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排序方式: 共有86条查询结果,搜索用时 15 毫秒
1.
mtDNA diversity in rhesus monkeys reveals overestimates of divergence time and paraphyly with neighboring species 总被引:4,自引:0,他引:4
Reconstructions of the human-African great ape phylogeny by using
mitochondrial DNA (mtDNA) have been subject to considerable debate. One
confounding factor may be the lack of data on intraspecific variation. To
test this hypothesis, we examined the effect of intraspecific mtDNA
diversity on the phylogenetic reconstruction of another Plio- Pleistocene
radiation of higher primates, the fascicularis group of macaque (Macaca)
monkey species. Fifteen endonucleases were used to identify 10 haplotypes
of 40-47 restriction sites in M. mulatta, which were compared with similar
data for the other members of this species group. Interpopulational,
intraspecific mtDNA diversity was large (0.5%- 4.5%), and estimates of
divergence time and branching order incorporating this variation were
substantially different from those based on single representatives of each
species. We conclude that intraspecific mtDNA diversity is substantial in
at least some primate species. Consequently, without prior information on
the extent of genetic diversity within a particular species, intraspecific
variation must be assessed and accounted for when reconstructing primate
phylogenies. Further, we question the reliability of hominoid mtDNA
phylogenies, based as they are on one or a few representatives of each
species, in an already depauperate superfamily of primates.
相似文献
2.
S A Shoup W W Johnston H F Siegler J W Tello J Schlom D D Bigner S H Bigner 《Acta cytologica》1990,34(3):385-392
Five antibodies, 2D.1 (pan-leukocyte), AE-1,3 (anti-keratin), B72.3 (anti-carcinoma), ME 1-14 (alpha-chondroitin sulfate proteoglycan) and polyclonal S-100 protein (P-S100), were tested to determine if this panel could be used immunocytochemically to differentiate melanoma from nonmelanoma. A total of 161 cases were evaluated: 145 fine needle aspirates of various body sites and 16 effusions, consisting of 52 melanomas, 41 adenocarcinomas, 11 squamous cell carcinomas, 14 undifferentiated carcinomas, 8 small cell carcinomas, 8 miscellaneous carcinomas, 8 primary central nervous system (CNS) tumors, 7 lymphomas/leukemias, 4 sarcomas and 8 benign effusions. The 52 melanomas were stained by ME 1-14 (in 31 cases) and by P-S100 (in 39 cases), but not by B72.3, AE-1,3 or 2D.1. The 82 carcinomas reacted with P-S100 (in 25 cases), B72.3 (in 37 cases), AE-1,3 (in 68 cases) and 2D.1 (in 1 case), but not with ME 1-14. Lymphomas were stained only by 2D.1 (5 of 7 cases). The eight primary CNS tumors reacted solely with ME1-14 (in 3 cases) and P-S100 (in 3 cases). The eight benign effusions exhibited staining by ME 1-14 (in 1 case), P-S100 (in 1 case), AE-1,3 (in 3 cases) and 2D.1 (in 8 cases), but not by B72.3. Thirty-six cases (including 11 melanomas) failed to stain with any antibody. In summary, 41 of 52 melanomas and 4 of 8 CNS tumors stained with ME1-14, P-S100 or both and were negative for B72.3, AE-1,3 and 2D.1. Only 2 of 101 other nonmelanomas exhibited this pattern. Thus, this panel distinguishes melanoma from other neoplastic and nonneoplastic processes in the majority of cases. 相似文献
3.
Summary The Sex Reversed factor (Sxr) leads to development of XX males. The condition is transmitted by XY-Sxr males. The testes of XY-Sxr carriers are characterized by patches of defective spermatogenesis with meiotic failure and appearance of extraordinary large spermatids. In the present study DNA content of the large spermatids is determined by Feulgen DNA measurement using a scanning cytophotometer. The large spermatids in XY-Sxr testes are shown to be 2n.This study is dedicated to Prof. Dr. W. Graumann on occasion of his 65th birthday 相似文献
4.
The Friend murine erythroleukemia cell system and the Daudi Burkitt's lymphoma cell system were used to study the effect of growth-inhibitory concentrations of interferon on membrane functions. Experiments with Friend-cell clones sensitive and resistant to interferon indicated that a number of changes in membrane transport occur rapidly after the addition of interferon to sensitive cells. While no change was observed in the activity of the (Na+/K+) ATPase in Friend cells sensitive or resistant to interferon, a piretanide-inhibitable Na+,K+, 2Cl- co-transport system was specifically inhibited after interferon treatment of sensitive cells. In contrast, treatment of Daudi cells with purified molecularly cloned or standard preparations of human leukocyte interferon gave rise to no early changes in the transport of amino acids, 32Pi, sugars, or 86Rb+. The major change observed in Daudi cells was a marked reduction in the uptake and incorporation of thymidine, which begins to decrease after 8-10 h of exposure to interferon. 相似文献
5.
6.
Reavis Zackery W. Mirjankar Nikhil Sarangi Srikant Boyle Stephen H. Kuhn Cynthia M. Matson Wayne R. Babyak Michael A. Matson Samantha A. Siegler Ilene C. Kaddurah‑Daouk Rima Suarez Edward C. Williams Redford B. Grichnik Katherine Stafford‑Smith Mark Georgiades Anastasia 《Metabolomics : Official journal of the Metabolomic Society》2021,17(6):1-13
Metabolomics - Metabolomics applications to the aquaculture research are increasing steadily. The use of standardized proton nuclear magnetic resonance (1H NMR) spectroscopy can provide the... 相似文献
7.
Daniel J. Peart Richard J. Kirk Leigh A. Madden Jason C. Siegler Rebecca V. Vince 《Amino acids》2013,44(3):903-910
The aim of this study was to observe the intracellular heat shock protein 72 (HSP72) and heme oxygenase-1 (HSP32) response to prolonged interval cycling following the ingestion of carbohydrates (CHO) and sodium bicarbonate (NaHCO3). Six recreationally active males (mean ± SD; age 23.2 ± 2.9 years, height 179.5 ± 5.5 cm, body mass 76.5 ± 6.8 kg, and peak power output 315 ± 36 W) volunteered to complete a 90 min interval cycling exercise on four occasions. The trials were completed in a random and blinded manner following ingestion of either: placebo and an artificial sweetener (P–P), NaHCO3 and sweetener (B–P), placebo and CHO (P–CHO), and NaHCO3 and CHO (B–CHO). Both HSP72 and HSP32 were significantly increased in monocytes and lymphocytes from 45 min post-exercise (p ≤ 0.039), with strong relationships between both cell types (HSP72, r = 0.83; HSP32, r = 0.89). Exogenous CHO had no influence on either HSP72 or HSP32, but the ingestion of NaHCO3 significantly attenuated HSP32 in monocytes and lymphocytes (p ≤ 0.042). In conclusion, the intracellular stress protein response to 90 min interval exercise is closely related in monocytes and lymphocytes, and HSP32 appears to be attenuated with a pre-exercise alkalosis. 相似文献
8.
The median neuroblast lineage of grasshopper has provided a model for the development of differing neuronal types within the insect central nervous system. According to the prevailing model, neurons of different types are produced in sequence. Contrary to this, we show that each ganglion mother cell from the median neuroblast produces two neurons of asymmetric type: one is Engrailed positive (of interneuronal fate); and one is Engrailed negative (of efferent fate). The mature neuronal population, however, results from differential neuronal death. This yields many interneurons and relatively few efferent neurons. Also contrary to previous reports, we find no evidence for glial production by the median neuroblast. We discuss evidence that neuronal lineages typically produce asymmetric progeny, an outcome that has important developmental and evolutionary implications. 相似文献
9.
Sebastian Weiterer Florian Uhle Christoph Lichtenstern Benedikt H. Siegler Sabin Bhuju Michael Jarek Marek Bartkuhn Markus A. Weigand 《PloS one》2015,10(3)
Background
Sepsis is a global burden and the primary cause of death in intensive care units worldwide. The pathophysiological changes induced by the host’s systemic inflammatory response to infection are not yet fully understood. During sepsis, the immune system is confronted with a variety of factors, which are integrated within the individual cells and result in changes of their basal state of responsiveness. Epigenetic mechanisms like histone modifications are known to participate in the control of immune reactions, but so far the situation during sepsis is unknown.Methods and Findings
In a pilot approach, we performed combined chromatin immunoprecipitation followed by high-throughput sequencing to assess the genome-wide distribution of the chromatin modifications histone 3 lysine 4 and 27 trimethylation and lysine 9 acetylation in monocytes isolated from healthy donors (n = 4) and patients with sepsis (n = 2). Despite different underlying causes for sepsis, a comparison over promoter regions shows a high correlation between the patients for all chromatin marks. These findings hold true also when comparing patients to healthy controls. Despite the global similarity, differential analysis reveals a set of distinct promoters with significant enrichment or depletion of histone marks. Further analysis of overrepresented GO terms show an enrichment of genes involved in immune function. To the most prominent ones belong different members of the HLA family located within the MHC cluster together with the gene coding for the major regulator of this locus—CIITA.Conclusions
We are able to show for the first time that sepsis in humans induces selective and precise changes of chromatin modifications in distinct promoter regions of immunologically relevant genes, shedding light on basal regulatory mechanisms that might be contributing to the functional changes occurring in monocytes. 相似文献10.
Moon DK Tripathi A Sullivan D Siegler MA Parkin S Posner GH 《Bioorganic & medicinal chemistry letters》2011,21(9):2773-2775
Four 5-carbon-linked trioxane dimer orthoesters (6a-6d) have been prepared in 4 or 5 chemical steps from the natural trioxane artemisinin (1). When administered orally to malaria-infected mice using a single dose of only 6 mg/kg body weight along with 18 mg/kg of mefloquine hydrochloride, trioxane dimer orthoester sulfone 6d completely and safely cured the mice; after 30 days, the cured mice showed no detectable parasitemia, gained at least as much weight as the control mice (no infection), and behaved normally. 相似文献