Issues

Summary: ‘Endoderm Development and Disease’, a Keystone symposium held in February 2018, emphasized the importance of using a variety of models, including organoids, for gaining a more complete understanding of endoderm development.

Summary: A role for Piwi-interacting RNAs (piRNAs) in the regulation of endogenous gene expression challenges dogma in the piRNA field. This Review focuses on recent data addressing the biological and developmental functions of piRNAs.

Highlighted Article: Intermediate progenitors (IPs) in early developing mouse neocortex produce neuronal clones of diverse sizes (1-12 cells), including multilayer clones; remarkably, ∼2/3 of early IP divisions lead to asymmetric cell death.

Summary: The fly testis niche directly controls expression of stem cell proliferation associated genes, independent of a binary cell fate decision between stemness and proliferation.

Highlighted Article: Here, we report the first mammalian model to investigate the role of the minor spliceosome in cortical development and microcephaly – a conditional knockout mouse for Rnu11, the gene encoding the U11 small nuclear RNA.

Summary: Drosophila ovarian germline cells with altered replication-coupled chromatin assembly show a compromised identity and DNA damage, both of which are associated with a defect in heterochromatin-mediated transcriptional silencing.

Summary: Examination of conditional mouse mutants reveals a novel role for Gli3 in controlling the cell cycle of radial glial cells and thereby neuron generation and growth of the cerebral cortex.

Summary: In chicken, feather keratinocytes interpret the global Wnt signaling gradient through coupling with the local apical-basal polarity cue and change their shape accordingly.

Summary: In vivo transplantation studies demonstrate that both sox32-dependent endodermal specification and Nodal ligand reception are necessary to drive sorting of ectopic endodermal cells to the zebrafish inner layer.

Summary: A knockdown study of lysophosphatidic acid receptor 4 in the developing mouse neocortex reveals that it regulates bipolar morphology and radial migration of newborn neurons through F-actin reorganization.

Summary: Systematic quantification of morphological traits in Arabidopsis thaliana cytochrome P450 mutants shows that CYP77A4 is a novel element for embryo development through polar transport of the phytohormone auxin.

Summary: Spastin main isoforms play crucial and specific roles in zebrafish motor circuit wiring and larval locomotion through their distinct regulation of the BMP and neuropilin 1 axon guidance pathways.

Summary: The E3 ubiquitin ligase RNF220 modulates the protein stability of multiple progenitor factors in cooperation with ZC4H2, limiting the borders of ventral progenitor domains and affecting interneuron cell fate specification in the developing spinal cord.

Summary: The conduction system, which controls cardiac electrical activity, develops from a network of Tbx3-expressing precursor cells in the embryonic heart.

Summary: The developmental mechanisms that cause ectopic pancreas are poorly understood. Here, we show that aberrant dorsal pancreas morphogenesis in Hes1 mutants leads to ectopic pancreas, depending on the pro-endocrine gene Neurog3.

Highlighted Article: Misexpression of the Drosophila axon guidance molecule Sidestep results in a permanent loss of neuromuscular junctions and severe innervation and locomotion defects in embryos and larvae.

Summary: A novel function for the Ma2/d auxiliary subunit of the Ca²⁺ channel in promoting the perinuclear association of the sarcoplasmic reticulum and in maintaining myonuclear position in muscles.

Summary: Glypican 4 promotes efficient migration of the anterior endodermal cells in a non-cell autonomous manner, interacting with Mmp14 to limit extracellular matrix deposition, creating an environment conducive to this migration.

Summary: The first description of genes (for example, Rasip1) and mechanisms participating in lumen maintenance and valve formation in the lymphatic vasculature.

Highlighted Article: Embryonic cell lineage tracing of adipose tissue reveals that perigonadal fat arises from distinct mesodermal subcompartments in males and females, and that <50% of interscapular brown fat arises from central dermomyotome.