新功能、新界面、新体验,扫描即可下载生物谷APP!
首页 » 生物芯片 » PNAS:硅藻也可用于制造计算机芯片

PNAS:硅藻也可用于制造计算机芯片

来源:PNAS 2008-01-23 09:34

生物谷报道:无论是海洋,湖泊,还是沼泽地,只要有水的地方,就有硅藻。硅藻是一种单细胞的藻类,由几个或很多个细胞可以联结形成复杂有序的、草样的外壳。令人奇怪的是,这些极其微小的浮游植物,却可能是下一代计算机芯片重大突破的关键。

 

硅藻坚硬的细胞壁由排成线状的硅质组成,硅质与半导体工业最关键的材料硅有关。威斯康星大学麦迪逊分校(University of Wisconsin-Madison)的生化教授、UW-Madison生物技术中心的主任Michael Sussman说,如果我们能够在遗传上控制硅藻细胞壁生成的过程,我们就发明了一种新的纳米制造方法,使我们能用硅藻制造芯片。

 

为了实现这个目的,Sussman和华盛顿大学的硅藻专家Virginia Armbrust领导的一个小组对硅藻进行研究,结果在海链藻(Thalassiosira pseudonan)中发现涉及硅质生物合成的75个基因。研究结果发表在1月21日在线版的PNAS上。硅藻的基因组序列在2004年就由Armbrust教授主导完成。Armbrust是海洋学教授,主要研究硅藻的生态学。

 

硅藻的基因组序列使得Sussan教授可以开始操纵与硅质生成有关的基因,有可能利用它们来生产计算机芯片的超精细线。Sussman表示,这将极大提高芯片的速度,因为硅藻生产出的超精细线,远远小于现今技术所能达到的极限。

 

Sussman表示,每隔几年,半导体工业就能够将计算机晶体管的密度增加一半。在过去的30年通过光刻法实现这种飞速发展,但现在却遇到了瓶颈,因为人们已达到可见光的分辨极限。

 

Armbrust’实验室的博士后、该论文的第一作者Thomas Mock表示,在硅藻超凡的工程技术被发现之前,生态学家感兴趣的,主要是硅藻在地球碳循环中的作用。这些光合作用细胞吸收二氧化碳并沉入海底。每年从环境中移除的二氧化碳,有超过20%是被硅藻吸收的,这个数字与地球上所有的热带雨林吸收的二氧化碳相当。

 

但研究这些水藻发现了其它迷人的前景。大约100,000种硅藻,每一种都有结构独特的细胞壁。在研究硅藻的过程中,这一点让Sussman着迷不已。

 

为了确定与这些独特的细胞壁有关的基因,研究人员使用了由Sussman、UW-Madison电气工程师Franco Cerrina和遗传学家Fred Blattner设计制造的DNA芯片。上述三人联合创建了一家生物技术公司NimbleGen。简单地说,DNA芯片能够让科学家找出一个特定的细胞反应过程,涉及到哪些基因。在这个例子中,硅藻在低浓度的硅酸(合成硅质的原料)环境生长,DNA芯片用来鉴定那些基因起了作用。

 

在硅酸缺乏时,表达量增高最多的30个基因中,有25个完全是新的,与已知的基因没有任何相似性。

 

Sussman说,现在我们知道了这个单细胞浮游植物的13,000个基因中,哪一些与硅质的生物合成过程有关。我们可以从零开始研究这30个基因,并以基因工程的方法操纵这些基因的表达,看看结果如何。

 

Sussman非常有信心,他表示,长远来看,这些发现能够帮助他进一步改进这个研究中所用的DNA芯片。这就像狮子王在唱主题曲“生生不息”。

 

生物谷推荐原始出处:

Published online before print January 22, 2008
Proc. Natl. Acad. Sci. USA, 10.1073/pnas.0707946105

ENVIRONMENTAL SCIENCES

Whole-genome expression profiling of the marine diatom Thalassiosira pseudonana identifies genes involved in silicon bioprocesses

Thomas Mock*, Manoj Pratim Samanta, Vaughn Iverson*, Chris Berthiaume*, Matthew Robison, Karie Holtermann*, Colleen Durkin*, Sandra Splinter BonDurant, Kathryn Richmond, Matthew Rodesch, Toivo Kallas, Edward L. Huttlin¶, Francesco Cerrina,||, Michael R. Sussman,¶,**, and E. Virginia Armbrust*,**

*School of Oceanography, University of Washington, Box 357940, Seattle, WA 98195; Systemix Institute, Los Altos, CA 94024; Biotechnology Center, University of Wisconsin, Madison, WI 53706; Department of Biology and Microbiology, University of Wisconsin, Oshkosh, WI 54901; and Departments of ¶Biochemistry and ||Electrical and Computer Engineering, University of Wisconsin, Madison, WI 53706

Edited by David M. Karl, University of Hawaii, Honolulu, HI, and approved December 3, 2007 (received for review August 22, 2007)

Abstract

Formation of complex inorganic structures is widespread in nature. Diatoms create intricately patterned cell walls of inorganic silicon that are a biomimetic model for design and generation of three-dimensional silica nanostructures. To date, only relatively simple silica structures can be generated in vitro through manipulation of known diatom phosphoproteins (silaffins) and long-chain polyamines. Here, we report the use of genome-wide transcriptome analyses of the marine diatom Thalassiosira pseudonana to identify additional candidate gene products involved in the biological manipulation of silicon. Whole-genome oligonucleotide tiling arrays and tandem mass spectrometry identified transcripts for >8,000 genes, 3,000 of which were not previously described and included noncoding and antisense RNAs. Gene-specific expression profiles detected a set of 75 genes induced only under low concentrations of silicon but not under low concentrations of nitrogen or iron, alkaline pH, or low temperatures. Most of these induced gene products were predicted to contain secretory signals and/or transmembrane domains but displayed no homology to known proteins. Over half of these genes were newly discovered, identified only through the use of tiling arrays. Unexpectedly, a common set of 84 genes were induced by both silicon and iron limitations, suggesting that biological manipulation of silicon may share pathways in common with iron or, alternatively, that iron may serve as a required cofactor for silicon processes. These results provide insights into the transcriptional and translational basis for the biological generation of elaborate silicon nanostructures by these ecologically important microbes.

silica | transcriptome | iron | nitrogen | temperature

温馨提示:87%用户都在生物谷APP上阅读,扫描立刻下载! 天天精彩!


相关标签

最新会议 培训班 期刊库