PP10 Sexed Semen X

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PP10Sexed SemenX Y Sex ChromosomesChapter
10 pg 236-239ANS 3319Dr Michael J.
FieldsUniversity of Florida
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Y Chromosome

• One third the size of the X chromosome
  
  
  
  
• Has only 1/100th the genes of the X chromosome
• Recombination occurs only between the tips of the
  Y and X chromosome
• Reptiles lack sex chromosomes instead depend on
  temperature to determine sex
• Contains Testes Determining Factor (TDF)
  results in formation of testes

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Reptiles (No X Y)

• Lack sex chromosomes all together.
• The sex is dependent on the temperature.
• For example, in red ear slider turtle eggs,
  temperature around 30o C will hatch a female
  whereas temperature below 30o C will hatch a
  male.
• Alligators must have an increased temperature
  to produce males.

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X and Y Chromosome

• Females produce double the amount of proteins
  from the two X chromosomes
• Males can only produce 1 dose
• In females, one X chromosome is silenced
• Silenced X is called a Barr body

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Function of the Y Chromosome

• Formation of the testes
• Testis Determining Factor (TDF)
  
  
  
  
• Production of Testosterone (Leydig Cells)
• Visual traits of the male
• Sperm cell production (Seminiferous Tubules)

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Function of the Y Chromosome

• Responsible for downed gates and fence
• Responsible for neighbors bred cows
• Responsible for back jarring bull holes
• Responsible for dent in new pickup trucks

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Physical Traits of Y vs X Chromosomes

• X sperm is larger than Y sperm
• X sperm has more DNA
• X 5 of DNA / Y 2 of DNA
• Y sperm has faster motility

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Y Chromosome Controls

• Testis Determining Factor (TDF) - Substance that
  controls the pathway for development of either a
  male or a female.
• X chromosome lacks this gene, hence why males
  choose the sex.

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XY Sperm Separation

• Sort by size
• Doesnt really work
• Sort by DNA content
• Preferred method

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Detection of Y Chromosome

• Fluorescence staining of the long arm of the Y
  chromosome
• Fluorescence activated cell Sorter coupled with
  an Ultraviolet Laser
• Useful for evaluation of X and Y separation
  technique
• Monsanto abandoned selling sexed semen with 85
  efficiency of sex selection

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Detection of Y Chromosome
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Movie Epididymal Sperm Maturation and Transport