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Cephalopods are emerging animal models and iconic species to study the link between genomic innovations and physiological and behavioral complexities. Coleoid cephalopods possess the largest nervous system among invertebrates, both for cell counts and body-to-brain ratio.Octopus vulgarishas been at the center of a long-standing tradition of research into diverse aspects of cephalopod biology, including behavioral and neural plasticity, learning and memory recall, regeneration, and sophisticated cognition. However, no chromosome-scale genome assembly is available forO. vulgaristo aid in functional studies. To fill this gap, we sequenced and assembled a chromosome-scale genome of the common octopus,O. vulgaris. The final assembly spans 2.8 billion basepairs, 99.34% of which are in 30 chromosome-scale scaffolds. Hi-C heatmaps support a karyotype of 1n=30 chromosomes. Comparisons with other octopus species’ genomes show a conserved octopus karyotype, and a pattern of local genome rearrangements between species. This new chromosome-scale genome ofO. vulgariswill further facilitate molecular research in all aspects of cephalopod biology, including various forms of plasticity and the neural machinery underlying sophisticated cognition, as well as an understanding of cephalopod evolution.

Soft-bodied cephalopods such as the octopus are exceptionally intelligent invertebrates with a highly complex nervous system that evolved independently from vertebrates. Because of elevated RNA editing in their nervous tissues, we hypothesized that RNA regulation may play a major role in the cognitive success of this group. We thus profiled mRNAs and small RNAs in 18 tissues of the common octopus. We show that the major RNA innovation of soft-bodied cephalopods is a massive expansion of the miRNA gene repertoire. These novel miRNAs were primarily expressed in neuronal tissues, during development, and had conserved and thus likely functional target sites. The only comparable miRNA expansions happened, strikingly, in vertebrates. Thus, we propose that miRNAs are intimately linked to the evolution of complex animal brains.One-Sentence SummarymiRNAs are deeply linked to the emergence of complex brains.

Gene expression analysis has been instrumental to understand the function of key factors during embryonic development of many species. Marker analysis is also used as a tool to investigate organ functioning and disease progression. As these processes happen in three dimensions, the development of technologies that enable detection of gene expression in the whole organ or embryo is essential. Here, we describe an optimized protocol of whole mount multiplexed RNA in situ hybridization chain reaction version 3.0 (HCR v3.0) in combination with immunohistochemistry (IHC), followed by fructose-glycerol clearing and light sheet fluorescence microscopy (LSFM) imaging on whole-mount Octopus vulgaris embryos. We developed a code to automate probe design which can be applied for designing HCR v3.0 type probe pairs for fluorescent in situ mRNA visualization. As proof of concept, neuronal (Ov-elav) and glial (Ov-apolpp) markers were used for multiplexed HCR v3.0. Neural progenitor (Ov-ascl1) and precursor (Ov-neuroD) markers were combined with an immunostaining for phosphorylated-histone H3, a marker for mitosis. After comparing several tissue clearing methods, fructose-glycerol clearing was found optimal in preserving the fluorescent signal of HCR v3.0. The expression that was observed in whole-mount octopus embryos matched with the previous expression data gathered from paraffin-embedded transverse sections. Three-dimensional reconstruction revealed additional spatial organization that had not been discovered using two-dimensional methods.

Here, we are providing an optimized, step-by-step clearing protocol that retains the signal generated by HCR v3.0 in whole mount Octopus vulgaris embryos, even in combination with immunohistochemistry. Please cite (Elagoz et al., 2022) if you use this protocol. For designing HCR v3.0 probe pairs, we have developed an automated tool called Easy_HCR which can be found at https://github.com/SeuntjensLab/Easy_HCR.

The aging central nervous system (CNS) of mammals displays progressive limited regenerative abilities. Recovery after loss of neurons is extremely restricted in the aged brain. Many research models fall short in recapitulating mammalian aging hallmarks or have an impractically long lifespan. We established a traumatic brain injury model in the African turquoise killifish (Nothobranchius furzeri), a regeneration‐competent vertebrate that evolved to naturally age extremely fast. Stab‐wound injury of the aged killifish dorsal telencephalon unveils an impaired and incomplete regeneration response when compared to young individuals. In the young adult killifish, brain regeneration is mainly supported by atypical non‐glial progenitors, yet their proliferation capacity clearly declines with age. We identified a high inflammatory response and glial scarring to also underlie the hampered generation of new neurons in aged fish. These primary results will pave the way to unravel the factor age in relation to neurorepair, and to improve therapeutic strategies to restore the injured and/or diseased aged mammalian CNS., Neuroregeneration after stab‐wound injury is incomplete in aged killifish, caused by reduced proliferation of specialized non‐glial progenitors (NGPs) and mammalian‐like glial scarring. It seems that aged killifish deploy the restricted regenerative program, typically associated with mammals, instead of successful neurorepair as shown here for young adult killifish.

Worldwide, people are getting older, and this prolonged lifespan unfortunately also results in an increased prevalence of age-related neurodegenerative diseases, contributing to a diminished life quality of elderly. Age-associated neuropathies typically include diseases leading to dementia (Alzheimer's and Parkinson's disease), as well as eye diseases such as glaucoma and age-related macular degeneration. Despite many research attempts aiming to unravel aging processes and their involvement in neurodegeneration and functional decline, achieving healthy brain aging remains a challenge. The African turquoise killifish (Nothobranchius furzeri) is the shortest-lived reported vertebrate that can be bred in captivity and displays many of the aging hallmarks that have been described for human aging, which makes it a very promising biogerontology model. As vision decline is an important hallmark of aging as well as a manifestation of many neurodegenerative diseases, we performed a comprehensive characterization of this fish's aging visual system. Our work reveals several aging hallmarks in the killifish retina and brain that eventually result in a diminished visual performance. Moreover, we found evidence for the occurrence of neurodegenerative events in the old killifish retina. Altogether, we introduce the visual system of the fast-aging killifish as a valuable model to understand the cellular and molecular mechanisms underlying aging in the vertebrate central nervous system. These findings put forward the killifish for target validation as well as drug discovery for rejuvenating or neuroprotective therapies ensuring healthy aging. ispartof: npj Aging and Mechanisms of Disease vol:7 issue:1 pages:1-17 ispartof: location:England status: published

SummaryThe African turquoise killifish combines a short lifespan with spontaneous age-dependent loss of neuroregenerative capacity. The stem cell niches driving neuroregeneration and their molecular signatures remain elusive. To investigate this, we performed scRNA-seq of the adult telencephalon, combined with full-length transcriptomics using ISO-seq. Our results unveil about 25 cell types including neurons and progenitors of glial-and non-glial nature. Subclustering of progenitors identifies four radial glia (RG), and two non-glial progenitor (NGP) cell states. Combining the molecular profiles with spatial mapping of the RG clusters, reveals two spatially divergent astroglia, one ependymal, and one neuroepithelial-like subtype. We propose neuroepithelial-like RG and NGPs to be the start and intercessor populations of both neuro- and gliogenic lineages. Neuronal classification reveals distinct subtypes and lineages corresponding to excitatory and inhibitory neurons. This catalogue of telencephalon cell types is an extensive resource to understand the molecular basis of intrinsic plasticity shaping adult neuro- and gliogenesis.HighlightsScRNA-seq and ISO-seq identified a complete cell catalogue of the adult killifish telencephalonProgenitor diversity revealed the presence of spatially-defined (astro)glial subtypesA neuroepithelial radial glia population marks the start point of neurogenesis, accompanied by proliferative non-glial progenitorsImmature neurons form transcriptional subgroups that correspond to excitatory and inhibitory mature neuronal cell typesThis cellular atlas is a basis for studying neurogenesis and neuro-regeneration upon injury, disease and aging

Protocadherins (Pcdhs) are cell adhesion molecules that belong to the cadherin superfamily, and are subdivided into clustered (cPcdhs) and non-clustered Pcdhs (ncPcdhs) in vertebrates. In this review, we summarize their discovery, expression mechanisms, and roles in neuronal development and cancer, thereby highlighting the context-dependent nature of their actions. We furthermore provide an extensive overview of current structural knowledge, and its implications concerning extracellular interactions between cPcdhs, ncPcdhs, and classical cadherins. Next, we survey the known molecular action mechanisms of Pcdhs, emphasizing the regulatory functions of proteolytic processing and domain shedding. In addition, we outline the importance of Pcdh intracellular domains in the regulation of downstream signaling cascades, and we describe putative Pcdh interactions with intracellular molecules including components of the WAVE complex, the Wnt pathway, and apoptotic cascades. Our overview combines molecular interaction data from different contexts, such as neural development and cancer. This comprehensive approach reveals potential common Pcdh signaling hubs, and points out future directions for research. Functional studies of such key factors within the context of neural development might yield innovative insights into the molecular etiology of Pcdh-related neurodevelopmental disorders. ispartof: Frontiers In Molecular Neuroscience vol:13 ispartof: location:Switzerland status: published

Background: Octopus vulgaris has been an iconic cephalopod species for neurobiology research as well as for cephalopod aquaculture. It is one of the most intelligent and well-studied invertebrates, possessing both long- and short-term memory and the striking ability to perform complex cognitive tasks. Nevertheless, how the common octopus developed these uncommon features remains enigmatic. O. vulgaris females spawn thousands of small eggs and remain with their clutch during their entire development, cleaning, venting and protecting the eggs. In fact, eggs incubated without females usually do not develop normally, mainly due to biological contamination (fungi, bacteria, etc.). This high level of parental care might have hampered laboratory research on the embryonic development of this intriguing cephalopod. Results: Here, we present a completely parameter-controlled artificial seawater standalone egg incubation system that replaces maternal care and allows successful embryonic development of a small-egged octopus species until hatching in a laboratory environment. We also provide a practical and detailed staging atlas based on bright-field and light sheet fluorescence microscopy imaging for precise monitoring of embryonic development. The atlas has a comparative section to benchmark stages to the different scales published by Naef (1928), Arnold (1965) and Boletzky (2016). Finally, we provide methods to monitor health and wellbeing of embryos during organogenesis. Conclusion: Besides introducing the study of O. vulgaris embryonic development to a wider community, this work can be a high-quality reference for comparative evolutionary developmental biology., Sí

The transcription factor Zeb2 controls fate specification and subsequent differentiation and maturation of multiple cell types in various embryonic tissues. It binds many protein partners, including activated Smad proteins and the NuRD co-repressor complex. How Zeb2 subdomains support cell differentiation in various contexts has remained elusive. Here, we have studied the role of Zeb2 and its domains in neurogenesis and neural differentiation in the young postnatal ventricular-subventricular zone (V-SVZ), where neural stem cells generate olfactory bulb-destined interneurons. Conditional Zeb2 knockouts and separate acute loss- and gain-of-function approaches indicated that Zeb2 is essential to control apoptosis and neuronal differentiation of V-SVZ progenitors before and after birth, and identified Sox6 as Zeb2-dependent and potential downstream target gene. Zeb2 genetic inactivation impaired the differentiation potential of the V-SVZ niche in a cell-autonomous fashion. We also provide evidence that its normal function in the V-SVZ involves non-autonomous mechanisms as well. Additionally, we could demonstrate distinct roles for Zeb2 protein-binding domains, suggesting that Zeb2 partners co-determine neuronal output from the mouse V-SVZ in both quantitative and qualitative manners in early postnatal life. ispartof: Development vol:147 issue:10 ispartof: location:England status: published

Replicating the human genome efficiently and accurately is a daunting challenge involving the duplication of upward of three billion base pairs. At the core of the complex machinery that achieves this task are three members of the B family of DNA polymerases: DNA polymerases α, δ, and ε. Collectively these multimeric polymerases ensure DNA replication proceeds at optimal rates approaching 2 × 103 nucleotides/min with an error rate of less than one per million nucleotides polymerized. The majority of DNA replication of undamaged DNA is conducted by DNA polymerases δ and ε. The DNA polymerase α-primase complex performs limited synthesis to initiate the replication process, along with Okazaki-fragment synthesis on the discontinuous lagging strand. An increasing number of human disorders caused by defects in different components of the DNA-replication apparatus have been described to date. These are clinically diverse and involve a wide range of features, including variable combinations of growth delay, immunodeficiency, endocrine insufficiencies, lipodystrophy, and cancer predisposition. Here, by using various complementary approaches, including classical linkage analysis, targeted next-generation sequencing, and whole-exome sequencing, we describe distinct missense and splice-impacting mutations in POLA1 in five unrelated families presenting with an X-linked syndrome involving intellectual disability, proportionate short stature, microcephaly, and hypogonadism. POLA1 encodes the p180 catalytic subunit of DNA polymerase α-primase. A range of replicative impairments could be demonstrated in lymphoblastoid cell lines derived from affected individuals. Our findings describe the presentation of pathogenic mutations in a catalytic component of a B family DNA polymerase member, DNA polymerase α. ispartof: American Journal Of Human Genetics vol:104 issue:5 pages:957-967 ispartof: location:United States status: published

The common octopus, Octopus vulgaris, is an active marine predator known for the richness and plasticity of its behavioral repertoire, and remarkable learning and memory capabilities. Octopus and other coleoid cephalopods, cuttlefish and squid, possess the largest nervous system among invertebrates, both for cell counts and body to brain size. O. vulgaris has been at the center of a long-tradition of research into diverse aspects of its biology. To leverage research in this iconic species, we generated 270 Gb of genomic sequencing data, complementing those available for the only other sequenced congeneric octopus, Octopus bimaculoides. We show that both genomes are similar in size, but display different levels of heterozygosity and repeats. Our data give a first quantitative glimpse into the rate of coding and non-coding regions and support the view that hundreds of novel genes may have arisen independently despite the close phylogenetic distance. We furthermore describe a reference-guided assembly and an open genomic resource (CephRes-gdatabase), opening new avenues in the study of genomic novelties in cephalopods and their biology., Design Type(s)species comparison design • sequence analysis objective • sequence assembly objectiveMeasurement Type(s)whole genome sequencing assayTechnology Type(s)DNA sequencingFactor Type(s) Sample Characteristic(s)Octopus vulgaris • testis • ocean biome Machine-accessible metadata file describing the reported data (ISA-Tab format)

To understand traumas to the nervous system, the relation between mechanical load and functional impairment needs to be explained. Cellular-level computational models are being used to capture the mechanism behind mechanically-induced injuries and possibly predict these events. However, uncertainties in the material properties used in computational models undermine the validity of their predictions. For this reason, in this study the squid giant axon was used as a model to provide a description of the axonal mechanical behavior in a large strain and high strain rate regime $$({\boldsymbol{\varepsilon }}={\bf{10}}{\boldsymbol{ \% }},\,\mathop{{\boldsymbol{\varepsilon }}}\limits^{\cdot }={\bf{1}}{{\boldsymbol{s}}}^{-{\bf{1}}})$$ ( ε = 10 % , ε ⋅ = 1 s − 1 ) , which is relevant for injury investigations. More importantly, squid giant axon membrane sheaths were isolated and tested under dynamic uniaxial tension and relaxation. From the lumen outward, the membrane sheath presents: an axolemma, a layer of Schwann cells followed by the basement membrane and a prominent layer of loose connective tissue consisting of fibroblasts and collagen. Our results highlight the load-bearing role of this enwrapping structure and provide a constitutive description that could in turn be used in computational models. Furthermore, tests performed on collagen-depleted membrane sheaths reveal both the substantial contribution of the endoneurium to the total sheath’s response and an interesting increase in material nonlinearity when the collagen in this connective layer is digested. All in all, our results provide useful insights for modelling the axonal mechanical response and in turn will lead to a better understanding of the relationship between mechanical insult and electrophysiological outcome.

In response to viral infections, activated CD8+ T cells differentiate into terminal effector and memory T cells. This developmental process is controlled by the transcriptional repressor Zeb2, which acts downstream of T-bet., ZEB2 is a multi-zinc-finger transcription factor known to play a significant role in early neurogenesis and in epithelial-mesenchymal transition–dependent tumor metastasis. Although the function of ZEB2 in T lymphocytes is unknown, activity of the closely related family member ZEB1 has been implicated in lymphocyte development. Here, we find that ZEB2 expression is up-regulated by activated T cells, specifically in the KLRG1hi effector CD8+ T cell subset. Loss of ZEB2 expression results in a significant loss of antigen-specific CD8+ T cells after primary and secondary infection with a severe impairment in the generation of the KLRG1hi effector memory cell population. We show that ZEB2, which can bind DNA at tandem, consensus E-box sites, regulates gene expression of several E-protein targets and may directly repress Il7r and Il2 in CD8+ T cells responding to infection. Furthermore, we find that T-bet binds to highly conserved T-box sites in the Zeb2 gene and that T-bet and ZEB2 regulate similar gene expression programs in effector T cells, suggesting that T-bet acts upstream and through regulation of ZEB2. Collectively, we place ZEB2 in a larger transcriptional network that is responsible for the balance between terminal differentiation and formation of memory CD8+ T cells.

We present a male patient with sporadic Aarskog syndrome, cleft palate, mild intellectual disability, and autism spectrum disorder (ASD). A submicroscopic discontiguous deletion was detected on chromosome Xp11.2 encompassing FGD1, FAM120C, and PHF8. That the deletion encompassed FGD1 (exons 2-8) explains the Aarskog features while the deletion of PHF8 most likely explains the cleft palate and mild intellectual disability. We identify FAM120C as a novel X-linked candidate gene for autism for two reasons: first, a larger deletion encompassing FAM120C segregates with autism in a previously reported family and second, there is recent evidence that FAM120C interacts with CYFIP1, part of the FMRP (Fragile X Mental Retardation Protein) network. In the current study, resequencing of FAM120C in 87 Belgian male patients with autism spectrum disorder identified no novel mutations. Expression of Fam120c in mouse tissues showed enriched expression in pituitary, cerebellum, cortex, and pancreatic islets of Langerhans. Additionally, we found a cortical expression pattern of Fam120c similar to that of Fmr1. In conclusion, FAM120C is a novel candidate gene for autism spectrum disorder based on genetic evidence and the brain expression pattern. Thereby we highlight a role for FMRP network genes in ASD. (c) 2014 Wiley Periodicals, Inc.

Background Smad-interacting protein 1 (also named Zeb2 and Zfhx1b) is a transcription factor that plays an important role in neuronal development and, when mutated, causes Mowat–Wilson syndrome (MWS). A corresponding mouse model carrying a heterozygous Zeb2 deletion was comprehensively analysed in the German Mouse Clinic. The most prominent phenotype was the reduced pain sensitivity. In this study, we investigated the role of Zeb2 in inflammatory and neuropathic pain. Methods For this, we tested mutant Zeb2 animals in different models of inflammatory pain like abdominal constriction, formalin and carrageenan test. Furthermore, we studied the pain reactivity of the mice after peripheral nerve ligation. To examine the nociceptive transmission of primary sensory dorsal root ganglia (DRG) neurons, we determined the neuronal activity in the spinal dorsal horn after the formalin test using staining of c-Fos. Next, we characterized the neuronal cell population in the DRGs and in the sciatic nerve to study the effect of the Zeb2 mutation on peripheral nerve morphology. Results The present data show that Zeb2 is involved in the development of primary sensory DRG neurons, especially of C- and Aδ fibres. These alterations contribute to a hypoalgesic phenotype in inflammatory but not in neuropathic pain in these Zeb2+/− mice. Conclusion Our data suggest that the under-reaction to pain observed in MWS patients results from a reduced responsivity to nociceptive stimulation rather than an inability to communicate discomfort.

GABAergic interneurons mainly originate in the medial ganglionic eminence (MGE) of the embryonic ventral telencephalon (VT) and migrate tangentially to the cortex, guided by membrane-bound and secreted factors. We found that Sip1 (Zfhx1b, Zeb2), a transcription factor enriched in migrating cortical interneurons, is required for their proper differentiation and correct guidance. The majority of Sip1 knockout interneurons fail to migrate to the neocortex and stall in the VT. RNA sequencing reveals that Sip1 knockout interneurons do not acquire a fully mature cortical interneuron identity and contain increased levels of the repulsive receptor Unc5b. Focal electroporation of Unc5b-encoding vectors in the MGE of wild-type brain slices disturbs migration to the neocortex, whereas reducing Unc5b levels in Sip1 knockout slices and brains rescues the migration defect. Our results reveal that Sip1, through tuning of Unc5b levels, is essential for cortical interneuron guidance. ispartof: Neuron vol:77 issue:1 pages:70-82 ispartof: location:United States status: published

During neurogenesis, generation, migration and integration of the correct numbers of each neuron sub-type depends on complex molecular interactions in space and time. MicroRNAs represent a key control level allowing the flexibility and stability needed for this process. Insight into the role of this regulatory pathway in the brain is still limited. We performed a sequential experimental approach using postnatal olfactory bulb neurogenesis in mice, starting from global expression analyses to the investigation of functional interactions between defined microRNAs and their targets. Deep sequencing of small RNAs extracted from defined compartments of the postnatal neurogenic system demonstrated that the miR-200 family is specifically induced during late neuronal differentiation stages. Using in vivo strategies we interfered with the entire miR-200 family in loss- and gain-of-function settings, showing a role of miR-200 in neuronal maturation. This function is mediated by targeting the transcription factor Zeb2. Interestingly, so far functional interaction between miR-200 and Zeb2 has been exclusively reported in cancer or cultured stem cells. Our data demonstrate that this regulatory interaction is also active during normal neurogenesis.

During neurogenesis, generation, migration and integration of the correct numbers of each neuron sub-type depends on complex molecular interactions in space and time. MicroRNAs represent a key control level allowing the flexibility and stability needed for this process. Insight into the role of this regulatory pathway in the brain is still limited. We performed a sequential experimental approach using postnatal olfactory bulb neurogenesis in mice, starting from global expression analyses to the investigation of functional interactions between defined microRNAs and their targets. Deep sequencing of small RNAs extracted from defined compartments of the postnatal neurogenic system demonstrated that the miR-200 family is specifically induced during late neuronal differentiation stages. Using in vivo strategies we interfered with the entire miR-200 family in loss- and gain-of-function settings, showing a role of miR-200 in neuronal maturation. This function is mediated by targeting the transcription factor Zeb2. Interestingly, so far functional interaction between miR-200 and Zeb2 has been exclusively reported in cancer or cultured stem cells. Our data demonstrate that this regulatory interaction is also active during normal neurogenesis. ispartof: Scientific Reports vol:6 issue:1 ispartof: location:England status: published

During development, spinal motoneurons (MNs) diversify into a variety of subtypes that are specifically dedicated to the motor control of particular sets of skeletal muscles or visceral organs. MN diversification depends on the coordinated action of several transcriptional regulators including the LIM-HD factor Isl1, which is crucial for MN survival and fate determination. However, how these regulators cooperate to establish each MN subtype remains poorly understood. Here, using phenotypic analyses of single or compound mutant mouse embryos combined with gain-of-function experiments in chick embryonic spinal cord, we demonstrate that the transcriptional activators of the Onecut family critically regulate MN subtype diversification during spinal cord development. We provide evidence that Onecut factors directly stimulate Isl1 expression in specific MN subtypes and are therefore required to maintain Isl1 production at the time of MN diversification. In the absence of Onecut factors, we observed major alterations in MN fate decision characterized by the conversion of somatic to visceral MNs at the thoracic levels of the spinal cord and of medial to lateral MNs in the motor columns that innervate the limbs. Furthermore, we identify Sip1 (Zeb2) as a novel developmental regulator of visceral MN differentiation. Taken together, these data elucidate a comprehensive model wherein Onecut factors control multiple aspects of MN subtype diversification. They also shed light on the late roles of Isl1 in MN fate decision. ispartof: Development vol:139 issue:17 pages:3109-3119 ispartof: location:England status: published

Signaling by the many ligands of the TGFβ family strongly converges towards only five receptor-activated, intracellular Smad proteins, which fall into two classes i.e. Smad2/3 and Smad1/5/8, respectively. These Smads bind to a surprisingly high number of Smad-interacting proteins (SIPs), many of which are transcription factors (TFs) that co-operate in Smad-controlled target gene transcription in a cell type and context specific manner. A combination of functional analyses in vivo as well as in cell cultures and biochemical studies has revealed the enormous versatility of the Smad proteins. Smads and their SIPs regulate diverse molecular and cellular processes and are also directly relevant to development and disease. In this survey, we selected appropriate examples on the BMP-Smads, with emphasis on Smad1 and Smad5, and on a number of SIPs, i.e. the CPSF subunit Smicl, Ttrap (Tdp2) and Sip1 (Zeb2, Zfhx1b) from our own research carried out in three different vertebrate models. ispartof: Cytokine & Growth Factor Reviews vol:22 issue:5 pages:287-300 ispartof: location:England status: published

Zeb2 (Sip1/Zfhx1b) is a member of the zinc-finger E-box-binding (ZEB) family of transcriptional repressors previously demonstrated to regulate epithelial-to-mesenchymal transition (EMT) processes during embryogenesis and tumor progression. We found high Zeb2 mRNA expression levels in HSCs and hematopoietic progenitor cells (HPCs), and examined Zeb2 function in hematopoiesis through a conditional deletion approach using the Tie2-Cre and Vav-iCre recombination mouse lines. Detailed cellular analysis demonstrated that Zeb2 is dispensable for hematopoietic cluster and HSC formation in the aorta-gonadomesonephros region of the embryo, but is essential for normal HSC/HPC differentiation. In addition, Zeb2-deficient HSCs/HPCs fail to properly colonize the fetal liver and/or bone marrow and show enhanced adhesive properties associated with increased β1 integrin and Cxcr4 expression. Moreover, deletion of Zeb2 resulted in embryonic (Tie2-Cre) and perinatal (Vav-icre) lethality due to severe cephalic hemorrhaging and decreased levels of angiopoietin-1 and, subsequently, improper pericyte coverage of the cephalic vasculature. These results reveal essential roles for Zeb2 in embryonic hematopoiesis and are suggestive of a role for Zeb2 in hematopoietic-related pathologies in the adult. ispartof: Blood vol:117 issue:21 pages:5620-5630 ispartof: location:United States status: published

The fate of cortical progenitors, which progressively generate neurons and glial cells during development, is determined by temporally and spatially regulated signaling mechanisms. We found that the transcription factor Sip1 (Zfhx1b), which is produced at high levels in postmitotic neocortical neurons, regulates progenitor fate non-cell autonomously. Conditional deletion of Sip1 in young neurons induced premature production of upper-layer neurons at the expense of deep layers, precocious and increased generation of glial precursors, and enhanced postnatal astrocytogenesis. The premature upper-layer generation coincided with overexpression of the neurotrophin-3 (Ntf3) gene and upregulation of fibroblast growth factor 9 (Fgf9) gene expression preceded precocious gliogenesis. Exogenous application of Fgf9 to mouse cortical slices induced excessive generation of glial precursors in the germinal zone. Our data suggest that Sip1 restrains the production of signaling factors in postmitotic neurons that feed back to progenitors to regulate the timing of cell fate switch and the number of neurons and glial cells throughout corticogenesis.

Smad-interacting protein-1 (Sip1) [Zinc finger homeobox (Zfhx1b)] is a transcription factor implicated in the genesis of Mowat–Wilson syndrome in humans. Sip1 expression in the dorsal telencephalon of mouse embryos was documented from E12.5. We inactivated the gene specifically in cortical precursors. This resulted in the lack of the entire hippocampal formation. Sip1 mutant mice exhibited death of differentiating cells and decreased proliferation in the region of the prospective hippocampus and dentate gyrus. The expression of the Wnt antagonist Sfrp1 was ectopically activated, whereas the activity of the noncanonical Wnt effector, JNK, was down-regulated in the embryonic hippocampus of mutant mice. In cortical cells, Sip1 protein was detected on the promoter of Sfrp1 gene and both genes showed a mutually exclusive pattern of expression suggesting that Sfrp1 expression is negatively regulated by Sip1. Sip1 is therefore essential to the development of the hippocampus and dentate gyrus, and is able to modulate Wnt signaling in these regions.

SummaryFood intake and activity-induced thermogenesis are important components of energy balance regulation. The molecular mechanism underlying the coordination of food intake with locomotory behavior to maintain energy homeostasis is unclear. We report that the brain-specific homeobox transcription factor Bsx is required for locomotory behavior, hyperphagia, and expression of the hypothalamic neuropeptides Npy and Agrp, which regulate feeding behavior and body weight. Mice lacking Bsx exhibit reduced locomotor activity and lower expression of Npy and Agrp. They also exhibit attenuated physiological responses to fasting, including reduced increase of Npy/Agrp expression, lack of food-seeking behavior, and reduced rebound hyperphagia. Furthermore, Bsx gene disruption rescues the obese phenotype of leptin-deficient ob/ob mice by reducing their hyperphagia without increasing their locomotor activity. Thus, Bsx represents an essential factor for NPY/AgRP neuronal function and locomotory behavior in the control of energy balance.

The transcription factor Zeb2 cooperates with T-bet to control NK cell maturation, viability, and exit from the bone marrow and is essential for rejection of melanoma lung metastasis., Natural killer (NK) cell maturation is a tightly controlled process that endows NK cells with functional competence and the capacity to recognize target cells. Here, we found that the transcription factor (TF) Zeb2 was the most highly induced TF during NK cell maturation. Zeb2 is known to control epithelial to mesenchymal transition, but its role in immune cells is mostly undefined. Targeted deletion of Zeb2 resulted in impaired NK cell maturation, survival, and exit from the bone marrow. NK cell function was preserved, but mice lacking Zeb2 in NK cells were more susceptible to B16 melanoma lung metastases. Reciprocally, ectopic expression of Zeb2 resulted in a higher frequency of mature NK cells in all organs. Moreover, the immature phenotype of Zeb2−/− NK cells closely resembled that of Tbx21−/− NK cells. This was caused by both a dependence of Zeb2 expression on T-bet and a probable cooperation of these factors in gene regulation. Transgenic expression of Zeb2 in Tbx21−/− NK cells partially restored a normal maturation, establishing that timely induction of Zeb2 by T-bet is an essential event during NK cell differentiation. Finally, this novel transcriptional cascade could also operate in human as T-bet and Zeb2 are similarly regulated in mouse and human NK cells.