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1.
Science ; 377(6612): 1311-1314, 2022 09 16.
Artículo en Inglés | MEDLINE | ID: mdl-36107996

RESUMEN

The origin and early diversification of jawed vertebrates involved major changes to skeletal and soft anatomy. Skeletal transformations can be examined directly by studying fossil stem gnathostomes; however, preservation of soft anatomy is rare. We describe the only known example of a three-dimensionally mineralized heart, thick-walled stomach, and bilobed liver from arthrodire placoderms, stem gnathostomes from the Late Devonian Gogo Formation in Western Australia. The application of synchrotron and neutron microtomography to this material shows evidence of a flat S-shaped heart, which is well separated from the liver and other abdominal organs, and the absence of lungs. Arthrodires thus show the earliest phylogenetic evidence for repositioning of the gnathostome heart associated with the evolution of the complex neck region in jawed vertebrates.


Asunto(s)
Evolución Biológica , Bagres , Fósiles , Animales , Bagres/anatomía & histología , Bagres/clasificación , Maxilares/anatomía & histología , Filogenia , Australia Occidental
2.
J Cancer Res Ther ; 18(4): 1016-1022, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36149155

RESUMEN

Introduction: Radiotherapy (RT) combined with chemotherapy and surgery is the indicated treatment for head and neck cancers. Even with the advent of modern technological advances in RT and improved oral hygiene awareness, osteoradionecrosis (ORN) still remains as one of the most debilitating side effects of RT. Methodology: This is a retrospective review assessing 72 patients aged over 18 years of age reporting in the Dental Department, for treatment of ORN from April 2010 to July 2019. Each patient was clinically examined and treated according to standard protocol. The stage of ORN was noted at the diagnosis and at follow-up. The demographic data, the tumor characteristics, and the treatment of patients were evaluated using descriptive statistics. Results: At the time of diagnosis, 84.7% of the study population was found to have Epstein Type II chronic persistent nonprogressive lesions and 11.1% of the cohort had Type III active progressive lesions. Statistically significant correlation (P = 0.00) was found for ORN grade at diagnosis and at follow-up. ORN being a chronic pathology, stabilization of the disease was observed in 72.3% of cases. The resolution of the necrotic lesion and down staging of the disease was seen only in 2.8% of patients. Conclusion: ORN is mainly a chronic long standing pathology which is difficult to treat completely. Stabilization of symptoms and preventing further spread of the necrotic lesion should be the ultimate aim of the treatment to improve the quality of life of the patients.


Asunto(s)
Neoplasias de Cabeza y Cuello , Osteorradionecrosis , Adolescente , Adulto , Anciano , Estudios de Cohortes , Neoplasias de Cabeza y Cuello/radioterapia , Humanos , Maxilares , Osteorradionecrosis/diagnóstico , Osteorradionecrosis/epidemiología , Osteorradionecrosis/etiología , Calidad de Vida , Estudios Retrospectivos
3.
4.
Nature ; 609(7929): 959-963, 2022 09.
Artículo en Inglés | MEDLINE | ID: mdl-36171376

RESUMEN

Paired fins are a major innovation1,2 that evolved in the jawed vertebrate lineage after divergence from living jawless vertebrates3. Extinct jawless armoured stem gnathostomes show a diversity of paired body-wall extensions, ranging from skeletal processes to simple flaps4. By contrast, osteostracans (a sister group to jawed vertebrates) are interpreted to have the first true paired appendages in a pectoral position, with pelvic appendages evolving later in association with jaws5. Here we show, on the basis of articulated remains of Tujiaaspis vividus from the Silurian period of China, that galeaspids (a sister group to both osteostracans and jawed vertebrates) possessed three unpaired dorsal fins, an approximately symmetrical hypochordal tail and a pair of continuous, branchial-to-caudal ventrolateral fins. The ventrolateral fins are similar to paired fin flaps in other stem gnathostomes, and specifically to the ventrolateral ridges of cephalaspid osteostracans that also possess differentiated pectoral fins. The ventrolateral fins are compatible with aspects of the fin-fold hypothesis for the origin of vertebrate paired appendages6-10. Galeaspids have a precursor condition to osteostracans and jawed vertebrates in which paired fins arose initially as continuous pectoral-pelvic lateral fins that our computed fluid-dynamics experiments show passively generated lift. Only later in the stem lineage to osteostracans and jawed vertebrates did pectoral fins differentiate anteriorly. This later differentiation was followed by restriction of the remaining field of fin competence to a pelvic position, facilitating active propulsion and steering.


Asunto(s)
Evolución Biológica , Vertebrados , Aletas de Animales/anatomía & histología , Animales , China , Maxilares
5.
Nature ; 609(7929): 969-974, 2022 09.
Artículo en Inglés | MEDLINE | ID: mdl-36171377

RESUMEN

Modern representatives of chondrichthyans (cartilaginous fishes) and osteichthyans (bony fishes and tetrapods) have contrasting skeletal anatomies and developmental trajectories1-4 that underscore the distant evolutionary split5-7 of the two clades. Recent work on upper Silurian and Devonian jawed vertebrates7-10 has revealed similar skeletal conditions that blur the conventional distinctions between osteichthyans, chondrichthyans and their jawed gnathostome ancestors. Here we describe the remains (dermal plates, scales and fin spines) of a chondrichthyan, Fanjingshania renovata gen. et sp. nov., from the lower Silurian of China that pre-date the earliest articulated fossils of jawed vertebrates10-12. Fanjingshania possesses dermal shoulder girdle plates and a complement of fin spines that have a striking anatomical similarity to those recorded in a subset of stem chondrichthyans5,7,13 (climatiid 'acanthodians'14). Uniquely among chondrichthyans, however, it demonstrates osteichthyan-like resorptive shedding of scale odontodes (dermal teeth) and an absence of odontogenic tissues in its spines. Our results identify independent acquisition of these conditions in the chondrichthyan stem group, adding Fanjingshania to an increasing number of taxa7,15 nested within conventionally defined acanthodians16. The discovery of Fanjingshania provides the strongest support yet for a proposed7 early Silurian radiation of jawed vertebrates before their widespread appearance5 in the fossil record in the Lower Devonian series.


Asunto(s)
Fósiles , Maxilares , Animales , Evolución Biológica , China , Peces , Maxilares/anatomía & histología , Filogenia , Vertebrados
6.
J Mech Behav Biomed Mater ; 134: 105405, 2022 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-35947925

RESUMEN

Preclinical studies often require animal models for in vivo experiments. Particularly in dental research, pig species are extensively used due to their anatomical similarity to humans. However, there is a considerable knowledge gap on the multiscale morphological and mechanical properties of the miniature pigs' jawbones, which is crucial for implant studies and a direct comparison to human tissue. In the present work, we demonstrate a multimodal framework to assess the jawbone quantity and quality for a minipig animal model that could be further extended to humans. Three minipig genotypes, commonly used in dental research, were examined: Yucatan, Göttingen, and Sinclair. Three animals per genotype were tested. Cortical bone samples were extracted from the premolar region of the mandible, opposite to the teeth growth. Global morphological, compositional, and mechanical properties were assessed using micro-computed tomography (micro-CT) together with Raman spectroscopy and nanoindentation measurements, averaged over the sample area. Local mineral-mechanical relationships were investigated with the site-matched Raman spectroscopy and micropillar compression tests. For this, a novel femtosecond laser ablation protocol was developed, allowing high-throughput micropillar fabrication and testing without exposure to high vacuum. At the global averaged sample level, bone relative mineralization demonstrated a significant difference between the genotypes, which was not observed from the complementary micro-CT measurements. Moreover, bone hardness measured by nanoindentation showed a positive trend with the relative mineralization. For all genotypes, significant differences between the relative mineralization and elastic properties were more pronounced within the osteonal regions of cortical bone. Site-matched micropillar compression and Raman spectroscopy highlighted the differences between the genotypes' yield stress and mineral to matrix ratios. The methods used at the global level (averaged over sample area) could be potentially correlated to the medical tools used to assess jawbone toughness and morphology in clinics. On the other hand, the local analysis methods can be applied to quantify compressive bone mechanical properties and their relationship to bone mineralization.


Asunto(s)
Hueso Cortical , Maxilares , Animales , Humanos , Mandíbula/diagnóstico por imagen , Porcinos , Porcinos Enanos , Microtomografía por Rayos X
7.
PLoS One ; 17(8): e0272860, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35960777

RESUMEN

We studied the structure and attachment modes of the teeth of adult Anoplogaster cornuta using light- and scanning-electron microscopic techniques. All teeth were monocuspid, composed solely of orthodentin, and lacked a covering enameloid cap. Fourteen teeth were present in the oral jaws, with three teeth each on the left and right premaxilla and four teeth each on the left and right dentary. The anteriormost premaxillary and dentary teeth were considerably larger than the more posteriorly located ones. The oral jaw teeth were transparent, non-depressible and firmly ankylosed to their respective dentigerous bone by a largely anosteocytic bone of attachment. No evidence for replacement of the large oral jaw teeth was found in the analyzed adult specimens. The bone of attachment exhibited lower calcium and phosphorus concentrations and a higher Ca/P ratio than the orthodentin. The connection between dentinal tooth shaft and bone of attachment was stabilized by a collar of mineralized collagen fibers. In contrast to the oral jaw teeth, the pharyngeal teeth exhibited a ring-like fibrous attachment to their supporting bones. This mode of attachment provides the teeth with some lateral mobility and allows their depression relative to their supporting bones, which may facilitate intra-pharyngeal prey transport. In contrast, a firm ankylosis was observed in numerous small teeth located on the branchial arches. The function of these teeth is presumably to increase the tightness of the pharyngeal basket and thereby the retention of small prey items in a species living in a habitat with only sparse food supply. Our findings corroborate earlier statements on the tooth attachment modes of the oral jaw teeth of Anoplogaster cornuta, but provide new findings for the attachment modes of pharyngeal teeth in this species.


Asunto(s)
Diente , Animales , Región Branquial , Peces , Maxilares , Microscopía Electrónica de Rastreo
8.
J Exp Biol ; 225(16)2022 08 15.
Artículo en Inglés | MEDLINE | ID: mdl-35994028

RESUMEN

Elasmobranch fishes (sharks, skates and rays) consume prey of a variety of sizes and properties, and the feeding mechanism typically reflects diet. Spotted ratfish, Hydrolagus colliei (Holocephali, sister group of elasmobranchs), consume both hard and soft prey; however, the morphology of the jaws does not reflect the characteristics typical of durophagous elasmobranchs. This study investigated the mechanical properties and morphological characteristics of the jaws of spotted ratfish over ontogeny, including strain, stiffness and second moment of area, to evaluate the biomechanical function of the feeding structures. Compressive stiffness of the jaws (E=13.51-21.48 MPa) is similar to that of silicone rubber, a very flexible material. In Holocephali, the upper jaw is fused to the cranium; we show that this fusion reduces deformation experienced by the upper jaw during feeding. The lower jaw resists bending primarily in the posterior half of the jaw, which occludes with the region of the upper jaw that is wider and flatter, thus potentially providing an ideal location for the lower jaw to crush or crack prey. The mechanical properties and morphology of the feeding apparatus of spotted ratfish suggest that while the low compressive stiffness is a material limit of the jaw cartilage, spotted ratfish, and perhaps all holocephalans, evolved structural solutions (i.e. fused upper jaw, shape variation along lower jaw) to meet the demands of a durophagous diet.


Asunto(s)
Tiburones , Rajidae , Animales , Fenómenos Biomecánicos , Conducta Alimentaria , Peces , Maxilares/anatomía & histología , Tiburones/anatomía & histología , Rajidae/anatomía & histología
10.
Brain Behav ; 12(9): e2645, 2022 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-35916391

RESUMEN

BACKGROUND: In comparison with the people with normal sight, the mean center of gravity (COG) velocity is significantly higher among blind people. A strong relationship has been shown between jaw and neck sensorimotor and postural control. The purpose of this study was to determine the effect of different static and dynamic jaw positions on postural stability among subjects with blindness. METHODS: Postural stability was measured as COG velocity in 39 blind subjects under the following five conditions: resting jaw (natural jaw position with no instructions, control), open jaw (teeth of both jaws slightly apart), clenched jaw (teeth tightly closed across each other), chewing (a standard bolus of gum at the natural palace), and tongue position (positioned behind the upper incisors) while standing on firm and foam surfaces. RESULTS: The mean COG velocity while standing on the firm surface during resting, open jaw position, clenched jaw position, chewing, and tongue positions were 0.54, 0.50, 0.44, 0.59, and 0.46 deg/s, respectively. The mean COG velocity while standing on the foam surface during resting, open jaw position, clenched jaw position, chewing, and tongue positions were 1.42, 1.23, 1.10, 1.14, and 1.06 deg/s, respectively. Compared to the firm surface, the COG velocity was significantly higher on the foam surface in all five conditions (p < .001). In the comparison between the conditions, there were no significant differences in either the firm or foam surface in all five conditions (p > .05). CONCLUSION: People with blindness behave in the same way as sighted subjects on firm and foam surfaces. However, changes in static and dynamic jaw positions do not affect postural stability among them.


Asunto(s)
Maxilares , Equilibrio Postural , Ceguera , Cabeza , Humanos
11.
Comput Methods Programs Biomed ; 224: 107009, 2022 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-35872385

RESUMEN

BACKGROUND: State-of-the-art finite element studies on human jaws are mostly limited to the geometry of a single patient. In general, developing accurate patient-specific computational models of the human jaw acquired from cone-beam computed tomography (CBCT) scans is labor-intensive and non-trivial, which involves time-consuming human-in-the-loop procedures, such as segmentation, geometry reconstruction, and re-meshing tasks. Therefore, with the current practice, researchers need to spend considerable time and effort to produce finite element models (FEMs) to get to the point where they can use the models to answer clinically-interesting questions. Besides, any manual task involved in the process makes it difficult for the researchers to reproduce identical models generated in the literature. Hence, a quantitative comparison is not attainable due to the lack of surface/volumetric meshes and FEMs. METHODS: We share an open-access repository composed of 17 patient-specific computational models of human jaws and the utilized pipeline for generating them for reproducibility of our work. The used pipeline minimizes the required time for processing and any potential biases in the model generation process caused by human intervention. It gets the segmented geometries with irregular and dense surface meshes and provides reduced, adaptive, watertight, and conformal surface/volumetric meshes, which can directly be used in finite element (FE) analysis. RESULTS: We have quantified the variability of our 17 models and assessed the accuracy of the developed models from three different aspects; (1) the maximum deviations from the input meshes using the Hausdorff distance as an error measurement, (2) the quality of the developed volumetric meshes, and (3) the stability of the FE models under two different scenarios of tipping and biting. CONCLUSIONS: The obtained results indicate that the developed computational models are precise, and they consist of quality meshes suitable for various FE scenarios. We believe the provided dataset of models including a high geometrical variation obtained from 17 different models will pave the way for population studies focusing on the biomechanical behavior of human jaws.


Asunto(s)
Maxilares , Análisis de Elementos Finitos , Humanos , Maxilares/diagnóstico por imagen , Reproducibilidad de los Resultados
12.
J Craniomaxillofac Surg ; 50(8): 657-663, 2022 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-35820979

RESUMEN

This study's objective is to determine if the combined use of bone substitutes and collagen membranes is related to worse postoperative outcomes after intra-osseous oral cystectomies. Additional risk factors mentioned in the existing literature were retrospectively analysed by reviewing the medical records and imaging tests of adult patients. Age, gender, smoking habit, cyst location, size, shape, histopathology, perilesional osteosclerosis and associated intracystic third molars were registered. The type of biomaterials applied and the number of bony walls remaining after surgery were also identified. All factors were analysed in relation to wound dehiscence and postoperative infection. Simple and multiple logistic regression analyses were performed to exclude possible confounding effects between the risk factors identified. In a sample of 211 cystectomies, guided bone regeneration was not significantly associated with infection, only the presence of impacted third molars was (p = 0.0219). This finding remained true, even in cysts larger than 25 mm. However, the risk of wound dehiscence was 4.9 times higher when biomaterials were applied (CI 95%, 1.6818-12.8274, p = 0.0014). In accordance with recent studies, these findings suggest that whenever guided bone regeneration might prove useful after cyst enucleation, avoiding chemically cross-linked membranes should be considered.


Asunto(s)
Sustitutos de Huesos , Quistes , Adulto , Materiales Biocompatibles , Sustitutos de Huesos/uso terapéutico , Cistectomía/efectos adversos , Análisis Factorial , Regeneración Tisular Guiada Periodontal/efectos adversos , Regeneración Tisular Guiada Periodontal/métodos , Humanos , Maxilares , Membranas Artificiales , Complicaciones Posoperatorias/etiología , Estudios Retrospectivos , Factores de Riesgo , Dehiscencia de la Herida Operatoria/etiología
13.
Sci Rep ; 12(1): 11448, 2022 07 06.
Artículo en Inglés | MEDLINE | ID: mdl-35794235

RESUMEN

Today's mysticetes filter-feed using baleen, a novel integumentary structure with no apparent homolog in any living mammal. The origins of filter-feeding and baleen can be informed by the fossil record, including rare instances of soft tissue preservation of baleen and also by potential osteological correlates of baleen. Lateral palatal foramina on the roof of the mouth have been proposed as potential osteological correlates of baleen and their presence in some tooth-bearing stem mysticetes has led to the hypothesis that these early mysticetes possessed both teeth and incipient baleen. Here, we test this hypothesis by examining lateral palatal foramina in both filter-feeding and non-filter-feeding cetaceans, including crown and stem odontocetes and in stem cetaceans (or archaeocetes). We also confirm the presence of lateral palatal foramina in 61 species of terrestrial artiodactyls. CT scanning demonstrates consistent internal morphology across all observed taxa, suggesting that the lateral palatal foramina observed in extant mysticetes are homologous to those of terrestrial artiodactyls. The presence of lateral palatal foramina in terrestrial artiodactyls and non-filter-feeding whales (odontocetes and archaeocetes) suggests that these structures are not unique predictors for the presence of baleen in fossil whales; instead, these structures are more probably associated with gingiva or other oral tissue.


Asunto(s)
Fósiles , Diente , Animales , Evolución Biológica , Maxilares/anatomía & histología , Diente/anatomía & histología , Ballenas
14.
Evolution ; 76(9): 2076-2088, 2022 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-35848877

RESUMEN

A long-standing question in comparative biology is how the evolution of biomechanical systems influences morphological evolution. The need for functional fidelity implies that the evolution of such systems should be associated with tighter morphological covariation, which may promote or dampen rates of morphological evolution. I examine this question across multiple evolutionary origins of the trap-jaw mechanism in the genus Strumigenys. Trap-jaw ants have latch-mediated, spring-actuated systems that amplify the power output of their mandibles. I use Bayesian estimates of covariation and evolutionary rates to test the hypotheses that the evolution of this high-performance system is associated with tighter morphological covariation in the head and mandibles relative to nontrap-jaw forms and that this leads to shifts in rates of morphological evolution. Contrary to these hypotheses, there is no evidence of a large-scale shift to higher covariation in trap-jaw forms, while different traits show both increased and decreased evolutionary rates between forms. These patterns may be indicative of many-to-one mapping and/or mechanical sensitivity in the trap-jaw LaMSA system. Overall, it appears that the evolution of trap-jaw forms in Strumigenys did not require a correlated increase in morphological covariation, partly explaining the proclivity with which the system has evolved.


Asunto(s)
Hormigas , Animales , Hormigas/anatomía & histología , Hormigas/genética , Teorema de Bayes , Evolución Biológica , Fenómenos Biomecánicos , Maxilares/anatomía & histología
15.
Science ; 377(6602): 218-222, 2022 07 08.
Artículo en Inglés | MEDLINE | ID: mdl-35857544

RESUMEN

Pharyngeal arches are a key innovation that likely contributed to the evolution of the jaws and braincase of vertebrates. It has long been hypothesized that the pharyngeal (branchial) arch evolved from an unjointed cartilaginous rod in vertebrate ancestors such as that in the nonvertebrate chordate amphioxus, but whether such ancestral anatomy existed remains unknown. The pharyngeal skeleton of controversial Cambrian animals called yunnanozoans may contain the oldest fossil evidence constraining the early evolution of the arches, yet its correlation with that of vertebrates is still disputed. By examining additional specimens in previously unexplored techniques (for example, x-ray microtomography, scanning and transmission electron microscopy, and energy dispersive spectrometry element mapping), we found evidence that yunnanozoan branchial arches consist of cellular cartilage with an extracellular matrix dominated by microfibrils, a feature hitherto considered specific to vertebrates. Our phylogenetic analysis provides further support that yunnanozoans are stem vertebrates.


Asunto(s)
Evolución Biológica , Vertebrados , Animales , Fósiles , Maxilares/anatomía & histología , Filogenia , Vertebrados/anatomía & histología
16.
Zoology (Jena) ; 154: 126030, 2022 10.
Artículo en Inglés | MEDLINE | ID: mdl-35905540

RESUMEN

California moray eels, Gymnothorax mordax, are benthic predatory residents of southern California kelp forest ecosystems. California morays around Catalina Island move vertically through the water column to feed, exposing them to a wide range of temperatures. For a predatory fish, morays have a relatively large prey handling repertoire that enable them to manipulate their prey before swallowing. Prey manipulation behaviors include shaking, spinning, knotting, and ramming prey against other objects. Morays also have observable transport mechanics where they protract and retract their pharyngeal jaws to swallow prey. We examined prey manipulation and transport behaviors at four temperature treatments that simulated the range of environmental temperatures morays encounter in the wild. We hypothesized that higher temperatures will increase the prevalence, duration, and rate of whole body prey manipulation behaviors and decrease the duration of prey transport time. Previous temperature studies focused on fishes occupying intermediate trophic levels. Therefore, understanding how acute temperature affects feeding behavior of the California moray eel, an abundant predatory fish, is especially important, as changes in environmental temperature may have disproportionate effects in their marine community. Five morays were acutely exposed to 15, 18, 21, 24 °C temperatures and their subsequent feeding behaviors were filmed and quantified. Individuals were offered the same relative prey mass (15 %) in relation to their body mass throughout the study. We compared the number of times each prey manipulation behavior occurred, the mean time morays employed each behavior, and the rate (number of times per second) each behavior was performed across different temperatures. Our data demonstrates that absolute time spent knotting varies significantly across temperature. Knotting, often used to remove pieces from larger prey, was most frequent at 21 and 24 °C. The average duration of knotting also increased with temperature. The rates of prey manipulation behaviors did not vary significantly with temperature. Finally, transport behavior did not vary across treatments. Our study shows that knotting behavior in the California moray is responsive to environmental temperatures and that morays may be able to manipulate larger prey in warmer waters. These behavioral data may have important implications for predator-prey relationships under dynamic and future ocean conditions.


Asunto(s)
Ecosistema , Anguilas , Animales , Peces , Maxilares , Conducta Predatoria , Temperatura
17.
J Oral Pathol Med ; 51(7): 666-673, 2022 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-35706152

RESUMEN

BACKGROUND: Giant cell granuloma of the jaws are benign osteolytic lesions of the jaws. These lesions are genetically characterized by mutually exclusive somatic mutations at TRPV4, KRAS, and FGFR1, and a fourth molecular subgroup which is wild-type for the three mutations. Irrespective of the molecular background, giant cell granulomas show MAPK/ERK activation. However, it remains unclear if these mutations lead to differences in their molecular signaling in giant cell granulomas. METHODS: Metabolomics, proteomics, and phosphoproteomics analyses were carried out in formalin-fixed paraffin-embedded samples of giant cell granuloma of the jaws. The study cohort consisted of five lesions harboring mutations in FGFR1, six in KRAS, five in TRPV4, and five that were wild-type for these mutations. RESULTS: Lesions harboring KRAS or FGFR1 mutations showed overall similar proteomics and metabolomics profiles. In all four groups, metabolic pathways showed similarity in apoptosis, cell signaling, gene expression, cell differentiation, and erythrocyte activity. Lesions harboring TRPV4 mutations showed a greater number of enriched pathways related to tissue architecture. On the other hand, the wild-type group presented increased number of enriched pathways related to protein metabolism compared to the other groups. CONCLUSION: Despite some minor differences, our results revealed an overall similar molecular profile among the groups with different mutational profile at the metabolic, proteic, and phosphopeptidic levels.


Asunto(s)
Granuloma de Células Gigantes , Canales Catiónicos TRPV , Granuloma de Células Gigantes/genética , Granuloma de Células Gigantes/metabolismo , Humanos , Maxilares/metabolismo , Maxilares/patología , Metabolómica , Mutación , Proteómica , Proteínas Proto-Oncogénicas p21(ras)/genética , Proteínas Proto-Oncogénicas p21(ras)/metabolismo , Canales Catiónicos TRPV/genética , Canales Catiónicos TRPV/metabolismo
18.
Elife ; 112022 06 06.
Artículo en Inglés | MEDLINE | ID: mdl-35666955

RESUMEN

Precise developmental control of jaw length is critical for survival, but underlying molecular mechanisms remain poorly understood. The jaw skeleton arises from neural crest mesenchyme (NCM), and we previously demonstrated that these progenitor cells express more bone-resorbing enzymes including Matrix metalloproteinase 13 (Mmp13) when they generate shorter jaws in quail embryos versus longer jaws in duck. Moreover, if we inhibit bone resorption or Mmp13, we can increase jaw length. In the current study, we uncover mechanisms establishing species-specific levels of Mmp13 and bone resorption. Quail show greater activation of and sensitivity to transforming growth factor beta (TGFß) signaling than duck; where intracellular mediators like SMADs and targets like Runt-related transcription factor 2 (Runx2), which bind Mmp13, become elevated. Inhibiting TGFß signaling decreases bone resorption, and overexpressing Mmp13 in NCM shortens the duck lower jaw. To elucidate the basis for this differential regulation, we examine the Mmp13 promoter. We discover a SMAD-binding element and single nucleotide polymorphisms (SNPs) near a RUNX2-binding element that distinguish quail from duck. Altering the SMAD site and switching the SNPs abolish TGFß sensitivity in the quail Mmp13 promoter but make the duck promoter responsive. Thus, differential regulation of TGFß signaling and Mmp13 promoter structure underlie avian jaw development and evolution.


Asunto(s)
Resorción Ósea , Factor de Crecimiento Transformador beta , Animales , Subunidad alfa 1 del Factor de Unión al Sitio Principal , Patos , Maxilares/fisiología , Metaloproteinasa 13 de la Matriz/genética , Cresta Neural/fisiología , Codorniz
19.
Development ; 149(13)2022 07 01.
Artículo en Inglés | MEDLINE | ID: mdl-35762641

RESUMEN

The pseudobranch is a gill-like epithelial elaboration that sits behind the jaw of most fishes. This structure was classically regarded as a vestige of the ancestral gill arch-like condition of the gnathostome jaw. However, more recently, hypotheses of jaw evolution by transformation of a gill arch have been challenged, and the pseudobranch has alternatively been considered a specialised derivative of the second (hyoid) pharyngeal arch. Here, we demonstrate in the skate (Leucoraja erinacea) that the pseudobranch does, in fact, derive from the mandibular arch, and that it shares gene expression features and cell types with gills. We also show that the skate mandibular arch pseudobranch is supported by a spiracular cartilage that is patterned by a shh-expressing epithelial signalling centre. This closely parallels the condition seen in the gill arches, where cartilaginous appendages called branchial rays, which support the respiratory lamellae of the gills, are patterned by a shh-expressing gill arch epithelial ridge. Together with similar discoveries in zebrafish, our findings support serial homology of the pseudobranch and gills, and an ancestral origin of gill arch-like anatomical features from the gnathostome mandibular arch.


Asunto(s)
Branquias , Rajidae , Animales , Región Branquial/metabolismo , Branquias/metabolismo , Maxilares , Rajidae/genética , Pez Cebra
20.
Elife ; 112022 06 28.
Artículo en Inglés | MEDLINE | ID: mdl-35762575

RESUMEN

Whereas no known living vertebrate possesses gills derived from the jaw-forming mandibular arch, it has been proposed that the jaw arose through modifications of an ancestral mandibular gill. Here, we show that the zebrafish pseudobranch, which regulates blood pressure in the eye, develops from mandibular arch mesenchyme and first pouch epithelia and shares gene expression, enhancer utilization, and developmental gata3 dependence with the gills. Combined with work in chondrichthyans, our findings in a teleost fish point to the presence of a mandibular pseudobranch with serial homology to gills in the last common ancestor of jawed vertebrates, consistent with a gill origin of vertebrate jaws.


Asunto(s)
Evolución Biológica , Branquias , Animales , Región Branquial , Maxilares , Pez Cebra
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