Genetics

The number of events that produce mutated alleles per locus per generation.

If 4 of 100,000 births show a mutation from a recessive to a dominant allele, we've ctually sampled 200,000 genes because we have two copies of each gene. So the mutation rate would be 4/200,000 or 2/100,000.

Never be produced by recessie alleles

Always be fully expressed and completely penetrant so that mutant individuals can be indentified

Have clearly established paternity

Never be produced by nongeneric agents such as drus or infection and be produced by a dominantly inherited mutation of only one gene

Focused on environmental causes of mutations

Identified mutagenic agents but the disadvantage to this test was that he used bacteria, which is a different metabolic pathway than is found in rats or humans. Sonce the bacteria doesn't have that metabolic product, just abecause a chemical passes the Ames test, doesn't necessarily mean that it is not a mutanogen

Mutations that cause the substitution of one amino acied for another in a protein.

• Ex:
• CTC-->CAC (glutamic acid-->valine) (sickle cell anemia)

Mutations that change a termination codon into one that codes for an amino acid. Such mutations produce elongated protiens.

• Ex.
• UAA-->AAA (removal of termination codon

Mutations that change an amino acid specifying a codon to one of the three termination codons. This shortens the protein product.

• Ex.
• AAA-->UAA (termination codon)

Mutational events in which a number of bases (other than multiples of three) are added to or removed from DNA, causing a shift in the codon reading frame.

• Insertion: CAT CAT CAT GCA T
• Deletion: CAT CAT CAC AT

A form of mutation associated with the expansion in copy number of a nucleotide triplet in or near a gene

CGC - 230

CTG - 50 to 2,000 repeats

CAG - 42 to 100

Onset of a generic disorder at earlier ages and with increasing severity in successive generations

UV damage - thymine dimers (excision repair)

Xeroderma Pigmentosum - thymine dimer defect

Bloom Syndrome - DNA ligase defect

Activate certain genes and deactivate other genes. Sometimes, genes that are not necessary are activated and start influencing changes. This results in chance for mutations and an increase in the chance for cancer.

Fetal tissue mutations

A cell when it has the ability to give rise to an entire organism. Occurs during the 16 cell stage.

Genetically identical molecules, cells, or organisms all derived from a single ancestor.

The two types of stem cell cloning

• 1. telomeres of chromosomes of donor nuclei are shorter
• 2. genomic imprinting when chromosomes are passed via germ line
• 3. somatic cells accumulate mutations
• 4. X-inactivation pattern
• 5. mitochondria is from recipient cell not donor cell
• 6. coat color differences-pigmented cells move about differently
• 7. environmental factors during embryonic/fetal development: nutrition (methylation) stress, exposure to environmental diseases

• 1. Meiosis not involved (meiosis in the female completes fertilization)
• 2. Diploid nucleus is plunked into oocyte cytoplasm where signals direct it to do what a female secondary oocyte tends to do (a.) shed half of chromosomes as polar body--hapoid--lethal and (b.) replicates DNA--tetraploid--lethal

• 1. Violation of rights of early-stage embryos versus violation of rights of individuals who might benefit from such therapy
• 2. 2001 USA legislation outlaw creating or selling "any embryo produced by human cloning"

• 1. isolate plasmid DNA and human DNA
• 2. cut both DNA's with the same restriction endonuclease--resulting in DNA fragments
• 3. combine both DNA's--cut ends re-associate or anneal
• 4. seal gaps with DNA ligase
• 5. creates recombinant DNA molecules composed of human DNA and vector DNA
• 6. transfer vector into bacteria
• 7. at each bacterial cell division, the plasmid is replicated resulting in many copies or clones of the DNA insert
• 8. lyse bacteria--extract recombinant plasmids
• 9. cloned human DNA can be released from plasmid with same restriction enzyme used for cloning
• 10. cloned DNA can be used directly, put in expression vector and transfected into cells

• 1. A collection of clones that contain all of the genetic information in an individual--cut all DNA of donor cell--put in cloning vector (bacteriophage as an example)
• 2. Retrieve gene of interest ("needle in hay stack") by using DNA probe
• 3. DNA probe--a synthetic piece of labeled DNA that is complementary to part of gene of interest

Extract mRNA from cells, reverse transcribe to single stranded cDNA. DNA polymerase to give double-stranded cDNA, cut, put in cloning vector

A method for amplifying DNA segments using cycles of denaturation, annealing to primers, and DNA-polymerase-directed DNA synthesis.

• 1. DNA amplified by heating to break hydrogen bonds, yielding single strnded DNA
• 2. Short nucleotide sequences act as primers for DNA replication added
• 3. Enzyme, DNA polymerase, begins t primers and synthesizes a DNA strand complementary to the region between the primers, a proces called "primer extension"

• Ex.
• 10 cycles = 1,024 copies 30 cycles = 1,073,741,820 copies

A method for transferring DNA fragments from a gel to a membrane filter, developed by Edwin Souther for use in hybridization experiments

Used to find diferences in notmal and mutant alleles, identify related genes in other organisms, and study gene evolution

Used for identifying proteins

Uses same process in Southern Blotting only for proteins

Used for identifying RNA

Don't have to digest enzymes to study RNA like you would in Southern blots to study DNA

A series of techniques in which DNA fragments are linked to self-replicating vectors to create recombinant DNA molecules, which are replicated in a host cell.

Used in agriculture to make transgenic corn plants that are resistant to insects and to give transgenic pigs growth hormones

Used in medicine and pharmacology to make human insulin via bacteria or milk from cows, goats, or sheep

Used in cloning pigs for organ donors (knockout of carbohydrate that is involved in transplant rejection)

Bacterial enzymes that cut DNA at specific sites

Self-replicating DNA molecules that are used to transfer foreign DNA segments between host cells

Refers to the transfer of genes between species by recombinant DNA technology; transgenic organisms have received such a gene

RFLP (restriction fragment length polymorphism)

Prenatal (as well as postnatal screening for genetic defects)

Paternity

Nucleotide sequences 14 to 100 base pairs long organized into clusters of varying lengths; used in the construction of DNA fingerprints.

Short nucleotide sequences 2 to 9 base pairs long otganized into clusters of varying lengths; used in the construction of DNA profiles

The pattern of of STR allele frequencies used to identify individuals

Altered self cells that excape normal growth regulatory controls

1 in 3 wil develop cancer in a lifetime

1 in 8 women develop breast cancer if they live to be 80

90% of lung cancer due to tobacco

• 1. Initiation
• 2. Promotion
• 3. Progression/metastasis

Event that is associated with the first mutation that leads to cancer

Altered genes/cells increasing and recruiting mor growth factors, increasing the cells affected by the cancer.

Benign or malignant can be determined at this point

If tumor is malignant, the cells can spread to other parts of the body

• 1. Clonally derived
• 2. Accumulate mutations: display growth regulatory changes
• 3. Movement-metastases
• 4. Altered biochemical pathways
• 5. Disorganized cytoskeleton
• 6. Chromosomal abnormalities

• 1. Chemical--tobacco tar and SENCAR mice
• 2. Virus--(Rous Sacroma virus (Peyton Rous); ERB-B (Bishop and Varmus)
• 3. Translocation--Burkett's lymphoma (c-myc on chromosome #8 is translocated to Ig region on chromosome #14)

• 1. Environment--lung and skin cancer
• 2. Diet--fat: breast, prostate
• 3. Chemical
• 4. DNA and RNA viruses
• 5. Genetics (approximately 10% of cancers)

Genes encoding proteins that suppress cell division

Genes that initiate or maintain cell diveision and that may become cancer genes (oncogenes) by mutations

Genes that induce or continue uncontrolled cell proliferation

Genes that regulate cell growth and passage through the cell cycle, for example, tumor suppressor genes

Genes that help maintain the integrity of the genome, for example, DNA repair genes

How to enhance immune response to cancer antigens/immunogens

Disease-causing agents

Molecules carried or produced by microorganisms that initiate antibody production

Any molecule that can bind to a antibody.

Elicits celular and humoral response

A class of proteins produced by B cells that bind to foreign molecules (antigens)and inactivate them.

Made in response to immunogen according to the specificity of the immunogen.

• 1. Humoral
• 2. Cellular

B cells/plasma cells make and secrete antibody/immunoglobulins

T helpers enhance immune response; cytotoxic T cells destroy altered self

A type of lymphocyte that matures in the bone marrow and mediates antibody-directed immunity

White blood cells that originate in bone marrow and mediate the immune response

A type of lymphocyte that undergoes maturation in the thyus and mediates cellular immunity

A lymphocyte that stimulates the production of antibodies by B cells when an antigen is present, and stimulates division of B cells and cytotoxic T cells

• 1. Memory
• 2. Specificity

Once primed by immunogen, rapid response to immunogen

Reacts specifically with challenging immunogen

• 1. IgM
• 2. IgG
• 3. IgA
• 4. IgE

Early response, effective in defense against baceria infections

Major immunoglobulin, lasts for years; cross placenta

Found in body secretions

Involved in allergic responses

• 1. Agammaglobulinemias
• 2. Severe-Comined Immunodeficiency (SCID)
• 3. Athymic Nude mice
• 4. HIV--AIDS

ABO blood types, transfusions and incompatibility

IgE antibody ataches to blast cells in tissues, binds allergen, and cause blast cells to release pharmacological chemicals

Immune system recognize incompatible transplants as non-self and destroy the transplants. Must use immunosuppressive drugs to permit transplants to survive

Immune system attacks and destroys self

• Ex.
• Lupus
• Multiple Sclerosis
• Type 1 Diabetes
• Rheumatoid Arthrits