230 resultados para 7140-233


Relevância:

10.00% 10.00%

Publicador:

Resumo:

Amphioxus is a crucial organism for the study of vertebrate evolution. Although a genomic BAC library of Branchiostoma floridae has been constructed, we report here another BAC library construction of its distant relative species Branchiostoma belcheri. The amphioxus BAC library established in present study consists of 45,312 clones arrayed in one hundred and eighteen 384-well plates. The average insert fragment size was 120 kb estimated by Pulsed Field Gel Electrophoresis (PFGE) analysis of 318 randomly selected clones. The representation of the library is about 12 equivalent to the genome, allowing a 99.9995% probability of recovering any specific sequence of interest. We further screened the library with 4 single copied Amphi-Pax genes and identified total of 26 positive clones with average of 6.5 clones for each gene. The result indicates this library is well suited for many applications and should also serve as a useful complemental resource for the scientific community.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

国家自然科学基金资助项目。

Relevância:

10.00% 10.00%

Publicador:

Resumo:

果蝇Drosophila nasuta亚群由14个处于不同物种分化阶段的种、亚种和分类元组成。这个亚群的物种有许多进化上的独特之处,使得它在物种分化研究方面倍受关注。然而,在形态学、生殖隔离、染色体和同工酶多态、线粒体DNA RFLP、求偶歌特征以及线粒体和核基因序列分析等方面的研究都未能清楚地阐明这一亚群的系统进化关系。

Relevância:

10.00% 10.00%

Publicador:

Resumo:

1998 年在西藏墨脱县海拔1000 m 左右地方采到成年雌性环蛇1 号, 系我国新纪录。该蛇全长/ 尾长(mm) 1095/ 112 (尾尖断) 。通身背面黑褐色, 后3/ 4 有由背鳞白色点斑缀成的窄横纹约40 个; 腹面浅黑 色, 每隔3 或4 枚腹鳞有不规则的黄白色横斑。尾背有少数不完整的白色纹, 但尾腹面有7 条很明显的横斑。头 部斑纹与M. Smith (1943 : 410) 描述一致, 可能由于蛇龄较老而不清晰。背鳞通身15 行, 脊鳞略扩大; 腹鳞 233 , 尾下鳞35 (略低于文献记载的44~51 , 可能与尾尖断有关) , 除前端第三、四两枚成单外, 其余均成对。 没有颊鳞; 眶前鳞1 , 眶后鳞2 ; 颞鳞1 + 2 ; 上唇鳞7 (22223 式) ; 下唇鳞7 , 第一对在颏鳞后彼此相接, 前4 对 接前颔片; 前颔片大于后颔片, 后者后半介一小鳞。检查一侧, 除前沟牙及其预备牙外, 没有发现其他上颌齿。

Relevância:

10.00% 10.00%

Publicador:

Resumo:

以雅罗鱼亚科为外群,采用分支系统学的原理和方法对亚科17个属(须鳊属除外)进行了系统发育和动物地理学的分析。结果表明,(1)亚科这17个属为一个单系群,并由4个较小的单系群组成;(2 )亚科现在的地理分布格局除源自离散事件外,主要源于扩散事件。亚科的特征演化还表明,东亚地区地质历史的反转演化和平行演化可能在亚科系统发育过程中起了重要的作用。

Relevância:

10.00% 10.00%

Publicador:

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Sodium rutin sulfate (SRS) is a sulfated rutin modified from the natural flavonol glycoside rutin. Here, we investigated its in vitro anti-HIV and -HSV activities and its cytotoxic profile. Fifty percent inhibitory concentration (IC50) values of SRS against HIV-1 X4 virus IIIB, HIV-1 R5 isolates Ada-M and Ba-L were 2.3 +/- 0.2, 4.5 +/- 2.0 and 8.5 +/- 3.8 mu M with a selectivity index (SI) of 563, 575 and 329, respectively. Its IC50 against primary R5 HIV-1 isolate from Yunnan province in China was 13.1 +/- 5.5 mu M, with a Sl of 197. In contrast, unsulfated rutin had no activity against any of the HIV-1 isolates tested. Further study indicated that SRS blocked viral entry and virus-cell fusion likely through interacting with the HIV- I envelope glycoprotein. SRS also demonstrated some activity against human herpes simplex virus (HSV) with an IC50 of 88.3 +/- 0.1 mu M and a Sl of 30. The 50% cytotoxicity concentration (CC50) of SRS was >3.0 mM, as determined in human genital ME 180, HeLa and primary human foreskin fibroblast cells. Minimum inhibitory concentration of SRS for vaginal lactobacilli was >3.0 mM. These results collectively indicate that SRS represents a novel candidate for anti-HIV-1/HSV microbicide development. (C) 2007 Elsevier B.V. All rights reserved.

Relevância:

10.00% 10.00%

Publicador:

Relevância:

10.00% 10.00%

Publicador: