lecture 4-1 (DNA technology)

• RFLP stands for "Restriction Fragment Length Polymorphism"

  • It is a method to determine differences in the specific sequences of genes by using restriction enzymes to produce a unique pattern
  • Most individuals will produce a unique DNA pattern
  • Examples of how RFLP can be used in society:
  • Crime cases
  • Paternity cases
• PCR stands for Polymerase Chain Reaction

  • It is the use of primers to amplify a specific sequence in DNA and make multiple copies of it
  • Useful for amplifying small DNA samples for further analysis
  • Very useful in crime scenes for identifying suspected individuals
• Genetic engineering refers to combining DNA from different organisms to allow expression of genes from one organism in another

  • Examples of genetic engineering benefits to humans:
  • Producing human growth hormone and insulin in bacteria
  • Creating genetically modified foods expressing genes from bacteria, fish, insects, and even humans
• Genetic testing involves testing a person's DNA for genes that could cause diseases like cancer, diabetes, Alzheimer's, etc.

  • Used in fetuses to test for Down's syndrome and other chromosome abnormalities
  • Genetic counseling is necessary after testing
• Examples of how DNA technology benefits society:

  • Genomics: study of genomes and their functions
  • Bioinformatics: use of computer technology to understand genome function
  • Proteomics: study of protein functions
• In 1869, DNA was discovered by Swiss researcher Friedrich Miescher by accidentally isolating DNA instead of white blood cells from a cell nucleus
• In 1881, Albrecht Kossel, who named DNA, isolated the five nitrogen bases: adenine, cytosine, guanine, thymine, and uracil.
• In 1882, Walther Flemming discovered mitosis, being the first biologist to execute a wholly systematic study of the division of chromosomes.
• Knowledge of the entire genome sequence can be used to differentiate people's DNA and can be used to identify the presence of genes involved in causing disease. It led to the development of gene therapies, genetic testing, and cloning.
• The recombination of DNA is the process by which the genetic material of two organisms is exchanged and can be used to genetically modify organisms.
• The human genome project was a project completed in 1990 to map the entire human genome.
• Genes have to be identified from sequences of DNA bases, which are the building blocks of DNA. Sequencers are the machines used to read the DNA bases.
• Applications of the human genome project include:

  • Genomics – study of genomes and their functions

  • Bioinformatics – Use of computer technology to understand the genome function

  • Proteomics – Study of protein functions

  • Biotechnology – Applications of DNA technology

  • Medicinal genomics – Applications of genome understanding to medicine

  • Pharmacogenomics – Interactions of pharmacology and genomics • Personalized medicine – Applying knowledge of an individuals genetic make-up to study drug efficacy
• DNA fingerprinting is used to determine the differences in the specific sequences of genes using restriction enzymes to produce a pattern specific to an individual. This unique pattern is called "restriction fragment length polymorphism" or RFLP.
• DNA fingerprinting can be used in crime cases to identify suspects from their genetic material and paternity cases to identify the father's by comparing the DNA sequences of the child and potential father.
• Polymerase chain reaction (PCR) amplifies a particular sequence of DNA to make multiple copies of it. It requires primers, nucleotides and DNA polymerase. After PCR is completed, the sample can be subjected to electrophoresis to identify the DNA band. Can be used in crime scenes to make a small piece of genetic material testable.
• A segment of an organism's DNA can be put in and expressed by a different organism. This can occur because the genetic code is universal. This is genetic engineering.
• DNA engineering of recombinant organisms led to bacteria that can produced bacteria that can produce insulin and genetically modified foods.
• Genetically modified foods is overseen by the Canadian Food Inspection Agency, Environment Canada, and Health Canada.
• An example of a genetically modified animal is a salmon who has been given growth hormones to make them grow faster.
• Genetic testing allows for the screening of a person's DNA for the presence of genes that can eventually cause disease. It can also be conducted on fetuses for Down's syndrome and other chromosome abnormalities, however, this must be followed with genetic counseling before a decision is made considering the results.
• Types of prenatal genetic testing for screening are maternal blood serum prenatal ultrasounds, and non-invasive prenatal testing.
• Types of prenatal genetic testing are chorionic villus sampling and amniocentesis.
• Genetic tests can help diagnose and predict the severity of a disease, find best medicine and correct dosage specific to a person, and find genetic factors that can be inherited by future children.
• The testing process starts with the DNA extraction from a sample of blood, then DNA sequencing which results in raw data, which is followed by interpretation, and finally, reports.
• Gene therapy is the replacement of a nonfunctional allele of a gene with a new functional allele that is introduced in the cell through a virus vector. This is then expressed in the cell and the modified cells replicated. However, this has not proved to be a very successful technique yet.
• Stem cells can be utilized in gene therapy by transplanting a patient's stem cells with the new specific gene back into the patient through a virus.
• Animals can be cloned using a somatic cell, resulting in a genetically identical copy of the parent. This can be done to replicate a desired organism. This clone will still retain the features of the older individual (ex: arthritis, shorter telomere regions).
• Despite being genetically identical, the cloned cat CC had a different personality from her mother

  
• The introduction of DNA technology introduces some moral, societal, ethical, and religious beliefs. While it can be used for medical applications, there is also a risk of genetic discrimination.
• Restrictions of DNA technology include

  • humans cannot be cloned
  • humans cannot be genetically engineered
  • research on human cells require special permits
  • research on recombinant DNA requires special permits
  • there are many ethical and scientific regulations on conducting research involving human subjects
• RFLP stands for "Restriction Fragment Length Polymorphism"
• The stages of PCR are

  1. denaturation: DNA strands are separated
  2. annealing: RNA primers bind to the separated DNA strands
  3. extension: nucleotides are added to the RNA primers by DNA polymerase