Rbpms2 promotes female fate upstream of the nutrient sensing Gator2 complex component Mios

Area of Science:

• Developmental Biology
• Genetics
• Molecular Biology

Background:

• Reproductive success depends on establishing and maintaining biological sex.
• The primary gonad is initially ovary-biased in many animals, including mammals.
• The RNA binding protein Rbpms2 is crucial for ovary fate determination in zebrafish.

Purpose of the Study:

• To identify Rbpms2 targets in oocytes (rboRNAs).
• To elucidate the role of Rbpms2 in regulating gene expression at the translational level.
• To investigate the mechanism by which Rbpms2 influences early gonocyte development and sexual differentiation.

Main Methods:

• Identification of Rbpms2-bound oocyte RNAs (rboRNAs).
• Analysis of Rbpms2's translational regulatory function.
• Genetic analyses to determine Rbpms2's role in the mTorc1 signaling pathway and nucleolar amplification.

Main Results:

• Rbpms2 targets include genes involved in testis development and ribosome biogenesis.
• Rbpms2 functions as a translational regulator of these target RNAs.
• Rbpms2 promotes nucleolar amplification via the mTorc1 signaling pathway, specifically through the Mios component of Gator2.

Conclusions:

• Early gonocytes exist in a bipotential state where Rbpms2 acts as a binary fate-switch.
• Rbpms2 represses male-determining factors and promotes female-determining factors for oocyte progression.
• Rbpms2 integrates sexual differentiation pathways with nutrient availability signaling (mTorc1) in zebrafish oogenesis.