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91.
Peder Zipperlen Knud Nairz Ivo Rimann Konrad Basler Ernst Hafen Michael Hengartner Alex Hajnal 《Genome biology》2004,6(2):R19
Small insertions or deletions (InDels) constitute a ubiquituous class of sequence polymorphisms found in eukaryotic genomes.
Here, we present an automated high-throughput genotyping method that relies on the detection of fragment-length polymorphisms
(FLPs) caused by InDels. The protocol utilizes standard sequencers and genotyping software. We have established genome-wide
FLP maps for both Caenorhabditis elegans and Drosophila melanogaster that facilitate genetic mapping with a minimum of manual input and at comparatively low cost. 相似文献
92.
Charalampos Valmas Melanie N. Grosch Michael Schümann Judith Olejnik Osvaldo Martinez Sonja M. Best Verena Kr?hling Christopher F. Basler Elke Mühlberger 《PLoS pathogens》2010,6(1)
Previous studies have demonstrated that Marburg viruses (MARV) and Ebola viruses (EBOV) inhibit interferon (IFN)-α/β signaling but utilize different mechanisms. EBOV inhibits IFN signaling via its VP24 protein which blocks the nuclear accumulation of tyrosine phosphorylated STAT1. In contrast, MARV infection inhibits IFNα/β induced tyrosine phosphorylation of STAT1 and STAT2. MARV infection is now demonstrated to inhibit not only IFNα/β but also IFNγ-induced STAT phosphorylation and to inhibit the IFNα/β and IFNγ-induced tyrosine phosphorylation of upstream Janus (Jak) family kinases. Surprisingly, the MARV matrix protein VP40, not the MARV VP24 protein, has been identified to antagonize Jak and STAT tyrosine phosphorylation, to inhibit IFNα/β or IFNγ-induced gene expression and to inhibit the induction of an antiviral state by IFNα/β. Global loss of STAT and Jak tyrosine phosphorylation in response to both IFNα/β and IFNγ is reminiscent of the phenotype seen in Jak1-null cells. Consistent with this model, MARV infection and MARV VP40 expression also inhibit the Jak1-dependent, IL-6-induced tyrosine phosphorylation of STAT1 and STAT3. Finally, expression of MARV VP40 is able to prevent the tyrosine phosphorylation of Jak1, STAT1, STAT2 or STAT3 which occurs following over-expression of the Jak1 kinase. In contrast, MARV VP40 does not detectably inhibit the tyrosine phosphorylation of STAT2 or Tyk2 when Tyk2 is over-expressed. Mutation of the VP40 late domain, essential for efficient VP40 budding, has no detectable impact on inhibition of IFN signaling. This study shows that MARV inhibits IFN signaling by a mechanism different from that employed by the related EBOV. It identifies a novel function for the MARV VP40 protein and suggests that MARV may globally inhibit Jak1-dependent cytokine signaling. 相似文献
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96.
Evolution at the tip and base of the X chromosome in an African population of Drosophila melanogaster 总被引:1,自引:0,他引:1
Hitchhiking effects of advantageous mutations have been invoked to explain
reduced polymorphism in regions of low crossing-over in Drosophila. Besides
reducing DNA heterozygosity, hitchhiking effects should produce strong
linkage disequilibrium and a frequency spectrum skewed toward an excess of
rare polymorphisms (compared to the neutral expectation). We measured DNA
polymorphism in a Zimbabwe population of D. melanogaster at three loci,
yellow, achaete, and suppressor of forked, located in regions of reduced
crossing-over. Similar to previously published surveys of these genomic
regions in other populations, we observed low levels of nucleotide
variability. However, the frequency spectrum was compatible with a neutral
model, and there was abundant evidence for recombination in the history of
the yellow and ac genes. Thus, some aspects of the data cannot be accounted
for by a simple hitchhiking model. An alternative hypothesis, background
selection, might be compatible with the observed patterns of linkage
disequilibrium and the frequency spectrum. However, this model cannot
account for the observed reduction in nucleotide heterozygosity. Thus,
there is currently no satisfactory theoretical model for the data from the
tip and base of the X chromosome in D. melanogaster.
相似文献
97.
Ligand-independent activation of the sevenless receptor tyrosine kinase changes the fate of cells in the developing Drosophila eye 总被引:20,自引:0,他引:20
Cell fate in the developing eye is determined by a cascade of inductive interactions. In this process, the sevenless protein--a receptor tyrosine kinase--is required for the specification of the R7 photoreceptor cell fate. We have constructed a gain-of-function sevenless mutation (SevS11) by overexpressing a truncated sevenless protein in the cells where sevenless is normally expressed. In SevS11 mutant flies, all sevenless-expressing cells initiate neural development. This results in the formation of multiple R7-like photoreceptors per ommatidium. Therefore, sevenless activity appears to be necessary and sufficient for the determination of R7 cell fate. These results illustrate the central role receptor tyrosine kinases can play in the specification of cell fate during development. 相似文献
98.
The effects of abscisic acid (ABA) and gibberellic acid (GA)on the translocation of 2,4,5-trichlorophenoxyacetic acid (2,4,5-T)in beans (Phaseolus vulgaris L. cv. Stringless Greenpd) seedlingswere determined. 14C-labeled 2,4,5-T was injected in the stemtissue at the cotyledonary node in 1-µl amounts alongwith the AB or GA. ABA caused an enhancement of 2,4,5-T translocationto the lower hypocotyl and roots and promoted a decrease inthe accumulation of 2,4,5-T in the young expanding shoots andprimary leaves. GA promoted the accumulation of 2,4,5-T in youngshoots. The enhanced basipetal translocation of 2,4,5-T wasmeasurable after a few hours of treatment and was partiallyeffective even in the presence of the protein synthesis inhibitorcychloheximide. The GA effects on 2,4,5-T translocation werenullified by cycloheximide and were also noted after only afew hours of treatment.
1Journal Article 2618 of the Agricultural Experiment Station,Oklahoma State University. (Received October 1, 1973; ) 相似文献
99.
Twenty-eight day old field bindweed plants grown in culture solutions deficient in nitrogen (N) or phosphorus (P) for the last seven days of growth translocated significantly less foliarly applied dicamba (3,6-dichloro-o-anisic acid) and 2,4-D [(2,4-dichlorophenoxy) acetic acid] to their roots than did plants grown in complete nutrient solutions. In contrast, N deficiency stimulated basipetal translocation of glyphosate [N-(phosphonomethyl) glycine] and inhibited its acropetal translocation in field bindweed. Deficiencies of both N and P decreased translocation of dicamba from the treated area, but had no influence on translocation of glyphosate or 2,4-D from the treated area.Journal Article No. 4406 of the Agric. Exp. Stn., Oklahoma State University. 相似文献
100.
Tempo and mode of concerted evolution in the L1 repeat family of mice 总被引:10,自引:0,他引:10
Martin SL; Voliva CF; Hardies SC; Edgell MH; Hutchison CA d 《Molecular biology and evolution》1985,2(2):127-140
A 300-bp DNA sequence has been determined for 30 (10 from each of three
species of mice) random isolates of a subset of the long interspersed
repeat family L1. From these data we conclude that members of the L1 family
are evolving in concert at the DNA sequence level in Mus domesticus, Mus
caroli, and Mus platythrix. The mechanism responsible for this phenomenon
may be either duplicative transposition, gene conversion, or a combination
of the two. The amount of intraspecies divergence averages 4.4%, although
between species base substitutions accumulate at the rate of approximately
0.85%/Myr to a maximum divergence of 9.1% between M. platythrix and both M.
domesticus and M. caroli. Parsimony analysis reveals that the M. platythrix
L1 family has evolved into a distinct clade in the 10-12 Myr since M.
platythrix last shared a common ancestor with M. domesticus and M. caroli.
The parsimony tree also provides a means to derive the average half-life of
L1 sequences in the genome. The rates of gain and loss of individual copies
of L1 were estimated to be approximately equal, such that approximately
one-half of them turn over every 3.3 Myr.
相似文献