THE EVOLUTION OF GENETIC MATERIAL ON THE Y CHROMOSOME AND ITS ROLE IN GENDER DETERMINATION

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THE EVOLUTION OF GENETIC MATERIAL ON THE Y
CHROMOSOME AND ITS ROLE IN GENDER
DETERMINATION 

• Sam Taylor and Lauren RussellBiology 101HDr.
  Jean DeSaixDr. Moriah BeckApril 15, 2009 

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• http//www.youtube.com/watch?vnlOAnL9xI74

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Sex Determination

• Women are XX
• Men are XY
• Primary vs. Secondary sex characteristics

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Evolution of Y chromosome
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Evolution of Y and SRY
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SRY AND SOXS(SOX9 AND SOX3)
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SRY enables SOX9 expression
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• http//www.youtube.com/watch?v5yia5MmDXFw

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XX Male Sex Reversal Syndrome

• Human genetic disorder characterized by male
  physical characteristics and XX chromosomal
  karyotype
• In case study, tested to determine why
  self-identified male is infertile and has
  undescended testicles
• Gel electrophoresis compared subjects DNA with
  normal male and normal female DNA

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SRS Patient Normal Male
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XX Sex Reversal Syndrome Case Study Conclusion

• This subjects SRS syndromes caused by
  translocation of fathers SRY gene from Y to X
  chromosome during meiosis
• Confirmed SRY is required for physical male
  characteristics to be expressed
• Strengthened hypothesis that SRY silences SOX3
  and enhances SOX9 on male X chromosomes

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Bibliography

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•  
• Waters, P. D., Wallis, M. C., Marshall Graves,
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•  
• Schartl, M. (2004). Sex Chromosome evolution in
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• secondary sex character. (2009). In Encyclopædia
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  http//www.britannica.com/EBchecked/topic/531812/s
  econdary-sex-character