Influence on spatiotemporal patterns of a male-specific Sox9 activation by ectopic Sry expression during early phases of testis differentiation in mice.
Testis induction is associated with gonadal Sry and Sox9 expression in mammals. This study investigated whether Sry expression directly induces male-specific Sox9 activation during early phases of testis differentiation. We have established an XX sex-reversal mouse line carrying the Sry transgene driven by a weak basal promoter of the Hsp70.3 gene (Hsp-Sry), whereby the transgene was activated in the gonads along the entire anteroposterior axis from earlier stages. The effects of misexpression and overexpression of Sry on the spatiotemporal pattern of Sox9 expression were examined using both XX and XY gonads of Hsp-Sry transgenic embryos. It was shown that ectopic expression of Sry transcripts in the entire gonadal area from earlier stages promotes neither any advance in the timing nor any appreciable ectopic activation of endogenous Sox9 expression. Immediately after the onset of Sox9 activation, however, both the level of Sox9 expression and the number of SOX9-positive cells were significantly enhanced in Hsp-Sry/XY gonads, as compared with those in wild-type/XY and Hsp-Sry/XX gonads. These findings suggest that, although Sry is capable of up-regulating Sox9 expression dose-dependently, Sry mRNA expression alone is not likely to provide positional or timing information needed for male-specific Sox9 activation in developing XY gonads.
Kidokoro
Tomohide
T
Department of Veterinary Anatomy, The University of Tokyo, Yayoi 1-1-1, Tokyo 113-8657, Japan.
Matoba
Shogo
S
Hiramatsu
Ryuji
R
Fujisawa
Masahiko
M
Kanai-Azuma
Masami
M
Taya
Choji
C
Kurohmaru
Masamichi
M
Kawakami
Hayato
H
Hayashi
Yoshihiro
Y
Kanai
Yoshiakira
Y
Yonekawa
Hiromichi
H
D000818:Animals; D001483:Base Sequence; D019521:Body Patterning / Q000235:genetics*; D002454:Cell Differentiation; D017931:DNA Primers; D004268:DNA-Binding Proteins / Q000235:genetics*; D012734:Disorders of Sex Development; D005260:Female; D018507:Gene Expression Regulation, Developmental; D006609:High Mobility Group Proteins / Q000235:genetics*; D008297:Male; D008322:Mammals; D051379:Mice; D008822:Mice, Transgenic; D009687:Nuclear Proteins / Q000235:genetics*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D055758:SOX9 Transcription Factor; D051876:Sex-Determining Region Y Protein; D013623:Tail / Q000196:embryology; D013737:Testis / Q000166:cytology / Q000196:embryology*; D014157:Transcription Factors / Q000235:genetics*; D014158:Transcription, Genetic
D017931:DNA Primers; D004268:DNA-Binding Proteins; D006609:High Mobility Group Proteins; D009687:Nuclear Proteins; D055758:SOX9 Transcription Factor; D051876:Sex-Determining Region Y Protein; C527933:Sox9 protein, mouse; C497746:Sry protein, mouse; D014157:Transcription Factors