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During gastrulation and neurulation, the chordamesoderm and overlying neuroectoderm of vertebrate embryos converge under the control of a specific genetic programme to the dorsal midline, simultaneously extending along it. However, whether mechanical tensions resulting from these morphogenetic movements play a role in long-range feedback signaling that in turn regulates gene expression in the chordamesoderm and neuroectoderm is unclear. In the present work, by using a model of artificially stretched explants of Xenopus midgastrula embryos and full-transcriptome sequencing, we identified genes with altered expression in response to external mechanical stretching. Importantly, mechanically activated genes appeared to be expressed during normal development in the trunk, i.e., in the stretched region only. By contrast, genes inhibited by mechanical stretching were normally expressed in the anterior neuroectoderm, where mechanical stress is low. These results indicate that mechanical tensions may play the role of a long-range signaling factor that regulates patterning of the embryo, serving as a link coupling morphogenesis and cell differentiation. [ABSTRACT FROM AUTHOR]

Ferroptosis is a unique variety of non-apoptotic cell death, driven by massive lipid oxidation in an iron-dependent manner. Since ferroptosis was introduced as a concept in 2012, it has demonstrated its essential role in the pathogenesis in neurodegenerative diseases and an important role in therapy-resistant cancer cells. Thus, detailed molecular understanding of both canonical and alternative ferroptosis pathways is required. There is a set of widely used chemical agents to modulate ferroptosis using different pathway targets: erastin blocks cystine–glutamate antiporter, system xc-; ML210 directly inactivates GPX4; and L-buthionine sulfoximine (BSO) inhibits γ-glutamylcysteine synthetase, an essential enzyme for glutathione synthesis de novo. Most studies have focused on the lipidomic profiling of model systems undergoing death in a ferroptotic modality. In this study, we developed high-quality shotgun proteome sequencing during ferroptosis induction by three widely used chemical agents (erastin, ML210, and BSO) before and after 24 and 48 h of treatment. Chromato-mass spectra were registered in DDA mode and are suitable for further label-free quantification. Both processed and raw files are publicly available and could be a valuable dynamic proteome map for further ferroptosis investigation. Dataset: Shotgun proteomics are available at the PRoteomics IDEntifications (PRIDE) Archive database with the following dataset identifiers: Erastin experiment—PXD041463 (https://www.ebi.ac.uk/pride/archive/projects/PXD041463 , DOI: 10.6019/PXD041463); ML210 experiment—PXD041327 (https://www.ebi.ac.uk/pride/archive/projects/PXD041327 , DOI: 10.6019/PXD041327); BSO—PXD041415 (https://www.ebi.ac.uk/pride/archive/projects/PXD041415 , DOI: 10.6019/PXD041415). Dataset License: CC-BY-NC [ABSTRACT FROM AUTHOR]

How embryos scale patterning according to size is still not fully understood. Through in silico screening and analysis of reaction-diffusion systems that could be responsible for scaling, we predicted the existence of genes whose expression is sensitive to embryo size and which regulate the scaling of embryonic patterning. To find these scalers , we identified genes with strongly altered expression in half-size Xenopus laevis embryos compared with full-size siblings at the gastrula stage. Among found genes, we investigated the role of matrix metalloproteinase-3 (mmp3), which was most strongly downregulated in half-size embryos. We show that Mmp3 scales dorsal-ventral patterning by degrading the slowly diffusing embryonic inducers Noggin1 and Noggin2 but preventing cleavage of the more rapidly diffusing inducer Chordin via degradation of a Tolloid-type proteinase. In addition to unraveling the mechanism underlying the scaling of dorsal-ventral patterning, this work provides proof of principal for scalers identification in embryos of other species. [Display omitted] • Scalers are patterning genes whose expression is sensitive to embryo size • Search for scalers using model of Xenopus wild-type and half-size embryos • Mmp3 scales dorsal-ventral patterning to match embryo size • Mmp3 protects Chordin from cleavage by Tolloid but promotes Noggin1/2 degradation Orlov, Nesterenko et al. investigate embryonic scaling, the mechanism ensuring that embryonic structures are proportional to size. In a screen for " scalers " — genes with size-dependent expression — they identify matrix metalloproteinase 3 (mmp3) and show that it scales dorsal-ventral patterning in frog embryos by oppositely regulating the Chordin and Noggin1/2 morphogens. [ABSTRACT FROM AUTHOR]

The Agr family genes, Ag1, Agr2, and Agr3, encode for the thioredoxin domain containing secreted proteins and are specific only for vertebrates. These proteins are attracting increasing attention due to their involvement in many physiological and pathological processes, including exocrine secretion, cancer, regeneration of the body appendages, and the early brain development. At the same time, the mode by which Agrs regulate intracellular processes are poorly understood. Despite that the receptor to Agr2, the membrane anchored protein Prod1, has been firstly discovered in Urodeles, and it has been shown to interact with Agr2 in the regenerating limb, no functional homologs of Prod1 were identified in other vertebrates. This raises the question of the mechanisms by which Agrs can regulate regeneration in other lower vertebrates. Recently, we have identified that Tfp4 (three-fingers Protein 4), the structural and functional homolog of Prod1 in Anurans, interacts with Agr2 in Xenopus laevis embryos. In the present work we show by several methods that the activity of Tfp4 is essential for the tadpole tail regeneration as well as for the early eye and forebrain development during embryogenesis. These data show for the first time the common molecular mechanism of regeneration regulation in amphibians by interaction of Prod1 and Agr2 proteins., (© 2019 Wiley Periodicals, Inc.)