Introducing dorsoventral patterning in adult regenerating lizard tails with gene-edited embryonic neural stem cells

Lizards regenerate amputated tails but fail to recapitulate the dorsoventral patterning achieved during embryonic development. Regenerated lizard tails form ependymal tubes (ETs) that, like embryonic tail neural tubes (NTs), induce cartilage differentiation in surrounding cells via sonic hedgehog (Shh) signaling. However, adult ETs lack characteristically roof plate-associated structures and express Shh throughout their circumferences, resulting in the formation of unpatterned cartilage tubes. Both NTs and ETs contain neural stem cells (NSCs), but only embryonic NSC populations differentiate into roof plate identities when protected from endogenous Hedgehog signaling. NSCs were isolated from parthenogenetic lizard embryos, rendered unresponsive to Hedgehog signaling via CRISPR/Cas9 gene knockout of smoothened (Smo), and implanted back into clonally-identical adults to regulate tail regeneration. Here we report that Smo knockout embryonic NSCs oppose cartilage formation when engrafted to adult ETs, representing an important milestone in the creation of regenerated lizard tails with dorsoventrally patterned skeletal tissues.

Completion of neural crest cell production and emigration is regulated by retinoic acid-dependent inhibition of BMP signaling

Production and emigration of neural crest cells is a transient process followed by the emergence of the definitive roof plate. The mechanisms regulating the end of neural crest ontogeny are poorly understood. Whereas early crest development is stimulated by mesoderm-derived retinoic acid, we report that the end of the neural crest period is regulated by retinoic acid synthesized in the dorsal neural tube. Inhibition of retinoic acid signaling in the neural tube prevents the normal upregulation of BMP inhibitors in the nascent roof plate and prolongs the period of BMP responsiveness which otherwise ceases close to roof plate establishment. Consequently, neural crest production and emigration are extended well into the roof plate stage. Although several roof plate-specific genes are normally expressed in the absence of retinoic acid signaling, roof plate and crest markers are co-expressed in single cells and this domain also contains dorsal interneurons. Hence, the cellular and molecular architecture of the roof plate is compromised. Collectively, our results demonstrate that neural tube-derived retinoic acid, via inhibition of BMP signaling, is an essential factor responsible for the end of neural crest generation and the proper segregation of dorsal neural lineages.

Morphological and Functional Changes of Roof Plate Cells in Spinal Cord Development

The most dorsal region, or roof plate, is the dorsal organizing center of developing spinal cord. This region is also involved in development of neural crest cells, which are the source of migratory neural crest cells. During early development of the spinal cord, roof plate cells secrete signaling molecules, such as Wnt and BMP family proteins, which regulate development of neural crest cells and dorsal spinal cord. After the dorso-ventral pattern is established, spinal cord dynamically changes its morphology. With this morphological transformation, the lumen of the spinal cord gradually shrinks to form the central canal, a cavity filled with cerebrospinal fluid that is connected to the ventricular system of the brain. The dorsal half of the spinal cord is separated by a glial structure called the dorsal (or posterior) median septum. However, underlying mechanisms of such morphological transformation are just beginning to be understood. Recent studies reveal that roof plate cells dramatically stretch along the dorso-ventral axis, accompanied by reduction of the spinal cord lumen. During this stretching process, the tips of roof plate cells maintain contact with cells surrounding the shrinking lumen, eventually exposed to the inner surface of the central canal. Interestingly, Wnt expression remains in stretched roof plate cells and activates Wnt/β-catenin signaling in ependymal cells surrounding the central canal. Wnt/β-catenin signaling in ependymal cells promotes proliferation of neural progenitor and stem cells in embryonic and adult spinal cord. In this review, we focus on the role of the roof plate, especially that of Wnt ligands secreted by roof plate cells, in morphological changes occurring in the spinal cord.

Expression Pattern of 5-HT (Serotonin) Receptors during Normal Development of the Human Spinal Cord and Ganglia and in Fetus with Cervical Spina Bifida

The expression of 5-HT (serotonin) receptors (sr) was analyzed in the spinal cord and ganglia of 15 human conceptuses (5–10-weeks), and in the 9-week fetus with spina bifida. We used immunohistochemical method to detect sr-positive, apoptotic (caspase-3) and proliferating (Ki-67) cells, double immunofluorescence for co-localization with protein gene peptide (pgp) 9.5 and GFAP, as well as semiquantification and statistical measurements. Following the neurulation process, moderate (sr1 and sr2) and mild (sr3) expression characterized neuroblasts in the spinal cord and ganglia. During further development, sr1 expression gradually increased in the motoneurons, autonomic and sensory neurons, while sr2 and sr3 increased strongly in floor and roof plates. In the ganglia, sr3 expression increased during limited developmental period, while sr1 and sr2 increased throughout the investigated period. Co-expression of sr/pgp 9.5 characterized developing neurons, while sr/GFAP co-localized in the roof plate. In the spinal cord and ganglia of malformed fetus, weaker sr1 and sr2 and stronger sr3 expression accompanied morphological abnormalities. Anomalous roof plate morphology showed an excess of apoptotic and proliferating cells and increased sr3 expression. Our results indicate a human-species specific sr expression pattern, and the importance of sr1 in neuronal differentiation, and sr2 and sr3 in the control of the roof plate morphogenesis in normal and disturbed development.

ANALYSIS OF DIMENSIONAL AND CALCULATIONS STRUCTURE DESIGNED BASED ON SNI 2847-2013

Floor slabs are structural components of a building that have certain dimensions to transmit dead and live loads on them to be distributed to their supports. Designing the floor slabs of a building, load data will be borne by the structure, so that the planned structure is able to bear the loads and forces that work. With careful planning, it is expected that the dimensions and reinforcement of the floor slabs are economical and safe which can avoid deflection and cracks. The building being reviewed is hospitals in Surabaya. This building consists of 9 floors with a height of up to 37 m. Planning dimensions and reinforcement in this hospital building includes two-way slabs with different size variations. The analysis was carried out using the 'envelope method' in accordance with SNI 2847: 2013 (Basics of Reinforced Concrete Planning). The results of the analysis of dimensions and reinforcement in this hospital building are: a) the dimensions / thickness of the plate on the roof plate is 125 mm, while b) the reinforcement used on this floor plate is Ø10-125 and the reinforcement for Ø10-200. Each moment analyzed is contained in the analysis results table and floor slab reinforcement drawings.

Natural loss of function of ephrin-B3 shapes spinal flight circuitry in birds

Flight in birds evolved through patterning of the wings from forelimbs and transition from alternating gait to synchronous flapping. In mammals, the spinal midline guidance molecule ephrin-B3 instructs the wiring that enables limb alternation, and its deletion leads to synchronous hopping gait. Here, we show that the ephrin-B3 protein in birds lacks several motifs present in other vertebrates, diminishing its affinity for the EphA4 receptor. The avian ephrin-B3 gene lacks an enhancer that drives midline expression and is missing in galliforms. The morphology and wiring at brachial levels of the chicken embryonic spinal cord resemble those of ephrin-B3 null mice. Dorsal midline decussation, evident in the mutant mouse, is apparent at the chick brachial level and is prevented by expression of exogenous ephrin-B3 at the roof plate. Our findings support a role for loss of ephrin-B3 function in shaping the avian brachial spinal cord circuitry and facilitating synchronous wing flapping.

PERENCANAAN ULANG GEDUNG UNIVERSITAS KATOLIK DARMA CENDIKA (UKDC) SURABAYA

In the era of globalization various innovations are needed to meet human needs, in the civil engineering world various innovations are also needed to realize a variety of modern designs that continue to grow. The development starts from the function of the building, the shape of the building, the aesthetics of the building and the strength of the building to accept the burden to be received.This research discusses the structural planning of reinforced concrete covering plates, beams and columns with method of Special Moment Resisting Frame System (SRPMK). Planning is done based on the Procedure of Calculation of Concrete Structure for Building Building (SNI 2847-2013). Minimum load regulations for the design of buildings and other structures (SNI 1727-2013). Regulation of earthquake resistance planning procedures for building structures (SNI 1726-2012). Earthquake calculations are based on seismic map 2017 which is the basis of consideration to determine the degree of structural ductality that depends on the moment frame system bearer. The result of this research is to know the dimension of primary structure (beam, column) and secondary structure (floor plate, roof plate) and to know the dimension of steel reinforcement on primary structure (beam, column) and secondary structure (floor plate, roof plate).AbstrakDi era globalisasi berbagai inovasi dibutuhkan untuk memenuhi kebutuhan manusia, dalam dunia teknik sipil juga dibutuhkan berbagai inovasi untuk mewujudkan berbagai desain modern yang terus berkembang. Pembangunan dimulai dari fungsi bangunan, bentuk bangunan, nilai estetika bangunan dan kekuatan bangunan untuk menerima beban yang akan diterima. Penelitian ini membahas tentang perencanaan struktur beton bertulang yang meliputi pelat, balok dan kolom dengan metode Sistem Rangka Pemikul Momen Khusus (SRPMK). Perencanaan dilakukan berdasarkan Tata Cara Perhitungan Struktur Beton Bangunan Gedung (SNI 2847-2013). Peraturan beban minimum untuk desain gedung dan struktur lainnya (SNI 1727-2013). Pengaturan tata cara perencanaan ketahanan gempa untuk struktur bangunan gedung (SNI 1726-2012). Perhitungan gempa didasarkan pada peta seismik 2017 yang menjadi dasar pertimbangan untuk menentukan derajat daktalitas struktur yang bergantung pada pemikul sistem kerangka momen. Hasil dari penelitian ini adalah untuk mengetahui dimensi struktur primer (balok, kolom) dan struktur sekunder (pelat lantai, pelat atap) serta mengetahui dimensi tulangan baja pada struktur primer (balok, kolom) dan struktur sekunder (pelat lantai) dan dimensi tulangan baja pada struktur primer (balok, kolom) dan struktur sekunder (pelat lantai) , pelat atap). Kata kunci: Sistem Rangka Pemikul Momen Khusus, SNI 1726-2012, SNI 1727-2013, SNI 2847-2013, Peta Seismik 2017.

Notch signaling is a critical initiator of roof plate formation as revealed by the use of RNA profiling of the dorsal neural tube

BackgroundThe dorsal domain of the neural tube is an excellent model to investigate the generation of complexity during embryonic development. It is a highly dynamic and multifaceted region being first transiently populated by prospective neural crest (NC) cells that sequentially emigrate to generate most of the peripheral nervous system. Subsequently, it becomes the definitive roof plate (RP) of the central nervous system. The RP, in turn, constitutes a patterning center for dorsal interneuron development. The factors underlying establishment of the definitive RP and its segregation from NC and dorsal interneurons are currently unknown.ResultsWe performed a transcriptome analysis at trunk levels of quail embryos comparing the dorsal neural tube at premigratory NC and RP stages. This unraveled molecular heterogeneity between NC and RP stages, and within the RP itself. By implementing these genes, we asked whether Notch signaling is involved in RP development. First, we observed that Notch is active at the RP-interneuron interface. Furthermore, gain and loss of Notch function in quail and mouse embryos, respectively, revealed no effect on early NC behavior. Constitutive Notch activation caused a local downregulation of RP markers with a concomitant development of dI1 interneurons, as well as an ectopic upregulation of RP markers in the interneuron domain. Reciprocally, in mice lacking Notch activity, both the RP and dI1 interneurons failed to form and this was associated with expansion of the dI2 population.ConclusionsCollectively, our results offer a new resource for defining specific cell types, and provide evidence that Notch is required to establish the definitive RP, and to determine the choice between RP and interneuron fates, but not the segregation of RP from NC.

From Neural Crest to Definitive Roof Plate: The Dynamic Behavior of the Dorsal Neural Tube

Research on the development of the dorsal neural tube is particularly challenging. In this highly dynamic domain, a temporal transition occurs between early neural crest progenitors that undergo an epithelial-to-mesenchymal transition and exit the neural primordium, and the subsequent roof plate, a resident epithelial group of cells that constitutes the dorsal midline of the central nervous system. Among other functions, the roof plate behaves as an organizing center for the generation of dorsal interneurons. Despite extensive knowledge of the formation, emigration and migration of neural crest progenitors, little is known about the mechanisms leading to the end of neural crest production and the transition into a roof plate stage. Are these two mutually dependent or autonomously regulated processes? Is the generation of roof plate and dorsal interneurons induced by neural tube-derived factors throughout both crest and roof plate stages, respectively, or are there differences in signaling properties and responsiveness as a function of time? In this review, we discuss distinctive characteristics of each population and possible mechanisms leading to the shift between the above cell types.