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31.
The phylogenetic relationships among Primates (human), Artiodactyla (cow), Cetacea (whale), Carnivora (seal), and Rodentia (mouse and rat) were estimated from the inferred amino acid sequences of the mitochondrial genomes using Marsupialia (opossum), Aves (chicken), and Amphibia (Xenopus) as an outgroup. The overall evidence of the maximum likelihood analysis suggests that Rodentia is an outgroup to the other four eutherian orders and that Cetacea and Artiodactyla form a clade with Carnivora as a sister taxon irrespective of the assumed model for amino acid substitutions. Although there remains an uncertainty concerning the relation among Artiodactyla, Cetacea, and Carnivora, the existence of a clade formed by these three orders and the outgroup status of Rodentia to the other eutherian orders seems to be firmly established. However, analyses of individual genes do not necessarily conform to this conclusion, and some of the genes reject the putatively correct tree with nearly 5% significance. Although this discrepancy can be due to convergent or parallel evolution in the specific genes, it was pointed out that, even without a particular reason, such a discrepancy can occur in 5% of the cases if the branching among the orders in question occurred within a short period. Due to uncertainty about the assumed model underlying the phylogenetic inference, this can occur even more frequently. This demonstrates the importance of analyzing enough sequences to avoid the danger of concluding an erroneous tree.  相似文献   
32.
Enzyme activity, protein contents, and mRNA contents of group II phospholipase A2 (PLA2) in hepatocellular carcinoma (HCC) surgically obtained from 8 patients were compared with those in either its neighboring liver tissues or control liver tissues. The PLA2 specific activity towards the mixed micelles of 1-palmitoyl-2-oleoyl-phosphatidylglycerol and cholate was significantly greater in the tumor tissues (6.62 ± 1.46 nmol/min/mg) than those in the surrounding liver tissues (1.33 ± 0.22 nmol/min/mg) and controls (0.43 ± 0.04 nmol/min/mg). The results of immunoblot analysis using a specific anti-human group II PLA2 antibody and of Northern blot analysis using a human group II PLA2 cDNA as a probe demonstrated that group II PLA2 was responsible for the increased enzyme activity. The contents of immunoreactive group II PLA2 in the tumor tissues (8.81 ± 1.24 ng/mg) were significantly higher than those in the surrounding liver tissues (1.77 ± 0.27 ng/mg); those in the control tissues were below the analytical range of the method used. The group II PLA2 mRNA was also significantly increased in the tumor tissues, compared with that in the surrounding liver tissues, whereas it was not detectable in th controls. This indicates that group II PLA2 in HCC is induced at the pretranslational level.  相似文献   
33.
零下低温对杂交杨树皮层膜脂组成的影响   总被引:3,自引:0,他引:3  
以不耐寒的美洲黑杨(Populusdeltoidescv.“Lux”I-69/55,父本)和耐寒性较强的欧美杨(P.euramericanaclcv.I-45/51,母本)的4个杂交F_1代无性系(95杨、559杨、600杨和1381杨)为材料,分析了零下低温寒潮前后枝条皮层的脂质组成。结果表明,寒潮影响下,皮层中磷脂含量增加而组成基本不变,膜脂脂肪酸组成的变化规律是:寒潮前脂肪酸不饱和指数(IUFA)值大的无性系,寒潮前后的IUFA值变化量小;寒潮前IUFA值较小的无性系,寒潮前后IUFA值变化量较大。本文借用力学概念,提出相对抗性概念,给出杨树无性系的相对抗性序列。序列表明F_1代无性系的耐寒性已较不耐寒的父本提高,这与田间观察基本一致。  相似文献   
34.
Based on small-scale synthesis (0.3 g), a 100-g scale-up synthesis of crude [Aib8, Arg34]-glucagon-like peptide-1 (GLP-1) (7–37) was completed. The crude [Aib8, Arg34]-GLP-1 (7–37) was purified using a dynamic axial compression column 200 (DAC-200). Approximately 61 g of [Aib8, Arg34]-GLP-1 (7–37) with a purity of >99% was obtained through one-step reverse-phase chromatography. The purification yield was approximately 92%. The yield from the total reaction was approximately 60%. In summary, we developed an economical and environmentally friendly route to the synthesis and purification of crude [Aib8, Arg34]-GLP-1 (7–37), laying a foundation for subsequent industrial production.  相似文献   
35.
Linkage map of seven polymorphic markers on rat Chromosome 18   总被引:8,自引:0,他引:8  
A genetic linkage map of seven polymorphic markers was created with F2 intercross progeny of F344/N and LEW/N rats and assigned to rat Chromosome (Chr) 18. Five of the markers described were defined by simple sequence length polymorphisms (SSLPs) associated with five genes: transthyretin (TTR), trypsin inhibitor-like protein (TILP), 2 adrenergic receptor (ADRB2), olfactory neuron-specific G protein (OLF), and gap junction protein (GJA1). One marker was defined by a restriction fragment length polymorphism (RFLP) detected with a probe for the human colony stimulating factor 1 receptor (CSF1R) gene. The D18N1R locus was defined by an anonymous DNA fragment amplified by the randomly amplified polymorphic DNA (RAPD) technique with a single short primer. These seven DNA loci formed a single genetic linkage group 30.4 cM in length with the following order: TTR-6.8 cM-D18N1R-9.1 cM-TILP-4.3 cM-CSF1R-0 cM-ADRB2-10.2 cM-OLF-0 cM-GJA1. The five SSLP markers were highly polymorphic. In a total of 13 inbred rat strains analyzed (F344/ N, LEW/N, LOU/MN, WBB1/N, WBB2/N, MR/N, MNR/N, ACI/N, SHR/N, WKY/N, BN/SsN, BUF/N, and LER/N), three to six alleles were detected for each marker. Remarkable linkage conservation was detected between the region of rat Chr 18 mapped and a region of mouse Chr 18. However, genes associated with these markers have been mapped to three different human chromosomes (Chrs 5, 6, and 18). The markers described here should be useful for genetic mapping studies and genetic monitoring of inbred rat strains.  相似文献   
36.
Wang  Zunxin  Wang  Xianyu  Liu  Siqin  Yang  Ying  Li  Yang  Chen  Siyuan  Wang  Guangpeng  Zhang  Xincheng  Ye  Yuxiu  Hu  Laibao  Zhou  Qing  Wang  Feibing  Chen  Xinhong 《Journal of Plant Growth Regulation》2023,42(1):294-303
Journal of Plant Growth Regulation - Zinc is an important micronutrient for the growth and development of human body and plants. Proper use of nitrogen fertilizer and foliar application of Zn have...  相似文献   
37.
目的 利用果蝇作为遗传工具从个体和分子层面研究果蝇的训练免疫效应,并为后续深入研究其分子机制提供依据。方法 首先构建无菌果蝇模型,在此基础上构建果蝇成虫及跨发育阶段训练免疫模型,用两种革兰氏阴性菌——胡萝卜软腐欧文氏菌(Erwinia carotovora carotovora 15)及铜绿假单胞菌(Pseudomonas aeruginosa)分别经口腔感染果蝇。在第一次感染完全消退后进行再次感染,然后通过比较果蝇在两个感染阶段的存活率和细菌量来衡量训练免疫的潜在效果。通过实时荧光定量PCR检测相应先天免疫相关基因的表达水平,研究革兰氏阴性菌对免疫缺陷(IMD)通路的诱导作用。结果 果蝇成虫及幼虫初次感染均可提高二次感染后的生存率、细菌清除效率及死亡时能承受的最高细菌负荷;二次感染的果蝇中,IMD通路中免疫反应基因的基础表达比未感染的高,这提供了获得感染抗性的分子基础;果蝇的免疫反应主要发生在中肠,二次免疫比初次免疫的效应更迅速且剧烈;二次免疫的果蝇中,肠道干细胞的数量显著多于初次感染。结论 果蝇肠道中强大的训练免疫可由同源或异源革兰氏阴性菌口腔感染引发,且免疫记忆可在整个发育阶段持...  相似文献   
38.
Genetic studies on attention have mainly focused on children with attention-deficit/hyperactivity disorder (ADHD), so little systematic research has been conducted on genetic correlates of attention performance and their potential brain mechanisms among healthy individuals. The current study included a genome-wide association study (GWAS, N = 1145 healthy young adults) aimed to identify genes associated with sustained attention and an imaging genetics study (an independent sample of 483 healthy young adults) to examine any identified genes' influences on brain function. The GWAS found that TTLL11 showed genome-wide significant associations with sustained attention, with rs13298112 as the most significant SNP and the GG homozygotes showing more impulsive but also more focused responses than the A allele carriers. A retrospective examination of previously published ADHD GWAS results confirmed an un-reported, small but statistically significant effect of TTLL11 on ADHD. The imaging genetics study replicated this association and showed that the TTLL11 gene was associated with resting state activity and connectivity of the somatomoter network, and can be predicted by dorsal attention network connectivity. Specifically, the GG homozygotes showed lower brain activity, weaker brain network connectivity, and non-significant brain-attention association compared to the A allele carriers. Expression database showed that expression of this gene is enriched in the brain and that the G allele is associated with lower expression level than the A allele. These results suggest that TTLL11 may play a major role in healthy individuals' attention performance and may also contribute to the etiology of ADHD.  相似文献   
39.
Four new germacrane-type sesquiterpenes commiphoranes M1-M4 ( 1 - 4 ) together with eighteen sesquiterpenes were isolated from the Resina Commiphora. The structures and relative configurations of new substances were determined by using spectroscopic methods. Biological activity investigation revealed that nine compounds including 7 , 9 , 14 , 16 , (+)- 17 , (−)- 17 , 18 , 19 , and 20 could induce the apoptosis of prostate cancer originated PC-3 cells, through classic apoptosis signaling pathway, even using flow cytometry showed that the compound (+)- 17 caused apoptosis of PC-3 cells more than 40 %, suggesting their potential therapeutic application in the development of novel drugs against prostate cancer.  相似文献   
40.
Three previously undescribed diterpenoids, helioscopnoids A–C, and eight known compounds were isolated from the whole plants of Euphorbia helioscopia. Their structures were established by extensive analysis of spectra and data comparison with previous literatures. Among them, compound 4 was identified as 24,24-dimethoxy-25,26,27-trinoreuphan-3β-ol with revised configurations of C-13, C-14, and C-17 (13R*, 14R*, 17R*). Cytotoxicity assays revealed that all compounds exhibited varying levels of cytotoxicity against H1975 cells, with compound 9 displaying the most potent activity, as indicated by cell viability rates of 18.13 % and 20.76 % at concentrations of 20 μM and 5 μM, respectively. This study expands the understanding of E. helioscopia terpenoids’ structural diversity and biological activities, contributing to the exploration of potential therapeutic applications.  相似文献   
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