Differential patterns of expression of DAX-1 and steroidogenic factor-1 (SF-1) in the fetal rat testis.
Gonadal differentiation is dependent upon a cascade of molecular and morphological events. Steroidogenic factor 1 (SF-1) and DAX-1 have been implicated in this process. A SF-1 binding site has been reported to be present on the DAX-1 gene. We therefore used immunocytochemistry to determine whether these two transcription factors are co-expressed in the fetal testis. DAX-1 was immunolocalised to the cytoplasm of interstitial cells from fetal testis of rat and human from day 15.5 and 16 weeks of gestation respectively. SF-1 was detected in nuclei of fetal Sertoli and interstitial cells. In the fetal rat expression of SF-1 in interstitial cells was not uniform; cells with abundant SF-1 all contained 3-beta HSD and were classified as Leydig cells. DAX-1 expression was not exclusive to cells which contained SF-1 and SF-1/DAX-1 co-expressing cells were not exclusively fetal Leydig cells. We conclude that in the fetal testis expression of the DAX-1 protein is not dependent upon the presence of SF-1 although SF-1 is present at an earlier stage of gestation in the gonad. DAX-1 may therefore play a separate or complementary role to that of SF-1 in the modulation of testicular gene expression and differentiation.
Majdic
G
G
MRC Reproductive Biology Unit, Edinburgh, UK.
Saunders
P T
PT
D015096:3-Hydroxysteroid Dehydrogenases / Q000378:metabolism; D000818:Animals; D057137:DAX-1 Orphan Nuclear Receptor; D004268:DNA-Binding Proteins / Q000378:metabolism*; D005333:Fetus / Q000378:metabolism*; D051717:Fushi Tarazu Transcription Factors; D018398:Homeodomain Proteins; D006801:Humans; D007150:Immunohistochemistry / Q000379:methods; D008297:Male; D051381:Rats; D018160:Receptors, Cytoplasmic and Nuclear; D018168:Receptors, Retinoic Acid / Q000378:metabolism*; D012097:Repressor Proteins; D013194:Staining and Labeling; D054339:Steroidogenic Factor 1; D013737:Testis / Q000196:embryology* / Q000378:metabolism; D014157:Transcription Factors / Q000378:metabolism*
D057137:DAX-1 Orphan Nuclear Receptor; D004268:DNA-Binding Proteins; D051717:Fushi Tarazu Transcription Factors; D018398:Homeodomain Proteins; C539965:NR0B1 protein, human; C515057:NR5A1 protein, human; C539967:Nr0b1 protein, rat; D018160:Receptors, Cytoplasmic and Nuclear; D018168:Receptors, Retinoic Acid; D012097:Repressor Proteins; D054339:Steroidogenic Factor 1; D014157:Transcription Factors; C515060:steroidogenic factor 1, rat; D015096:3-Hydroxysteroid Dehydrogenases