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991.
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993.
Jun Chen Xueqing Zhou Yingjun Ma Xiulian Lin Zong Dai Xiaoyong Zou 《Nucleic acids research》2016,44(15):e130
The sensitive and specific analysis of microRNAs (miRNAs) without using a thermal cycler instrument is significant and would greatly facilitate biological research and disease diagnostics. Although exponential amplification reaction (EXPAR) is the most attractive strategy for the isothermal analysis of miRNAs, its intrinsic limitations of detection efficiency and inevitable non-specific amplification critically restrict its use in analytical sensitivity and specificity. Here, we present a novel asymmetric EXPAR based on a new biotin/toehold featured template. A biotin tag was used to reduce the melting temperature of the primer/template duplex at the 5′ terminus of the template, and a toehold exchange structure acted as a filter to suppress the non-specific trigger of EXPAR. The asymmetric EXPAR exhibited great improvements in amplification efficiency and specificity as well as a dramatic extension of dynamic range. The limit of detection for the let-7a analysis was decreased to 6.02 copies (0.01 zmol), and the dynamic range was extended to 10 orders of magnitude. The strategy enabled the sensitive and accurate analysis of let-7a miRNA in human cancer tissues with clearly better precision than both standard EXPAR and RT-qPCR. Asymmetric EXPAR is expected to have an important impact on the development of simple and rapid molecular diagnostic applications for short oligonucleotides. 相似文献
994.
Development of near-isogenic lines with different alleles of Piz locus and analysis of their breeding effect under Yangdao 6 background 总被引:1,自引:0,他引:1
Yunyu Wu Ling Yu Cunhong Pan Zhengyuan Dai Yuhong Li Ning Xiao Xiaoxiang Zhang Hongjuan Ji Niansheng Huang Buhong Zhao Changhai Zhou Guangqing Liu Xiaojing Liu Xuebiao Pan Chengzhi Liang Aihong Li 《Molecular breeding : new strategies in plant improvement》2016,36(2):12
Rice blast is one of the most destructive diseases of rice. The most effective way of managing this disease is to develop resistant cultivars by introducing resistance genes into elite rice recipients. In this study, the near-isogenic lines (NILs) of six resistance alleles of the Piz locus (Pizt, Pi2, Pigm, Pi40, Pi9 and Piz) were constructed with Yangdao 6 as genetic background. Seedling inoculation tests showed that most of the NILs, namely NIL-Pi2, NIL-Pigm, NIL-Pi9, NIL-Pizt and NIL-Pi40, exhibited good resistance to blast with resistance frequencies (RFs) of over 82.50 %, execpt NIL-Piz which showed lower resistance with a RF of only 36.13 %. Furthermore, the improved-resistance NILs exhibited high similarity of their resistance spectra, with overlapping degrees of resistance spectrum (OD) of more than 75.83 %. However, the RF of panicle blast for all NILs decreased significantly compared with seedling blast in an artificial inoculation test. Although NIL-Pigm showed a higher panicle blast RF of 80 %, other NILs with outstanding performance in seedling blast resistance, namely NIL-Pizt, NIL-Pi2, NIL-Pi9 and NIL-Pi40, exhibited middle or low RFs of panicle blast with values from 56.67 to 33.30 %. Natural induction in a disease nursery showed a consistent trend in artificial inoculation results at seedling and heading stages. While NIL-Pigm was found to exhibit good resistance to leaf blast and panicle blast, NIL-Pi9 and NIL-Pizt were further demonstrated to show excellent resistance in Suichuan, Jiangxi province and Enshi, Hubei province, respectively, because of the race–region specificity. Agronomic traits of NILs were also investigated in order to evaluate the linkage drag effect of different alleles of the Piz locus. The resistance effects of the different alleles of the Piz locus under identical genetic background against seedling blast and panicle blast was first reported in this study, and the above results are expected to provide a theoretical support for the rational utilization of broad-spectrum resistance genes in breeding practice. 相似文献
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996.
997.
Han D Dai P Zhu Q Liu X Huang D Yuan Y Yuan H Wang X Qian Y Young WY Guan MX 《Biochemical and biophysical research communications》2007,357(2):554-560
We report here the clinical, genetic, and molecular characterization of a large Han Chinese family with aminoglycoside-induced and nonsyndromic hearing loss. Two and 13 of 66 matrilineal relatives suffered from aminoglycoside-induced and nonsyndromic hearing loss, respectively. These matrilineal relatives exhibited a wide range of severity of hearing loss, varying from profound to normal hearing. In the absence of aminoglycosides, the age-at-onset of hearing impairment in these matrilineal relatives ranged from 13 to 50years. Furthermore, these affected matrilineal relatives shared some common features: bilateral hearing loss of high frequencies and symmetries. Sequence analysis of mitochondrial DNA (mtDNA) in the pedigree identified the homoplasmic 12S rRNA C1494T mutation and other 34 variants belonging to Eastern Asian haplogroup F1. Of these, the variant T5628C occurs at an extremely conserved nucleotide (A31) of tRNA(Ala). This variant converted a very conservative A-U to a G-U base-pairing at AC-stem of this tRNA. The disruption of this base-pairing in tRNAs by mtDNA mutations has been associated with several clinical abnormalities. The alteration of structure of the tRNA(Ala) by the T5628C mutation may lead to a failure in tRNA metabolism and lead to impairment of mitochondrial translation, thereby worsening mitochondrial dysfunctions, caused by the C1494T mutation. Therefore, this mtDNA mutation may influence the phenotypic manifestation of the 12S rRNA C1494T mutation in this Chinese pedigree. 相似文献
998.
半干旱黄土丘陵区沙棘优良品种引种选育试验研究 总被引:7,自引:2,他引:5
1985-1998年先后在黄土高原半干旱区的陕西吴旗,安塞县进行了沙棘优良品种引种选育试验研究。通过引种国内不同地理种源20余种优良沙棘类型。引进俄罗斯优良沙棘品种,采用家系选择法进行试验研究,初步筛选出生态经济型5种沙棘类型,经济型2种类型。前者生长迅速,树冠好,根系发达,郁闭快,水土保持效益好,且果实较大(果径0.8-0.9cm,百果重20-31g),单株产果量为2-3.5kg,Vc和含油量较高,其生态,经济性状较当地野生沙棘为好。此种类型沙棘适于在黄土丘陵大面积荒沟,荒坡种植,通过引种俄罗斯大果,无刺沙棘为好。此种类型沙棘适于在黄土丘陵大面积荒沟,荒坡种植,通过引种俄罗斯大果,无刺沙棘优良品种与本地野生中国沙棘对比分析看,出,其适应性,抗性较中国沙棘差,经济性状较好,通过试验筛选出2种优良类型,果径为0.9-1.3cm,百果重46-52g,单株产果量2-3.5kg,无刺或少刺,此项研究为在半干旱黄土丘陵区大面积荒山,荒沟建造高产,优质沙棘林,高效,持续发展沙棘产业具重要意义,在引种试验中必须掌握好其关键技术,建立好采穗圃,种子园,并建立一定面积的集约经营的高产,优质沙棘园及良种繁育基地,掌握好抚育管理技术,特别是水,肥管理技术。 相似文献
999.
The nopaline synthase (nos) promoter is active in a wide range of plant tissues and regulated by various environmental stimuli. It was previously found
that the CAAT box region is important for nos promoter activity. In the present study, the location of the CAAT box element
was determined by site specific mutation analysis. Point mutations within the conserved CAAT box element significantly reduced
the promoter response in transgenic tobacco plants and calli to wounding, H2O2, methyl jasmonate, and 2,4-D, but not to salicylic acid. However, mutations immediately upstream from the CAAT box did not
affect these responses. These results suggest that the CAAT box element is important in responding to certain stimuli. 相似文献
1000.
This paper reports epidermal features of leaves in Ophiopogonoideae. Thirty-nine
species and one variety (29 species, 1 variety in Ophiopogon, 6 species in Liriope, 4 species
in Peliosanthes)were examined under scanning electron microscope. In addition, transections
of stomatal apparatuses of six species (Ophiopogon: 3 species; Liriope: 2 species;
Peliosanthes: 1 species) were made and examined under light microscope.
The stomatal apparatus in Liriope, Ophiopogon and Peliosanthes is of the anomocytic
type. These types of epidermal features of leaves in these genera are recognized: Cuticular
processes type, No cuticular processes type and No stomatal band type. The cuticular
processes type can be further divided into three patterns: Fibrillose, Massive and
Wrinkled-massive. The taxonomic value of the epidermal features of leaves in
Ophiopogonoideae is rather evident. (1)These epidermal features can be used to distinguish
among those species of Ophiopogon, Liriope and Peliosanthes, even in their vegetative state;
(2) The different patterns of cuticular processes are helpful to reasonable classification of
some species in Ophiopogon, (3)They are of great value for recognizing some sections, (4)
These epidermal features of leaves also provide evidence for further discussion on relationships among Ophiopogon, Liriope, and Peliosanthes.
The evolutionary trend of the epidermal features of leaves in Ophiopogonoideae
is No stomatal band type→No cuticular process type(stomatal band)→Cuticular process
type (stomatal band). According to the epidermal features of leaves, flowers and
fruits, Ophiopogon, Liriope and Peliosanthes are closely related, forming a subfamily
Ophiopogonoideae. Ophiopogon is more close to Liriope than to Peliosanthes, and they
should be grouped into the same tribe-Ophiopogoneae. Liriope seems to be more primitive than Ophiopogon. Peliosanthes, which constitutes another tribe of its ownPeliosantheae, is more advanced than Ophiopogon and Liriope, and it might have beenderived from its ancestor early. 相似文献