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31.
This study sought to define the role of memory lymphocytes in the protection from homologous influenza A virus re-challenge in rhesus macaques. Depleting monoclonal antibodies (mAb) were administered to the animals prior to their second experimental inoculation with a human seasonal influenza A virus strain. Treatment with either anti-CD8α or anti-CD20 mAbs prior to re-challenge had minimal effect on influenza A virus replication. Thus, in non-human primates with pre-existing anti-influenza A antibodies, memory B cells and CD8α+ T cells do not contribute to the control of virus replication after re-challenge with a homologous strain of influenza A virus. 相似文献
32.
M. Zandipour M. Khodarahmi E. Majidi SH. Ebrahim-nejad 《Archives Of Phytopathology And Plant Protection》2013,46(12):1459-1465
In order to investigate heritability and gene action for yellow rust resistance in wheat, a resistance yellow rust cultivar Aflak was crossed to susceptible cultivar Avocet‘s’. Parents, F1, F2 and F3 generations were cultured according to randomised complete block design with two replications in the research station of Gharakhil, Iran. Parents and other generations were inoculated with 70E0A+ race. Traits including severity and infection type were recorded and then coefficient of infection was calculated. For this trait, generations mean and variance analysis were performed and results showed that there were significant differences among generations for coefficient of infection. Results showed that in addition to additive and dominance effects, at least one kind of epistasis interaction (additive × additive) control this trait. Although additive and dominance effects control this trait, but with attention to generations variance analysis, the results showed that additive variance had important role to control this trait. 相似文献
33.
Sara E. Simmonds Allison L. Fritts‐Penniman Samantha H. Cheng Gusti Ngurah Mahardika Paul H. Barber 《Ecology and evolution》2020,10(4):1817-1837
The fluid nature of the ocean, combined with planktonic dispersal of marine larvae, lowers physical barriers to gene flow. However, divergence can still occur despite gene flow if strong selection acts on populations occupying different ecological niches. Here, we examined the population genomics of an ectoparasitic snail, Coralliophila violacea (Kiener 1836), that specializes on Porites corals in the Indo‐Pacific. Previous genetic analyses revealed two sympatric lineages associated with different coral hosts. In this study, we examined the mechanisms promoting and maintaining the snails’ adaptation to their coral hosts. Genome‐wide single nucleotide polymorphism (SNP) data from type II restriction site‐associated DNA (2b‐RAD) sequencing revealed two differentiated clusters of C. violacea that were largely concordant with coral host, consistent with previous genetic results. However, the presence of some admixed genotypes indicates gene flow from one lineage to the other. Combined, these results suggest that differentiation between host‐associated lineages of C. violacea is occurring in the face of ongoing gene flow, requiring strong selection. Indeed, 2.7% of all SNP loci were outlier loci (73/2,718), indicative of divergence with gene flow, driven by adaptation of each C. violacea lineage to their specific coral hosts. 相似文献
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35.
Depo-Provera abrogates attenuated lentivirus-induced protection in male rhesus macaques challenged intravenously with pathogenic SIVmac239 总被引:1,自引:0,他引:1
Genescà M Li J Fritts L Chohan P Bost K Rourke T Blozis SA McChesney MB Miller CJ 《Journal of medical primatology》2007,36(4-5):266-275
BACKGROUND: Progesterone administration prior to intravaginal challenge with pathogenic SIVmac239 decreases the protective efficacy of live attenuated vaccines in rhesus macaques. METHODS: To determine if progesterone alters the efficacy of live attenuated vaccines through local or systemic effects, seven male rhesus macaques were immunized with SHIV89.6 and then challenged intravenously with SIVmac239. Three of these animals were treated with Depo-Provera 30 days prior to the SIV challenge. RESULTS: The SHIV animals had significantly lower plasma viral RNA levels than the unimmunized control monkeys, but the Depo-Provera treated, SHIV-immunized animals did not. Despite the lack of protection, the Depo-Provera SHIV animals had strong SIV specific T-cell responses. However, altered patterns of NK frequency and CD38 T-cell expression prior to SIV challenge were observed in Depo-Provera SHIV animals. CONCLUSIONS: Depo-Provera eliminates live-attenuated lentivirus vaccine efficacy in male rhesus monkeys through systemic effects on antiviral immunity and/or viral replication. 相似文献
36.
One of the strategies that can be used to reduce predation impacts to valued fish species is by swamping predators with more
prey than they can eat. We examined whether this approach was viable by calculating the maximum bioenergetic consumption potential
of non-native smallmouth bass Micropterus dolomieu on fall Chinook salmon Oncorhynchus tshawytscha juveniles in the Yakima River throughout the spring between 1998 and 2002 and comparing those estimates to previously published
estimates of fall Chinook salmon consumption. We found that the smallmouth bass population consumed fall Chinook salmon well
below their bioenergetic potential. However, individual smallmouth bass that were piscivorous were eating other food items
at a level near satiation. Furthermore, the maximum consumption potential was relatively low prior to mid-April, and then
increased substantially to a peak in May. Predation mortality to hatchery fall Chinook salmon could be reduced within a year
by releasing hatchery fall Chinook salmon that will emigrate quickly prior to mid-April, when predation potential is still
very low. However, attempting to swamp predators with hatchery Chinook salmon to benefit naturally produced Chinook salmon
poses uncertain benefits to natural origin fish and likely unacceptable costs to hatchery fish. Considerable swamping is occurring
by other naturally produced fish species in the Yakima River such as dace Rhinichthys spp., mountain whitefish Prosopium williamsoni, and crayfish Pacificastus spp. Therefore, it is important to consider impacts to these non-target species because they could have indirect predation
impacts on Chinook salmon. 相似文献
37.
38.
Alexei A Sharov Geppino Falco Yulan Piao Suresh Poosala Kevin G Becker Alan B Zonderman Dan L Longo David Schlessinger Minoru SH Ko 《BMC biology》2008,6(1):24
Background
The aging of reproductive organs is not only a major social issue, but of special interest in aging research. A long-standing view of 'immortal germ line versus mortal soma' poses an important question of whether the reproductive tissues age in similar ways to the somatic tissues. As a first step to understand this phenomenon, we examine global changes in gene expression patterns by DNA microarrays in ovaries and testes of C57BL/6 mice at 1, 6, 16, and 24 months of age. In addition, we compared a group of mice on ad libitum (AL) feeding with a group on lifespan-extending 40% calorie restriction (CR). 相似文献39.
The distribution of flourescently labeled α-actinin after microinjection into fibroblasts has been determined in both living and fixed cells. We have found that the distribution of the injected tetramethylrhodamine isthiocyanate-labeled protein (TMRITC-α-actinin) in living cells, which is in ruffling membranes, actin microfilament bundles, and polygonal microfilament networks (Feramisco, 1979, Proc. Natl. Acad. Sci. U. S. A. 76:3967-3971), was virtually unaffected by the fixation (3.5 percent formaldehyde) and extraction (absolute acetone) used for the preparation of the cells for immunoflourescence. Also, these patterns were found to coincide with the α-actinin revealed by immunoflourescence. Also, these patterns were found to coincide with the α-actinin revealed by immunoflourescence. These findings offer, for the first time, evidence indicating the validity of the immunoflourescence technique in the localization of α-actinin in cultured cells. With the combination of the injection procedure and the immunoflourescence localization of endogenous structural proteins, it was determined that nearly all of the actin stress fibers were decorated in a periodic manner with the injected α-actinin. Endogenous tropomyosin in the injected cells was found to be distributed with a periodic pattern along the stress fibers that was antiperiodic to the pattern observed for the microinjected α-actinin. The tropomyosin antibody stained the polygonal microfilament networks and was excluded from the foci, whereas the microinjected α-actinin was incorporated into the foci of the networks. Thus, the microinjected fluorescent derivative of α-actinin appears to be incorporated into the functional pools of α-actinin within the living cell and to be utilized by the cell with fidelity. 相似文献
40.
SCA8 RAN polySer protein preferentially accumulates in white matter regions and is regulated by eIF3F 下载免费PDF全文
Hannah K Shorrock Tao Zu Monica Banez‐Coronel Tammy Reid Hirokazu Furuya H Brent Clark Juan C Troncoso Christopher A Ross SH Subramony Tetsuo Ashizawa Eric T Wang Anthony T Yachnis Laura PW Ranum 《The EMBO journal》2018,37(19)
Spinocerebellar ataxia type 8 (SCA8) is caused by a bidirectionally transcribed CTG·CAG expansion that results in the in vivo accumulation of CUG RNA foci, an ATG‐initiated polyGln and a polyAla protein expressed by repeat‐associated non‐ATG (RAN) translation. Although RAN proteins have been reported in a growing number of diseases, the mechanisms and role of RAN translation in disease are poorly understood. We report a novel toxic SCA8 polySer protein which accumulates in white matter (WM) regions as aggregates that increase with age and disease severity. WM regions with polySer aggregates show demyelination and axonal degeneration in SCA8 human and mouse brains. Additionally, knockdown of the eukaryotic translation initiation factor eIF3F in cells reduces steady‐state levels of SCA8 polySer and other RAN proteins. Taken together, these data show polySer and WM abnormalities contribute to SCA8 and identify eIF3F as a novel modulator of RAN protein accumulation. 相似文献