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821.
Yongchang Tang Lei Xu Yupeng Ren Yuxuan Li Feng Yuan Mingbo Cao Yong Zhang Meihai Deng Zhicheng Yao 《International journal of biological sciences》2022,18(1):261
MVI has significant clinical value for treatment selection and prognosis evaluation in hepatocellular carcinoma (HCC). We aimed to construct a model based on MVI-Related Genes (MVIRGs) for risk assessment and prognosis prediction in patients with HCC. This study utilized various statistical analysis methods for prognostic model construction and validation in the Cancer Genome Atlas (TCGA) and International Cancer Genome Consortium (ICGC) cohorts, respectively. In addition, immunohistochemistry and qRT-PCR were used to analyze and identify the value of the model in our cohort. After the analyses, 153 differentially expressed MVIRGs were identified, and three key genes were selected to construct a prognostic model. The high-risk group showed significantly lower overall survival (OS), and this trend was observed in all subgroups: different age groups, genders, stages, and grades. Risk score was a risk factor independent of age, gender, stage, and grade. Moreover, the ICGC cohort validated the prognostic value of the model corresponding to the TCGA. In our cohort, qRT-PCR and immunohistochemistry showed that all three genes had higher expression levels in HCC samples than in normal controls. High expression levels of genes and high-risk scores showed significantly lower recurrence-free survival (RFS) and OS, especially in MVI-positive HCC samples. Therefore, the prognostic model constructed by three MVIRGs can reliably predict the RFS and OS of patients with HCC and is valuable for guiding clinical treatment selection and prognostic assessment of HCC. 相似文献
822.
Plastome phylogeny and lineage diversification of Salicaceae with focus on poplars and willows 下载免费PDF全文
Phylogenetic relationships and lineage diversification of the family Salicaceae sensu lato (s.l.) remain poorly understood. In this study, we examined phylogenetic relationships between 42 species from six genera based on the complete plastomes. Phylogenetic analyses of 77 protein coding genes of the plastomes produced good resolution of the interrelationships among most sampled species and the recovered clades. Of the sampled genera from the family, Flacourtia was identified as the most basal and the successive clades comprised both Itoa and Poliothyrsis, Idesia, two genera of the Salicaceae sensu stricto (s.s.) (Populus and Salix). Five major subclades were recovered within the Populus clade. These subclades and their interrelationships are largely inconsistent with morphological classifications and molecular phylogeny based on nuclear internal transcribed spacer sequence variations. Two major subclades were identified for the Salix clade. Molecular dating suggested that species diversification of the major subclades in the Populus and Salix clades occurred mainly within the recent Pliocene. In addition, we found that the rpl32 gene was lost and the rps7 gene evolved into a pseudogene multiple times in the sampled genera of the Salicaceae s.l. Compared with previous studies, our results provide a well‐resolved phylogeny from the perspective of the plastomes. 相似文献
823.
The genus Sarcocheilichthys is a group of small cyprinid fishes comprising 10 species/sub‐species widely distributed in East Asia, which represents a valuable model for understanding the speciation of freshwater fishes in East Asia. In the present study, the molecular phylogenetic relationship of the genus Sarcocheilichthys was investigated using a 1140 bp section of the mitochondrial cytochrome b gene. Two different tree‐building methods, maximum parsimony (MP) and Bayesian methods, yielded trees with almost the same topology, yielding high bootstrap values or posterior probabilities. The results showed that the genus Sarcocheilichthys consists of two large clades, clades I and II. Clade I contains Sarcocheilichthys lacustris, Sarcocheilichthys sinensis and Sarcocheilichthys parvus, with S. parvus at a basal position. In clade II, Sarcocheilichthys variegatus microoculus is at a basal position; samples of the widespread species, Sarcocheilichthys nigripinnis, form a large subclade containing another valid species Sarcocheilichthys czerskii. Sarcocheilichthys kiangsiensis is retained at an intermediate position. Since S. czerskii is a valid species in the S. nigripinnis clade, remaining samples of S. nigripinnis form a paraphyly. This speciation process is attributed to geographical isolation and special environmental conditions experienced by S. czerskii and stable environments experienced by the other S. nigripinnis populations. This type of speciation process was suggested to be very common. Samples of Sarcocheilichthys sinensis sinensis and Sarcocheilichthys sinensis fukiensis that did not form their own monophyletic groups suggest an early stage of speciation and support their sub‐species status. Molecular clock analysis indicates that the two major lineages of the genus Sarcocheilichthys, clades I and II diverged c. 8·89 million years ago (mya). Sarcocheilichthys v. microoculus from Japan probably diverged 4·78 mya from the Chinese group. The northern–southern clades of S. nigripinnis began to diverge c. 2·12 mya, while one lineage of S. nigripinnis evolved into a new species, S. czerski, c. 0·34 mya. 相似文献
824.
Díaz-Valencia JD Morelli MM Bailey M Zhang D Sharp DJ Ross JL 《Biophysical journal》2011,100(10):2440-2449
Microtubule (MT) length and location is tightly controlled in cells. One novel family of MT-associated proteins that regulates MT dynamics is the MT-severing enzymes. In this work, we investigate how katanin (p60), believed to be the first discovered severing enzyme, binds and severs MTs via single molecule total internal reflection fluorescence microscopy. We find that severing activity depends on katanin concentration. We also find that katanin can remove tubulin dimers from the ends of MTs, appearing to depolymerize MTs. Strikingly, katanin localizes and severs at the interface of GMPCPP-tubulin and GDP-tubulin suggesting that it targets to protofilament-shift defects. Finally, we observe that binding duration, mobility, and oligomerization are ATP dependent. 相似文献
825.
Construction of a high density integrated genetic map for cucumber (Cucumis sativus L.) 总被引:1,自引:0,他引:1
Zhang WW Pan JS He HL Zhang C Li Z Zhao JL Yuan XJ Zhu LH Huang SW Cai R 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2012,124(2):249-259
The high-density consensus map was constructed based on the GY14 × PI 183967 map from an inter-subspecific cross and the extended
S94 × S06 map from an intra-subspecific cross. The consensus map was composed of 1,369 loci, including 1,152 SSR loci, 192
SRAP loci, 21 SCAR loci and one STS locus as well as three gene loci of fruit external quality traits in seven chromosomes,
and spanned 700.5 cM, of which 682.7 cM (97.5%) were covered by SSR markers. The average genetic distance and physical interval
between loci were 0.51 cM and ~268 kbp, respectively. Additionally, the physical position of the sequence-associated markers
aligned along the assembled cucumber genome sequence established a relationship between genetic maps and cucumber genome sequence
and to a great extent validated the order of markers in individual maps and consensus map. This consensus map with a high
marker density and well-ordered markers is a saturated and reliable linkage map for genetic analysis of cucumber or the Cucurbitaceae
family of plants. 相似文献
826.
Chloroplast phylogeographic patterns of Calligonum sect. Pterococcus (Polygonaceae) in arid Northwest China 下载免费PDF全文
To understand the impacts of past climatic change and geological events on the evolutionary history of Calligonum sect. Pterococcus, including C. aphyllum, C. rubicundum and C. leucocladum, a total of 128 individuals from 14 populations, mainly from arid Northwest China, were sampled. Two cpDNA intergenic spacer regions (rpl32‐trnL and ycf6‐psbM) were sequenced and 11 haplotypes were identified. Levels of genetic differentiation between populations was low in C. rubicundum (FST = 0.54317, p < 0.001) and C. aphyllum (FST = 0.55795), while much higher in C. leucocladum (FST = 0.95800, p < 0.001), possibly as an effct of differences in geographic distributions and habitats. Analysis of molecular variance (AMOVA) revealed that most of the total genetic variations occurred among species (72.97%). Among eleven identified haplotypes, only H1 and H2 were shared between C. aphyllum and C. rubicundum, while nine were private for one of the three species. The eleven identified haplotypes were divided into two major clades, but they did not yield three species‐specific lineages. Calligonum sect. Pterococcus therefore not appeared reciprocally monophyletic, more likely due to incomplete lineage sorting than hybridization. Mismatch distribution analysis suggested that only C. aphyllum has experienced recent demographic expansion. Divergence time among the 11 haplotypes was estimated at between 2.84 Ma and 0.06 Ma. Within the two clades, haplotype divergence began in early Pleistocene and mainly occurred during the middle to late Pleistocene and was most likely triggered by Quaternary climatic oscillations and increasing aridity of the region. 相似文献
827.
828.
摘要:【目的】本研究通过百日咳杆菌黏附素(PRN)基因的分段克隆表达及其在BALB/c小鼠的主动和被动免疫保护试验筛选PRN中的保护性抗原肽。【方法和结果】利用大肠杆菌进行PRN的完整蛋白、N端和C端多肽及其RI和RII区域多肽(双拷贝)的表达,命名为GST-PRN、GST-PN、GST-PC、GST-2PRI和GST-2PRII。Western blot检测证实5种表达产物均具有良好的反应原性。在主动免疫保护试验中,5种表达产物均能诱导小鼠产生较高的PRN抗体水平;当使用3 LD50的支气管败血波氏杆菌 相似文献
829.
Hormonal regulation of fruit set, parthenogenesis induction and fruit expansion in Japanese pear 总被引:2,自引:1,他引:2
The effects of applied gibberellins (GAs), GA1, GA3, GA4 and GA7 with a cytokinin, N-(2-chloro-4-pyridyl)-N′-phenylurea (CPPU) and indole-3-acetic acid (IAA) on fruit set, parthenogenesis induction and fruit expansion of a number
of Rosaceae species were assessed. These included Japanese pear cv. ‘Akibae’ (self-compatible) and cv. ‘Iwate yamanashi’ (a
seedless cultivar). Other Rosaceae species (Pyrus communis, Chaenomeles sinensis, Cydonia oblonga, and Malus pumila) were also investigated. GA4, GA7 and CPPU are very effective in inducing parthenocarpic fruit growth, whereas GA1, GA3 and IAA, have no ability to induce parthenogenesis in Japanese pear. GA4- and GA7-induced parthenocarpic fruit tended to be smaller in size, higher in flesh hardness, and showed advanced fruit ripening in
comparison to pollinated fruit and to parthenocarpic fruit induced by CPPU. GA4- and GA7-induced parthenocarpic fruit also had an increased pedicel length and fruit shape index and also showed a slight protrusion
of the calyx end. CPPU, GA4 and GA7 alone or combination with uniconazole were also active in inducing parthenogenesis in three other Rosaceae species, although
final fruit set was extremely low. GA1 was essentially inactive in promoting fruit expansion unlike the other bioactive GAs, whose effectiveness in promoting fruit
cell expansion was as follow: GA4 ≈ GA7 > GA3 > GA1. 相似文献
830.