17.3 Whole-Genome Sequencing

The NCBI has created a tool to simplify the data-mining process by using global positioning systems instead of paper maps.

There is a comparison of the genes of organisms to the human genes on the web page.

Pick the groups of organisms needed for testing the hypothesis from the top portion of the data.
The needed information can be found in which columns.

Not all of the options are necessary for the task, however it might give more insight to the value of genome/gene comparisons.

The history and research of each trait and disorder can be found on this website.

Although there have been advances in the medical sciences in recent years, doctors are still confused by some diseases and are using whole-genome sequencing to find the root of the problem.

When there is a genetic basis at the core of a disease, whole-genome sequencing is a brute-force approach to problem solving.
Several laboratories offer services to sequence, analyze, and interpret genomes.

The doctor uses exome sequencing to sequence only the genes that produce exons.
In 2010, doctors used whole-exome sequencing to save a young boy.
The child had a lot of operations.
Whole-exome sequencing revealed a defect in a pathway that controls cell death.
The doctors used a bone-marrow transplant to cure the boy.
He was the first person to receive successful treatment.
Results from human genome sequencing can be found within two days for about $1,000.

The dideoxy method, which was developed in the 1970s, is the basic sequence technique used in modern day projects.

The ddNTPs are missing a hydroxyl group at the site where another nucleotide usually attach to form a chain.
Each ddNTP has a different color.

When the reaction mixture is separated into single strands, multiple newly replicated DNA strands form a ladder because of the different sizes.

Each band on the gel reflects the size of the DNA strand and the ddNTP that ended the reaction.
The different colors of the ddNTPs help identify them.
The template strand's sequence is produced by reading the gel on the basis of each band's color on the ladder.

The dideoxynucleotide is missing the 3' hydroxyl group, but it is similar in structure to a deoxynucleotide.

When a dideoxynucleotide is incorporated into a strand of DNA, it stops the synthesis of the strand.

Scientists can reform the entire DNA sequence by matching overlaps at each fragment's end.

Consider that someone has four copies of a landscape photograph that you have never seen before and don't know how it should look.
The person takes a photograph with their hands and puts different size pieces in each copy.
The person mixes all of the pieces together and asks you to reconstruct the picture.
You can see a mountain in one of the smaller pieces.
You can see the mountain behind the lake in a larger piece.
There is a cabin on the shore of the lake in a third fragment.
The picture contains a mountain behind a lake that has a cabin on its shore.
This principle is used to reconstruct entire DNA.

It is easier to reconstruct the sequence when there is more information available.

In a single day, these automated low-cost sequencers can generate hundreds of thousands or millions of short fragments.

Click "BLAST" to compare the inputted sequence against the known sequence of the human genome.
The human genome contains over a hundred places where this sequence occurs.
A description of each of the matching hits can be found below the graphic with the horizontal bars.
You can see the location of the sequence on the page.
You can see the sequence immediately around the selected gene by moving the green flag-inspired sliders.
You can return to your selected sequence by clicking the "ATG" button.

The first genome was completely sequence by Fred Sanger with the help of a bacterial virus.

Several other scientists were able to sequence the organelle and viral genomes.
Craig Venter, an American geneticist and businessman, was the first to sequence the bacterium.
The yeast Saccharomyces cerevisiae, which began in 1989 and was completed in 1996, was 60 times bigger than any other genome sequencing.
The genomes of the yeast Saccharomyces cerevisiae and the bacterium Escherichia coli K12 were available in 1997.
The genomes of other model organisms, such as the mouse Mus musculus, the fruit fly Drosophila melanogaster, and the nematode Caenorhabditis, are now known.
Basic research in model organisms can be applied to similar organisms.
The research efforts in these model organisms can be improved by having the entire genomes mapped.
Basic experiments in molecular biology can be done with annotating genes.