Supplementary Material for: Inhibiting p38α and β MAPK affects testis development in the marsupial tammar wallaby

Introduction: The MAPK genes are critical for gonadal differentiation in eutherian mammals but their role in marsupial mammals is unknown. Characterisation and phylogenetic analyses of the tammar wallaby MAPK genes shows these genes are highly conserved with their orthologues in mammalian and non-mammalian species.
Methods: We cultured sexually indifferent tammar gonads in the presence of p38α and β MAPK inhibitor, SB202190.
Results: SB202190 downregulated SOX9 and AMH levels in XY treated gonads when compared to controls, similar to the effects of oestrogen on the MAPK pathway in males. In contrast, XX gonads treated with the SB202190 inhibitor showed no change in mRNA expression between the control and treated gonads for any of the markers tested.
Conclusions: This study confirms that components of the MAPK pathway drive testis differentiation via the key downstream genes SOX9 and AMH in marsupials as is observed in eutherian mammals.

引言：丝裂原活化蛋白激酶（mitogen-activated protein kinase，MAPK）基因在真兽类哺乳动物的性腺分化中发挥关键作用，但其在有袋类哺乳动物中的功能尚不明确。对塔马尔沙袋鼠（tammar wallaby）的MAPK基因进行表征与系统发育分析后发现，这些基因与哺乳类及非哺乳类物种的同源基因高度保守。
方法：我们将处于性别未分化阶段的塔马尔沙袋鼠性腺置于添加了p38α和β型MAPK抑制剂SB202190的培养基中进行体外培养。
结果：与对照组相比，经SB202190处理的XY性腺中，SOX9与AMH的mRNA水平显著下调，该效应与雌激素对雄性个体MAPK通路的调控作用相似。与之相反，经SB202190处理的XX性腺中，所有检测标志物的mRNA表达量在实验组与对照组间均无显著差异。
结论：本研究证实，正如在真兽类哺乳动物中观察到的现象，MAPK通路的相关组分通过关键下游基因SOX9与AMH介导了有袋类动物的睾丸分化过程。