Streamlining mouse genome editing by integrating AAV repair template delivery and CRISPR-Cas electroporation.

Recent genome editing techniques have substantially simplified the generation of genetically modified mice. A new study combines adeno-associated viruses (AAV) and electroporation to generate a robust pipeline to deliver CRISPR-Cas reagents into mouse embryos.

A gene regulatory network for neural induction.

During early vertebrate development, signals from a special region of the embryo, the organizer, can redirect the fate of non-neural ectoderm cells to form a complete, patterned nervous system. This is called neural induction and has generally been imagined as a single signalling event, causing a switch of fate. Here, we undertake a comprehensive analysis, in very fine time course, of the events following exposure of competent ectoderm of the chick to the organizer (the tip of the primitive streak, Hensen's node).

USP28 deletion and small-molecule inhibition destabilizes c-MYC and elicits regression of squamous cell lung carcinoma.

Lung squamous cell carcinoma (LSCC) is a considerable global health burden, with an incidence of over 600,000 cases per year. Treatment options are limited, and patient's 5-year survival rate is less than 5%. The ubiquitin-specific protease 28 (USP28) has been implicated in tumourigenesis through its stabilization of the oncoproteins c-MYC, c-JUN, and Δp63.

Secreted gelsolin inhibits DNGR-1-dependent cross-presentation and cancer immunity.

Cross-presentation of antigens from dead tumor cells by type 1 conventional dendritic cells (cDC1s) is thought to underlie priming of anti-cancer CD8 T cells. cDC1 express high levels of DNGR-1 (a.k.

Neural induction by the node and placode induction by head mesoderm share an initial state resembling neural plate border and ES cells.

Around the time of gastrulation in higher vertebrate embryos, inductive interactions direct cells to form central nervous system (neural plate) or sensory placodes. Grafts of different tissues into the periphery of a chicken embryo elicit different responses: Hensen's node induces a neural plate whereas the head mesoderm induces placodes. How different are these processes? Transcriptome analysis in time course reveals that both processes start by induction of a common set of genes, which later diverge.

Genetic tracing via DNGR-1 expression history defines dendritic cells as a hematopoietic lineage.

Mononuclear phagocytes are classified as macrophages or dendritic cells (DCs) based on cell morphology, phenotype, or select functional properties. However, these attributes are not absolute and often overlap, leading to difficulties in cell-type identification. To circumvent this issue, we describe a mouse model to define DCs based on their ontogenetic descendence from a committed precursor.

Dial M(RF) for myogenesis.

The transcriptional regulatory network that controls the determination and differentiation of skeletal muscle cells in the embryo has at its core the four myogenic regulatory factors (MRFs) Myf5, MyoD, Mrf4 and MyoG. These basic helix-loop-helix transcription factors act by binding, as obligate heterodimers with the ubiquitously expressed E proteins, to the E-box sequence CANNTG. While all skeletal muscle cells have the same underlying function their progenitors arise at many sites in the embryo and it has become apparent that the upstream activators of the cascade differ in these various populations so that it can be switched on by a variety of inductive signals, some of which act by initiating transcription, some by maintaining it.

Musculin and TCF21 coordinate the maintenance of myogenic regulatory factor expression levels during mouse craniofacial development.

The specification of the skeletal muscle lineage during craniofacial development is dependent on the activity of MYF5 and MYOD, two members of the myogenic regulatory factor family. In the absence of MYF5 or MYOD there is not an overt muscle phenotype, whereas in the double Myf5;MyoD knockout branchiomeric myogenic precursors fail to be specified and skeletal muscle is not formed. The transcriptional regulation of Myf5 is controlled by a multitude of regulatory elements acting at different times and anatomical locations, with at least five operating in the branchial arches.

Members of the TEAD family of transcription factors regulate the expression of Myf5 in ventral somitic compartments.

The transcriptional regulation of the Mrf4/Myf5 locus depends on a multitude of enhancers that, in equilibria with transcription balancing sequences and the promoters, regulate the expression of the two genes throughout embryonic development and in the adult. Transcription in a particular set of muscle progenitors can be driven by the combined outputs of several enhancers that are not able to recapitulate the entire expression pattern in isolation, or by the action of a single enhancer the activity of which in isolation is equivalent to that within the context of the locus. We identified a new enhancer element of this second class, ECR111, which is highly conserved in all vertebrate species and is necessary and sufficient to drive Myf5 expression in ventro-caudal and ventro-rostral somitic compartments in the mouse embryo.

Evidence for a myotomal Hox/Myf cascade governing nonautonomous control of rib specification within global vertebral domains.

Hox genes are essential for the patterning of the axial skeleton. Hox group 10 has been shown to specify the lumbar domain by setting a rib-inhibiting program in the presomitic mesoderm (PSM). We have now produced mice with ribs in every vertebra by ectopically expressing Hox group 6 in the PSM, indicating that Hox genes are also able to specify the thoracic domain.

HOXB4's road map to stem cell expansion.

Homeodomain-containing transcription factors are important regulators of stem cell behavior. HOXB4 mediates expansion of adult and embryo-derived hematopoietic stem cells (HSCs) when expressed ectopically. To define the underlying molecular mechanisms, we performed gene expression profiling in combination with subsequent functional analysis with enriched adult HSCs and embryonic derivatives expressing inducible HOXB4.

Evolution of GnRH ligands and receptors in gnathostomata.

Gonadotropin-releasing hormone (GnRH) is the final common signaling molecule used by the brain to regulate reproduction in all vertebrates. Until now, a total of 24 GnRH structural variants have been characterized from vertebrate, protochordate and invertebrate nervous tissue. Almost all vertebrates already investigated have at least two GnRH forms coexisting in the central nervous system.

Brain aromatase from pejerrey fish (Odontesthes bonariensis): cDNA cloning, tissue expression, and immunohistochemical localization.

The brain-type aromatase (CYP19A2) cDNA from pejerrey Odontesthes bonariensis was characterized. Its sequence differs from the ovarian-derived aromatase (CYP19A1) previously reported for the same species. The cDNA is 2305bp in length and the deduced protein comprises 501 amino-acids.

Five gonadotrophin-releasing hormone receptors in a teleost fish: isolation, tissue distribution and phylogenetic relationships.

Gonadotrophin-releasing hormone (GnRH) is the main neurohormone controlling gonadotrophin release in all vertebrates, and in teleost fish also of growth hormone and possibly of other adenohypophyseal hormones. Over 20 GnRHs have been identified in vertebrates and protochoordates and shown to bind cognate G-protein couple receptors (GnRHR). We have searched the puffer fish, Fugu rubripes, genome sequencing database, identified five GnRHR genes and proceeded to isolate the corresponding complementary DNAs in European sea bass, Dicentrachus labrax.

Vitellogenin detection in surface mucus of the South American cichlid fish Cichlasoma dimerus (Heckel, 1840) induced by estradiol-17beta. Effects on liver and gonads.

During the last decade, special attention has been focused on the consequences of exposure to environmental estrogens on reproduction in wild fish species. For this reason, characterization of biomarkers of such exposures could result in useful tools for these studies. The detection of vitellogenin (Vtg), a precursor of yolk proteins, is being intensely studied since its synthesis in the liver is regulated by the estradiol-17beta and is influenced by other estrogenic compounds.