Mitosis

1
__________________________

• Genetic screening to identify those with an
  increased risk of inheriting a disorder
• Often tied to ethnic background
• May involve karyotyping or biochemical tests
• Then treatment or counselling can be given
• Huntingtons disease can be screened for
  (autosomal dominant trait)

2
_____________________________

• Risk groups
• Pregnant women over 35 years old
• Parents with genetic abnormality in previous
  children
• Parents who have family members with genetic
  abnormalities
• Couple from high risk backgrounds for a specific
  disease

3

• ___________________________
• involves checking the fetus for a problem
• One of the processes is called amniocentesis
• during 16 week of pregnancy by inserting needle
• Uses amniotic fluid, which contains fetus cells
• An ultrasound can be used to prevent injury to
  mother or fetus
• to visually identify physical abnormalities

4
_________________________ is the result of
foreign DNA inserted into an organisms DNA
5
Dr. Barbara _____________________ (1902-1992)

• Research focused on making the connection between
  the behaviour of chromosomes in a special type of
  crossing over and the phenotypic effects on corn
  kernals
• 1951 - Jumping gene theory, now known as
  transposons
• Little attention was paid to her theories
• Transposons have large role in gene
• regulation and help explain wide
• range of variation in certain
• proteins (pigments)
• Received a Nobel Prize
• for her work in 1983 (over 30 years later)

6

• ____________________________
• direct use of genetic techniques to treat a
  genetic condition
• Two methods
• 1. Normal gene product can be given to an
  affected individual
• Used extensively today, example is insulin.
• 2. Manipulate the abnormal DNA in parent or
  offspring in order to better the disease

7
____________________ Physical alteration of
genes.

• Can be used to correct some hereditary defects
• Involve inserting a proper working gene into the
  cell that lack the ability to produce their own
  protein
• Insulin, inserting that gene into pancreatic
  cells
• Need to use a vector to insert the gene, like a
  virus, which is site specific to pancreatic cells
• Once there the virus would insert the genes,
  giving these cells the ability to produce their
  own insulin

8
_____________________

• Transfer of technology to the private sector
• Interesting facts
• 50 of HG is non-coding junk DNA
• 30 000 35 000 genes
• gene transfer from bacteria
• Mutations 50 more likely in ? vs ?
• 50 of HG is similar (transposable elements)
• 3 164 700 million nucleotides
• Crossing over more frequent in short chromosomes

9
_________________

• Clones have identical DNA to parent
• Dolly the Sheep (1997) by Ian Wilmut
• First mammal cloned from the nucleus of another
  adult mammal

10
___________________

• A technology that has replaced blood typing for
  paternity or criminal prosecutions
• Each person has a unique DNA fingerprint that
  can be identified from a small sample of DNA

11
Can you give possible points in support of or
opposition to the following statements?

• Prospective parents who have a family history of
  a genetic condition that can be identified in
  prenatal testing and are at risk should be
  required to undergo genetic screening.
• b) Ultimately you would hope all parents would
  take advantage of screening techniques in an
  effort to reduce the frequency of children born
  with genetic abnormalities.
• c) As long as there are strict guidelines
  controlling gene therapy, society will not have
  to be concerned about abuses of this technology.
• d) Private biotech companies that have invested
  millions of dollar in the Human Genome Project
  have a right to obtain patents for specific gene
  sequences. Other private companies or research
  facilities should have to ask permission or even
  pay to use this information in their studies.

12
PRACTICE QUESTIONS

• 1. Why is it advantageous to control breeding
  in plants and animals?
• 2. How is inbreeding performed in a) plants, b)
  animals?
• 3. List the problems that can result from
  inbreeding.
• 4. Briefly outline three of the roles of genetics
  in medicine.
• 5. What types of individuals are most likely to
  consult with a genetic counsellor?
• 6. Briefly explain how amniocentesis is
  performed.