IN THIS ISSUE
Summary: This Hypothesis article highlights several fundamental differences between rodent and primate early development and exploits these to predict key hallmarks of naïve pluripotency in primates.
Summary: This Review discusses how the planar cell polarity pathway functions to regulate dynamic cell behaviors, in both individual and collectively migrating cells.
STEM CELLS AND REGENERATION
Highlighted article: Primary cilia regulate ventricle morphogenesis in mice by modulating the mTORC1 pathway, highlighting a new role for mTOR signalling during brain development.
Summary: In an ex vivo gland reconstitution model, perfusion-independent signaling by CD31+ endothelial cells opposes the emergence of K19+/K7+ cells in the endbuds of early developing submandibular salivary glands.
Cartilage to bone transformation during fracture healing is coordinated by the invading vasculature and induction of the core pluripotency genes
Summary: During fracture repair in mice, chondrocytes at the chondro-osseous border adjacent to the invading vasculature transdifferentiate into osteoblasts by activating pluripotency programs and initiating cell division.
Ascl2 inhibits myogenesis by antagonizing the transcriptional activity of myogenic regulatory factors
Summary: The transcription factor Ascl2 is identified as a novel inhibitor of myogenic regulatory factors in mice, acting to inhibit myogenic differentiation and facilitate the generation of postnatal satellite cells.
The mammal-specific Pdx1 Area II enhancer has multiple essential functions in early endocrine cell specification and postnatal β-cell maturation
Summary: A crucial enhancer element in the Pdx1 promoter, termed Area II, is required for endocrine progenitor specification, α/β-cell lineage diversification and β-cell maturation in mice.
Summary: Despite their distinct embryonic origins, anterior and posterior neural precursors within the ascidian larval central nervous system are patterned by similar signaling mechanisms.
A vertebrate-specific and essential role for osterix in osteogenesis revealed by gene knockout in the teleost medaka
Summary: A mutation in the medaka osterix (sp7) gene results in severe bone defects and larval lethality, establishing a key role for Osterix in bone formation in a non-mammalian species.
Brassinosteroid signaling directs formative cell divisions and protophloem differentiation in Arabidopsis root meristems
Highlighted article: In addition to controlling cell expansion, brassinosteroid signaling acts cell-autonomously and non-cell-autonomously to promote protophloem differentiation and restrict formative divisions in root meristems.
Basal filopodia and vascular mechanical stress organize fibronectin into pillars bridging the mesoderm-endoderm gap
Highlighted article: In developing quail embryos, pulsations from the dorsal aorta help establish fibronectin pillars that bridge the somite-endoderm gap, potentially aiding communication between these tissues.
High-throughput analysis reveals novel maternal germline RNAs crucial for primordial germ cell preservation and proper migration
Summary: RNA-sequencing analysis identifies 90 novel mRNAs that are enriched at the vegetal pole of Xenopus laevis oocytes, and reveals novel roles for some of these mRNAs in primordial germ cell development.
Summary: CenpH, a component of the kinetochore inner plate protein, is necessary for cyclin B1 stabilization and is responsible for the G2/M transition in meiotic mouse oocytes.
Summary: Analyses of knockout mice indicate that the transcription factor mohawk regulates osteogenic changes associated with age and is essential for homeostasis of the periodontal ligament.
Summary: The analysis of Xenopus loss-of-function mutants reveals that Sipa1l3 – a gene associated with congenital cataracts in humans – interacts with Epha4 signaling to regulate retinal and lens development.
Osteocrin, a peptide secreted from the heart and other tissues, contributes to cranial osteogenesis and chondrogenesis in zebrafish
Summary: Osteocrin functions as a hormone that controls remote bone/cartilage formation in zebrafish by modulating CNP-dependent nuclear export of the transcriptional cofactors Yap1 and Wwtr1.
TECHNIQUES AND RESOURCES
TAEL: a zebrafish-optimized optogenetic gene expression system with fine spatial and temporal control
Summary: Re-engineering the blue light-activated EL222 system, renamed TAEL, provides optogenetic gene expression that enables robust spatial and temporal regulation of gene expression in zebrafish.