Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

What Happens in the Presence/Absence of SRY

  1. Jan 27, 2005 #1
    I'm confused as to what happens when the SRY gene is not present. In the book I use it says the gonads will become ovaries,but in my class notes it says testes will form. Can someone please explain to me SRY and what it relates to? Thanks
  2. jcsd
  3. Jan 27, 2005 #2


    User Avatar
    Staff Emeritus
    Science Advisor
    Gold Member

    SRY is present on the Y chromosome and is responsible for regulating a cascade of other genes required for differentiation of the primordial gonads into testes. In case studies in which individuals with an XY karyotype had a mutation of the SRY gene, they developed into phenotypic females, but had what are referred to as streak gonads, not ovaries. (i.e., Jager RJ, Anvret M, Hall K, Scherer G. A human XY female with a frame shift mutation in the candidate testis-determining gene SRY.
    Nature. 1990 Nov 29;348(6300):452-4.) So, while SRY is a testis determining factor, something else seems necessary as an ovary determining factor.

    However, there is a current case report out of a phenotypic male with a 46XX karyotype who does not have the SRY gene and still has testicular development (though is infertile). This suggests it is not SRY itself that is involved in testicular development, but other genes it may regulate (that might be the source of the mutation in this patient).

    Edit: I realize I didn't define a streak gonad for you.
    From: here.
    Last edited: Jan 27, 2005
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook