Background: RNA-binding motif protein 19 (RBM19, NCBI Accession # NP_083038) is a conserved nucleolar protein containing 6 conserved RNA recognition motifs. Its biochemical function is to process rRNA for ribosome biogenesis, and it has been shown to play a role in digestive organ development in zebrafish. Here we analyzed the role of RBM19 during mouse embryonic development by generating mice containing a mutation in the Rbm19 locus via gene-trap insertion. Results: Homozygous mutant embryos failed to develop beyond the morula stage, showing defective nucleologenesis, activation of apoptosis, and upregulation of P53 target genes. A unique feature of RBM19 is its localization to the cytoplasm in morula stage-embryos, whereas most other nucleolar proteins are localized to the nucleolar precursor body (NPB). The nucleoli in the Rbm19 mutant embryos remain immature, yet they can carry out rRNA synthesis. The timing of developmental arrest occurs after expression of the inner cell mass markers OCT3/4 and NANOG, but prior to the specification of trophectoderm as reflected by CDX2 expression. Conclusion: The data indicate that RBM19 is essential for preimplantation development, highlighting the importance of de novo nucleologenesis during this critical developmental stage.

In multiple vertebrate organisms, including chick, Xenopus, and zebrafish, Fibroblast Growth Factor (FGF) and Wnt signaling cooperate during formation of the otic placode. However, in the mouse, although FGF signaling induces Wnt8a expression during induction of the otic placode, it is unclear whether these two signaling pathways functionally cooperate. Sprouty (Spry) genes encode intracellular antagonists of receptor tyrosine kinase signaling, including FGF signaling. We previously demonstrated that the Sprouty1 (Spry1) and Sprouty2 (Spry2) genes antagonize FGF signaling during induction of the otic placode. Here, we investigate cross talk between FGF/SPRY and Wnt signaling during otic placode induction and assess whether these two signaling pathways functionally cooperate during early inner ear development in the mouse. Embryos were generated carrying combinations of a Spry1 null allele, Spry2 null allele, β-catenin null allele, or a Wnt reporter transgene. Otic phenotypes were assessed by in situ hybridization, semi-quantitative reverse transcriptase PCR, immunohistochemistry, and morphometric analysis of sectioned tissue. Comparison of Spry1, Spry2, and Wnt reporter expression in pre-otic and otic placode cells indicates that FGF signaling precedes and is active in more cells than Wnt signaling. We provide in vivo evidence that FGF signaling activates the Wnt signaling pathway upstream of TCF/Lef transcriptional activation. FGF regulation of Wnt signaling is functional, since early inner ear defects in Spry1 and Spry2 compound mutant embryos can be genetically rescued by reducing the activity of the Wnt signaling pathway. Interestingly, we find that although the entire otic placode increases in size in Spry1 and Spry2 compound mutant embryos, the size of the Wnt-reporter-positive domain does not increase to the same extent as the Wnt-reporter-negative domain. This study provides genetic evidence that FGF and Wnt signaling cooperate during early inner ear development in the mouse. Furthermore, our data suggest that although specification of the otic placode may be globally regulated by FGF signaling, otic specification of cells in which both FGF and Wnt signaling are active may be more tightly regulated.

Introduction: Providing quality healthcare for children includes assessing and responding to needs of their family caregivers. Three salient domains to consider are caregivers’ early adverse childhood experiences (ACEs), their current levels of distress, and their resilience in coping with both prior and current stressors. Objective: Determine acceptability of assessing caregiver ACEs, current distress, and resilience in pediatric subspecialty care settings. Methods: Caregivers of patients in two pediatric specialty care clinics completed questionnaires about their ACEs, recent emotional distress, and resilience. Importantly, caregivers also rated the acceptability of being asked these questions. Participants included 100 caregivers of youth ages 3–17 across Sickle Cell Disease and Pain clinic settings. The majority of participants were mothers (91.0%) who identified as non-Hispanic (86.0%). Caregiver race was primarily African American/Black (53.0%) and White (41.0%). The Area Deprivation Index (ADI) was used to assess socioeconomic disadvantage. Results: High levels of caregiver acceptability or neutrality with assessing ACEs and distress, as well as high ACEs, distress, and resilience. Associations were found between caregiver ratings of acceptability with caregiver resilience and socioeconomic disadvantage. Caregivers reported openness to being asked about their experiences during childhood and recent emotional distress, although ratings of acceptability varied according to other contextual variables, such as level of socioeconomic disadvantage and caregiver resilience. In general, caregivers perceived themselves to be resilient in the face of adversity. Conclusions: Assessing caregiver ACEs and distress in a trauma-informed way may provide opportunities for better understanding the needs of caregivers and families in order to support them more effectively in the pediatric setting.