6.3.2 applications of gene sequencing

Question 1

when was the human genome project launched

Answer 1

1990

Question 2

when was the genome sequenced by & how many genes was it found to contain

Answer 2

• sequenced by 2003
• contains ~24,000 genes

Question 3

what does understanding the human genome allow

Answer 3

genome-wide comparisons between individuals & species

Question 4

where are sequenced genomes stored

Answer 4

gene banks

Question 5

what does whole genome sequencing determine

Answer 5

compete DNA sequence of organisms genome

Question 6

how does genome sequencing allow comparisons between species

Answer 6

• most of our genes have counterparts in other organisms (eg. share over 99% genes with chimpanzees)
• genes which work well are conserved by evolution
• sometimes genes co-opted to perform new tasks as evolution progresses
• many differences between organisms due to some of shared genes being altered & working differently (eg. changes to regulatory regions of DNA which don’t code directly for proteins altered expression of genomes)

Question 7

how does genome sequencing allow further understanding of evolutionary relationships

Answer 7

• comparing genomes thought to be closely related has helped confirm evolutionary relationships, led to new knowledge about relationships or certain organisms becoming reclassified
• DNA from bones/teeth of extinct animals amplified/sequenced so evolutionary history can be verified

Question 8

how does genome sequencing allow further understanding of variation between individuals

Answer 8

• all humans have same genes, but different alleles (mostly)
• about 0.01% of DNA isn’t shared due to random mutations (eg. places on DNA where substitutions occur causes single nucleotide polymorphisms (SNPs)
• methylation of certain chemical groups in DNA plays major role in regulating gene expression in eukaryotic cells (methods to map methylation of whole human genomes helps researchers understand development of diseases - epigenetics)

Question 9

describe predicting amino acid sequence of proteins

Answer 9

• laborious & time-consuming
• if researchers have organism’s genome sequenced & know which genes code for specific proteins = can determine primary structures of proteins
• researchers must know which part of gene codes for introns & exons

Question 10

describe synthetic biology

Answer 10

• interdisciplinary science concerned with designing & building useful biological devices/systems
• sequences of DNA found by analysing genomes provides potential building block for synthetic biologists to build devices
• encompasses biotechnology, evolutionary biology, molecular biology, systems biology & biophysics

Question 11

examples of application of synthetic biology

Answer 11

◦ information storage = scientists encode lots of digital information onto single strand of synthetic DNA

◦ production of medicines = escherichia coli & yeast have been genetically engineered to produce precursor of antimalarial drug (artemisinin)

◦ novel proteins = designed proteins produced (eg. similar to haemoglobin but binds to only oxygen, not carbon monoxide)

◦ biosensors = modified bioluminescent bacteria (placed on coating of microchip) glow if air is polluted with petroleum pollutants

◦ nanotechnology = material can be produced for nanotechnology for functions (eg. adhesion)

Question 12

bioethics of synthetic biology

Answer 12

• synthetic biology raises issues of ethics & biosecurity
• regulations in place
• many advisory panels & scientific papers written on how to manage risks