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71.
Jing B  Heng S  Tong D  Wan Z  Fu T  Tu J  Ma C  Yi B  Wen J  Shen J 《Journal of experimental botany》2012,63(3):1285-1295
Cytoplasmic male sterility (CMS) is a widespread phenomenon in higher plants, and several studies have established that this maternally inherited defect is often associated with a mitochondrial mutant. Approximately 10 chimeric genes have been identified as being associated with corresponding CMS systems in the family Brassicaceae, but there is little direct evidence that these genes cause male sterility. In this study, a novel chimeric gene (named orf288) was found to be located downstream of the atp6 gene and co-transcribed with this gene in the hau CMS sterile line. Western blotting analysis showed that this predicted open reading frame (ORF) was translated in the mitochondria of male-sterile plants. Furthermore, the growth of Escherichia coli was significantly repressed in the presence of ORF288, which indicated that this protein is toxic to the E. coli host cells. To confirm further the function of orf288 in male sterility, the gene was fused to a mitochondrial-targeting pre-sequence under the control of the Arabidopsis APETALA3 promoter and introduced into Arabidopsis thaliana. Almost 80% of transgenic plants with orf288 failed to develop anthers. It was also found that the independent expression of orf288 caused male sterility in transgenic plants, even without the transit pre-sequence. Furthermore, transient expression of orf288 and green fluorescent protein (GFP) as a fused protein in A. thaliana protoplasts showed that ORF288 was able to anchor to mitochondria even without the external mitochondrial-targeting peptide. These observations provide important evidence that orf288 is responsible for the male sterility of hau CMS in Brassica juncea.  相似文献   
72.
Females of Zeiraphera canadensis Mut. & Free., the spruce bud moth, were reared in the laboratory at constant and alternating temperatures, and in an outdoor insectary, to (1) determine the effects of temperature, age and size on several reproductive parameters and, (2) to test the hypothesis that body size-temperature interactions influence longevity and realized fecundity. Egg maturation was linearly related to age and large moths developed eggs at a higher rate than small ones. Mcan lifetime oviposition rate reached a maximum and remained stable at temperatures 20° C while the mean lifetime rate of egg maturation increased linearly with temperature, indicating that higher temperatures adversely affect oviposition. The production of nonviable eggs increased with age but also with temperature, suggesting high temperature (25° C) reduces egg quality and/or hinders fertilization. The realized fecundity and longevity of females reared under an alternating temperature regime (mean 20° C) was significantly less than that of females reared at constant 20° C. Similar realized fecundity, longevity and mean lifetime oviposition rates for females reared at temperatures alternating between 10 and 25° C (mean 20° C) and those at constant 25° C reflected the inability of females to recover from elevated diurnal temperatures. Longevity was positively related to female body size at constant 15 and 20° C but the relationships were negative for moths exposed to diurnal temperatures equal to or exceeding 25° C. Due to the reduced longevity of large moths at high temperatures, linear regressions between size and realized fecundity were only significant at constant temperatures 20° C. At higher temperatures, the size-fecundity relationship became curvilinear as a result of the diminished reproductive output of large individuals. Reduced fecundity and longevity of large females at high temperatures may have been due to elevated internal temperatures of large-bodied moths. Large females in a controlled-environment chamber maintained at 25° C developed an internal temperature excess (i.e. temperature above ambient) of nearly 2° C while small-bodied females exceeded ambient by only 0.3° C. However, when held at 20° C, the temperature excess of large-bodied moths was much less than 1° C and small-bodied females did not differ from ambient. Such interactions between temperature and body size suggest that there should be stabilizing selection toward moderate-sized individuals and may explain the absence of size-related effects on fecundity and longevity previously reported for several other lepidopterans.  相似文献   
73.
目的:构建2型猪链球菌强毒株05ZYH33中MocR家族转录调控因子SSU0562基因敲除的突变株,探索SSU0562基因缺失对细菌基本生物学特性和毒力的影响。方法:构建左右两侧为SSU0562基因上下游的同源序列,中间部分为壮观霉素抗性基因(Spcr)的基因敲除质粒,通过同源重组的方法筛选SSU0562基因敲除突变株Δ0562。对突变株与野生株的基本生物学特性进行系统的比较分析,并且将小鼠作为动物感染的模型来研究突变株的毒力。结果:组合PCR的分析及基因测序结果均表明Spcr完全取代了S.suis2中SSU0562基因位点,表明基因敲除突变体Δ0562构建成功,反转录PCR(RT-PCR)证实了突变株Δ0562中SSU0562基因在转录水平的缺失;在溶血活性、生长速率及对小鼠的致病力方面,突变株Δ0562与野生株05ZYH33相比均无显著差别,然而革兰染色实验显示突变株Δ0562的成链能力明显减弱。结论:猪链球菌强毒株05ZYH33的毒力并未因SSU0562基因的缺失而发生显著性改变,表明SSU0562基因并非猪链球菌的毒力决定因子,但很有可能参与猪链球菌成链能力的调控。  相似文献   
74.
We hypothesized that interference of opiate antagonist-precipitated withdrawal signs under anesthesia is anesthetic-specific. Three groups of morphine-dependent rats were compared in different experimental conditions using a protocol of rapid withdrawal induction by an antagonist under anesthesia. We observed that ketamine and midazolam have different effects on the expression of withdrawal. This brings specific insights into the pharmacological basis of therapy with induction of opiate antagonist.  相似文献   
75.
Studies of multicomponent membranes suggest lateral inhomogeneity in the form of membrane domains, but the size of small (nanoscale) domains in situ cannot be determined with current techniques. In this article, we present a model that enables extraction of membrane domain size from time-resolved fluorescence resonance energy transfer (FRET) data. We expand upon a classic approach to the infinite phase separation limit and formulate a model that accounts for the presence of disklike domains of finite dimensions within a two-dimensional infinite planar bilayer. The model was tested against off-lattice Monte Carlo calculations of a model membrane in the liquid-disordered (l(d)) and liquid-ordered (l(o)) coexistence regime. Simulated domain size was varied from 5 to 50 nm, and two fluorophores, preferentially partitioning into opposite phases, were randomly mixed to obtain the simulated time-resolved FRET data. The Monte Carlo data show clear differences in the efficiency of energy transfer as a function of domain size. The model fit of the data yielded good agreement for the domain size, especially in cases where the domain diameter is <20 nm. Thus, data analysis using the proposed model enables measurement of nanoscale membrane domains using time-resolved FRET.  相似文献   
76.
A 3‐year study (2014–2016) was conducted at Rocky Harbour near the west coast of Newfoundland, Canada, to record the abundance and phenology of adult spruce budworms captured at traps, using a factorial design (light traps and pheromone traps deployed contiguously or segregated spatially). Budworms were most abundant and occurred seasonally earlier in 2014 than in 2015 and 2016; these findings held generally true for males and females. The geographic setting of Newfoundland (large island isolated from the mainland by an oceanic barrier of >100 km across) provides an ideal location to discriminate local flight from long‐range immigrations; in our study, however, immigrations cannot be ruled out for any single day of trapping due to broad overlap in emergence patterns at Rocky Harbour relative to forest stands with known populations of budworms on the mainland. Based on moderate daily variation in adult abundance, however, major immigration events (defined as external deposition of budworms with large numerical amplitude) likely did not take place at Rocky Harbor between 2014 and 2016. Males were more abundant at light traps coupled with pheromone traps, whereas abundance of males at pheromone traps was similar with or without contiguous light traps. This outcome may be mediated by lower range of attraction for light traps (usually <100 m) and (generally assumed to be several hundreds of meters). Females were equally abundant at light traps with or without pheromone traps. As expected, males were captured earlier in the season at pheromone traps than at light traps, and females occurred later in the season due to protandry. The onset of flight observed at light traps or pheromone traps in 2015 and 2016 occurred 10–15 days later than simulated predictions; caution is thus warranted as to conclusions derived on computer modeling of adult emergence.  相似文献   
77.
以3年生桃品种‘保佳红’为试材,于不同生育时期采用人工遮阴的方法,在叶片生长的不同时期分别设置100%(CK)、80%、60%、40%和20% 自然光照的5个光照强度处理,利用快速叶绿素荧光诱导动力学曲线分析技术,研究了不同光强对桃树叶片快速叶绿素荧光诱导动力学曲线及其参数的影响。结果表明:(1)桃树各生长时期的叶片最大荧光值均随着光照强度的减弱而依次升高。(2)在PSⅡ能量分配比率方面,遮阴下的叶片提高了用于电子传递的量子比率(φEo),降低了用于热耗散的的量子比率(φDo)。(3)在PSⅡ反应中心活性方面,遮阴使得单位反应中心吸收的光能(ABS/RC)、捕获的光能(TRo/RC)、用于传递电子的能量(ETo/RC)和用于热耗散的能量(DIo/RC)均下降。(4)各时期不同光强处理的最大光化学效率Fv/Fm均在中午时段出现下降,且光照强度越大,降幅越大,说明桃叶在中午会出现强光抑制。研究认为:在遮阴条件下,桃叶天线色素吸收和捕获的光能减少,PSⅡ反应中心活性降低,但其可以通过增加能量在电子传递方面的分配比率来提高对光能的利用。  相似文献   
78.
Non-small-cell lung cancer (NSCLC) is one of the main causes of death induced by cancer globally. However, the molecular aberrations in NSCLC patients remain unclearly. In the present study, four messenger RNA microarray datasets (GSE18842, GSE40275, GSE43458, and GSE102287) were downloaded from the Gene Expression Omnibus (GEO) database. Differentially expressed genes (DEGs) between NSCLC tissues and adjacent lung tissues were obtained from GEO2R and the overlapping DEGs were identified. Moreover, functional and pathway enrichment were performed by Funrich, while the protein–protein interaction (PPI) network construction were obtained from STRING and hub genes were visualized and identified by Cytoscape software. Furthermore, validation, overall survival (OS) and tumor staging analysis of selected hub genes were performed by GEPIA. A total of 367 DEGs (95 upregulated and 272 downregulated) were obtained through gene integration analysis. The PPI network consisted of 94 nodes and 1036 edges in the upregulated DEGs and 272 nodes and 464 edges in the downregulated DEGs, respectively. The PPI network identified 46 upregulated and 27 downregulated hub genes among the DEGs, and six (such as CENPE, NCAPH, MYH11, LRRK2, HSD17B6, and A2M) of that have not been identified to be associated with NSCLC so far. Moreover, the expression differences of the mentioned hub genes were consistent with that in lung adenocarcinoma and lung squamous cell carcinoma in the TCGA database. Further analysis showed that all the six hub genes were associated with tumor staging except MYH11, while only the upregulated DEG CENPE was associated with the worse OS of patients with NSCLC. In conclusion, the current study showed that CENPE, NCAPH, MYH11, LRRK2, HSD17B6, and A2M might be the key genes contributed to tumorigenesis or tumor progression in NSCLC, further functional study is needed to explore the involved mechanisms.  相似文献   
79.
Various tissue optical clearing techniques have sprung up for large volume imaging. However, there are few methods showed clearing and imaging data on different organs while most of them were focused on mouse brain, and as a result, it is difficult to select the suitable method for organs in practical applications due to lack of quantitative evaluation and comprehensive comparison. Therefore, it is necessary to evaluate and compare the performances of clearing methods for different organs. In this paper, several typical optical clearing methods were applied, including 3DISCO, uDISCO, SeeDB, FRUIT, CUBIC, ScaleS and PACT to clear intact brain, heart, kidney, liver, spleen, stomach, lung, small intestine, skin and muscle. The clearing efficiency, sample deformation, fluorescence preservation and imaging depth of these methods were quantitatively evaluated. Finally, based on the systemic evaluation of various parameters described above, the appropriate clearing method for specific organ including kidney or intestine was screened out. This paper will provide important references for selection of appropriate clearing methods in related researches.   相似文献   
80.

Background

Urothelial bladder cancer is a highly heterogeneous disease. Cancer cell lines are useful tools for its study. This is a comprehensive genomic characterization of 40 urothelial bladder carcinoma (UBC) cell lines including information on origin, mutation status of genes implicated in bladder cancer (FGFR3, PIK3CA, TP53, and RAS), copy number alterations assessed using high density SNP arrays, uniparental disomy (UPD) events, and gene expression.

Results

Based on gene mutation patterns and genomic changes we identify lines representative of the FGFR3-driven tumor pathway and of the TP53/RB tumor suppressor-driven pathway. High-density array copy number analysis identified significant focal gains (1q32, 5p13.1-12, 7q11, and 7q33) and losses (i.e. 6p22.1) in regions altered in tumors but not previously described as affected in bladder cell lines. We also identify new evidence for frequent regions of UPD, often coinciding with regions reported to be lost in tumors. Previously undescribed chromosome X losses found in UBC lines also point to potential tumor suppressor genes. Cell lines representative of the FGFR3-driven pathway showed a lower number of UPD events.

Conclusions

Overall, there is a predominance of more aggressive tumor subtypes among the cell lines. We provide a cell line classification that establishes their relatedness to the major molecularly-defined bladder tumor subtypes. The compiled information should serve as a useful reference to the bladder cancer research community and should help to select cell lines appropriate for the functional analysis of bladder cancer genes, for example those being identified through massive parallel sequencing.

Electronic supplementary material

The online version of this article (doi:10.1186/s12864-015-1450-3) contains supplementary material, which is available to authorized users.  相似文献   
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