Zebrafish sex determination and differentiation: involvement of FTZ-F1 genes.
Sex determination is the process deciding the sex of a developing embryo. This is usually determined genetically; however it is a delicate process, which in many cases can be influenced by environmental factors. The mechanisms controlling zebrafish sex determination and differentiation are not known. To date no sex linked genes have been identified in zebrafish and no sex chromosomes have been identified. However, a number of genes, as presented here, have been linked to the process of sex determination or differentiation in zebrafish. The zebrafish FTZ-F1 genes are of central interest as they are involved in regulating interrenal development and thereby steroid biosynthesis, as well as that they show expression patterns congruent with reproductive tissue differentiation and function. Zebrafish can be sex reversed by exposure to estrogens, suggesting that the estrogen levels are crucial during sex differentiation. The Cyp19 gene product aromatase converts testosterone into 17 beta-estradiol, and when inhibited leads to male to female sex reversal. FTZ-F1 genes are strongly linked to steroid biosynthesis and the regulatory region of Cyp19 contains binding sites for FTZ-F1 genes, further linking FTZ-F1 to this process. The role of FTZ-F1 and other candidates for zebrafish sex determination and differentiation is in focus of this review.
von Hofsten
Jonas
J
Department of Molecular Biology, Umeå University, Umeå, Sweden. jonas.von.hofsten@molbiol.umu.se
Olsson
Per-Erik
PE
D000818:Animals; D054304:Anti-Mullerian Hormone; D001141:Aromatase / Q000235:genetics; D004268:DNA-Binding Proteins / Q000235:genetics; D050981:Erythroid-Specific DNA-Binding Factors / Q000235:genetics; D005260:Female; D051717:Fushi Tarazu Transcription Factors / Q000235:genetics*; D006023:Glycoproteins / Q000235:genetics; D024002:HMGB Proteins / Q000235:genetics; D018398:Homeodomain Proteins / Q000235:genetics; D008297:Male; D008957:Models, Genetic; D018160:Receptors, Cytoplasmic and Nuclear / Q000235:genetics; D055758:SOX9 Transcription Factor; D019849:Sex Determination Processes; D012733:Sex Differentiation / Q000502:physiology*; D054339:Steroidogenic Factor 1; D013735:Testicular Hormones / Q000235:genetics; D014157:Transcription Factors / Q000235:genetics; D025721:WT1 Proteins / Q000235:genetics; D015027:Zebrafish / Q000235:genetics*; D029961:Zebrafish Proteins / Q000235:genetics
C110547:DMRT1 protein; D004268:DNA-Binding Proteins; D050981:Erythroid-Specific DNA-Binding Factors; D051717:Fushi Tarazu Transcription Factors; D006023:Glycoproteins; D024002:HMGB Proteins; D018398:Homeodomain Proteins; D018160:Receptors, Cytoplasmic and Nuclear; D055758:SOX9 Transcription Factor; C504918:Sox9a protein, zebrafish; C504919:Sox9b protein, zebrafish; D054339:Steroidogenic Factor 1; D013735:Testicular Hormones; D014157:Transcription Factors; D025721:WT1 Proteins; D029961:Zebrafish Proteins; C478921:nr5a1a protein, zebrafish; C503714:nr5a1b protein, zebrafish; D054304:Anti-Mullerian Hormone; D001141:Aromatase; C440729:Cyp19a1a protein, zebrafish