The massive quantity of information that has accumulated in recent years, backed by functional genomic studies in the mouse, numerous authors have Title Loaded From File suggested that the mouse model is not wholly relevant to other mammalian species. As reported by other folks ( and references therein), a Carnegie stage comparison on the major developmental stages in male sexual improvement across various mammalian species showed that genital ridge emergence, SRY and SOX gene expression, and testis cord formation occur at an earlier stage inside the mouse than in all other species. Furthermore, inside the other mammals studied, which include the rabbit species, these events had been reported at comparable developmental stages. Considering the length of gestation, the occurrence of meiosis at around birth inside the female, the high number of foetuses inside the litter and recent possibilities to investigate gene function in non-mouse species by utilizing enzymes created to target precise regions of any genome, the rabbit species may very well be utilized conveniently to study the gene pathways involved in sex determination and gonad improvement. The key options of the present study have already been reported inside a schematic conclusion figure (Figure ). Determined by our present data, we’re capable to confirm inside the rabbit the relevance on the classic model for mammalian sex determination. Indeed, because it is clearly visible in Figure, within the testis, expression in the SRY gene started from dpc just following genital crest individualization, together with that from the DMRT, SOX and AMH genes, when in the ovary, the onset of expression of your FOXL, RSPO and WNT genes marked the female commitment from the gonad from dpc. Nonetheless, it really is worth highlighting some particular capabilities of the rabbit, as reported inside the present study. The patterns of SRY andmeiosis happens around birth. The first indicators of leptoten stages are visible at dpc, and later stages are clearly observed from birth. Meiosis spans for two weeks following birth. Finally, ovocytes are blocked in the diploten stage. In XY rabbit, various authors have reported figures of germ cells in the preleptoten stage prior to birth, at the similar stage as within the female, without the need of any indicators of further true meiosis; nonetheless, the first signs of correct meiosis were only observed within the male months following birth. Within this study, the expression of genes certain to meiotic events was analysed throughout gestation until adulthood. 3 genes have been studied in distinct (Figure ). The STRA gene is expressed beneath retinoic acid (RA) activation, and is known to become mandatory for the onset of meiosis. DMC is usually a recombinase A connected protein vital for the progression of meiosis. Within the mouse, NANOS is essential for the survival of primordial germ cells, and it has been recommended that it acts inside the testis as a meiotic repressor. As expected, the STRA gene was drastically expressed inside the ovary from dpc, at the onset of meiosis (Figure A). ItsplosoneRabbit Gonad DifferentiationFigure. Expression of germinal-specific marker genes. Expression levels of your OCT and VASA genes had been determined in testes and ovaries. Values are provided as percentages immediately after normalisation for the highest worth. A, A and B, B immunofluorescence detection of OCT and VASA proteins in paraffin sections of gonads. Immunofluorescence pictures are offered with every DAPI counterstaining. The antibody against OCT stains the nuclei of germ cells in dpc testis (A) or ovary (A).