Table of Contents
IN THIS ISSUE
- Blood stem cells: from beginning to end
Summary: This report highlights the major themes and advances presented at the recent EMBL conference 'Hematopoietic stem cells: from the embryo to the aging organism'.
- Making sense out of spinal cord somatosensory development
Summary: This review discusses the mechanisms that generate neuronal diversity in the spinal cord, highlighting how different developmental populations produce neurons with distinct somatosensory functions.
STEM CELLS AND REGENERATION
- Control of germline stem cell differentiation by Polycomb and Trithorax group genes in the niche microenvironment
- The human PRD-like homeobox gene LEUTX has a central role in embryo genome activation
- Identification, visualization and clonal analysis of intestinal stem cells in fish
Summary: Adult medaka intestinal stem cells (ISCs) proliferate within a niche functionally equivalent to that in the mammal. Like mammalian ISCs, but unlike medaka retinal stem cells, their mode of division is largely symmetric.
- Activation of Smad2 but not Smad3 is required to mediate TGF-β signaling during axolotl limb regeneration
Summary: TGFβ signaling has been implicated in scar formation after wounding. During axolotl limb regeneration, differential regulation of Smad effectors may explain why these animals do not scar.
- Beryllium nitrate inhibits fibroblast migration to disrupt epimorphic regeneration
Summary: Inhibiting fibroblast migration during regeneration in axolotl reveals the importance of fibroblasts for blastema-based limb regeneration but not non-blastemal skin regrowth.
- Ebi modulates wing growth by ubiquitin-dependent downregulation of Crumbs in Drosophila
Summary: In the fly wing, the transmembrane protein Crumbs antagonises Notch signalling. Crumbs, in turn, is inhibited by the WD40 domain protein Ebi, thus promoting Notch activity.
- Inhibition of Shh signalling in the chick wing gives insights into digit patterning and evolution
- Vinculin b deficiency causes epicardial hyperplasia and coronary vessel disorganization in zebrafish
Summary: The focal adhesion protein vinculin is required in epicardium and endocardium; its depletion leads to dysregulated FAK signalling and a phenotype mimicking dilated cardiomyopathy.
- Brg1 plays an essential role in development and homeostasis of the duodenum through regulation of Notch signaling
Summary: Brg1, a core subunit of the SWI/SNF chromatin remodeling complex, regulates morphogenesis, differentiation and cell survival of the duodenum, by modulating expression of Notch pathway ligands.
- A novel small molecule that disrupts a key event during the oocyte-to-embryo transition in C. elegans
Summary: The small molecule C22 induces expression of the LET-607 transcription factor, leading to mis-regulation of protein trafficking and thus impairing eggshell formation and the oocyte-to-embryo transition.
- Early formation of the Müllerian duct is regulated by sequential actions of BMP/Pax2 and FGF/Lim1 signaling
Summary: In the developing female reproductive tract, BMP/Pax2 and FGF/Lim1 axes operate in a spatio-temporally regulated manner to promote specification and invagination of Müllerian duct precursors.
- Tbx3 represses bmp4 expression and, with Pax6, is required and sufficient for retina formation
Summary: The transcription factor Tbx3 is required for eye formation. Although neither Tbx3 nor Pax6 alone is sufficient, together they can determine retina from pluripotent cells in Xenopus.
- The histone methyltransferase Setd7 promotes pancreatic progenitor identity
Summary: In both mouse and Xenopus, Setd7 is a key regulator of the pancreatic differentiation program, modulating chromatin state at pancreatic regulatory regions in cooperation with Foxa2.
- cAMP-dependent protein kinase A (PKA) regulates angiogenesis by modulating tip cell behavior in a Notch-independent manner
Summary: During zebrafish angiogenesis, endothelial PKA activity regulates the transition from sprouting to stabilisation of nascent vessels, preventing excessive tip cell formation and hypersprouting.
- Complex cis-regulatory landscape of the insulin receptor gene underlies the broad expression of a central signaling regulator
Summary: Although the Drosophila insulin gene is broadly expressed, its regulation is complex - with multiple cis-regulatory elements integrating nutritional and tissue-specific inputs.
- Microtubule-severing activity of the AAA+ ATPase Katanin is essential for female meiotic spindle assembly
Summary: In C. elegans, the MEI-2 subunit of Katanin is required for its microtubule-severing activity. Katanin variants that can bind but not sever microtubules can not support normal meiotic spindle assembly.
- Genetic basis for the evolution of organ morphogenesis: the case of spalt and cut in the development of insect trachea
Summary: Changes in the expression domains of the spalt and cut transcription factors are associated with the acquisition of tracheal morphology innovations in insects.
- The evolutionarily conserved transcription factor Sp1 controls appendage growth through Notch signaling
Summary: Analysis of the transcription factor Sp1 in the fly leg reveals its key role in regulating segmentation, acting at least in part through the Notch ligand Serrate.
TECHNIQUES AND RESOURCES
- Mapping a multiplexed zoo of mRNA expression
Summary: Multiplexed in situ hybridisation chain reaction allows visualisation of multiple mRNAs in a single sample with subcellular resolution. This technology can be applied in many species.
ARTICLES OF INTEREST IN OUR OTHER JOURNALS
From Journal of Cell Science