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Morphogen-mediated signaling is critical for proper organ development and stem cell function, and well-characterized mechanisms spatiotemporally limit the expression of ligands, receptors, and ligand-binding cell-surface glypicans. Here, we show that in the developing Drosophila ovary, canonical Wnt signaling promotes the formation of somatic escort cells (ECs) and their protrusions, which establish a physical permeability barrier to define morphogen territories for proper germ cell differentiation. The protrusions shield germ cells from Dpp and Wingless morphogens produced by the germline stem cell (GSC) niche and normally only received by GSCs. Genetic disruption of EC protrusions allows GSC progeny to also receive Dpp and Wingless, which subsequently disrupt germ cell differentiation. Our results reveal a role for canonical Wnt signaling in specifying the ovarian somatic cells necessary for germ cell differentiation. Additionally, we demonstrate the morphogen-limiting function of this physical permeability barrier, which may be a common mechanism in other organs across species.

A new 8,17-epoxybriarane, briastecholide O (1), was isolated from an encrusting algae-containing cultured octocoral Briareum stechei. Moreover, wild-type B. stechei collected from Okinawan waters yielded a new 8,17-epoxybriarane, briastecholide P (2), along with two known analogs, namely, briaexcavatins G (3) and X (4). Single-crystal X-ray diffraction was conducted to determine the absolute configurations of 2 – 4 , while the structure of 1 was established by spectroscopic elucidation. Briaranes 1 and 3 were active in enhancing the growth of MG-63 human mesenchymal stem cells. [Display omitted] • New briaranes, briastecholides O (1) and P (2), were isolated from Briareum stechei. • The absolute configuration of briarane 2 was determined via X-ray analysis. • Briarane 1 enhanced the growth of MG-63 human mesenchymal stem cells. [ABSTRACT FROM AUTHOR]

The mRNA 5'-cap structure removal by the decapping enzyme DCP2 is a critical step in gene regulation. While DCP2 is the catalytic subunit in the decapping complex, its activity is strongly enhanced by multiple factors, particularly DCP1, which is the major activator in yeast. However, the precise role of DCP1 in metazoans has yet to be fully elucidated. Moreover, in humans, the specific biological functions of the two DCP1 paralogs, DCP1a and DCP1b, remain largely unknown. To investigate the role of human DCP1, we generated cell lines that were deficient in DCP1a, DCP1b, or both to evaluate the importance of DCP1 in the decapping machinery. Our results highlight the importance of human DCP1 in decapping process and show that the EVH1 domain of DCP1 enhances the mRNA-binding affinity of DCP2. Transcriptome and metabolome analyses outline the distinct functions of DCP1a and DCP1b in human cells, regulating specific endogenous mRNA targets and biological processes. Overall, our findings provide insights into the molecular mechanism of human DCP1 in mRNA decapping and shed light on the distinct functions of its paralogs. [ABSTRACT FROM AUTHOR]