神经网络计算与DNA链位移级联
Lulu Qian1, Erik Winfree, Jehoshua Bruck
1Bioengineering, California Institute of Technology, Pasadena, California 91125, USA.
Nature
|July 22, 2011
概括
研究人员使用DNA链位移级联创建了人工神经网络. 这些分子系统可以执行类似大脑的功能,包括模式识别和记忆回忆,为智能化学系统铺平了道路.
科学领域:
- 生物分子计算计算技术
- 人工智能的人工智能是人工智能.
- 合成生物学 合成生物学
背景情况:
- 哺乳动物的大脑功能激发了人工智能 (AI) 系统的发展.
- 早期的细胞生存依赖于复杂的生物分子电路,但它们的计算潜力尚未被充分探索.
- 现有的人工化学系统缺乏多样化的计算模型和应用.
研究的目的:
- 为了证明分子系统可以表现出自主的大脑类行为.
- 使用DNA计算和链位移电路开发人工神经网络.
- 在分子水平上实现功能性的霍普菲尔德关联记忆.
主要方法:
- 利用DNA门架构进行可扩展的多层数字电路.
- 将线性值电路 (人工神经网络模型) 转换为DNA链位移级联.
- 使用DNA链位移实现了四个神经元的霍普菲尔德关联记忆.
主要成果:
- 从DNA链位移级联中成功创建了小型神经网络.
- 展示了表现出自主,类似大脑行为的分子系统.
- 开发了一种霍普菲尔德关联记忆,可以从不完整的输入回忆训练的DNA模式.
结论:
- DNA链位移级联可以被设计成神经网络的功能.
- 这种方法使自主化学系统能够识别分子模式并做出决策.
- 分子计算为具有类似大脑能力的智能化学系统提供了一个新的范式.
相关概念视频
Lagging Strand Synthesis
During replication, the complementary strands in double-stranded DNA are synthesized at different rates. Replication first begins on the leading strand. Replication starts later, occurs more slowly, and proceeds discontinuously on the lagging strand.
There are several major differences between synthesis of the leading strand and synthesis of the lagging strand. 1) Leading strand synthesis happens in the direction of replication fork opening, whereas lagging strand synthesis happens in the...
There are several major differences between synthesis of the leading strand and synthesis of the lagging strand. 1) Leading strand synthesis happens in the direction of replication fork opening, whereas lagging strand synthesis happens in the...
Lagging Strand Synthesis
During replication, the complementary strands in double-stranded DNA are synthesized at different rates. Replication first begins on the leading strand. Replication starts later, occurs more slowly, and proceeds discontinuously on the lagging strand.
There are several major differences between synthesis of the leading strand and synthesis of the lagging strand. 1) Leading strand synthesis happens in the direction of replication fork opening, whereas lagging strand synthesis happens in the...
There are several major differences between synthesis of the leading strand and synthesis of the lagging strand. 1) Leading strand synthesis happens in the direction of replication fork opening, whereas lagging strand synthesis happens in the...
Next-generation Sequencing
The first human genome sequencing project cost $2.7 billion and was declared complete in 2003, after 15 years of international cooperation and collaboration between several research teams and funding agencies. Today, with the advent of next-generation sequencing technologies, the cost and time of sequencing a human genome have dropped over 100 fold.
Next-Generation Sequencing Methods
Although all next-generation methods use different technologies, they all share a set of standard features.
Next-Generation Sequencing Methods
Although all next-generation methods use different technologies, they all share a set of standard features.
Restarting Stalled Replication Forks
DNA replication is initiated at sites containing predefined DNA sequences known as origins of replication. DNA is unwound at these sites by the minichromosome maintenance (MCM) helicase and other factors such as Cdc45 and the associated GINS complex.The unwound single strands are protected by replication protein A (RPA) until DNA polymerase starts synthesizing DNA at the 5’ end of the strand in the same direction as the replication fork. To prevent the replication fork from falling apart, a...
The DNA Replication Fork
An organism’s genome needs to be duplicated in an efficient and error-free manner for its growth and survival. The replication fork is a Y-shaped active region where two strands of DNA are separated and replicated continuously. The coupling of DNA unzipping and complementary strand synthesis is a characteristic feature of a replication fork. Organisms with small circular DNA, such as E. coli, often have a single origin of replication; therefore, they have only two replication forks, one in...
The Replisome
DNA replication is carried out by a large complex of proteins that act in a coordinated matter to achieve high-fidelity DNA replication. Together this complex is known as the DNA replication machinery or the replisome.
The synthesis of the leading and lagging strands is a highly coordinated process. To explain this, the “Trombone model” was proposed by Bruce Alberts in 1980. The DNA loop formation starts when a primer is synthesized on the parent lagging strand. The loop grows with the...
The synthesis of the leading and lagging strands is a highly coordinated process. To explain this, the “Trombone model” was proposed by Bruce Alberts in 1980. The DNA loop formation starts when a primer is synthesized on the parent lagging strand. The loop grows with the...


