Horm Metab Res 2009; 41(1): 30-34
DOI: 10.1055/s-0028-1087174
Original Basic

© Georg Thieme Verlag KG Stuttgart · New York

DAX-1A (NR0B1A) Expression Levels are Extremely Low Compared to DAX-1 (NR0B1) in Human Steroidogenic Tissues

Y. Nakamura 1 , 2 , C. Vargas Morris 1 , H. Sasano 2 , W. E. Rainey 1
  • 1Department of Physiology, Medical College of Georgia, Augusta, Georgia, USA
  • 2Department of Pathology, Tohoku University Graduate School of Medicine, Sendai, Japan
Further Information

Publication History

received 14.04.2008

accepted 01.07.2008

Publication Date:
25 September 2008 (online)


The orphan nuclear receptor DAX-1 (dosage-sensitive sex reversal-AHC critical region on the X chromosome gene 1; NR0B1) is known for its role in human development, specifically sex determination and steroidogenesis. Several recent publications have described an alternatively spliced form of DAX-1 called DAX-1A (NR0B1A). DAX-1A is encoded by exons 1 and 2A of DAX-1, with exon 2A located within the DAX-1 intron 1. DAX-1A expression has been observed in several tissues, including adrenal gland, ovary, and testis. Transfection studies have further shown that DAX-1A has an inhibitory effect on DAX-1, suggesting a role for DAX-1A in the regulation of adrenal and gonadal differentiation/function. However, the relative level of DAX-1 versus DAX-1A transcripts still remains unclear. Herein, we developed and performed quantitative real-time RT-PCR to measure DAX-1 and DAX-1A mRNA expression levels in H295R human adrenal carcinoma cell lines, human adult and fetal adrenal glands, corpus luteum, testis, whole pre- and postmenopausal ovaries, ovarian follicles, placenta, liver, and kidney. These mRNA expression levels were quantified using DAX-1 and DAX-1A standard curves. In addition, Western blotting analysis was performed to examine both DAX-1 and DAX-1A protein levels in H295R cells, adrenal glands, corpus luteum, and liver. Both DAX-1 and DAX-1A mRNA were detected in all samples of H295R cells, human fetal and adult adrenals, testis, ovary, ovarian follicles, and corpus luteum. However, DAX-1 mRNA levels were significantly higher (> 37-fold) than that seen for DAX-1A (p<0.01). DAX-1A mRNA expression levels were undetectable in human liver, placenta, and kidney. Western blotting analysis results demonstrated that DAX-1 protein was predominantly expressed in H295R cells, human adult adrenal, and corpus luteum. These results suggest that in comparison to DAX-1A, DAX-1 is, by far, the predominant mRNA isoform found in human adrenal glands and gonads.



W. E. Rainey, PhD 

Department of Physiology

Medical College of Georgia

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30912 Georgia


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Fax: +1/706/721 83 60

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