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1.
Zoolog Sci ; 38(5): 397-404, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34664914

RESUMO

Vulnerability of animals immediately after hatching may induce plasticity in early ontology that becomes important for subsequent survival and growth. Ezo salamanders (Hynobius retardatus) are amphibians inhabiting ponds in Hokkaido, Japan where ezo brown frogs (Rana pirica) spawn on occasion. The salamander larvae must achieve sufficient size in order to successfully capture frog tadpoles, and we examined whether the presence of tadpoles causes development of greater body and/or gape size in newly hatched salamander larvae, which will in turn result in advantageous future prey-predator interactions. To examine this hypothesis, we conducted three laboratory experiments to demonstrate the phenotypic plasticity of salamander hatchlings in response to the presence or absence of frog tadpoles and to screen the type of signals involved in the expression of the phenotypic plasticity. First, salamander hatchlings were reared alone or with tadpoles, and the growth and morphological traits of the hatchlings were compared. The results showed that hatchling larvae grew faster with a more developed gape in the presence of tadpoles. Next, to identify the type of signals inducing this plasticity, two separate experiments with manipulated chemical and visual signals from tadpoles were conducted. The findings showed that faster growth and a more developed gape were induced by chemical but not visual signals. This plasticity may be an adaptive strategy because it increases the likelihood of preying on tadpoles in future prey-predator interactions.


Assuntos
Adaptação Fisiológica , Urodelos/crescimento & desenvolvimento , Animais , Sinais (Psicologia) , Larva/crescimento & desenvolvimento , Larva/fisiologia , Boca/anatomia & histologia , Boca/crescimento & desenvolvimento , Comportamento Predatório , Ranidae , Urodelos/fisiologia , Água/química
2.
Int J Mol Sci ; 22(12)2021 Jun 21.
Artigo em Inglês | MEDLINE | ID: mdl-34205668

RESUMO

Matricellular proteins (MCPs) are defined as extracellular matrix (ECM) associated proteins that are important regulators and integrators of microenvironmental signals, contributing to the dynamic nature of ECM signalling. There is a growing understanding of the role of matricellular proteins in cellular processes governing tissue development as well as in disease pathogenesis. In this review, the expression and functions of different MP family members (periostin, CCNs, TSPs, SIBLINGs and others) are presented, specifically in relation to craniofacial development and the maintenance of orofacial tissues, including bone, gingiva, oral mucosa, palate and the dental pulp. As will be discussed, each MP family member has been shown to have non-redundant roles in development, tissue homeostasis, wound healing, pathology and tumorigenesis of orofacial and dental tissues.


Assuntos
Moléculas de Adesão Celular/fisiologia , Proteínas da Matriz Extracelular/fisiologia , Boca/crescimento & desenvolvimento , Osteonectina/fisiologia , Trombospondinas/fisiologia , Animais , Proteínas de Sinalização Intercelular CCN/fisiologia , Neoplasias de Cabeça e Pescoço/etiologia , Humanos , Boca/embriologia , Tenascina/fisiologia , Cicatrização
3.
Fish Physiol Biochem ; 47(4): 1087-1103, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34036482

RESUMO

Antioxidant system is crucial for protecting against environmental oxidative stress in fish life cycle. Although the effects of starvation on the antioxidant defenses in several adult fish have been defined, no relevant researches have been reported in the larval stage, particularly during the transition from endogenous to exogenous feeding. To clarify the molecular response of antioxidant system that occurs during the mouth-opening stage under starvation stress and explore its association with energy metabolism, we employed RNA-seq to analyze the gene expression profiles in zebrafish larvae that received a delayed first feeding for 3 days. Our data showed that delayed feeding resulted in downregulation of 7078 genes and upregulation of 497 genes. These differentially expressed genes are mainly involved in growth regulation (i.e., DNA replication and cell cycle), energy metabolism (i.e., glycolysis/gluconeogenesis and fatty acid metabolism), and antioxidant defenses. We demonstrated that the starved larvae are in an extremely malnourished state in the absence of exogenous nutrition, and the consequence is that numerous antioxidant genes are downregulated. Meanwhile, the antioxidant defenses also respond negatively to oxidative stress. After nutritional supply, the expression of these inhibited antioxidant genes was restored. These results suggest that the establishment of antioxidant defenses during the mouth-opening stage depends highly on exogenous nutrition. Our findings would contribute to comprehending the nutritional stress and metabolic switches during the mouth-opening stage and are essential for reducing high mortality in commercial fish farming.


Assuntos
Boca/crescimento & desenvolvimento , Inanição/genética , Transcriptoma , Peixe-Zebra/crescimento & desenvolvimento , Peixe-Zebra/genética , Animais , Apoptose , Feminino , Perfilação da Expressão Gênica , Regulação da Expressão Gênica no Desenvolvimento , Glutationa/genética , Larva/crescimento & desenvolvimento , Estado Nutricional , Oviparidade , Estresse Oxidativo , Oxirredutases/genética
4.
Zoology (Jena) ; 143: 125850, 2020 12.
Artigo em Inglês | MEDLINE | ID: mdl-33130490

RESUMO

Nudibranch molluscs represent an interesting model group to study the evolution of feeding apparatus and feeding modes, being characterized by specialized buccal complex in combination with extremely diverse dietary preferences and multiply prey shifts in evolutionary history. However, the plasticity of the buccal complex morphology in response to diet and specific feeding modes remains understudied. Here we study the general morphology and ontogenesis of the buccal complex in Eubranchus rupium (Nudibranchia: Fionidae). Specific goals are to provide a detailed description of buccal structures morphology in post-larval stages, suggest the feeding mechanism and discuss the phylogenetic value of the morphological characteristics of buccal armature within the genus Eubranchus. Methods included in vivo observations of the feeding process for E. rupium, light microscopic methods, scanning electron microscopy (SEM), transmission electron microscopy (TEM) and confocal laser scanning microscopy (cLSM). According to our results, E. rupium is a mechanical driller, boring holes in hydrozoan perisarc and sucking internal content. The mechanical drilling is supplied by functionally uniserial radula with plate-like laterals teeth of exclusively supportive function and by massive buccal musculature. Comparative phylogeny-based analysis suggests that the drilling feeding mode is common for the genus Eubranchus and indicates radular characters may have a high phylogenetic signal. The buccal complex morphology and feeding mode were found to be similar in both adults and post-metamorphic specimens, its general structures occur even in settled veligers. Juveniles and adults compete for food source, but the competition is smoothed due to characteristics of prey species growth and life cycle.


Assuntos
Moluscos/anatomia & histologia , Moluscos/crescimento & desenvolvimento , Boca/anatomia & histologia , Boca/crescimento & desenvolvimento , Animais , Comportamento Alimentar , Larva , Moluscos/genética , Filogenia
5.
Eur J Oral Sci ; 128(4): 299-307, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32749023

RESUMO

To investigate age-related changes in oral motor strategies in response to unpredictable load demands. Sixty-five healthy children (aged 3-17 yr) were divided into five age-groups based on their dental eruption stages and compared with a group of healthy adults (aged 18-35 yr). Each participant was asked to perform a standardized motor control task involving 'pulling' and 'holding' a force transducer with the anterior teeth. Different loads were attached to the force transducer in an unpredictable manner. The temporal force profile was divided into two time-segments (an initial segment and a later segment). The peak force and peak force rate during the initial time-segment, and the holding force and intra-trial variability (coefficient of variation) during the later time-segment, were measured. The results showed no differences in the peak force, peak force rate, holding force, and force variability in children compared with adults. However, the trends in the data evaluated using a segmented regression analysis showed that a breakpoint (abrupt change) consistently occurred in the late-mixed dentition group (age 9-11 yr) for most of the outcome variables. The results indicate that while the motor control strategies in children appear to be similar to those in adults, there is a shift in the oral motor developmental trend during the late-mixed dentition stage.


Assuntos
Destreza Motora , Boca , Adolescente , Adulto , Criança , Pré-Escolar , Humanos , Boca/crescimento & desenvolvimento , Boca/fisiologia , Adulto Jovem
6.
Integr Comp Biol ; 60(3): 619-629, 2020 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-32492167

RESUMO

During evolution, there has been a trend to reduce both the number of teeth and the location where they are found within the oral cavity. In mammals, the formation of teeth is restricted to a horseshoe band of odontogenic tissue, creating a single dental arch on the top and bottom of the jaw. Additional teeth and structures containing dental tissue, such as odontogenic tumors or cysts, can appear as pathologies. These tooth-like structures can be associated with the normal dentition, appearing within the dental arch, or in nondental areas. The etiology of these pathologies is not well elucidated. Reawakening of the potential to form teeth in different parts of the oral cavity could explain the origin of dental pathologies outside the dental arch, thus such pathologies are a consequence of our evolutionary history. In this review, we look at the changing pattern of tooth formation within the oral cavity during vertebrate evolution, the potential to form additional tooth-like structures in mammals, and discuss how this knowledge shapes our understanding of dental pathologies in humans.


Assuntos
Evolução Biológica , Boca/crescimento & desenvolvimento , Odontogênese , Vertebrados/crescimento & desenvolvimento , Animais , Humanos , Mamíferos/anatomia & histologia , Mamíferos/crescimento & desenvolvimento , Dente/patologia
7.
J Exp Zool B Mol Dev Evol ; 332(7): 238-244, 2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-31602780

RESUMO

Complex phenotypes result from developmental processes integrating genetic, epigenetic, and environmental information. Although changing environments combine several signals that may induce multitrait plastic responses, literature often decodes developmental plasticity into single trait variation as a function of isolated environmental signals. To address the multivariate nature of developmental plasticity, we evaluated how different combinations of environmental signals influence the development of morphological and behavioral traits. We raised Megaleporinus macrocephalus (Anostomidae) in four different developmental environments, and found that foraging position and structural complexity during development induced different morphotypes, which overlapped with behavioral patterns. Foraging position induced distinct patterns of mouth and fin positioning and overall body shape, which were accentuated by structural complexity. Moreover, fish most often chose conditions similar to their developmental environments. Combined signals during development, therefore, revealed environment-specific phenotypic patterns associating morphology and behavior. Such results endorse the ability of developmental processes to influence the variation present in natural populations. Implications of addressing the multivariate essence of developmental plasticity transcend the evolutionary theory and inspire applications in several fields.


Assuntos
Adaptação Fisiológica , Caraciformes/crescimento & desenvolvimento , Ecossistema , Nadadeiras de Animais/anatomia & histologia , Nadadeiras de Animais/crescimento & desenvolvimento , Animais , Comportamento Apetitivo , Caraciformes/anatomia & histologia , Caraciformes/fisiologia , Boca/anatomia & histologia , Boca/crescimento & desenvolvimento
8.
Dokl Biol Sci ; 486(1): 76-78, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-31317449

RESUMO

The transitory dermal infoldings are described for the first time in front and behind the upper jaw in the larvae and postlarvae of the American paddlefish, Polyodon spathula Walbaum, 1858. In sturgeons these infoldings are necessary for the jaw protraction. In the paddlefishes, they, probably recapitulate the ancestral state. At the same time, the presence of these folds at the larval stages might indicate that the paddlefish larvae possess the protractive jaws. Further developmental studies of the jaw kinematics in Polyodon spathula are needed to test both hypotheses.


Assuntos
Peixes/anatomia & histologia , Arcada Osseodentária/anatomia & histologia , Desenvolvimento Maxilofacial , Boca/anatomia & histologia , Animais , Peixes/crescimento & desenvolvimento , Boca/crescimento & desenvolvimento
9.
Nanomedicine ; 21: 102010, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31195135

RESUMO

The phosphorylation of (+) alpha tocopherol produces adhesive nanostructures that interact with oral biofilms to restrict their growth. The aim of this work was to understand if these adhesive (+) alpha tocopheryl phosphate (α-TP) nanostructures could also control macrophage responses to the presence of oral bacteria. The (+) α-TP planar bilayer fragments (175 nm ±â€¯21 nm) formed in a Trizma®/ethanol vehicle swelled when exposed to the cell lines (maximum stabilized size = 29 µm). The swelled (+) α-TP aggregates showed selective toxicity towards THP-1 macrophages (LD50 = 304 µM) compared to human gingival fibroblasts (HGF-1 cells; LD50 > 5 mM), and they inhibited heat killed bacteria stimulated MCP-1 production in both macrophages (control 57.3 ±â€¯18.1 pg/mL vs (+) α-TP 6.5 ±â€¯3.2 pg/mL) and HGF-1 cells (control 673.5 ±â€¯133 pg/mL vs (+) α-TP - 463.9 ±â€¯68.9 pg/mL).


Assuntos
Macrófagos/efeitos dos fármacos , Boca/efeitos dos fármacos , Nanoestruturas/administração & dosagem , alfa-Tocoferol/análogos & derivados , Biofilmes/efeitos dos fármacos , Adesão Celular/efeitos dos fármacos , Linhagem Celular , Quimiocina CCL2/genética , Gengiva/efeitos dos fármacos , Gengiva/crescimento & desenvolvimento , Gengiva/microbiologia , Gengiva/patologia , Fator de Crescimento de Hepatócito/genética , Humanos , Macrófagos/metabolismo , Macrófagos/microbiologia , Monócitos/efeitos dos fármacos , Monócitos/microbiologia , Boca/crescimento & desenvolvimento , Boca/microbiologia , Boca/patologia , Nanoestruturas/química , Fosforilação/efeitos dos fármacos , Fator de Necrose Tumoral alfa/genética , alfa-Tocoferol/química , alfa-Tocoferol/farmacologia
10.
Arch Oral Biol ; 100: 69-74, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30807873

RESUMO

OBJECTIVE: The present study aimed to describe the morphology of oral apparatus and oral cavity of bullfrog tadpoles during their development and metamorphosis. DESIGN: The oral apparatus and oropharyngeal cavity of tadpoles from hatching up to metamorphosis stage was dissected for further analysis. These structures were fixed in Karnovsky solution, afterwards in osmium tetroxide and metalized in palladium gold and electron-micrographed using the scanning electron microscope. RESULTS: The development of oral apparatus started with the formation and keratinization of the jaw sheaths and labial teeth followed by the formation of marginal and sub-marginal papillae. Degeneration of oral apparatus and formation of mouth was observed during metamorphosis. From stage-42 (metamorphic climax) to stage-43, the jaw sheath and labial tooth rows were disappeared progressively while the size and number of labial papillae were decreased. At stage-44, mouth formation started with the development of anterior and posterior labium though the labial papillae were still present. At stage-45 and 46, mouth was already formed, being very similar to the adult and characterized by the progressive increase in size. CONCLUSION: The sequence of events that happen during the development of oral apparatus of Lithobates catesbeianus Shaw, 1802 tadpoles follows the same pattern as occur in other anuran species but metamorphic atrophy of the oral apparatus follows the sequence of morphogenesis.


Assuntos
Metamorfose Biológica , Boca/crescimento & desenvolvimento , Ranidae/crescimento & desenvolvimento , Animais , Larva/crescimento & desenvolvimento
11.
Gen Comp Endocrinol ; 260: 41-50, 2018 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-29462599

RESUMO

Mature male Pacific salmon (Oncorhynchus spp.) develop a hooknose, as a secondary male sexual characteristic, during the spawning period. It is likely that androgens regulate hooknose formation. However, endocrinological and histochemical details about the relationship between androgens and hooknose formation are poorly understood. In this study, we performed assays of serum androgens, detection of androgen receptor (AR) in hooknose tissues, external morphological measurement of hooknose-related lengths, and microscopic observation of hooknose tissues of pink salmon (O. gorbuscha) at different stages of sexual maturation. Expression of the arß gene was detected in hooknose tissues of males but not females. The elongation of these tissues was mediated directly via androgens. Serum 11-ketotestosterone (11-KT) concentrations indicated a significant positive correlation with both jaw lengths during sexual maturation of males. In the upper jaw, cartilage tissue developed during hooknose formation, and AR-immunoreactive chondrocytes were located in the rostal-vetral regions of hooknose cartilage in maturing male. The chondrocytes in maturing males before entering into rivers exhibited rich-cytoplasm with high cell activity than at other sexual development stages. On the other hand, in the lower jaw, the development of the spongiosa-like bone meshworks. AR-immunoreactivity was detected in a proportion of the osteocytes and osteoblast-like cells in the spongiosa-like bone meshworks. These results indicate that hooknose formation in pink salmon, which is associated with the buildup of a structure with sufficient strength that it can be used to attack other males on the spawning ground, is regulated by 11-KT.


Assuntos
Desenvolvimento Maxilofacial , Boca/crescimento & desenvolvimento , Salmão , Maturidade Sexual/fisiologia , Testosterona/análogos & derivados , Androgênios/sangue , Animais , Cartilagem/crescimento & desenvolvimento , Cartilagem/metabolismo , Regulação da Expressão Gênica no Desenvolvimento , Arcada Osseodentária , Masculino , Rios , Salmão/sangue , Salmão/genética , Salmão/crescimento & desenvolvimento , Testosterona/sangue , Testosterona/fisiologia
12.
Sleep Med ; 37: 98-104, 2017 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-28899547

RESUMO

OBJECTIVES: To establish normative data of upper airway structure in Chinese Han infants and preschool children. METHODS: Magnetic resonance imaging (MRI) scans of 521 Chinese Han infants and preschool children (225 girls, 296 boys) aged from 1 day to 72 months were selected from the children who underwent head MRI at the Capital Institute of Pediatrics Affiliated Children Hospital, Beijing, China. No subjects had sleep-disordered breathing or associated conditions that may have affected the upper airway anatomy. The upper airway dimensions and surrounding soft tissue sizes were measured along the mid-sagittal and axial images. RESULTS: On images from the mid-sagittal image, the normative values of the following were obtained for all age group: thickness of the adenoid and nasopharyngeal area, length and thickness of the soft palate, length and height of the tongue, length of upper airway, distance between the mental spine and clivus, and the adenoid oblique width, soft palate oblique width, and tongue oblique width along the mental spine-clivus line. Normative values of the mean tonsillar width and intertonsillar space on the axial images were also obtained. There were no differences in any measurements between boys and girls in either infants or preschool children. Older children had larger airway dimensions, as expected. CONCLUSION: Normative values for upper airway structure in Chinese Han infants and preschool children assessed by MRI were established. The upper airway dimension and surrounding soft tissues size, including soft palate, adenoid, tongue, and tonsils, were increased with age. There were no gender differences during the first six years of life. These data may prove useful when studying airway disease in Chinese Han children.


Assuntos
Imageamento por Ressonância Magnética , Boca/diagnóstico por imagem , Nariz/diagnóstico por imagem , Faringe/diagnóstico por imagem , Criança , Pré-Escolar , China , Feminino , Humanos , Lactente , Masculino , Boca/crescimento & desenvolvimento , Nariz/crescimento & desenvolvimento , Tamanho do Órgão , Faringe/crescimento & desenvolvimento , Valores de Referência , Sono , Inquéritos e Questionários
13.
Zhonghua Kou Qiang Yi Xue Za Zhi ; 52(9): 574-577, 2017 Sep 09.
Artigo em Chinês | MEDLINE | ID: mdl-29972925

RESUMO

Oral and maxillofacial development is the course that the oral students first learn, and their mastery directly influences the study of other courses that follow. The application of mind mapping in the teaching of the development of oral maxillofacial region can make the temporal and spatial features of oral and maxillofacial development in the form of visual presentation, help students build development mode of thinking, stimulate students' interest in learning, improve the quality of teaching of oral histopathology, and promote the new teaching concept in oral pathology teaching.


Assuntos
Algoritmos , Aprendizagem , Desenvolvimento Maxilofacial , Boca/crescimento & desenvolvimento , Patologia Bucal/educação , Ensino , Pensamento , Humanos , Estudantes
14.
Dev Dyn ; 246(2): 100-115, 2017 02.
Artigo em Inglês | MEDLINE | ID: mdl-28032936

RESUMO

BACKGROUND: The buccopharyngeal membrane is a thin layer of cells covering the embryonic mouth. The perforation of this structure creates an opening connecting the external and the digestive tube which is essential for oral cavity formation. In humans, persistence of the buccopharyngeal membrane can lead to orofacial defects such as choanal atresia, oral synechiaes, and cleft palate. Little is known about the causes of a persistent buccopharyngeal membrane and, importantly, how this structure ruptures. RESULTS: We have determined, using antisense and pharmacological approaches, that Xenopus embryos deficient c-Jun N-terminal kinase (JNK) signaling have a persistent buccopharyngeal membrane. JNK deficient embryos have decreased cell division and increased cellular stress and apoptosis. However, altering these processes independently of JNK did not affect buccopharyngeal membrane perforation. JNK deficient embryos also have increased intercellular adhesion and defects in e-cadherin localization. Conversely, embryos with overactive JNK have epidermal fragility, increased E-cadherin internalization, and increased membrane localized clathrin. In the buccopharyngeal membrane, clathrin is colocalized with active JNK. Furthermore, inhibition of endocytosis results in a persistent buccopharyngeal membrane, mimicking the JNK deficient phenotype. CONCLUSIONS: The results of this study suggest that JNK has a role in the disassembly adherens junctions by means of endocytosis that is required during buccopharyngeal membrane perforation. Developmental Dynamics 246:100-115, 2017. © 2016 Wiley Periodicals, Inc.


Assuntos
Membranas Intracelulares/metabolismo , Proteínas Quinases JNK Ativadas por Mitógeno/fisiologia , Boca/embriologia , Xenopus laevis/embriologia , Junções Aderentes , Animais , Caderinas/metabolismo , Bochecha , Endocitose , Boca/crescimento & desenvolvimento , Faringe
15.
Sci Rep ; 6: 38151, 2016 11 30.
Artigo em Inglês | MEDLINE | ID: mdl-27901084

RESUMO

Development of the mouthparts in the cicada Meimuna mongolica (Distant) is investigated here for the first time using scanning electron microscopy in order to document changes occurring in different nymphal instars and from nymph to adult, during which a shift from subterranean root-feeding to feeding on aboveground parts of the host plant occurs. The structure and component of mouthparts is similar to those found in other hemipteran insects. Fourteen types of sensilla and five types of cuticular processes were found on the mouthparts of nymphs and adults. Significant general transformations during development include changes in: (a) the size and shape of the labrum from square to long and shovel-shaped; (b) increases in type and quantity of sensilla with the stage of development; (c) the ridges at the tips of the mandiblar stylets become more prominent in later stages of nymphal development, while odontoid protrusions more prominent in the female than in the male of the adult; and (d) the cross section of the stylets is subcircular in nymphal stages but oblong elliptical in the adult. The implications of these mouthpart transformations on the feeding ability of nymphs and adults and their possible relationship to the feeding niche are discussed.


Assuntos
Hemípteros/crescimento & desenvolvimento , Boca/crescimento & desenvolvimento , Ninfa/crescimento & desenvolvimento , Sensilas/crescimento & desenvolvimento , Animais , Diferenciação Celular , Comportamento Alimentar , Feminino , Hemípteros/anatomia & histologia , Hemípteros/ultraestrutura , Estágios do Ciclo de Vida , Masculino , Microscopia Eletrônica de Varredura , Boca/anatomia & histologia , Boca/ultraestrutura , Ninfa/anatomia & histologia , Ninfa/ultraestrutura , Sensilas/anatomia & histologia , Sensilas/ultraestrutura , Fatores de Tempo
16.
Zootaxa ; 4126(2): 262-70, 2016 Jun 17.
Artigo em Inglês | MEDLINE | ID: mdl-27395586

RESUMO

A new species of the Eigenmannia trilineata species-group is described from the rio São Francisco basin, Brazil. It is distinguished from closely related species by a unique set of characters, including a subterminal mouth, the presence of ii,13-14 pectoral-fin rays, a coronomeckelian bone that is 30% the length of Meckel's cartilage, the specific pattern of the dentition of the premaxilla and dentary, and the more anterior origin of the superior midlateral stripe. Comments on species of the E. trilineata species-group are presented.


Assuntos
Gimnotiformes/classificação , Distribuição Animal , Animais , Tamanho Corporal , Brasil , Feminino , Gimnotiformes/anatomia & histologia , Gimnotiformes/crescimento & desenvolvimento , Masculino , Boca/anatomia & histologia , Boca/crescimento & desenvolvimento , Tamanho do Órgão , Dente Decíduo/anatomia & histologia , Dente Decíduo/crescimento & desenvolvimento
17.
Anat Rec (Hoboken) ; 299(8): 1099-109, 2016 08.
Artigo em Inglês | MEDLINE | ID: mdl-27262165

RESUMO

While the identification of conserved processes across multiple taxa leads to an understanding of fundamental developmental mechanisms, the ways in which different animals fail to conform to common developmental processes can elucidate how evolution modifies development to result in the vast array of morphologies seen today-the developmental mechanisms that lead to anatomical variation. Odontogenesis-how teeth are initiated and formed-is well suited to the examination of both developmental conservation and phenotypic diversity. We suggest here that the study of early tooth development, the period of odontogenic band development, reveals departures from conserved mechanisms that question the role of players in the developmental process. In the earliest stages of odontogenesis, Sonic hedgehog (Shh) gene expression is interpreted as critical evidence of tooth initiation prior to any histological indication. However, a detailed examination of studies of tooth development across a wide range of taxa reveals that several vertebrate species fail to conform to the expectations of the Shh Consensus Model, calling for a reconsideration of the assumed causality of epithelial Shh in tooth initiation. We present new Shh gene expression data for an amphibian, the frog Silurana (Xenopus) tropicalis. In these animals, craniofacial and odontogenic developmental processes are more disjunct, and thereby provide a natural test of the hypothesis that Shh is immediately required for subsequent tooth development. Our results suggest that Shh expression may actually be related to the formation of the mouth rather than a required precursor to subsequent tooth formation. Anat Rec, 299:1099-1109, 2016. © 2016 Wiley Periodicals, Inc.


Assuntos
Evolução Biológica , Regulação da Expressão Gênica no Desenvolvimento , Proteínas Hedgehog/metabolismo , Boca/crescimento & desenvolvimento , Odontogênese/fisiologia , Dente/crescimento & desenvolvimento , Animais , Anuros , Boca/metabolismo , Dente/metabolismo
18.
Integr Comp Biol ; 56(3): 404-15, 2016 09.
Artigo em Inglês | MEDLINE | ID: mdl-27260858

RESUMO

Developmental constraints can have significant influence on the magnitude and direction of evolutionary change, and many studies have demonstrated that these effects are manifested on macroevolutionary scales. Phenotypic integration, or the strong interactions among traits, has been similarly invoked as a major influence on morphological variation, and many studies have demonstrated that trait integration changes through ontogeny, in many cases decreasing with age. Here, we unify these perspectives in a case study of the ontogeny of the mammalian cranium, focusing on a comparison between marsupials and placentals. Marsupials are born at an extremely altricial state, requiring, in most cases, the use of the forelimbs to climb to the pouch, and, in all cases, an extended period of continuous suckling, during which most of their development occurs. Previous work has shown that marsupials are less disparate in adult cranial form than are placentals, particularly in the oral apparatus, and in forelimb ontogeny and adult morphology, presumably due to functional selection pressures on these two systems during early postnatal development. Using phenotypic trajectory analysis to quantify prenatal and early postnatal cranial ontogeny in 10 species of therian mammals, we demonstrate that this pattern of limited variation is also apparent in the development of the oral apparatus of marsupials, relative to placentals, but not in the skull more generally. Combined with the observation that marsupials show extremely high integration of the oral apparatus in early postnatal ontogeny, while other cranial regions show similar levels of integration to that observed in placentals, we suggest that high integration may compound the effects of the functional constraints for continuous suckling to ultimately limit the ontogenetic and adult disparity of the marsupial oral apparatus throughout their evolutionary history.


Assuntos
Evolução Biológica , Marsupiais/anatomia & histologia , Marsupiais/crescimento & desenvolvimento , Boca/anatomia & histologia , Boca/crescimento & desenvolvimento , Animais
19.
Curr Biol ; 26(9): R367-8, 2016 05 09.
Artigo em Inglês | MEDLINE | ID: mdl-27166696

RESUMO

Deuterostomes - a key subdivision of animals - are characterized by the mouth developing anteriorly as a rupture between the outer epithelium and the foregut wall. A new study of amphioxus challenges this view and proposes separate evolutionary origins of deuterostome oral openings.


Assuntos
Anfioxos/anatomia & histologia , Anfioxos/crescimento & desenvolvimento , Boca/anatomia & histologia , Boca/crescimento & desenvolvimento , Animais , Evolução Biológica , Anfioxos/genética
20.
Ortodontia ; 49(2): 143-148, mar.-abr.2016. ilus, graf
Artigo em Português | LILACS | ID: lil-788875

RESUMO

A presente pesquisa visou avaliar os hábitos bucais mais prevalentes em crianças estudantes da Escola Municipal Joaquim Pinto e Souza, do município de Vassouras/RJ, verificando a influência do tempo de amamentação na determinação desses hábitos relacionados à má-oclusão. O estudo foi realizado por meio de um questionário estruturado, encaminhado aos pais das 57 crianças, com idades entre quatro e 15 anos. Em seguida, foi realizado exame clínico para avaliação da oclusão e os dados obtidos foram organizados e processados quantitativamente. Os hábitos questionados aos pais foram: o ato de roer as unhas, o uso de mamadeiras, chupetas, sucção de dedo, morder ou chupar objetos, ranger os dentes e respiração bucal, que tiveram efetiva importância para o estudo. A maioria das crianças que interrompeu a amamentação precocemente, desenvolveu hábitos parafuncionais, apresentando-se como os mais prevalentes a sucção de chupeta, respiração bucal e o ato de roer unhas, sendo que algumas dessas crianças possuíam um ou mais destes hábitos. Os questionários foram analisados e comparados com o exame clínico, onde verificou-se que as crianças que tiveram o desmame precoce apresentaram maior prevalência de mordida aberta anterior...


This cross-sectional study evaluated the most prevalent oral habits from students of the Municipal School Joaquim Pinto e Souza, at the city of Vassouras, RJ, verifying the influence of breastfeeding time on these malocclusion related habits. A questionnaire was sent to parents of 57 children, aged from 4 to 15 years. Next, a clinical exam was made to evaluate the occlusal conditions, and data was organized and interpreted quantitatively. The following habits were studied: nail biting, baby bottle, pacifiers, thumbnail sucking, object biting or sucking, tooth grinding, and oral breathing. Most children with early breastfeeding interruption developed parafunctional habits, being the most prevalent pacifier sucking, oral breathing, and nail biting, with some having one or more habits. Children with early interruption of breastfeeding had more prevalence of anterior open bite...


Assuntos
Humanos , Masculino , Feminino , Pré-Escolar , Criança , Aleitamento Materno , Boca/crescimento & desenvolvimento , Hábitos , Má Oclusão , Desmame , Comportamento , Bruxismo , Sucção de Dedo , Respiração Bucal , Hábito de Roer Unhas , Mamadeiras , Chupetas
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