rats was not different from that of the control rats under normal conditions, but was significantly higher than that of the controls when ChE was inhibited. These results demonstrate that chronic lithium treatment increases spontaneous ACh release in the hippocampus under conditions of ChE inhibition, but not under normal conditions, and enhances cholinergic neurotransmission through 5-HT1A receptor-mediated pathways, and suggest that activation of 5-HT1A receptor function by lithium is related to the enhancement of hippocampal cholinergic neurotransmission. Key words: Acetylcholine (ACh), hippocampus, 8-hydroxy-2-(di-n-propylamino)tetralin (8-OH-DPAT), lithium, serotonin1A (5-HT1A) receptor.
Predictors of Torsades de Pointes in rabbit ventricles perfused with sedating and nonsedating histamine H1-receptor antagonists
Authors: Gilbert Jeremy D , Cahill Sean A , McCartney Douglas G , Lukas Anton , Gross Gil J 
Published: April 2011

Several nonsedating histamine H1-receptor antagonists are associated with torsades de pointes ventricular tachycardia. The objectives of this study were to: (i) compare electrocardiographic, monophasic action potential, and arrhythmogenic effects of sedating and nonsedating H1-receptor antagonists, and (ii) identify correlates of drug-induced torsades de pointes in an isolated ventricle model. Isolated, electrically paced (1-3 Hz) rabbit ventricles were Langendorff-perfused with either drug-free Tyrode's solution or one of the following: (i) the sedating H1-receptor antagonist hydroxyzine (0.1-30 µM), (ii) cetirizine, a nonsedating metabolite of hydroxyzine (1-300 µM), and (iii) the nonsedating, putatively arrhythmogenic H1-receptor antagonist astemizole (0.1-30 µM). Volume conducted electrocardiographic signals and monophasic action potentials from the periapical left ventricular endocardium and epicardium were recorded. There were no apparent changes in control (n = 15) or hydroxyzine-perfused (n = 7) hearts. Cetirizine (n = 13) produced a mild biphasic electrocardiographic QT interval prolongation and was associated with early afterdepolarizations, but not with torsades de pointes. Astemizole (n = 11) lengthened QT intervals, and at high concentration (30 µM) induced torsades de pointes in 10 of 11 hearts (P < 0.001 vs. all other groups). These findings are consistent with previously reported repolarizing current inhibition by cetirizine, but may additionally indicate "compensatory" inhibition of inward currents at higher concentrations. By contrast, astemizole-induced changes are consistent with unopposed repolarizing current inhibition. Key words: Langendorff preparation, rabbit ventricle, H1-receptor antagonists, QT interval, ventricular arrhythmias.
The effect of adrenalectomy on the cardiac response to subacute fetal anemia
Authors: Jonker Sonnet S. , Scholz Thomas D. , Segar Jeffrey L. 
Published: April 2011

The mechanisms that stimulate fetal heart growth during anemia are unknown. To examine the hypothesis that adrenal hormones contribute to this process, we determined the effects of adrenalectomy (Adx) on heart growth and the activation of cardiac mitogen-activated protein kinases (MAPKs) in the presence and absence of fetal anemia. To identify mechanisms contributing to the initiation of cardiac growth, the duration of anemia was limited to a period shorter than that previously described to result in increased cardiac mass. Four groups of fetal sheep were studied (Adx-Anemic, Adx-Control, Intact-Anemic, Intact-Control). Anemia was created by daily controlled hemorrhage for 5 days; hearts were collected for analysis at 133 d gestation (term 145 d). Cardiomyocyte morphometry, immunohistochemistry for Ki-67 (proliferation marker), and Western blotting for protein levels of MAPKs and proliferating cell nuclear antigen (PCNA) were performed. Blood pressure, heart rate, heart weight-to-body weight ratio, and cardiomyocyte length and width remained similar among groups throughout the study. PCNA levels in the Adx-Anemic group were twice as high as in any other group (both ventricles, p < 0.05). Levels of phosphorylated extracellular signal-regulated kinase (ERK) were ~60% higher in the Intact-Anemic and Adx-Anemic groups, compared with the Intact-Control and Adx-Control groups (p < 0.02). These results suggest that adrenal hormones may attenuate fetal cardiomyocyte proliferation in response to anemia (as evidenced by the increased PCNA in Adx-Anemic fetuses) and that phosphorylation of myocardial ERK results from fetal anemia, irrespective of the status of the fetal adrenal gland.