Selective Breeding

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Selective Breeding

• Definition breeding or crossing of organisms
  with favorable traits
• Allows the favorable allele to remain in the
  population
• Cats
• Domestic Crops
• (Corn, Wheat, Fruit)
• Cows

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Inbreeding

• Definition mating of closely related organisms
• Ensures that offspring are homozygous for favored
  traits
• Greater chance of harmful recessive traits to
  appear

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Hybrid

• Definition the offspring of parents that have
  different forms of a trait
• Closely related species are crossed
• Most Frequent in Plants (eg. Crops)
• Lion Tiger LIGER!!!

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How can a breeder determine which organism
(genotype) should be used for breeding?

• By crossing an organism with a homozygous
  recessive organism we can determine the genotype
  of our dominant individual by examining their
  offspring!

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Test Cross

• Definition a cross of an individual of unknown
  genotype with an individual of a known genotype
• The known genotype is usually homozygous recessive

In German Shepherds DD or Dd Normal Height
Dog dd Dwarf Dog
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• If known parent is homozygous recessive (dd)
  and the unknown is homozygous dominant (DD)

D
D
Dd Dd
Dd Dd
d
d
All offspring are Dd and show dominant
trait Normal Height
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• If known parent is homozygous recessive (dd)
  and the unknown is heterozygous (Dd)

D
d
Dd dd
Dd dd
d
d
50 of the offspring will be heterozygous and
show dominant trait and 50 will show the
recessive trait
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Genetic Engineering

• Much faster and more valuable method for
  increasing allele frequency (favorable traits) in
  a population.
• Must cut or cleave the DNA and insert it into
  host organism.
• Also called Recombinant DNA Technology

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Recombinant DNA Technology

• Made by connecting or recombining fragments of
  DNA from different sources
• Transgenic organism organism that contains
  foreign DNA
• In order to do this you must isolate a fragment
  or small part of the DNA using restriction enzymes

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Restriction Enzymes

• Definition bacterial proteins that have the
  ability to cut both strands of the DNA molecule
  at specific nucleotide sequences
• There are hundreds of restrictions enzymes, each
  different in length and specification
• Gene Splicing the rejoining of DNA fragments
• join sticky ends of fragmented DNA

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Vector

• Definition a means by which DNA from another
  species can be carried into the host cell
• Can be mechanical or biological

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Types of Vectors

• Biological
• Viruses
• Plasmid small circular bacterial DNA
• Mechanical
• Micropipette inserts DNA into host cell
• Bullet coated with DNA and shot into nucleus
  with gene gun

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Stem Cells

• Stem cell a cell that can continuously divide
  and differentiate into various tissues
• Adult humans have stem cells in bone marrow,
  these cells can be collected and used for medical
  treatments
• Stem cells from embryos have much more potential
  to develop into new tissues and have more
  potential uses

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Stem Cells Is it ethical?

• Leftover embryos from fertility clinics was main
  source for stem cells
• Now, stem cells can be cloned
• Which method is more acceptable?

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Cloning

• Clone organism or piece of genetic material that
  is genetically identical to one that was
  previously existing

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Cloning Is it ethical?
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Applications of DNA Technology

• Animals Used to investigate human diseases
• Mice
• Roundworms
• Fruit fly
• Agriculture
• Strawberries built-in frost protection
• Resistance to herbicides, produce internal
  pesticides, and increase protein production

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Applications of DNA Technology

• Industry
• 1. Bacteria engineered
• to degrade oil
• 2. Bacteria engineered to
• extract minerals from ore
• Medicine Bacteria engineered to
• Produce of growth hormone to treat dwarfism
• Produce insulin for people w/ diabetes
• Making of Aspartame artificial sweetener

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• Gene Therapy insertion of normal genes into
  human cells to correct genetic disorders
• DNA Fingerprinting
• Used by law enforcement
• to determine if suspect was
• at the crime scene
• Uses PCR technique
• Especially helpful because
• no two people are genetically
• identical

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The Human Genome Project

• Organized in 1990, projected to be a 30 year
  project, rough completion in 2001
• International effort
• Wanted to map and sequence the HUMAN GENOME
  80,000 genes on our 46 chromosomes

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The Human Genome Project

• Made possible by the use of linkage maps
• Linkage maps genetic map that shows the location
  of genes on a chromosome
• Helps to also evaluate the rate of crossing-over

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Why the Human Genome Project?

• Better understanding
• of the human body
• and condition
• Diagnosis of genetic
• disorders
• Identification of suspects in a criminal case