Proceedings of The Physiological Society

Europhysiology 2018 (London, UK) (2018) Proc Physiol Soc 41, PCA206

Poster Communications

Differential regulation of mRNA expression by the transcription factors WT1 and GATA4 during murine gonad development

K. M. Kirschner1, L. K. Sciesielski2, R. Vidal3, Q. Gao3, W. Chen3, S. Sauer3, H. Scholz1

1. Inst. of Vegetative Physiology, Charité - Universitätsmedizin Berlin, Berlin, Germany. 2. Department of Neonatology, Charité - Universitätsmedizin Berlin, Berlin, Germany. 3. Max Delbrück Center for Molecular Medicine, Berlin, Germany.

Gonad morphogenesis relies on the correct spatiotemporal expression of a number of genes that together fulfill the differentiation of the bipotential gonad into either testes or ovaries. Mutations in the human genes encoding the transcription factors GATA4 and WT1 cause malformations of the genitourinary system. Furthermore, mice with disrupted Gata4 or Wt1 genes are embryonic lethal and fail to develop gonads. WT1 and GATA4 are both expressed in the bipotential embryonic gonad and in the adult ovaries and testes. To compare the influence of WT1 and GATA4 on gene expression in male and female gonads during embryonic development, we combined a morpholino-induced gene knockdown technique with ex vivo embryonic organ cultures. For this purpose, WT1 and GATA4 protein translation were inhibited in cultured murine embryonic gonads by transfection with specific antisense vivo-morpholinos. Samples were analyzed by next generation mRNA sequencing (RNASeq). Our data analysis revealed striking differences between WT1 and GATA4 in the regulation of mRNA expression in male and female gonads. WT1 knockdown decreased testis promoting mRNAs and increased ovarian promoting transcripts in developing XY-gonads. Furthermore, antisense inhibition of WT1 in embryonic XX-gonads reduced mRNAs favoring ovary formation. This sex-specific mRNA expression pattern was not observed upon knockdown of GATA4, which regulates the same set of genes in male and female gonads. These data demonstrate that WT1 and GATA4 play different roles in the embryonic gonads. While WT1 accounts for a sex-specific gene expression pattern, GATA4 may be required to adjust the mRNA levels that are necessary for normal gonad differentiation in both sexes.

Where applicable, experiments conform with Society ethical requirements