Team:HUST-Innovators
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Home | ||||
We are currently working on providing teams with some easy to use design templates.
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Evolution of Synthetic Biology | ||||
Overture(IGS and Bioinformatics)In 1977 Sanger and colleagues introduced the "dideoxy" chain-termination method for sequencing DNA molecules, also known as the "Sanger method".This was a major breakthrough and allowed long stretches of DNA to be rapidly and accurately sequenced. It earned him his second Nobel prize in Chemistry in 1980, which he shared with Walter Gilbert and Paul Berg.The new method was used by Sanger and colleagues to sequence human mitochondrial DNA (16,569 base pairs) and bacteriophage λ (48,502 base pairs).The dideoxy method was eventually used to sequence the entire human genome. As the accumulation of sequence data, databases formed, which announced the birth of the bioinformatics. Sonata(NGS and Synthetic Biology)In short, the First GS has some fatal drawbacks such as high cost and low throughput. This is why it was replaced by NGS, such as 454, Solexa, Hiseq, etc. The NGS has distinct effects on cost-reduction and time-saving with high accuracy. For instance, it took only one week to finish the human genome project by NGS, while the time using by First GS is 3 years. As more and more species were sequenced, the size of genomic data is enlarged. As is known, the sequence of species is the major prerequisite of the SB. So the conclusion is drawn that the emergence of the NGS indicated the naissance of SB. |
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Tips | ||||
We are currently working on providing teams with some easy to use design templates.
For a full wiki list, you can visit iGEM 2013 web sites and iGEM 2012 web sites lists. |
This wiki will be your team’s first interaction with the rest of the world, so here are a few tips to help you get started:
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What is SMRT | ||||
Single molecule real time sequencing (also known as SMRT) is a parallelized single molecule DNA sequencing by synthesis technology developed by Pacific Biosciences. Single molecule real time sequencing utilizes the zero-mode waveguide (ZMW), developed in the laboratories of Harold G. Craighead and Watt W. Webb[1] at Cornell University. A single DNA polymerase enzyme is affixed at the bottom of a ZMW with a single molecule of DNA as a template. The ZMW is a structure that creates an illuminated observation volume that is small enough to observe only a single nucleotide of DNA (also known as a base) being incorporated by DNA polymerase. Each of the four DNA bases is attached to one of four different fluorescent dyes. When a nucleotide is incorporated by the DNA polymerase, the fluorescent tag is cleaved off and diffuses out of the observation area of the ZMW where its fluorescence is no longer observable. A detector detects the fluorescent signal of the nucleotide incorporation, and the base call is made according to the corresponding fluorescence of the dye. The DNA sequencing is done on a chip that contains many ZMWs. Inside each ZMW, a single active DNA polymerase with a single molecule of single stranded DNA template is immobilized to the bottom through which light can penetrate and create a visualization chamber that allows monitoring of the activity of the DNA polymerase at a single molecule level. The signal from a phospho-linked nucleotide incorporated by the DNA polymerase is detected as the DNA synthesis proceeds which results in the DNA sequencing in real time. Phospholinked nucleotideFor each of the nucleotide bases, there are four corresponding fluorescent dye molecules that enable the detector to identify the base being incorporated by the DNA polymerase as it performs the DNA synthesis. The fluorescent dye molecule is attached to the phosphate chain of the nucleotide. When the nucleotide is incorporated by the DNA polymerase, the fluorescent dye is cleaved off with the phosphate chain as a part of a natural DNA synthesis process during which a phosphodiester bond is created to elongate the DNA chain. The cleaved fluorescent dye molecule then diffuses out of the detection volume so that the fluorescent signal is no longer detected. Zero-mode waveguideThe zero-mode waveguide (ZMW) is a nanophotonic confinement structure that consists of a circular hole in an aluminum cladding film deposited on a clear silica substrate.[3] The ZMW holes are ~70 nm in diameter and ~100 nm in depth. Due to the behavior of light when it travels through a small aperture, the optical field decays exponentially inside the chamber.[4] The observation volume within an illuminated ZMW is ~20 zeptoliters (20 X 10−21 liters). Within this volume, the activity of DNA polymerase incorporating a single nucleotide can be readily detected. |
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Why is SMRT(The merits compared to the NGS) | ||||
Relative TerminologiesContigsA sequence contig is a contiguous, overlapping sequence read resulting from the reassembly of the small DNA fragments generated by bottom-up sequencing strategies. This meaning of contig is consistent with the original definition by Rodger Staden (1979). The bottom-up DNA sequencing strategy involves shearing genomic DNA into many small fragments ("bottom"), sequencing these fragments, reassembling them back into contigs and eventually the entire genome ("up"). Because current technology allows for the direct sequencing of only relatively short DNA fragments (300–1000 nucleotides), genomic DNA must be fragmented into small pieces prior to sequencing. In bottom-up sequencing projects, amplified DNA is sheared randomly into fragments appropriately sized for sequencing. The subsequent sequence reads, which are the data that contains the sequence of each fragment, are assembled into contigs, which are finally connected by sequencing the gaps between them resulting in a sequenced genome. The ability to assemble contigs depends on the overlap of reads. Because shearing is random and performed on multiple copies of DNA, each portion of the genome should be represented multiple times in different fragment frames. In other words, the sequences of the fragments (and thus the reads) should overlap. After sequencing, the overlapping reads are assembled into contigs by assembly software. ScaffoldScaffolds consist of overlapping contigs separated by gaps of known length. The new constraints placed on the orientation of the contigs allows for the placement of highly repeated sequences in the genome. If one end read has a repetitive sequence, as long as its mate pair is located within a contig, its placement is known. The remaining gaps between the contigs in the scaffolds can then be sequenced by a variety of methods, including PCR amplification followed by sequencing (for smaller gaps) and BAC cloning methods followed by sequencing for larger gaps. Advancement from NGSExtremely Long ReadsThe NGS sequencing Technology requires prohibitive storage space and operation time for the sake of relatively short digital crumbs( In fact, the average length of NGS reads is far longer than the Sanger, the first GS reads). Clearly, the shortage of NGS is their assembly, like puzzle games. The shorter the reads are, the more barriers we will meet in the concatenation process. Unfortunately, this problem is fundamental data property, even if we have more proper modeling and more efficient algorithms. Until now we have found no chance to compensate this demerit. Comparatively speaking, the SMRT sequencing operating on PacBio RS II
1. incredibly long read length: the average read length is between 5,000 to 8,000 bases per read( the average length of NGS read ranges from 150 to 400 bp). The maximum read length can reach 20,000 bp.
2.High accuracy:In short, the accuracy of sequencing can reach 99.999%.
3.GC Problem:For the NGS, areas with high GC concentration mean low coverage. Only insufficient info can be dug out for assembly. This is why many gaps between DNA sequences emerge in the result.
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Our Project | ||||
SequencingFirst, we decided to sequence the unknown Thraustochytrium roseum. As we read the thesis on Velvet, SSpace, GRASS and so on, we finally made a determination to use the struture of the GRASS to do the scaffolding process after finishing getting contigs. As the data is sequenced from the 3rd Generation Sequencing Method, we had changed some lines of the code in order to fix the characteristics of the data.
Then, with the help of Nextomics, we finished the annotation and found that the scaffold shown above is the required one. |
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Tips | ||||
We are currently working on providing teams with some easy to use design templates.
For a full wiki list, you can visit iGEM 2013 web sites and iGEM 2012 web sites lists. |
This wiki will be your team’s first interaction with the rest of the world, so here are a few tips to help you get started:
|
|||
Tips | ||||
We are currently working on providing teams with some easy to use design templates.
For a full wiki list, you can visit iGEM 2013 web sites and iGEM 2012 web sites lists. |
This wiki will be your team’s first interaction with the rest of the world, so here are a few tips to help you get started:
|
|||
Tips | ||||
We are currently working on providing teams with some easy to use design templates.
For a full wiki list, you can visit iGEM 2013 web sites and iGEM 2012 web sites lists. |
This wiki will be your team’s first interaction with the rest of the world, so here are a few tips to help you get started:
|
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Part Submitted | ||||
Tube | Part | Plasmid Backbone | Resistance Status | Notes |
1 | BBa_K1551000 | pSB1C3 | Accepted | User sequenced |
Tips | ||||
We are currently working on providing teams with some easy to use design templates.
For a full wiki list, you can visit iGEM 2013 web sites and iGEM 2012 web sites lists. |
This wiki will be your team’s first interaction with the rest of the world, so here are a few tips to help you get started:
|
|||
Tips | ||||
We are currently working on providing teams with some easy to use design templates.
For a full wiki list, you can visit iGEM 2013 web sites and iGEM 2012 web sites lists. |
This wiki will be your team’s first interaction with the rest of the world, so here are a few tips to help you get started:
|
|||
Tips | ||||
We are currently working on providing teams with some easy to use design templates.
For a full wiki list, you can visit iGEM 2013 web sites and iGEM 2012 web sites lists. |
This wiki will be your team’s first interaction with the rest of the world, so here are a few tips to help you get started:
|