The mandibular and hyoid arches collectively make up the facial skeleton, also known as the viscerocranium. Although all three germ layers come together to assemble the pharyngeal arches, the majority of tissue within viscerocranial skeletal components differentiates from the neural crest. Since nearly one third of all birth defects in humans affect the craniofacial region, it is important to understand how signalling pathways and transcription factors govern the embryogenesis and skeletogenesis of the viscerocranium. This review focuses on mouse and zebrafish models of craniofacial development. We highlight gene regulatory networks directing the patterning and osteochondrogenesis of the mandibular and hyoid arches that are actually conserved among all gnathostomes. The first part of this review describes the anatomy and development of mandibular and hyoid arches in both species. The second part analyses cell signalling and transcription factors that ensure the specificity of individual structures along the anatomical axes. The third part discusses the genes and molecules that control the formation of bone and cartilage within mandibular and hyoid arches and how dysregulation of molecular signalling influences the development of skeletal components of the viscerocranium. In conclusion, we notice that mandibular malformations in humans and mice often co-occur with hyoid malformations and pinpoint the similar molecular machinery controlling the development of mandibular and hyoid arches.

• Klíčová slova
• bone, cartilage, chondrogenesis, craniofacial development, hyoid bone, jaw development, neural crest cells, osteogenesis, patterning, pharyngeal arches,
• MeSH
• chrupavka cytologie   embryologie   MeSH
• mandibula embryologie   MeSH
• os hyoideum embryologie   MeSH
• rozvržení tělního plánu * MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• přehledy MeSH

Two theories address the origin of repeating patterns, such as hair follicles, limb digits, and intestinal villi, during development. The Turing reaction-diffusion system posits that interacting diffusible signals produced by static cells first define a prepattern that then induces cell rearrangements to produce an anatomical structure. The second theory, that of mesenchymal self-organisation, proposes that mobile cells can form periodic patterns of cell aggregates directly, without reference to any prepattern. Early hair follicle development is characterised by the rapid appearance of periodic arrangements of altered gene expression in the epidermis and prominent clustering of the adjacent dermal mesenchymal cells. We assess the contributions and interplay between reaction-diffusion and mesenchymal self-organisation processes in hair follicle patterning, identifying a network of fibroblast growth factor (FGF), wingless-related integration site (WNT), and bone morphogenetic protein (BMP) signalling interactions capable of spontaneously producing a periodic pattern. Using time-lapse imaging, we find that mesenchymal cell condensation at hair follicles is locally directed by an epidermal prepattern. However, imposing this prepattern's condition of high FGF and low BMP activity across the entire skin reveals a latent dermal capacity to undergo spatially patterned self-organisation in the absence of epithelial direction. This mesenchymal self-organisation relies on restricted transforming growth factor (TGF) β signalling, which serves to drive chemotactic mesenchymal patterning when reaction-diffusion patterning is suppressed, but, in normal conditions, facilitates cell movement to locally prepatterned sources of FGF. This work illustrates a hierarchy of periodic patterning modes operating in organogenesis.

• MeSH
• buněčná diferenciace MeSH
• inbrední kmeny myší MeSH
• kůže cytologie   embryologie   metabolismus   MeSH
• myši MeSH
• rozvržení tělního plánu MeSH
• signální transdukce MeSH
• stanovení celkové genové exprese MeSH
• transformující růstový faktor beta metabolismus   fyziologie   MeSH
• vlasový folikul embryologie   MeSH
• zvířata MeSH
• Check Tag
• mužské pohlaví MeSH
• myši MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• transformující růstový faktor beta MeSH

Nucleated protein self-assembly of an azido modified spider silk protein was employed in the preparation of nanofibrillar networks with hydrogel-like properties immobilized on coatings of the same protein. Formation of the networks in a mild aqueous environment resulted in thicknesses between 2 and 60 nm, which were controlled only by the protein concentration. Incorporated azido groups in the protein were used to "click" short nucleic acid sequences onto the nanofibrils, which were accessible to specific hybridization-based modifications, as proved by fluorescently labeled DNA complements. A lipid modifier was used for efficient incorporation of DNA into the membrane of nonadherent Jurkat cells. Based on the complementarity of the nucleic acids, highly specific DNA-assisted immobilization of the cells on the nanohydrogels with tunable cell densities was possible. Addressability of the DNA cell-to-surface anchor was demonstrated with a competitive oligonucleotide probe, resulting in a rapid release of 75-95% of cells. In addition, we developed a photolithography-based patterning of arbitrarily shaped microwells, which served to spatially define the formation of the nanohydrogels. After detaching the photoresist and PEG-blocking of the surface, DNA-assisted immobilization of the Jurkat cells on the nanohydrogel microstructures was achieved with high fidelity.

• Klíčová slova
• DNA modification, cells, nanofibrils, nanohydrogels, patterning, self-assembly, surfaces,
• MeSH
• DNA * chemie   MeSH
• hedvábí * chemie   MeSH
• hybridizace nukleových kyselin MeSH
• hydrogely chemie   MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• DNA * MeSH
• hedvábí * MeSH
• hydrogely MeSH

In this paper, we introduce a method to efficiently use a high-energy pulsed 1.7 ps HiLASE Perla laser system for two beam interference patterning. The newly developed method of large-beam interference patterning permits the production of micro and sub-micron sized features on a treated surface with increased processing throughputs by enlarging the interference area. The limits for beam enlarging are explained and calculated for the used laser source. The formation of a variety of surface micro and nanostructures and their combinations are reported on stainless steel, invar, and tungsten with the maximum fabrication speed of 206 cm2/min. The wettability of selected hierarchical structures combining interference patterns with 2.6 µm periodicity and the nanoscale surface structures on top were analyzed showing superhydrophobic behavior with contact angles of 164°, 156°, and 150° in the case of stainless steel, invar, and tungsten, respectively.

• Klíčová slova
• LIPSS, Perla laser, interference patterning, superhydrophobicity,
• Publikační typ
• časopisecké články MeSH

How the embryonic body axis is generated is a fundamental question in developmental biology. The molecular mechanisms involved in this process have been the subject of intensive studies using traditional model organisms during the last few decades, and the results have provided crucial information for understanding the formation of animal body plans. In particular, studies exploring the molecular nature of Spemann's organizer have revealed the intricate interactions underlying several signaling pathways (namely the Wnt/β-catenin, Nodal and Bmp pathways) that pattern the dorsoventral (DV) axis in vertebrate embryos. Furthermore, recent comparative studies have shown that many of these signaling interactions are also employed in other non-vertebrate model organisms for their early embryonic axis patterning. These results suggest that there is deep homology in DV patterning mechanisms among bilaterian animals and that these mechanisms may be traced back to the common ancestor of cnidarians and bilaterians. However, the mechanism by which the DV axis became inverted in the chordate lineage relative to the DV axis in other bilaterian animals remains unclear. Cephalochordata (i.e., amphioxus) represent a basal chordate group which occupies a key phylogenetic position for explorations of the origin of the chordate body plan. In this review, we summarize what is currently known regarding the developmental mechanisms that establish the DV axis in amphioxus embryos. By comparing this to what is known in vertebrates, we can start to hypothesize about the ancestral DV patterning mechanisms in chordates and discuss their possible evolutionary origins.

• MeSH
• cytoskelet metabolismus   MeSH
• embryo nesavčí embryologie   metabolismus   MeSH
• kopinatci embryologie   genetika   metabolismus   MeSH
• rozvržení tělního plánu genetika   MeSH
• signální transdukce genetika   MeSH
• vývojová regulace genové exprese * MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• přehledy MeSH

When patterns are set during embryogenesis, it is expected that they are straightly established rather than subsequently modified. The patterning of the three mouse molars is, however, far from straight, likely as a result of mouse evolutionary history. The first-formed tooth signaling centers, called MS and R2, disappear before driving tooth formation and are thought to be vestiges of the premolars found in mouse ancestors. Moreover, the mature signaling center of the first molar (M1) is formed from the fusion of two signaling centers (R2 and early M1). Here, we report that broad activation of Edar expression precedes its spatial restriction to tooth signaling centers. This reveals a hidden two-step patterning process for tooth signaling centers, which was modeled with a single activator-inhibitor pair subject to reaction-diffusion (RD). The study of Edar expression also unveiled successive phases of signaling center formation, erasing, recovering, and fusion. Our model, in which R2 signaling center is not intrinsically defective but erased by the broad activation preceding M1 signaling center formation, predicted the surprising rescue of R2 in Edar mutant mice, where activation is reduced. The importance of this R2-M1 interaction was confirmed by ex vivo cultures showing that R2 is capable of forming a tooth. Finally, by introducing chemotaxis as a secondary process to RD, we recapitulated in silico different conditions in which R2 and M1 centers fuse or not. In conclusion, pattern formation in the mouse molar field relies on basic mechanisms whose dynamics produce embryonic patterns that are plastic objects rather than fixed end points.

• MeSH
• biologické modely * MeSH
• chemotaxe MeSH
• epitel embryologie   metabolismus   MeSH
• mutantní kmeny myší MeSH
• myši MeSH
• receptor Edar genetika   metabolismus   MeSH
• rozvržení tělního plánu * MeSH
• signální transdukce * MeSH
• vlasy, chlupy embryologie   MeSH
• vývojová regulace genové exprese MeSH
• zubní zárodek embryologie   metabolismus   MeSH
• zuby embryologie   metabolismus   MeSH
• zvířata MeSH
• Check Tag
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• Edar protein, mouse MeSH Prohlížeč
• receptor Edar MeSH

The Arabidopsis (Arabidopsis thaliana) gynoecium consists of two congenitally fused carpels made up of two lateral valve domains and two medial domains, which retain meristematic properties and later fuse to produce the female reproductive structures vital for fertilization. Polar auxin transport (PAT) is important for setting up distinct apical auxin signaling domains in the early floral meristem remnants allowing for lateral domain identity and outgrowth. Crosstalk between auxin and cytokinin plays an important role in the development of other meristematic tissues, but hormone interaction studies to date have focused on more accessible later-stage gynoecia and the spatiotemporal interactions pivotal for patterning of early gynoecium primordia remain unknown. Focusing on the earliest stages, we propose a cytokinin-auxin feedback model during early gynoecium patterning and hormone homeostasis. Our results suggest that cytokinin positively regulates auxin signaling in the incipient gynoecial primordium and strengthen the concept that cytokinin regulates auxin homeostasis during gynoecium development. Specifically, medial cytokinin promotes auxin biosynthesis components [YUCCA1/4 (YUC1/4)] in, and PINFORMED7 (PIN7)-mediated auxin efflux from, the medial domain. The resulting laterally focused auxin signaling triggers ARABIDOPSIS HISTIDINE PHOSPHOTRANSFER PROTEIN6 (AHP6), which then represses cytokinin signaling in a PAT-dependent feedback. Cytokinin also down-regulates PIN3, promoting auxin accumulation in the apex. The yuc1, yuc4, and ahp6 mutants are hypersensitive to exogenous cytokinin and 1-napthylphthalamic acid (NPA), highlighting their role in mediolateral gynoecium patterning. In summary, these mechanisms self-regulate cytokinin and auxin signaling domains, ensuring correct domain specification and gynoecium development.

• MeSH
• Arabidopsis embryologie   genetika   metabolismus   MeSH
• biologické modely MeSH
• biologický transport MeSH
• cytokininy metabolismus   MeSH
• homeostáza MeSH
• květy embryologie   MeSH
• kyseliny indoloctové metabolismus   MeSH
• proteiny huseníčku genetika   metabolismus   MeSH
• regulace genové exprese u rostlin MeSH
• regulátory růstu rostlin metabolismus   MeSH
• rostlinné geny MeSH
• rozvržení tělního plánu * MeSH
• signální transdukce * MeSH
• upregulace MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• cytokininy MeSH
• kyseliny indoloctové MeSH
• proteiny huseníčku MeSH
• regulátory růstu rostlin MeSH

Coordination of cell division and pattern formation is central to tissue and organ development, particularly in plants where walls prevent cell migration. Auxin and cytokinin are both critical for division and patterning, but it is unknown how these hormones converge upon tissue development. We identify a genetic network that reinforces an early embryonic bias in auxin distribution to create a local, nonresponding cytokinin source within the root vascular tissue. Experimental and theoretical evidence shows that these cells act as a tissue organizer by positioning the domain of oriented cell divisions. We further demonstrate that the auxin-cytokinin interaction acts as a spatial incoherent feed-forward loop, which is essential to generate distinct hormonal response zones, thus establishing a stable pattern within a growing vascular tissue.

• MeSH
• aminohydrolasy MeSH
• Arabidopsis účinky léků   genetika   růst a vývoj   MeSH
• buněčné dělení genetika   fyziologie   MeSH
• cévní svazky rostlin účinky léků   růst a vývoj   MeSH
• cytokiny biosyntéza   MeSH
• genové regulační sítě MeSH
• jaderné proteiny genetika   MeSH
• kyseliny indoloctové metabolismus   farmakologie   MeSH
• proteiny huseníčku genetika   metabolismus   MeSH
• regulace genové exprese u rostlin MeSH
• rozvržení tělního plánu účinky léků   genetika   fyziologie   MeSH
• trans-aktivátory metabolismus   MeSH
• transkripční faktory bHLH metabolismus   MeSH
• vývojová regulace genové exprese MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Research Support, U.S. Gov't, Non-P.H.S. MeSH
• Názvy látek
• aminohydrolasy MeSH
• cytokinin riboside 5'-monophosphate phosphoribohydrolase, Arabidopsis MeSH Prohlížeč
• cytokiny MeSH
• jaderné proteiny MeSH
• kyseliny indoloctové MeSH
• LHW protein, Arabidopsis MeSH Prohlížeč
• proteiny huseníčku MeSH
• TARGET OF MP 5 protein, Arabidopsis MeSH Prohlížeč
• trans-aktivátory MeSH
• transkripční faktory bHLH MeSH

Rodents are characterized by continuously renewing incisors whose growth is fueled by epithelial and mesenchymal stem cells housed in the proximal compartments of the tooth. The epithelial stem cells reside in structures known as the labial (toward the lip) and lingual (toward the tongue) cervical loops (laCL and liCL, respectively). An important feature of the rodent incisor is that enamel, the outer, highly mineralized layer, is asymmetrically distributed, because it is normally generated by the laCL but not the liCL. Here, we show that epithelial-specific deletion of the transcription factor Islet1 (Isl1) is sufficient to drive formation of ectopic enamel by the liCL stem cells, and also that it leads to production of altered enamel on the labial surface. Molecular analyses of developing and adult incisors revealed that epithelial deletion of Isl1 affected multiple, major pathways: Bmp (bone morphogenetic protein), Hh (hedgehog), Fgf (fibroblast growth factor), and Notch signaling were upregulated and associated with liCL-generated ectopic enamel; on the labial side, upregulation of Bmp and Fgf signaling, and downregulation of Shh were associated with premature enamel formation. Transcriptome profiling studies identified a suite of differentially regulated genes in developing Isl1 mutant incisors. Our studies demonstrate that ISL1 plays a central role in proper patterning of stem cell-derived enamel in the incisor and indicate that this factor is an important upstream regulator of signaling pathways during tooth development and renewal. © 2017 American Society for Bone and Mineral Research.

• Klíčová slova
• AMELOGENESIS, ECTOPIC ENAMEL, ISL1, MOUSE INCISOR, TOOTH DEVELOPMENT,
• MeSH
• delece genu MeSH
• epitel embryologie   metabolismus   MeSH
• fyziologická kalcifikace * MeSH
• mandibula metabolismus   MeSH
• mutace genetika   MeSH
• myši MeSH
• orgánová specificita MeSH
• proteiny s homeodoménou LIM genetika   metabolismus   MeSH
• řezáky embryologie   metabolismus   MeSH
• rozvržení tělního plánu * MeSH
• sekvenční analýza RNA MeSH
• signální transdukce MeSH
• stanovení celkové genové exprese MeSH
• transkripční faktory genetika   metabolismus   MeSH
• vývojová regulace genové exprese MeSH
• zubní sklovina embryologie   metabolismus   MeSH
• zvířata MeSH
• Check Tag
• myši MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• insulin gene enhancer binding protein Isl-1 MeSH Prohlížeč
• proteiny s homeodoménou LIM MeSH
• transkripční faktory MeSH

The patterning of repeated structures is a major theme in developmental biology, and the inter-relationship between spacing and size of such structures is an unresolved issue. Fungiform papillae are repeated epithelial structures that house taste buds on the anterior tongue. Here, we report that FGF signaling is a crucial regulator of fungiform papillae development. We found that mesenchymal FGF10 controls the size of the papillary area, while overall patterning remains unchanged. Our results show that FGF signaling negatively affects the extent of canonical Wnt signaling, which is the main activation pathway during fungiform papillae development; however, this effect does not occur at the level of gene transcription. Rather, our experimental data, together with computational modeling, indicate that FGF10 modulates the range of Wnt effects, likely via induction of Sostdc1 expression. We suggest that modification of the reach of Wnt signaling could be due to local changes in morphogen diffusion, representing a novel mechanism in this tissue context, and we propose that this phenomenon might be involved in a broader array of mammalian developmental processes.

• Klíčová slova
• FGF, Taste papilla, Tongue, Wnt,
• MeSH
• adaptorové proteiny signální transdukční MeSH
• biologické modely MeSH
• chuťové pohárky embryologie   metabolismus   MeSH
• fibroblastový růstový faktor 10 nedostatek   genetika   metabolismus   MeSH
• intracelulární signální peptidy a proteiny nedostatek   genetika   metabolismus   MeSH
• kostní morfogenetické proteiny genetika   metabolismus   MeSH
• membránové proteiny nedostatek   genetika   metabolismus   MeSH
• myši knockoutované MeSH
• myši transgenní MeSH
• myši MeSH
• počítačová simulace MeSH
• protein-serin-threoninkinasy MeSH
• proteiny hedgehog genetika   metabolismus   MeSH
• rozvržení tělního plánu genetika   fyziologie   MeSH
• signální dráha Wnt * MeSH
• těhotenství MeSH
• zvířata MeSH
• Check Tag
• mužské pohlaví MeSH
• myši MeSH
• těhotenství MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• adaptorové proteiny signální transdukční MeSH
• Fgf10 protein, mouse MeSH Prohlížeč
• fibroblastový růstový faktor 10 MeSH
• intracelulární signální peptidy a proteiny MeSH
• kostní morfogenetické proteiny MeSH
• membránové proteiny MeSH
• protein-serin-threoninkinasy MeSH
• proteiny hedgehog MeSH
• Shh protein, mouse MeSH Prohlížeč
• Sostdc1 protein, mouse MeSH Prohlížeč
• Spry2 protein, mouse MeSH Prohlížeč