Evolutionary dynamics of R2 retroelement and insertion inheritance in the genome of bisexual and parthenogenetic Bacillus rossius populations (Insecta Phasmida)

Theoretical and empirical studies have shown differential management of transposable elements in organisms with different reproductive strategies. To investigate this issue, we analysed the R2 retroelement structure and variability in parthenogenetic and bisexual populations of Bacillus rossius stick insects, as well as insertions inheritance in the offspring of parthenogenetic isolates and of crosses. The B. rossius genome hosts a functional (R2Br^fun) and a degenerate (R2Br^deg) element, their presence correlating with neither reproductive strategies nor population distribution. The median‐joining network method indicated that R2Br^fun duplicates through a multiple source model, while R2Br^deg is apparently still duplicating via a master gene model. Offspring analyses showed that unisexual and bisexual offspring have a similar number of R2Br‐occupied sites. Multiple or recent shifts from gonochoric to parthenogenetic reproduction may explain the observed data. Moreover, insertion frequency spectra show that higher‐frequency insertions in unisexual offspring significantly outnumber those in bisexual offspring. This suggests that unisexual offspring eliminate insertions with lower efficiency. A comparison with simulated insertion frequencies shows that inherited insertions in unisexual and bisexual offspring are significantly different from the expectation. On the whole, different mechanisms of R2 elimination in unisexual vs bisexual offspring and a complex interplay between recombination effectiveness, natural selection and time can explain the observed data.     

Non‐random expression of ribosomal DNA units in a grasshopper showing high intragenomic variation for the ITS2 region

We analyse intragenomic variation of the ITS2 internal transcribed spacer of ribosomal DNA (rDNA) in the grasshopper Eyprepocnemis plorans, by means of tagged PCR 454 amplicon sequencing performed on both genomic DNA (gDNA) and RNA‐derived complementary DNA (cDNA), using part of the ITS2 flanking coding regions (5.8S and 28S rDNA) as an internal control for sequencing errors. Six different ITS2 haplotypes (i.e. variants for at least one nucleotide in the complete ITS2 sequence) were found in a single population, one of them (Hap4) being specific to a supernumerary (B) chromosome. The analysis of both gDNA and cDNA from the same individuals provided an estimate of the expression efficiency of the different haplotypes. We found random expression (i.e. about similar recovery in gDNA and cDNA) for three haplotypes (Hap1, Hap2 and Hap5), but significant underexpression for three others (Hap3, Hap4 and Hap6). Hap4 was the most extremely underexpressed and, remarkably, it showed the lowest sequence conservation for the flanking 5.8‐28S coding regions in the gDNA reads but the highest conservation (100%) in the cDNA ones, suggesting the preferential expression of mutation‐free rDNA units carrying this ITS2 haplotype. These results indicate that the ITS2 region of rDNA is far from complete homogenization in this species, and that the different rDNA units are not expressed at random, with some of them being severely downregulated.     

肺癌患者T淋巴细胞rDNA转录活性分析(附112例报道)

目的　通过肺癌患者外周血T淋巴细胞rDNA转录活性分析 ,探讨其对肺癌辅助诊断、治疗结果判定和预后监测的意义。方法　利用CIAS 10 0 0型细胞图像分析系统及相关的细胞培养、银染等技术 ,对 2 0例健康人、2 0例炎症患者和 112例肺癌患者外周血T淋巴细胞rDNA转录活性进行分析 ,结果以核仁积分面积与细胞核积分面积的比值 (I .S % )和核仁银染积分光密度与细胞核银染积分光密度的比值 (I .O .D % )表达。结果　肿瘤患者外周血T淋巴细胞的rDNA转录活性明显下降 ,与健康人比较 ,差异有显著意义 (P <0 .0 1) ;肿瘤转移和 /或复发时 ,T淋巴细胞rDNA转录活性进一步下降 (P <0 .0 5 )。结论　外周血T淋巴细胞rDNA转录活性分析可以做为肺癌的辅助诊断、治疗疗效的判定和预后的监测指标。     

胃癌患者外周血T淋巴细胞rDNA转录活性和凋亡相关蛋白的检测

目的　探讨胃癌患者外周血T淋巴细胞rDNA转录活性和凋亡相关蛋白变化在肿瘤转移中的意义。方法　采用KL型肿瘤免疫图像分析系统和流式细胞仪测定正常人和胃癌患者外周血T淋巴细胞rDNA的转录活性和凋亡相关蛋白 (Fas/FasL)的表达。结果　胃癌患者外周血T淋巴细胞rDNA转录活性明显降低 ,凋亡相关蛋白Fas表达升高 ,与健康人相比 ,差异显著 (P <0 .0 1) ,随着病情的进展 ,这种趋势更为明显。结论　外周血T淋巴细胞rDNA转录活性和凋亡相关蛋白变化可以从淋巴细胞增殖和凋亡活性两方面评价肿瘤患者的免疫状态 ,在胃癌转移的临床监测中具有重要意义。     

Botanical origin of Indian celery seed (fruit)

In the course of our study on the traditional medicines and foodstuffs used in Pakistan, we investigated the origin of Indian celery by using the analysis of the internal transcribed spacer (ITS) sequence of nuclear rDNA and a phytochemical approach. We found that the source plant of the Indian celery containing coumarin derivatives such as seselin (1), bergapten (2) and isopimpinellin (3) was not common celery, Apium graveolens. Our results suggest the source plant is Seseli diffusum even though Indian workers reported that A. graveolens seeds contain the aforementioned compounds. In addition, a market survey of the Indian celery in Pakistan and related countries revealed that the Indian celery seeds in Pakistani markets are mainly composed of three species which have been confused in rural markets. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.

The influence of B chromosomes on rDNA organization in rye interphase nuclei

Patterns of rye rDNA organization in interphase nuclei were studied through the use ofin situ hybridization in spreads of root meristem cells from plants with and without B chromosomes (Bs). In cells from plants without Bs each rDNA locus is organized as a single perinucleolar knob of condensed chromatin with decondensed chromatin inside the nucleolus. In plants with Bs there is a marked modification of the pattern, found in more than 23% of nuclei, which involves several regions of condensed chromatin interspersed with decondensed chromatin inside the nucleolus. This B-induced alteration in rDNA interphase organization suggests a change in expression of the rRNA genes located on the A chromosomes probably related to the reduction in nuclear RNA observed previously in plants with Bs. The influence of the Bs on the expression of A chromosome genes, through rearrangement of interphase chromatin, could provide the basis of an explanation for some of the known phenotypic effects of B chromosomes in rye.     

乳腺癌患者外周血淋巴细胞rDNA转录活性的图像分析

本实验应用计算机图像分析系统对乳腺癌患者外周血淋巴细胞中核仁的银染强度进行测试,并同乳腺纤维腺瘤和正常人进行比较。结果发现,由核仁银染强度所反映出的淋巴细胞rDNA转录活性在体内癌变过程中显著下降,明显低于乳腺纤维腺瘤和正常人。表明淋巴细胞rDNA转录活性可以反映出体内癌变进展程度与机体免疫状况的相互关系。     

16S rDNA测序技术对细菌性眼内炎房水和玻璃体标本中细菌的鉴别作用

背景 眼内炎是多种内眼手术的严重并发症,以往感染菌的确定多采用细菌培养和涂片染色法,但存在花费时间长和阳性率低的问题.16S rDNA是细菌染色体上编码rRNA的序列,利用16S rDNA分子测序技术检测细菌具有高度的特异性. 目的 利用16S rDNA测序技术对细菌性眼内炎房水和/或玻璃体标本中的感染菌进行鉴定,探讨该技术在眼部感染性炎症诊断中的作用.方法 收集2015年6-12月在青岛眼科医院临床诊断为细菌性眼内炎的患者5例5眼,抽取每例患者的房水0.1～0.2 ml或玻璃标体标本0.5 ～1.0ml,各取50 μl用于高通量测序,剩余标本行涂片检查和细菌培养.采用D3096-01微量DNA试剂盒提取标本中细菌DNA,对收集的标本DNA样品进行16S rRNA基因V3-V4区PCR扩增,应用MiSeq 300测序仪对扩增的16S rDNA高变区序列进行测序,分析标本中病原菌的分类组成、分布特点以及各病原菌在标本中的相对含量,取50 μl无RNA酶水于一次性无菌离心管内作为空白对照. 结果 共收集到5份房水或玻璃体标本,涂片染色结果阳性者2例,外伤性细菌性眼内炎为革兰阳性杆菌,滤过泡感染性细菌性眼内炎为革兰阴性杆菌,而细菌培养法结果均为阴性.16S rDNA测序技术发现,5例标本检测阳性率为100％.外伤性细菌性眼内炎标本中高丰度菌属为葡萄球菌属、链球菌属和假单胞菌属,分别占65.28％、18.90％和12.76％;白内障术后2d急性细菌性眼内炎患眼标本中高丰度菌属有假单胞菌属、不动杆菌属和Limnobacter菌属,分别占53.68％、8.62％和5.96％;滤过泡感染性细菌性眼内炎标本中高丰度菌属有莫拉菌属和假单胞菌属,分别占88.89％和9.52％;白内障术后22 d迟发性细菌性眼内炎标本中相对含量较高的菌属有假单胞菌属,占84.63％;白内障术后1d急性细菌性眼内炎患眼标本中相对含量较高的有假单胞菌属,占97.89％.结论 16S rDNA测序可准确鉴别眼内炎患者房水和玻璃体标本中的致病菌,该方法检测的阳性率明显高于传统的涂片染色法和细菌培养法.     

芽孢杆菌BI1的鉴定及其抑菌性研究

目的 对本实验室分离得到芽孢杆菌B11进行鉴定.方法 将该菌株的16S rDNA基因序列与GeneBank中已鉴定的16S rDNA序列对比,并结合生理生化实验综合分析.结果 菌株B11与枯草芽孢杆菌亲缘关系最为接近,16S rDNA基因相似性达到99.6%,生理生化实验结果与标准枯草芽孢杆菌一致.结论 将芽孢杆菌B11鉴定为枯草芽孢杆菌.