Title: Pedigree Charts
1Pedigree Charts
- The family tree of genetics
2Pedigree Charts
I
II
III
3Overview
- What is a pedigree?
- Definition
- Uses
- Constructing a pedigree
- Symbols
- Connecting the symbols
- Interpreting a pedigree
4What is a Pedigree?
- A pedigree is a chart of the genetic history of
family over several generations. - Scientists or a genetic counselor would find out
about your family history and make this chart to
analyze.
5Constructing a Pedigree
6Connecting Pedigree Symbols
Examples of connected symbols
- Fraternal twins
- Identical twins
7Connecting Pedigree Symbols
Examples of connected symbols
8Example
- What does a pedigree chart look like?
9Symbols in a Pedigree Chart
- Affected
- X-linked
- Autosomal carrier
- Deceased
10Interpreting a Pedigree Chart
- Determine if the pedigree chart shows an
autosomal or X-linked disease. - If most of the males in the pedigree are affected
the disorder is X-linked - If it is a 50/50 ratio between men and women the
disorder is autosomal.
11Example of Pedigree Charts
- Is it Autosomal or X-linked?
12Answer
13Interpreting a Pedigree Chart
- Determine whether the disorder is dominant or
recessive. - If the disorder is dominant, one of the parents
must have the disorder. - If the disorder is recessive, neither parent has
to have the disorder because they can be
heterozygous.
14Example of Pedigree Charts
15Answer
16Example of Pedigree Charts
17Answer
https//www.youtube.com/watch?vIr1t9awmUl4
18Summary
- Pedigrees are family trees that explain your
genetic history. - Pedigrees are used to find out the probability of
a child having a disorder in a particular family. - To begin to interpret a pedigree, determine if
the disease or condition is autosomal or X-linked
and dominant or recessive.
19Pedigree Chart -Cystic Fibrosis
https//www.youtube.com/watch?vWuk0W10EveU
20Human Genetics
21Karyotype
22Chromosome Number
Homologous Chromosomes are the sets of each pair
- Different for different species
- Full set 2NDiploid
- N
- pairs
- 1 pair from mother
- 1 pair from father
- Humans 23 pairs or
- 46 total
23Autosomes Sex Chromosomes
Autosomes 1-22 for all traits except sex
Sex chromosomes Pair 23 XX(female)
or XY(male)
24Down Syndrome 3 of 21
25Klinefelters XXY
26Mutation
A to A G C
A T GC
- Change in DNA code
- Caused by
- Chemical damage
- Errors in Replication
- X-ray damage
- UV damage
X
27Mutation
- Changes in the DNA code
- Changes in the final proteins made
- Changes in the organism
28Mutations
- Chromosome mutations involve changes in the
structure of a chromosome or the loss or gain of
a chromosome. - There are three types of chromosome mutations
- 1. deletion the loss of a piece of a chromosome
due to breakage. - 2. inversion a chromosomal segment breaks off,
flips around backward and then re-attaches. - 3. translocation a piece of one chromosome
breaks off and re attaches to a non-homologous
chromosome.
29(No Transcript)
30Genetic Technology
- Recombinant DNA
- Bacterial Transformation
311. Mice that glow???
https//www.youtube.com/watch?vk7-ofCWJiUg
322. Genetic Engineering
- Altering the genetic makeup of an organism
- By Cutting DNA from one organism and inserting
fragments into a host - Recombinant DNA
- Alters the allele frequency of a population by
artificial means
33Recombinant DNA
- Recombine
- Connecting or reconnecting DNA fragments
- DNA of two different organisms
- Example lab of inserting human DNA into bacteria
34Genetic Engineering of Insulin
Human DNA cut out
Human DNA put into bacteria DNA
Many Bacteria Grow human insulin
Bacteria DNA is opened up
354. Transgenic Organism
- trans across
- genic race
- Contains genes from another organism
- Bacteria
- Virus
- Human
365. Tobacco Recombinant DNA Process
- Isolated DNA to be inserted into host
- Attach DNA fragment to a vehicle (vector)
- Transfer the vector to the host
- Transgenic organisms
37Restriction Enzymes
Bacterium DNA cut
Human Cut
Restriction Enzymes cut DNA at very specific
sites Separate the base pairs of both
strands Scissors in Recombinant DNA
38Vectors vehicles
- Carry foreign DNA fragments into the host
- Bacteria carried the firefly DNA into the tobacco
cells - Biological or
- Mechanical
39Vectors
- Biological
- Virus
- Bacterial plasmid (circular DNA)
- Mechanical
- Micropipette
- Metal bullet coated with DNA
https//www.youtube.com/watch?vnfC689ElUVk
40Recombinant DNA Uses
- Grow human hormones in bacteria cultures
- Artificial sweeteners using bacteria to make
amino acids - Study human diseases by inserting human DNA into
mice - Replace incorrect DNA sequences
- Replace harmful bacteria on plants
- Nitrogen bacteria in the soil plants to make
fertilizer - Improve transport of fruits
- Resist diseases
- Increase protein production
41Genetic engineering and Gene therapy Right or
wrong?
- Genetic engineering is one of the
- fastest growing medical sciences.
- There are 2 types of cell and so 2 types of
- gene therapy
- Somatic cells found in the body
- Germ-line - cells found in sperm and eggs
- (hereditary)
42Somatic Cell Therapy
- This is when a gene is introduced into a
- patient to help them recover from a
- disease.
- It could be used to help those suffering
- from cystic fibrosis.
- Only the patient is affected and so there
- are few ethical concerns.
43Germ Line Therapy
- Changes are made to genes that will
- affect subsequent generations.
- We do not know the consequences of this.
- It will affect what it means to be human.
- We take charge of our own evolution.
44The many uses of Genetic Engineering
- To repair a genetic defect.
- To enhance a natural effect e.g. growth.
- To increase crop resistance to disease or
climate. - To test and screen for genetically inherited
diseases. - To cure disease by altering the genes.
- To select human genes embryo selection
(designer babies)
45Embryo Selectionas a form of Genetic Engineering
Designer babies or a cure for genetically
inherited diseases? To select the sex of a child
or to create a healthy baby to cure a sick
sibling?
46- Embryo Selection is a relatively simple process.
An ovarian biopsy can yield many eggs which can
be fertilized in vitro with the partners sperm.
The cells can be grown in culture, and at the
eight cell stage, one of the cells can be removed
for diagnosis.
47Embryo Selection
- To the right is a picture of a glass micropipette
used to remove the cell for diagnosis. The width
of the pipette opening is one cell wide.
48- How is it done?
- The removal of one cell allows DNA tests to be
performed on the embryo. The embryo with the
desired trait can then be selected. - The final step is implanting the embryo into the
uterus, and letting the pregnancy continue to
term. - This process is called in vitro fertilization.
49Embryo selection is being done for certain select
conditions, like cystic fibrosis, Huntingtons
disease, and sickle cell anaemia.
50Questions raised by embryo selection
- What are the specifics of embryo selection, is
there a limit? - What are the benefits and consequences of embryo
selection? - What is the difference between embryo selection
and genetic engineering?
51Questions raised by embryo selection
- Is embryo selection ethical?
- Is it ethical to choose the sex of your baby?
- Is it ethical to choose the characteristics of
your baby? - Is it ethical to rid your baby of diseases
through this process? - What is done with the embryos that are not
selected? - How do you store and dispose of the unused
embryos?
52What are the specifics of embryo selection, is
there a limit?
- Bioethicists generally find current practices of
embryo selection not too problematic, because the
elimination of debilitating diseases justifies
the intrusion. However, if embryo selection can
be used to select deleterious traits, why
couldnt it be used to select for other
enhancing traits. Here bioethicists begin to
find the procedure more problematic because it
takes on eugenic nature.
53What are the benefits and consequences of embryo
selection?
- Benefits
- Many embryos are implanted back into the woman
(greater chance of pregnancy) - Child is without disease
- Other embryos can be cultured and frozen so they
can be used again
54What are the benefits and consequences of embryo
selection?
- Consequences
- Goes against nature
- Very expensive
- Not 100 guaranteed
- Not available to all women
55Is Embryo Selection Ethical?
- Some would say
- Embryo selection is ethical when
- looking for syndromes/diseases which later would
cause the child to die within the first few
years, - would cause severe retardation,
- cases which would be a better choice than
abortion, and to avoid emotional stress. - Embryo selection is not ethical when
- choosing specific sex,
- choosing character traits,
- killing discarded embryos.
56Issues for Ethics
- Personhood the morality of discarding an embryo
when it is considered a person. - The right to life what is done with spare
embryos. - The right to a child.
57Ethical Approaches4. Virtue Ethics
- The virtue of compassion is important when
considering those suffering from genetic
diseases. - But it is also important to consider compassion
to the embryos, so it could be argued both ways.
https//www.youtube.com/watch?vdKBfxoPnT7g