The Centre for Chemical Biology at Universiti Sains Malaysia (CCB@USM) has launched the human genome project with an achondroplasia volunteer of Asian origin, one of CCB@USM’s own graduate students.
High-throughput sequencing of all 23
individual chromosomes were completed in close collaboration with the
United States Joint Genome Institute (JGI) - Los Alamos National
Laboratory.
Achondroplasia is the most common cause
of short-limbed dwarfism in humans, with social and medical
complications. Achondroplasia is caused by single nucleotide mutations
in the gene encoding the type 3 receptor for fibroblast growth factor
(fgfr3) located in chromosome 4.
Initial sequence analysis of chromosome 4
indicates that the classical diagnostic mutations of achondroplasia and
hypochondroplasia were absent. It shows that the achondroplasia
indicator gene, fgfr3, is not the only marker. To identify other
possible markers, the remaining 22 chromosomes were isolated and
sequenced. This is the first genome of a Malaysian that has been
completed.
For further enquiry, please contact:Professor Nazalan Najimudin
Deputy Director of Research Innovation
Centre for Chemical Biology (CCB@USM)
Universiti Sains Malaysia
11900 Penang
MALAYSIA
Email: nazalan@ccbusm.edu.my
1. Achondroplasia is a Greek word meaning “without cartilage formation”.
Achondroplasia
2. Achondroplasia is short-limbed dwarfism in humans.
3. Achondroplasia involves short stature and abnormal formation of bone structures.
4. The achondroplasia disorder has different severities: mildly affected hypochondroplasia, severe achondroplasia with developmental delay and acanthosis nigricans (SADDAN), and lethal thanatophoric dysplasia.
5. Achondroplasia individuals have a long and narrow trunk, short limbs, large head with prominent forehead, flat depressed nasal bridge, curved spine, short hands and fingers with trident appearance. The average adult is approximately four (4) feet.
6. Delayed motor milestones, leg bowing, lower back pain, respiratory complications such as apnoea, middle ear disease, speech delay and articulation problems, obesity and dental crowding are major complications for achondroplasia.
7. This disorder is caused by a change in the genome, located at one of its chromosomes.
Whole Genome Sequencing
1. Whole genome sequencing is a laboratory process that determines the complete DNA sequence that makes up an organism.
2. DNA is the molecule that is the hereditary material in all living cells. DNA sequence is the chemical alphabet of our genes, consisting of different combinations of only A, T, C and G.
3. The human genome consists of over three (3) billion of these letters, which are stored on 23 pairs of chromosomes. Chromosomes are made of DNA and protein that help a cell to keep the large amount of genetic information neat, organized and compact.
4. A genome sequence is simply a very long string of letters.
5. Sequencing the genome is an important step towards understanding how the genome works as a whole. Examples of functions that can be understood are how genes work together to direct the growth, development and maintenance of an entire organism.
6. Human genome sequencing will provide the clues to the understanding of human biology, especially in diagnosing, treating and even preventing diseases.
Chromosome Isolation via Flow Cytometry
1. Chromosome isolation is to differentiate and separate one chromosome from each other.
2. Chromosomes can be collected from primary cell cultures such as whole blood.
3. The blood sample was separated by centrifugation and only the white blood cells were collected and cultured for further chromosome preparation steps.
4. Cultured cells were harvested and chromosomes were collected.
5. These chromosomes were stained with fluorescent dyes. The two (2) fluorescent dyes that are commonly used for staining of chromosomes are Hoescht 33258 and Chromomycin A3.
6. The stained chromosomes were then analysed through the flow cytometer.
7. The fluorescent dyes help to distinguish the different chromosomes from each other based on their DNA content and base composition.
8. All chromosomes can be resolved through the flow cytometer except cluster 9-12 as their DNA content is almost similar.
9. The chromosome of interest was gated to be isolated where a maximum of four (4) chromosomes can be isolated at one time.
10. The sorted chromosomes were then ready for further downstream process
Artikel dipetik daripada : SINI
Oleh:
Chuah How Siang
Exco Penerbitan, Publisiti & Informasi
Majlis Perwakilan Pelajar 2010/11
Universiti Sains Malaysia
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