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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
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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
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Oylum Erkus Victor CL de Jager Maciej Spus Ingrid J van Alen-Boerrigter Irma MH van Rijswijck Lucie Hazelwood Patrick WM Janssen Sacha AFT van Hijum Michiel Kleerebezem Eddy J Smid 《The ISME journal》2013,7(11):2126-2136
Maintenance of a high degree of biodiversity in homogeneous environments is poorly understood. A complex cheese starter culture with a long history of use was characterized as a model system to study simple microbial communities. Eight distinct genetic lineages were identified, encompassing two species: Lactococcus lactis and Leuconostoc mesenteroides. The genetic lineages were found to be collections of strains with variable plasmid content and phage sensitivities. Kill-the-winner hypothesis explaining the suppression of the fittest strains by density-dependent phage predation was operational at the strain level. This prevents the eradication of entire genetic lineages from the community during propagation regimes (back-slopping), stabilizing the genetic heterogeneity in the starter culture against environmental uncertainty. 相似文献
5.
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
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Wang XY Li Y Manjili MH Repasky EA Pardoll DM Subjeck JR 《Cancer immunology, immunotherapy : CII》2002,51(6):311-319
Several studies have suggested a positive correlation between heat shock protein (hsp) expression and tumor immunogenicity. Independently, many studies have shown that hsp purified from tumors can be used as a tumor-specific vaccine. In this study, we have explored the connection between hsp expression and anti-tumor immunity by transducing murine CT26 colon carcinoma cells with the cDNA of a major hsp, i.e. hsp110. We have shown that over-expression of hsp110 has no effect on CT26 tumor cell growth in vitro, and does not inhibit their anchorage-independent growth capacity. However, in situ, hsp110 over-expressing CT26 tumor (CT26-hsp110) grew at a significantly reduced rate as compared to the wild-type CT26 tumor in immunocompetent mice. Moreover, immunization of mice with inactivated CT26-hsp110 cells significantly inhibited the growth of wild-type CT26 tumor. This immunity was associated with an increased frequency of tumor-specific T cells after vaccination. An in vivo antibody depletion assay demonstrated that inactivated CT26-hsp110 cells elicited anti-tumor responses involving CD8(+) T cells and natural killer (NK) cells, but not CD4(+) T cells. Lastly, the effect of the addition of granulocyte-macrophage colony stimulating factor (GM-CSF) to these vaccine formulations was determined. Mice immunized with irradiated CT26-hsp110 cells combined with GM-CSF-producing bystander cells revealed a complete inhibition of CT26 tumor growth, indicating a synergy between inactivated CT26-hsp110 vaccine activity and GM-CSF. These observations demonstrate that manipulation of hsp110 expression in tumors, specifically when combined with GM-CSF, represents a potentially powerful approach to cancer vaccine formulation. 相似文献
8.
Kmieciak M Morales JK Morales J Bolesta E Grimes M Manjili MH 《Cancer immunology, immunotherapy : CII》2008,57(9):1391-1398
Using parental FVB mice and their neu transgenic counterparts, FVBN202, we showed for the first time that dangerous hyperplasia of mammary epithelial cells coincided with breaking immunological tolerance to the neu "self" tumor antigen, though such immune responses failed to prevent formation of spontaneous neu-overexpressing mammary carcinoma (MMC) or reject transplanted MMC in FVBN202 mice. On the other hand, neu-specific immune responses appeared to be effective against MMC in parental FVB mice because of the fact that rat neu protein was seen as "nonself" antigen in these animals and the protein was dangerously overexpressed in MMC. Interestingly, low/intermediate expression of the neu "nonself" protein in tumors induced immune responses but such immune responses failed to reject the tumor in FVB mice. Our results showed that self-nonself (SNS) entity of a tumor antigen or danger signal alone, while may equally induce an antigen-specific immune response, will not warrant the efficacy of immune responses against tumors. On the other hand, entity of antigen in the context of dangerous conditions, i.e. abnormal/dangerous overexpression of the neu nonself protein, will warrant effective anti-tumor immune responses in FVB mice. This unified "danger-SNS" model suggests focusing on identification of naturally processed cryptic or mutated epitopes, which are considered semi-nonself by the host immune system, along with novel dangerous adjuvant in vaccine design. 相似文献
9.
Hamidreza Kheiri Manjili Leila Ma’mani Sharareh Tavaddod Maedeh Mashhadikhan Abbas Shafiee Hossein Naderi-Manesh 《PloS one》2016,11(3)
A novel design of gold-coated iron oxide nanoparticles was fabricated as a potential delivery system to improve the efficiency and stability of d, l-sulforaphane as an anticancer drug. To this purpose, the surface of gold-coated iron oxide nanoparticles was modified for sulforaphane delivery via furnishing its surface with thiolated polyethylene glycol-folic acid and thiolated polyethylene glycol-FITC. The synthesized nanoparticles were characterized by different techniques such as FTIR, energy dispersive X-ray spectroscopy, UV-visible spectroscopy, scanning and transmission electron microscopy. The average diameters of the synthesized nanoparticles before and after sulforaphane loading were obtained ∼ 33 nm and ∼ 38 nm, respectively, when ∼ 2.8 mmol/g of sulforaphane was loaded. The result of cell viability assay which was confirmed by apoptosis assay on the human breast cancer cells (MCF-7 line) as a model of in vitro-cancerous cells, proved that the bare nanoparticles showed little inherent cytotoxicity, whereas the sulforaphane-loaded nanoparticles were cytotoxic. The expression rate of the anti-apoptotic genes (bcl-2 and bcl-xL), and the pro-apoptotic genes (bax and bak) were quantified, and it was found that the expression rate of bcl-2 and bcl-xL genes significantly were decreased when MCF-7 cells were incubated by sulforaphane-loaded nanoparticles. The sulforaphane-loaded into the designed gold-coated iron oxide nanoparticles, acceptably induced apoptosis in MCF-7 cells. 相似文献
10.
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