Using DNA Sequencing
Bioinformatics and Computational Biology
- Bioinformatics is the development of the software and computing tools needed to organise and analyse raw biological data, using algorithms, models and statistical tests to make sense of the data provided.
- Computational Biology is the use of bioinformatic data to create theoretical models of biological symptoms, which can then be used to predict what will happen under different circumstances. This is particularly important in working out 3D protein structure, sequencing DNA, and understanding molecular pathways, and working identifying genes linked to diseases and working out evolutionary relationships.
Genome-Wide Comparisons
- As genome sequencing has become automated it has become cheaper and quicker.
- Genomics is the field of biology which uses DNA sequencing and computational biology to analyse the structure and function of genomes.
- Tens of thousands of human genomes have been sequenced, and computers are able to analyse many individuals genomes, revealing patterns in gene inheritance and its link to disease, and who is vulnerable to certain diseases.
- Sequencing the genomes of pathogens has allowed...
- Doctors to find out the source of an infection.
- Doctors to identify antibiotic resistant strains of bacteria, ensuring antibiotics are used only when neccessary to prevent the spread of antibiotic resistant 'superbugs'.
- Scientists to track the process of an outbreak of potentially serious diseases which could lead to epidemics.
- Scientists to identify regions in pathogenic regions which may be useful targets in the development of new drugs, and genetic markers in vaccines.
- DNA barcoding is using a section of DNA common to all organisms, but vary between them to identify and compare the similarities and differences of organisms.
- The International Barcode of Life project was set up for scientists to identify organisms by a 648 base pair sequence in the mDNA. This section is short enough to be sequenced quickly and cheaply, but varies enough to show the difference between species.
- The DNA barcoding system is not perfect, the barcode areas for animals and plants are different, and there are no suitable regions for bacteria or fungi yet.
- DNA sequencing allows scientists to establish evolutionary relationships, as the basic mutation rate can calculated, the time at which two organisms had a common ancestor and diverged can be established.
- Genomics is the field of biology which uses DNA sequencing and computational biology to analyse the structure and function of genomes.
- Proteomics is the study of amino acid sequences of all proteins an organism can produce.
- Originally it was thought that there was one coding gene for each protein, but there are different numbers of possible proteins to coding genes.
- It is now thought that the sequence of amino acids can not be accurately predicted by the DNA sequence, as some genes code for multiple proteins.
- Before mRNA is translated called 'pre-mRNA' introns and sometimes exons are removed. Exons are then joined, and this mature functional mRNA is known as a spliceosome.
- The way spliceosomes join the same exons is variable, so this variation causes different types of mRNA, which in turn produces different proteins, and therefore different phenotypes.
- The way spliceosomes join the same exons is variable, so this variation causes different types of mRNA, which in turn produces different proteins, and therefore different phenotypes.
- A synthesised protein may be subject to post-translational modification, shortened or lengthened to produce a variety of proteins.
- Synthetic biology is a new area of biology focused on designing and constructing new biological pathways, devices or organisms, or the redesigning of existing biological systems.
- Different techniques in synthetic biology include...
- Genetic Engineering: direct manipulation of an organism's genome using biotechnology.
- Using biological systems in industrial techniques.
- Synthesising new genes to replace faulty ones, such as for cystic fibrosis.
- Synthesising entirely new organisms - in 2010 scientists had created an artificial genome for a bacterium and replaced the original genome with the synthetic one.
- Scientists discovered that alternative nucleotide bases can be incorporated into a strand of DNA using an enzyme, but are not held together by hydrogen bonds.
- This new DNA type was inserted into a bacterium, and found that as long as free synthetic nucleotide bases were provided, they would be continually replicated as normal.
- If these bases are are incorporated into an organism's DNA and the transcribed into RNA, scientists will have successfully synthetically expanded the genetic code for the first time.
- There was an outbreak MRSA in a Special Care Baby Unit in the UK, and the MRSA DNA was sequenced and found that the genome was very similar, so knew it was a hospital based outbreak.
- Later, another outbreak occurred, and it was the same strain so they realised it was a staff member carrying the MRSA.
- 150 staff members were screened, with one carrier found, who was then a rigorous to eradicate MRSA to stop further infection.
- Without DNA sequencing, cause of the outbreak may not have been isolated, so many more people would have been infected.