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1.
Hardies SC; Martin SL; Voliva CF; Hutchison CA d; Edgell MH 《Molecular biology and evolution》1986,3(2):109-125
2.
Recognition of pathogenic Yersinia enterocolitica by crystal violet binding and polymerase chain reaction 总被引:3,自引:1,他引:2
Cefsulodin-Irgasan-Novobiocin (CIN) agar is used for the selective isolation and enumeration of Yersinia enterocolitica from clinical specimens and food. The medium contains crystal violet and about 1 mmol l-1 calcium and can be used for the phenotypic characterization of strains that carry a virulence plasmid. At 32°C, irrespective of pathogenicity, colonies are translucent with a pale pink centre surrounded by a transparent border ('bullseye'), while at 37°C pathogenic strains grow as calcium-dependent microcolonies which, because of crystal violet binding, are intensely coloured. These results were confirmed by the polymerase chain reaction with primers directed at the vir F gene, which is present only in pathogenic strains of Y. enterocolitica. Pathogenic strains of Y. enterocolitica can be recognized by growth at 37°C on Yersinia selective agar. 相似文献
3.
A major difference between the divergence patterns within the lines-1 families in mice and voles 总被引:3,自引:0,他引:3
Vanlerberghe F; Bonhomme F; Hutchison CA d; Edgell MH 《Molecular biology and evolution》1993,10(4):719-731
L1 retroposons are represented in mice by subfamilies of interspersed
sequences of varied abundance. Previous analyses have indicated that
subfamilies are generated by duplicative transposition of a small number of
members of the L1 family, the progeny of which then become a major
component of the murine L1 population, and are not due to any active
processes generating homology within preexisting groups of elements in a
particular species. In mice, more than a third of the L1 elements belong to
a clade that became active approximately 5 Mya and whose elements are >
or = 95% identical. We have collected sequence information from 13 L1
elements isolated from two species of voles (Rodentia: Microtinae: Microtus
and Arvicola) and have found that divergence within the vole L1 population
is quite different from that in mice, in that there is no abundant
subfamily of homologous elements. Individual L1 elements from voles are
very divergent from one another and belong to a clade that began a period
of elevated duplicative transposition approximately 13 Mya. Sequence
analyses of portions of these divergent L1 elements (approximately 250 bp
each) gave no evidence for concerted evolution having acted on the vole L1
elements since the split of the two vole lineages approximately 3.5 Mya;
that is, the observed interspecific divergence (6.7%-24.7%) is not larger
than the intraspecific divergence (7.9%-27.2%), and phylogenetic analyses
showed no clustering into Arvicola and Microtus clades.
相似文献
4.
Irisin was first identified in muscle cells. We detected irisin immunoreactivity in various organs of the crested porcupine (Hystrix cristata). In the epidermis, irisin immunoreactivity was localized mainly in stratum basale, stratum spinosum and stratum granulosum layers; immunoreactivity was not observed in the stratum corneum. In the dermis, irisin was found in the external and internal root sheath, cortex and medulla of hair follicles, and in sebaceous glands. Irisin immunoreactivity was found in the neural retina and skeletal muscle fibers associated with the eye. The pineal and thyroid glands also exhibited irisin immunoreactivity. 相似文献
5.
6.
Luethy R Kessner DE Katz JE Maclean B Grothe R Kani K Faça V Pitteri S Hanash S Agus DB Mallick P 《Journal of proteome research》2008,7(9):4031-4039
Mass spectrometry-based proteomics experiments have become an important tool for studying biological systems. Identifying the proteins in complex mixtures by assigning peptide fragmentation spectra to peptide sequences is an important step in the proteomics process. The 1-2 ppm mass-accuracy of hybrid instruments, like the LTQ-FT, has been cited as a key factor in their ability to identify a larger number of peptides with greater confidence than competing instruments. However, in replicate experiments of an 18-protein mixture, we note parent masses deviate 171 ppm, on average, for ion-trap data directed identifications and 8 ppm, on average, for preview Fourier transform (FT) data directed identifications. These deviations are neither caused by poor calibration nor by excessive ion-loading and are most likely due to errors in parent mass estimation. To improve these deviations, we introduce msPrefix, a program to re-estimate a peptide's parent mass from an associated high-accuracy full-scan survey spectrum. In 18-protein mixture experiments, msPrefix parent mass estimates deviate only 1 ppm, on average, from the identified peptides. In a cell lysate experiment searched with a tolerance of 50 ppm, 2295 peptides were confidently identified using native data and 4560 using msPrefixed data. Likewise, in a plasma experiment searched with a tolerance of 50 ppm, 326 peptides were identified using native data and 1216 using msPrefixed data. msPrefix is also able to determine which MS/MS spectra were possibly derived from multiple precursor ions. In complex mixture experiments, we demonstrate that more than 50% of triggered MS/MS may have had multiple precursor ions and note that spectra with multiple candidate ions are less likely to result in an identification using TANDEM. These results demonstrate integration of msPrefix into traditional shotgun proteomics workflows significantly improves identification results. 相似文献
7.
8.
Mandel U; Hassan H; Therkildsen MH; Rygaard J; Jakobsen MH; Juhl BR; Dabelsteen E; Clausen H 《Glycobiology》1999,9(1):43-52
Mucin-type O-glycosylation is initiated by a large family of UDP- GalNAc:
polypeptide N -acetyl-galactosaminyltransferases (GalNAc- transferases).
Individual GalNAc-transferases appear to have different functions and
Northern analysis indicates that they are differently expressed in
different organs. This suggests that O-glycosylation may vary with the
repertoire of GalNAc-transferases expressed in a given cell. In order to
study the repertoire of GalNAc-transferases in situ in tissues and changes
in tumors, we have generated a panel of monoclonal antibodies (MAbs) with
well defined specificity for human GalNAc-T1, -T2, and -T3. Application of
this panel of novel antibodies revealed that GalNAc- transferases are
differentially expressed in different cell lines, in spermatozoa, and in
oral mucosa and carcinomas. For example, GalNAc-T1 and -T2 but not -T3 were
highly expressed in WI38 cells, and GalNAc-T3 but not GalNAc-T1 or -T2 was
expressed in spermatozoa. The expression patterns in normal oral mucosa
were found to vary with cell differentiation, and for GalNAc-T2 and -T3
this was reflected in oral squamous cell carcinomas. The expression pattern
of GalNAc-T1 was on the other hand changed in tumors to either total loss
or expression in cytological poorly differentiated tumor cells, where the
normal undifferentiated cells lacked expression. These results demonstrate
that the repertoire of GalNAc-transferases is different in different cell
types and vary with cellular differentiation, and malignant transformation.
The implication of this is not yet fully understood, but it suggests that
specific changes in sites of O-glycosylation of proteins may occur as a
result of changes in the repertoire of GalNAc-transferases.
相似文献
9.
Aaren S. Freeman Alejandro Frischeisen April MH. Blakeslee 《Biological invasions》2016,18(6):1653-1665
Interactions between anthropogenic disturbances and introduced and native species can shift ecological communities, potentially leading to the successful establishment of additional invaders. Since its discovery in New Jersey in 1988, the Asian shore crab (Hemigrapsus sanguineus) has continued to expand its range, invading estuarine and coastal habitats in eastern North America. In estuarine environments, H. sanguineus occupies similar habitats to native, panopeid mud crabs. These crabs, and a variety of fouling organisms (both NIS and native), often inhabit man-made substrates (like piers and riprap) and anthropogenic debris. In a series of in situ experiments at a closed dock in southwestern Long Island (New York, USA), we documented the impacts of these native and introduced crabs on hard-substrate fouling communities. We found that while the presence of native mud crabs did not significantly influence the succession of fouling communities compared to caged and uncaged controls, the presence of introduced H. sanguineus reduced the biomass of native tunicates (particularly Molgula manhattensis), relative to caged controls. Moreover, the presence of H. sanguineus favored fouling communities dominated by introduced tunicates (especially Botrylloides violaceous and Diplosoma listerianum). Altogether, our results suggest that H. sanguineus could help facilitate introduced fouling tunicates in the region, particularly in locations where additional solid substrates have created novel habitats. 相似文献
10.
Generation of marker-free transgenic maize by regular two-border <Emphasis Type="Italic">Agrobacterium</Emphasis> transformation vectors 总被引:8,自引:0,他引:8
Huang S Gilbertson LA Adams TH Malloy KP Reisenbigler EK Birr DH Snyder MW Zhang Q Luethy MH 《Transgenic research》2004,13(5):451-461
By introducing additional T-DNA borders into a binary plasmid used in Agrobacterium-mediated plant transformation, previous studies have demonstrated that the marker gene and the gene of interest (GOI) can be carried by independent T-strands, which sometimes integrate in unlinked loci in the plant genome. This allows the recovery of marker-free transgenic plants through genetic segregation in the next generation. In this study, we have found that by repositioning the selectable marker gene in the backbone and leaving only the GOI in the T-DNA region, a regular two-border binary plasmid was able to generate marker-free transgenic maize plants more efficiently than a conventional single binary plasmid with multiple T-DNA borders. These results also provide evidence that both the right and left borders can initiate and terminate T-strands. Such non-canonical initiation and termination of T-strands may be the basis for the elevated frequencies of cotransformation and unlinked insertions. 相似文献