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?