Chick Embryo Development

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Chick Embryo Development

• Dr. Douglas Rhoads
• Professor Biological Sciences
• Affiliated Faculty Center of Excellence for
  Poultry Science
• Director of Graduate Program in Cell and
  Molecular Biology
• University of Arkansas
• drhoads_at_uark.edu
• http//biscweb.uark.edu/drhoads

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The Egg
http//www.enchantedlearning.com/subjects/birds/in
fo/chicken/egg.shtml
http//www.ehow.com/how_4715979_tell-chicken-eggs-
fertile.html
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The Life of an Egg

• Male inseminates female
• Female stores sperm for up to 2 weeks
• Female has one ovary (left side)
• Ovary has multiple follicles in hierarchy
• One ovulation every 25 hours
• timed to light cycle

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Ovulation

• Primary Follicle ruptures
• Sperm attach to germinal disk over egg
• Acrosome reaction
• One sperm penetrates egg membrane
• Zygote begins development
• Transiting the oviduct
• Egg white albumen deposited
• Egg membrane deposited
• Shell added in Shell gland
• Oviposition
• about 22-24 hours after ovulation
• Embryo already at about 1000 cells

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Embryo Growth

• Embryo on side of yolk
• Floats up (hen rocks and reorients)
• Incubation temperature of 39 to 40 C
• Embryo divides into Embryo and Extra-embryonic
  tissue
• Extra-embryonic tissue
• Blood cell production
• Blood islands gtgt Blood ring
• Fuses with embryo circulatory system
• Grows out around yolk
• Heart pumps blood out around yolk and back to
  embryo
• Absorbs yolk and albumen
• Eventually, chick grows around and encompasses
  last of yolk through cloacal opening
• Chick emerges from egg after 21 days

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HH chart
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The First Three Days
http//geisha.arizona.edu/geisha/stages.jsp
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Day 4 to 8
http//geisha.arizona.edu/geisha/stages.jsp
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Embryo Dissection
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Embryo Dissection
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Embryo Dissection