Data from: Musashi exerts control of gonadotrope target mRNA translation during the mouse estrous cycle

<p class="MsoNormal">The anterior pituitary controls key biological processes, including growth, metabolism, reproduction and stress responses through distinct cell types that each secrete specific hormones. The anterior pituitary cells show a remarkable level of cell type plasticity that mediates the shifts in hormone producing cell populations that are required to meet organismal needs. The molecular mechanisms underlying pituitary cell plasticity are not well understood. Recent work has implicated the pituitary stem cell populations and specifically, the mRNA binding proteins of the Musashi family in control of pituitary cell type identity. In this study we have identified the target mRNAs that mediate Musashi function in the adult mouse pituitary and demonstrate the requirement for Musashi function <em>in vivo</em>. Using Musashi RNA immunoprecipitation, we identify a cohort of 1184 mRNAs that show specific Musashi binding. Identified Musashi targets include the <em>Gnrhr </em>mRNA, which encodes the gonadotropin releasing hormone receptor (GnRHR), and the <em>Fshb </em>mRNA, encoding <em>follicle-stimulating hormone</em> (FSH). Reporter assays reveal that Musashi functions to exert repression of translation of the <em>Fshb</em> mRNA, in addition to the previously observed repression of the <em>Gnrhr</em>mRNA. Importantly, mice engineered to lack Musashi in gonadotropes demonstrate a failure<em> </em>to repress translation of the endogenous <em>Gnrhr</em> and <em>Fshb</em> mRNAs during the estrous cycle and display a significant heterogeneity in litter sizes. The range of identified target mRNAs suggests that, in addition to these key gonadotrope proteins, Musashi may exert broad regulatory control over the pituitary proteome in a cell-type specific manner.</p>