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排序方式: 共有294条查询结果,搜索用时 15 毫秒
1.
Wendy A. Douglass Robert H. Hyland Christopher D. Buckley Aymen Al-Shamkhani Jacqueline M. Shaw Sarah L. Scarth David L. Simmons S.K.Alex Law 《FEBS letters》1998,440(3):125
The cysteine-rich region (CRR) of the β2 integrin subunit was replaced by that of β1 to give the chimera β2NV1. β2NV1 can combine with αL to form a variant leukocyte-function-associated antigen (LFA)-1 on COS cell surface, suggesting that the specificity of the β2 interaction with αL does not lie in the CRR. Unlike those expressing wild-type LFA-1, COS cells expressing αLβ2NV1 are constitutively active in intercellular adhesion molecule (ICAM)-1 adhesion. These results suggest that activation of LFA-1 involves the release of an intramolecular constraint, which is maintained, in part, by the authentic β2 CRR. 相似文献
2.
Induction of cellular DNA synthesis by a simian virus 40 mutant defective in nuclear transport of T antigen. 总被引:1,自引:1,他引:0
The simian virus 40 (SV40) (cT)-3 mutant [SV40(cT)-3], which is defective in nuclear transport of T antigen, was utilized to determine whether cellular DNA synthesis can be stimulated by SV40 in the absence of detectable nuclear T antigen. Cellular DNA synthesis was examined in the temperature-sensitive cell cycle mutants, BHK ts13 and BHK tsAF8, after microinjection of quiescent cells with plasmid DNA containing cloned copies of wild-type SV40 or SV40(cT)-3. The efficiency of induction of cellular DNA synthesis was identical for both wild-type SV40 and SV40(cT)-3 in both cell lines. The results suggest that cell surface-associated T antigen, either alone or possibly in combination with minimal amounts of nuclear T antigen below our limit of detection, is able to stimulate cellular DNA synthesis. 相似文献
3.
A new location for the human adenine phosphoribosyltransferase gene (APRT) distal to the haptoglobin (HP) and fra(16)(q23)(FRA16D) loci 总被引:8,自引:0,他引:8
A Fratini R N Simmers D F Callen V J Hyland J A Tischfield P J Stambrook G R Sutherland 《Cytogenetics and cell genetics》1986,43(1-2):10-13
The human adenine phosphoribosyltransferase gene (APRT) was mapped with respect to the haptoglobin gene (HP) and the fragile site at 16q23.2 (FRA16D). A subclone of APRT and a cDNA clone of HP were used for molecular hybridization to DNA from mouse-human hybrid cell lines containing specific chromosome 16 translocations. The APRT subclone was used for in situ hybridization to chromosomes expressing FRA16D. APRT was found to be distal to HP and FRA16D and was localized at 16q24, making the gene order cen-FRA16B-HP-FRA16D-APRT-qter. 相似文献
4.
These studies were designed to evaluate the ability of the zona-free hamster ova bioassay to detect differences in fertility of boar sperm. In the first study, sperm from two previously infertile boars were compared to sperm from seven previously fertile boars. The percentage of zona-free hamster ova penetrated by sperm from the previously infertile boars was significantly lower than the percentage of ova penetrated by sperm from previously fertile boars (18% of ova penetrated vs. 83%, P < .001). In the 14 ejaculates from the previously infertile boars that had ejaculate motilities of 50% or greater, the percentage of zona-free hamster ova penetrated continued to be lower than in ejaculates from the fertile boars. One of the two previously infertile boars consistently had a normal semen analysis. The only two observed manifestations of his reduced fertility were his zero conception rate and the limited ability of his sperm to penetrate zona-free hamster ova. In the second study, females were inseminated with equal numbers of sperm from two previously fertile males and the paternity of offspring determined at birth. The experiment was replicated with four combinations of six boars. A high correlation was observed between the percentage of offspring sired and the ability to penetrate zona-free hamster ova (R = .89). Neither morphology nor the ability of the sperm to undergo an acrosome reaction during in vitro incubation was correlated with fertility in the competitive mating situation. These results suggest the zona-free hamster ova bioassay can improve the in vitro fertility assessment of fresh boar semen. 相似文献
5.
Jocelyn de Lara Karen L. Wydner Katherine M. Hyland W. Steven Ward 《Journal of cellular biochemistry》1993,53(3):213-221
The flat, hooked-shaped architecture of the hamster sperm nucleus makes this an excellent model for in situ hybridization studies of the three dimensional structure of the genome. We have examined the structure of the telomere repeat sequence (TTAGGG)n with respect to the various nuclear structures present in hamster spermatozoa, using fluorescent in situ hybridization. In fully condensed, mature sperm nuclei, the telomere sequences appeared as discrete spots of various sizes interspersed throughout the volume of the nuclei. While the pattern of these signals was non-random, it varied significantly in different nuclei. These discrete telomere foci were seen to gradually lengthen into linear, beaded signals as sperm nuclei were decondensed, in vitro, and were not associated with the nuclear annulus. We also examined the relationship of telomeres to the sperm nuclear matrix, a residual nuclear structure that retains the original size and shape of the nucleus. In these structures the DNA extends beyond the perimeter of the nucleus to form a halo around it, representing the arrangement of the chromosomal DNA into loop domains attached at their bases to the nuclear matrix. Telomere signals in these structures were also linear and equal in length to those of the decondensed nuclei, and each signal represented part of a single DNA loop domain. The telomeres were attached at one end to the nuclear matrix and extended into the halo. Sperm nuclear matrices treated with Eco RI retained the telomere signals. These data support sperm DNA packaging models in which DNA is coiled into discrete foci, rather than spread out linearly along the length of the sperm nucleus. 相似文献
6.
Douglas E Bassett Jr Munira A Basrai Carla Connelly Katherine M Hyland Katsumi Kitagawa Melanie L Mayer Dwight M Morrow Andrew M Page Vicente A Resto Robert V Skibbens Philip Hieter 《Current opinion in genetics & development》1996,6(6):763-766
The completion of the genome sequence of the budding yeast Saccharomyces cerevisiae marks the dawn of an exciting new era in eukaryotic biology that will bring with it a new understanding of yeast, other model organisms, and human beings. This body of sequence data benefits yeast researchers by obviating the need for piecemeal sequencing of genes, and allows researchers working with other organisms to tap into experimental advantages inherent in the yeast system and learn from functionally characterized yeast gene products which are their proteins of interest. In addition, the yeast post-genome sequence era is serving as a testing ground for powerful new technologies, and proven experimental approaches are being applied for the first time in a comprehensive fashion on a complete eukaryotic gene repertoire. 相似文献
7.
Genetic mapping of new RFLPs at Xq27-q28. 总被引:15,自引:0,他引:15
G K Suthers I Oberlé J Nancarrow J C Mulley V J Hyland P J Wilson J McCure C P Morris J J Hopwood J L Mandel 《Genomics》1991,9(1):37-43
The development of the human gene map in the region of the fragile X mutation (FRAXA) at Xq27 has been hampered by a lack of closely linked polymorphic loci. The polymorphic loci DXS369 (detected by probe RN1), DXS296 (VK21A, VK21C), and DXS304 (U6.2) have recently been mapped to within 5 cM of FRAXA. The order of loci near FRAXA has been defined on the basis of physical mapping studies as cen-F9-DXS105-DXS98-DXS369-DXS297-FRAXA-++ +DXS296-IDS-DXS304-DXS52-qter. The probe VK23B detected HindIII and XmnI restriction fragment length polymorphisms (RFLPs) at DXS297 with heterozygote frequencies of 0.34 and 0.49, respectively. An IDS cDNA probe, pc2S15, detected StuI and TaqI RFLPs at IDS with heterozygote frequencies of 0.50 and 0.08, respectively. Multipoint linkage analysis of these polymorphic loci in normal pedigrees indicated that the locus order was F9-(DXS105, DXS98)-(DXS369, DXS297)-(DXS293,IDS)-DXS304-DXS52. The recombination fractions between adjacent loci were F9-(0.058)-DXS105-(0.039)-DXS98-(0.123)-DXS369-(0.00)- DXS297-(0.057)-DXS296- (0.00)-IDS-(0.012)-DXS304-(0.120)-DXS52. This genetic map will provide the basis for further linkage studies of both the fragile X syndrome and other disorders mapped to Xq27-q28. 相似文献
8.
Physical mapping of new DNA probes near the fragile X mutation (FRAXA) by using a panel of cell lines 总被引:15,自引:9,他引:6
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G. K. Suthers V. J. Hyland D. F. Callen I. Oberle M. Rocchi N. S. Thomas C. P. Morris C. E. Schwartz M. Schmidt H. H. Ropers E. Baker B. A. Oostra N. Dahl P. J. Wilson J. J. Hopwood G. R. Sutherland 《American journal of human genetics》1990,47(2):187-195
The fragile X syndrome is a very common disorder, but there has been little progress toward isolating the fragile X mutation (FRAXA). We describe a panel of 14 somatic cell hybrid lines, lymphoblastoid cell lines, and peripheral lymphocytes with X-chromosome translocation or deletion breakpoints near FRAXA. The locations of the breakpoints were defined with 16 established probes between pX45d (DXS100) and St14-1 (DXS52). Seven of the cell lines had breakpoints between the probes RN1 (DXS369) and U6.2 (DXS304), which flank FRAXA at distances of 3-5 centimorgans. The panel of cell lines was used to localize 16 new DNA probes in this region. Six of the probes-VK16, VK18, VK23, VK24, VK37, and VK47--detected loci near FRAXA, and it was possible to order both the X-chromosome breakpoints and the probes in relation to FRAXA. The order of probes and loci near FRAXA is cen-RN1,VK24-VK47-VK23-VK16,FRAXA-++ +VK21A-VK18-IDS-VK37-U6.2-qter. The breakpoints near FRAXA are sufficiently close together that probes localized with this panel can be linked on a large-scale restriction map by pulsed-field gel electrophoresis. This panel of cell lines will be valuable in rapidly localizing other probes near FRAXA. 相似文献
9.
Qing Yang Xiao-Feng Zhang David Van Goor Ashleigh P. Dunn Callen Hyland Nelson Medeiros Paul Forscher 《Molecular biology of the cell》2013,24(19):3097-3114
Protein kinase C (PKC) can dramatically alter cell structure and motility via effects on actin filament networks. In neurons, PKC activation has been implicated in repulsive guidance responses and inhibition of axon regeneration; however, the cytoskeletal mechanisms underlying these effects are not well understood. Here we investigate the acute effects of PKC activation on actin network structure and dynamics in large Aplysia neuronal growth cones. We provide evidence of a novel two-tiered mechanism of PKC action: 1) PKC activity enhances myosin II regulatory light chain phosphorylation and C-kinase–potentiated protein phosphatase inhibitor phosphorylation. These effects are correlated with increased contractility in the central cytoplasmic domain. 2) PKC activation results in significant reduction of P-domain actin network density accompanied by Arp2/3 complex delocalization from the leading edge and increased rates of retrograde actin network flow. Our results show that PKC activation strongly affects both actin polymerization and myosin II contractility. This synergistic mode of action is relevant to understanding the pleiotropic reported effects of PKC on neuronal growth and regeneration. 相似文献
10.
Nitrogen dynamics following field application of biochar in a temperate North American maize-based production system 总被引:5,自引:0,他引:5
David Güereña Johannes Lehmann Kelly Hanley Akio Enders Charles Hyland Susan Riha 《Plant and Soil》2013,365(1-2):239-254