Delayed Sry and Sox9 expression in developing mouse gonads underlies B6-Y(DOM) sex reversal

Dev Biol. 2005 Feb 15;278(2):473-81. doi: 10.1016/j.ydbio.2004.11.030.


The phenomenon of B6-Y(DOM) sex reversal arises when certain variants of the Mus domesticus Y chromosome are crossed onto the genetic background of the C57BL/6J (B6) inbred mouse strain, which normally carries a Mus musculus-derived Y chromosome. While the sex reversal has been assumed to involve strain-specific variations in structure or expression of Sry, the actual cause has not been identified. Here we used in situ hybridization to study expression of Sry, and the critical downstream gene Sox9, in strains containing different chromosome combinations to investigate the cause of B6-Y(DOM) sex reversal. Our findings establish that a delay of expression of Sry(DOM) relative to Sry(B6) underlies B6-Y(DOM) sex reversal and provide the first molecular confirmation that Sry must act during a critical time window to appropriately activate Sox9 and effect male testis determination before the onset of the ovarian-determining pathway.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Base Sequence
  • DNA-Binding Proteins / genetics*
  • Disorders of Sex Development*
  • Embryonic Development / genetics
  • Female
  • Gene Expression Regulation, Developmental*
  • Genes, sry / genetics*
  • High Mobility Group Proteins / genetics*
  • In Situ Hybridization
  • Male
  • Mice
  • Mice, Inbred C57BL
  • Nuclear Proteins / genetics*
  • Polymerase Chain Reaction
  • SOX9 Transcription Factor
  • Sex-Determining Region Y Protein
  • Transcription Factors / genetics*
  • Y Chromosome / genetics*


  • DNA-Binding Proteins
  • High Mobility Group Proteins
  • Nuclear Proteins
  • SOX9 Transcription Factor
  • Sex-Determining Region Y Protein
  • Sox9 protein, mouse
  • Sry protein, mouse
  • Transcription Factors