Gene expression during gonadogenesis in the chicken embryo.
Genes implicated in vertebrate sex determination and differentiation were studied in embryonic chicken gonads using reverse transcription and the polymerase chain reaction (RT-PCR). Expression profiles were obtained during gonadal sex differentiation for AMH, SOX9, SOX3, the Wilm's Tumour gene, WT1, and the orphan nuclear receptor genes, SF1 and DAX1. Some of these genes showed sexually dimorphic expression profiles during gonadal development, whereas others were expressed at similar levels in both sexes. The gene encoding Anti-Müllerian hormone (AMH) was expressed in both sexes prior to and during sexual differentiation of the gonads, with levels of expression consistently higher in males than in females. SOX9 expression was male-specific, and was up-regulated after the detection of AMH transcripts. SOX3 expression was observed prior to clear SOX9 expression and was up-regulated in both sexes at the onset of gonadal sex differentiation (but declined later in development). The WT1 gene was highly expressed in both sexes, whereas SF1 expression was clearly higher in developing ovaries compared to testes. DAX1 transcripts were observed in both sexes at all stages examined, but expression appeared somewhat higher in developing ovaries. These expression profiles are analysed in terms of current theories of vertebrate sex determination.
Department of Paediatrics and Centre for Hormone Research, The University of Melbourne, Royal Children's Hospital, Melbourne, Vic. 3052, Australia. smithc@cryptic.rch.unimelb.edu.au
C A
CA
Smith
M J
MJ
Smith
A H
AH
Sinclair
D000199:Actins / Q000235:genetics; D000818:Animals; D054304:Anti-Mullerian Hormone; D002642:Chick Embryo; D002645:Chickens; D057137:DAX-1 Orphan Nuclear Receptor; D004268:DNA-Binding Proteins / Q000235:genetics; D005260:Female; D018507:Gene Expression Regulation, Developmental; D006023:Glycoproteins; D006066:Gonads / Q000196:embryology* / Q000378:metabolism*; D006131:Growth Inhibitors / Q000235:genetics; D006609:High Mobility Group Proteins / Q000235:genetics; D008297:Male; D016601:RNA-Binding Proteins / Q000235:genetics; D018168:Receptors, Retinoic Acid / Q000235:genetics; D012097:Repressor Proteins; D020133:Reverse Transcriptase Polymerase Chain Reaction; D055758:SOX9 Transcription Factor; D055748:SOXB1 Transcription Factors; D019849:Sex Determination Processes; D012733:Sex Differentiation / Q000235:genetics; D013735:Testicular Hormones / Q000235:genetics; D014157:Transcription Factors / Q000235:genetics; D025721:WT1 Proteins
D000199:Actins; D057137:DAX-1 Orphan Nuclear Receptor; D004268:DNA-Binding Proteins; D006023:Glycoproteins; D006131:Growth Inhibitors; D006609:High Mobility Group Proteins; D016601:RNA-Binding Proteins; D018168:Receptors, Retinoic Acid; D012097:Repressor Proteins; D055758:SOX9 Transcription Factor; D055748:SOXB1 Transcription Factors; D013735:Testicular Hormones; D014157:Transcription Factors; D025721:WT1 Proteins; D054304:Anti-Mullerian Hormone