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1.
The 2-stage determination is based on changes in blood coaggulation activity brought about both by the administration of warfarin in conjunction with vitamin K1 epoxide and by feeding a vitamin K-free diet for 4 days. When it was applied to laboratory-bred rats of known warfarin-resistance genotype, 35/35 homozygous susceptible, 44/44 homozygous resistant and 131/133 heterozygous rats were correctly classified. This method was equally effective in identifying the genotype of wild rats carrying the warfarin-resistance gene, Rw2. The procedure is rapid and accurate. 相似文献
2.
Srinivasachary Gosman N Steed A Simmonds J Leverington-Waite M Wang Y Snape J Nicholson P 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2008,116(8):1145-1153
Fusarium head blight (FHB) is an important disease of wheat worldwide. The cultivar Spark is more resistant than most other UK winter
wheat varieties but the genetic basis for this is not known. A mapping population from a cross between Spark and the FHB susceptible
variety Rialto was used to identify quantitative trait loci (QTL) associated with resistance. QTL analysis across environments
revealed nine QTL for FHB resistance and four QTL for plant height (PH). One FHB QTL was coincident with the Rht-1D locus and accounted for up to 51% of the phenotypic variance. The enhanced FHB susceptibility associated with Rht-D1b is not an effect of PH per se as other QTL for height segregating in this population have no influence on susceptibility.
Experiments with near-isogenic lines supported the association between susceptibility and the Rht-D1b allele conferring the semi-dwarf habit. Our results demonstrate that lines carrying the Rht-1Db semi-dwarfing allele are compromised in resistance to initial infection (type I resistance) while being unaffected in resistance
to spread within the spike (type II resistance). 相似文献
3.
Gamma interferon blocks gammaherpesvirus reactivation from latency in a cell type-specific manner 下载免费PDF全文
Gammaherpesviruses are important pathogens whose lifelong survival in the host depends critically on their capacity to establish and reactivate from latency, processes regulated by both viral genes and the host immune response. Previous work has demonstrated that gamma interferon (IFN-gamma) is a key regulator of chronic infection with murine gammaherpesvirus 68 (gammaHV68), a virus that establishes latent infection in B lymphocytes, macrophages, and dendritic cells. In mice deficient in IFN-gamma or the IFN-gamma receptor, gammaHV68 gene expression is altered during chronic infection, and peritoneal cells explanted from these mice reactivate more efficiently ex vivo than cells derived from wild-type mice. Furthermore, treatment with IFN-gamma inhibits reactivation of gammaHV68 from latently infected wild-type peritoneal cells, and depletion of IFN-gamma from wild-type mice increases the efficiency of reactivation of explanted peritoneal cells. These profound effects of IFN-gamma on chronic gammaHV68 latency and reactivation raise the question of which cells respond to IFN-gamma to control chronic gammaHV68 infection. Here, we show that IFN-gamma inhibited reactivation of peritoneal cells and spleen cells harvested from mice lacking B lymphocytes, but not wild-type spleen cells, suggesting that IFN-gamma may inhibit reactivation in a cell type-specific manner. To directly test this hypothesis, we expressed the diphtheria toxin receptor specifically on either B lymphocytes or macrophages and used diphtheria toxin treatment to deplete these specific cells in vivo and in vitro after establishing latency. We demonstrate that macrophages, but not B cells, are responsive to IFN-gamma-mediated suppression of gammaHV68 reactivation. These data indicate that the regulation of gammaherpesvirus latency by IFN-gamma is cell type specific and raise the possibility that cell type-specific immune deficiency may alter latency in distinct and important ways. 相似文献
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5.
Background
Protein translocation across the membrane of the Endoplasmic Reticulum (ER) is the first step in the biogenesis of secretory and membrane proteins. Proteins enter the ER by the Sec61 translocon, a proteinaceous channel composed of three subunits, α, β and γ. While it is known that Sec61α forms the actual channel, the function of the other two subunits remains to be characterized.Results
In the present study we have investigated the function of Sec61β in Drosophila melanogaster. We describe its role in the plasma membrane traffic of Gurken, the ligand for the Epidermal Growth Factor (EGF) receptor in the oocyte. Germline clones of the mutant allele of Sec61β show normal translocation of Gurken into the ER and transport to the Golgi complex, but further traffic to the plasma membrane is impeded. The defect in plasma membrane traffic due to absence of Sec61β is specific for Gurken and is not due to a general trafficking defect.Conclusion
Based on our study we conclude that Sec61β, which is part of the ER protein translocation channel affects a post-ER step during Gurken trafficking to the plasma membrane. We propose an additional role of Sec61β beyond protein translocation into the ER. 相似文献6.
Location of a gene regulating drought-induced abscisic acid production on the long arm of chromosome 5A of wheat 总被引:3,自引:0,他引:3
S. A. Quarrie M. Gulli C. Calestani A. Steed N. Marmiroli 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1994,89(6):794-800
The accumulation of abscisic acid (ABA) by detached and partially dehydrated wheat leaves is known to be inherited in a quantitative manner. The location of genes having a major effect on drought-induced ABA accumulation in wheat was determined using a set of single chromosome substitution lines and populations derived from a cross between a high-ABA- and a low-ABA-producing genotype. Examination of a series of chromosome substitution lines of the high-ABA genotype Ciano 67 into the low-ABA recipient Chinese Spring showed that chromosome 5A carries gene(s) that have a major influence on ABA accumulation in a drought test with detached and partially dehydrated leaves (DLT). A similar DLT was used to examine ABA accumulation in a population of F2 plants and doubled haploid (DH) lines derived from the cross between Chinese Spring (low-ABA) and SQ1 (high-ABA) in which the F2 population (139 plants) and DH lines (96 lines) were also mapped partially with molecular markers. Analysis of variance of ABA accumulation between and within marker allele classes in the F2 confirmed the location of a gene(s) regulating ABA accumulation on the long arm of chromosome 5A. MAPMAKERQTL showed the most likely position for the ABA quantitative trait locus (QTL) to be between the loci Xpsr575 and Xpsr426, about 8 cM from Xpsr426. A similar trend for high ABA accumulation was found in DH lines having the SQ1 allele at marker loci in the same region of chromosome 5AL, but the QTL effect was not significant. The function of the QTL is discussed. 相似文献
7.
8.
9.
Bulk segregant analysis with molecular markers and its use for improving drought resistance in maize 总被引:7,自引:1,他引:7
Quarrie S; Lazic-Jancic V; Kovacevic D; Steed A; Pekic S 《Journal of experimental botany》1999,50(337):1299-1306
The usual method to locate and compare loci regulating quantitative traits
(QTLs) requires a segregating population of plants with each one genotyped
with molecular markers. However, plants from such segregating populations
can also be grouped according to phenotypic expression of a trait and
tested for differences in allele frequency between the population bulks:
bulk segregant analysis (BSA). The same probes used for making a genetic
map (e.g. isozyme, RFLP, RAPD, etc) can be used for BSA. A molecular marker
showing polymorphism between the parents of the population and which is
closely-linked to a major QTL regulating a particular trait will mainly
co-segregate with that QTL, i.e. segregate according to the phenotype if
the QTL has a large effect. Thus, if plants are grouped according to
expression of the trait and extreme groups tested with that polymorphic
marker, the frequency of the two marker alleles present within each of the
two bulks should deviate significantly from the ratio of 1 : 1 expected for
most populations. As chromosomal locations of many molecular markers have
now been determined in many species, the map location of closely-linked
QTLs can therefore be deduced without having to genotype every individual
in segregating populations. This has been used successfully with composite
populations of maize to locate QTLs associated with yield under severe
drought. An inbred line derived from one of the populations selected for
higher drought yield has been crossed with a drought-susceptible inbred
line to produce a mapping population for QTL analysis of physiological and
developmental traits likely to regulate yield under drought. Future work to
identify traits having QTLs with flanking markers showing significant
allele frequency differences in the GSA studies will indicate those traits
likely to be important in determining yield under drought.Key
words: Bulk segregant analysis (BSA), drought resistance,
genetic maps, maize, molecular markers, Zea mays (L.).
相似文献
10.
SIBYLLE STEINBEISS HOLGER BEßLER CHRISTOF ENGELS VICKY M. TEMPERTON NINA BUCHMANN CHRISTIANE ROSCHER YVONNE KREUTZIGER JUSSI BAADE MAIKE HABEKOST GERD GLEIXNER 《Global Change Biology》2008,14(12):2937-2949
Increasing atmospheric CO2 concentration and related climate change have stimulated much interest in the potential of soils to sequester carbon. In ‘The Jena Experiment’, a managed grassland experiment on a former agricultural field, we investigated the link between plant diversity and soil carbon storage. The biodiversity gradient ranged from one to 60 species belonging to four functional groups. Stratified soil samples were taken to 30 cm depth from 86 plots in 2002, 2004 and 2006, and organic carbon contents were determined. Soil organic carbon stocks in 0–30 cm decreased from 7.3 kg C m?2 in 2002 to 6.9 kg C m?2 in 2004, but had recovered to 7.8 kg C m?2 by 2006. During the first 2 years, carbon storage was limited to the top 5 cm of soil while below 10 cm depth, carbon was lost probably as short‐term effect of the land use change. After 4 years, carbon stocks significantly increased within the top 20 cm. More importantly, carbon storage significantly increased with sown species richness (log‐transformed) in all depth segments and even carbon losses were significantly smaller with higher species richness. Although increasing species diversity increased root biomass production, statistical analyses revealed that species diversity per se was more important than biomass production for changes in soil carbon. Below 20 cm depth, the presence of one functional group, tall herbs, significantly reduced carbon losses in the beginning of the experiment. Our analysis indicates that plant species richness and certain plant functional traits accelerate the build‐up of new carbon pools within 4 years. Additionally, higher plant diversity mitigated soil carbon losses in deeper horizons. This suggests that higher biodiversity might lead to higher soil carbon sequestration in the long‐term and therefore the conservation of biodiversity might play a role in greenhouse gas mitigation. 相似文献