Gonad Differentiation in Zebrafish Is Regulated by the Canonical Wnt Signalling Pathway1
Rajini Sreenivasan, Junhui Jiang, Xingang Wang, Richard Bartfai, Hsiao Yuen Kwan, Alan Christoffels and Laszlo Orban Introduction: Zebrafish is an undifferentiated specie described as a juvenile hermaphrodite as its gonadal transformation process into male species undergoes a “juvenile ovary to testis” change (Sreenivasan et al., 2013). One of the important enzymes seen to be involved in sex differentiation is the aromatase Cyp19a1a which is an enzyme important in converting androgens to oestrogens. It is seen to be in high concentrations in the ovaries and low in the testis as its down regulation during gonadal transformation has been hypothesised…show more content… Imuunohistochemistry involves the identification of tissue components by interacting antigens targeted at certain labelled antibodies (Taylor and Levenson, 2006) so its possible for a detection ofspecific components of the cell.
Real-Time RT-PCR was used for the validation of microarray results. This technique based on the principle of polymerase chain reaction (PCR) and is used in the amplification and detection of a certain DNA molecule. It can also be used to quantify the products generated from the PCR process (ncbi.nlm.nih.gov,…show more content… Furthermore, the transgenic inhibition of the Wnt signalling pathway encouraged the transformation into male gonads in Zebrafish. Conclusions: The transformation from a juvenile ovary to testis is reflected at the transcriptomic level with the Wnt signalling genes been expressed at different concentrations during the process. Transgenic inhibition of the Wnt signalling pathway results in a biased sex ratio favouring the males and a very low decrease in the aromatase enzyme’s expression levels in the gonads of the fish indicating the importance of the Wnt signalling pathway are expressed differentially during the transformation. Perspectives: one of the strengths of this study was In the use of microarrays to monitor the gene expression. Just like other techniques used in detecting DNA samples such as southern and Northern blots, microarrays also use hybridisation to detect samples or DNA or RNA in samples. One of the strengths of using microarrays is that unlike the southern blot which uses one single probe to search a mixture containing complex DNA, microarrays make use of a huge range of different probes to analyse the mixture (Abdullah-Sayani, Bueno-de-Mesquita and van de Vijver,
