Modern Genetics
Modern Genetics
• Considered one of the key research areas of modern medicine and sciences
• Two main areas of advancement– Medical genetics• Reproductive technologies
– Biotechnology• Genetically altering living organisms (plants,
bacteria, etc…) to create specific products for industries such as agriculture and medicine.
Reproductive Technologies
• Agriculture: to breed desirable livestock• Zoology: to maintain species at risk
• Assisted Reproduction– In vitro fertilization (IVF)– Artificial insemination
Reproductive Technologies
• Genetic Testing and Screening– Pre-conception screening • Recessive genetic disorders done if you have a
family history– Cystic Fibrosis, Tay-Sachs, Sickle Cell Anemia
– Pre-natal Screening• Checks for genetic abnormalities
– Downs Syndrome
Reproductive Technologies• Testing most often
done using a karyotype – Chromosomes
arranged and numbered by size, from largest to smallest.
• Helps identify aneuploidy – abnormal chromosome
number
Reproductive Technologies - Aneuploidy
• Trisomic/Trisomy– having 3 chromosomes 2n+1– Down’s syndrome caused by trisomy in
chromosome 21
• Monosomic – having 1 chromosome 2n-1
• Polyploidy – having move than 2 sets of chromosomes
• Triploidy - (3n)• Tetraploidy - (4n) common in plants
Reproductive Technologies – Aneuploidy cont’d
• Downs Syndrome (Trisomy 21)
Reproductive Technologies – Aneuploidy cont’d
• Most often caused by nondisjunction– Members of a chromosome pair fail to separate– Can occur in meiosis I or II, or mitosis
Reproductive Technologies – Aneuploidy cont’d
• Trisomy 18 (Edwards Disease)
Biotechnology• Recombinant DNA Technology– Recombining DNA from two or more organisms– DNA from one organism is inserted into another
– Used to make insulin• Human insulin genes are inserted into bacterial DNA• Bacteria produce insulin
– Works better than artificial insulin or insulin from other animals
Biotechnology: GMO or GE?• Genetically Modified Organisms (GMO)– DNA altered through any method, including
conventional breeding• Farmers have been creating GMO’s for hundreds of
years!
• Genetically Engineered (GE)– DNA modified using techniques that permit the
direct transfer or removal of genes in that organism. • Such techniques are also called recombinant DNA or
rDNA techniques
Biotechnology: Canola• 1973 – University of Manitoba
• Genus: Brassica
• Selective breeding generated a new species rapeseed. – GMO not GE! – New species had
• low level of saturated fat, • high levels of alpha-linolenic acid (ALA)
– Omega-3 fatty acid (Required by our body, but we cannot make it)
• Now canola is also GE– Resistant to herbicides that kill most plants.
• Genes from bacteria and other plants are inserted into the Brassica genes.
Biotechnology• Other GMO foods
• Tomatoes – pest resistance• Corn – Drought and pathogen resistance• BreakFree Eggs – enhanced omega 3 fatty acids
– Positives: • Decreases chemical use and tractor traffic• Higher yields allow more production
– Negatives:• Allows industry to corner the market.. They make the
plant resistant to their herbicide, and force producers to purchase their product.
• Concerns that weeds and insects will evolve to be resistant to stronger chemicals
Bioethics• The combination of the studies of biology and
ethics
• Considers a full range of concerns– private decisions made in clinical settings– controversies surrounding stem cell research– implications of reproductive technologies– GMO and GE products in agriculture– international human subject research
• Just because we can … should we?