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Developmental Dynamics : An Official... Jul 1995We describe a series of stages for development of the embryo of the zebrafish, Danio (Brachydanio) rerio. We define seven broad periods of embryogenesis--the zygote,...
We describe a series of stages for development of the embryo of the zebrafish, Danio (Brachydanio) rerio. We define seven broad periods of embryogenesis--the zygote, cleavage, blastula, gastrula, segmentation, pharyngula, and hatching periods. These divisions highlight the changing spectrum of major developmental processes that occur during the first 3 days after fertilization, and we review some of what is known about morphogenesis and other significant events that occur during each of the periods. Stages subdivide the periods. Stages are named, not numbered as in most other series, providing for flexibility and continued evolution of the staging series as we learn more about development in this species. The stages, and their names, are based on morphological features, generally readily identified by examination of the live embryo with the dissecting stereomicroscope. The descriptions also fully utilize the optical transparancy of the live embryo, which provides for visibility of even very deep structures when the embryo is examined with the compound microscope and Nomarski interference contrast illumination. Photomicrographs and composite camera lucida line drawings characterize the stages pictorially. Other figures chart the development of distinctive characters used as staging aid signposts.
Topics: Animals; Blastocyst; Cleavage Stage, Ovum; Embryo, Nonmammalian; Gastrula; Morphogenesis; Temperature; Time Factors; Zebrafish; Zygote
PubMed: 8589427
DOI: 10.1002/aja.1002030302 -
Annals of Medicine and Surgery (2012) Jan 2018Pediatric dentistry provides primary and comprehensive preventive and therapeutic oral health care for infants and children through adolescence, together with special... (Review)
Review
Pediatric dentistry provides primary and comprehensive preventive and therapeutic oral health care for infants and children through adolescence, together with special health care needs. This specialty encompasses a variety of skills, disciplines, procedures and techniques that share a common origin with other dental specialties however these have been modified and reformed to the distinctive requirements of infants, children, adolescents and special health care needs. Disciplines comprise of behavior guidance, care of the medically and developmentally compromised and disabled patient, supervision of orofacial growth and development, caries prevention, sedation, pharmacological management, and hospital dentistry including other traditional fields of dentistry. The skills apply to the ever-changing stages of dental, physical, and psychosocial development for treating conditions and diseases distinctive to growing individuals. Hence with the changing scope of practice it is imperative that the clinician stays updated with the current evidence based trends in practice, collaborates with other disciplines and Imparts quality oral health care tailored to the specific needs of every child.
PubMed: 29326814
DOI: 10.1016/j.amsu.2017.12.005 -
WormBook : the Online Review of C.... Aug 2018Dauer diapause is a stress-resistant, developmentally quiescent, and long-lived larval stage adopted by Caenorhabditis elegans when conditions are unfavorable for growth... (Review)
Review
Dauer diapause is a stress-resistant, developmentally quiescent, and long-lived larval stage adopted by Caenorhabditis elegans when conditions are unfavorable for growth and reproduction. This chapter contains methods to induce dauer larva formation, to isolate dauer larvae, and to study pre- and post-dauer stages.
Topics: Animals; Caenorhabditis elegans; Diapause; Larva
PubMed: 27417559
DOI: 10.1895/wormbook.1.180.1 -
Journal of Speech, Language, and... Aug 2019Purpose Current approaches to speech production aim to explain adult behavior and so make assumptions that, when taken to their logical conclusion, fail to adequately... (Review)
Review
Purpose Current approaches to speech production aim to explain adult behavior and so make assumptions that, when taken to their logical conclusion, fail to adequately account for development. This failure is problematic if adult behavior can be understood to emerge from the developmental process. This problem motivates the proposal of a developmentally sensitive theory of speech production. The working hypothesis, which structures the theory, is that feedforward representations and processes mature earlier than central feedback control processes in speech production. Method Theoretical assumptions that underpin the 2 major approaches to adult speech production are reviewed. Strengths and weaknesses are evaluated with respect to developmental patterns. A developmental approach is then pursued. The strengths of existing theories are borrowed, and the ideas are resynthesized under the working hypothesis. The speech production process is then reimagined in developmental stages, with each stage building on the previous one. Conclusion The resulting theory proposes that speech production relies on conceptually linked representations that are information-reduced holistic perceptual and motoric forms, constituting the phonological aspect of a system that is acquired with the lexicon. These forms are referred to as exemplars and schemas, respectively. When a particular exemplar and schema are activated with the selection of a particular lexical concept, their forms are used to define unique trajectories through an endogenous perceptual-motor space that guides implementation. This space is not linguistic, reflecting its origin in the prespeech period. Central feedback control over production emerges with failures in communication and the development of a self-concept.
Topics: Adult; Child; Child Language; Human Development; Humans; Models, Theoretical; Phonetics; Speech
PubMed: 31465709
DOI: 10.1044/2019_JSLHR-S-CSMC7-18-0130 -
Blood Jun 2022Fetal and neonatal megakaryocyte progenitors are hyperproliferative compared with adult progenitors and generate a large number of small, low-ploidy megakaryocytes....
Fetal and neonatal megakaryocyte progenitors are hyperproliferative compared with adult progenitors and generate a large number of small, low-ploidy megakaryocytes. Historically, these developmental differences have been interpreted as "immaturity." However, more recent studies have demonstrated that the small, low-ploidy fetal and neonatal megakaryocytes have all the characteristics of adult polyploid megakaryocytes, including the presence of granules, a well-developed demarcation membrane system, and proplatelet formation. Thus, rather than immaturity, the features of fetal and neonatal megakaryopoiesis reflect a developmentally unique uncoupling of proliferation, polyploidization, and cytoplasmic maturation, which allows fetuses and neonates to populate their rapidly expanding bone marrow and blood volume. At the molecular level, the features of fetal and neonatal megakaryopoiesis are the result of a complex interplay of developmentally regulated pathways and environmental signals from the different hematopoietic niches. Over the past few years, studies have challenged traditional paradigms about the origin of the megakaryocyte lineage in both fetal and adult life, and the application of single-cell RNA sequencing has led to a better characterization of embryonic, fetal, and adult megakaryocytes. In particular, a growing body of data suggests that at all stages of development, the various functions of megakaryocytes are not fulfilled by the megakaryocyte population as a whole, but rather by distinct megakaryocyte subpopulations with dedicated roles. Finally, recent studies have provided novel insights into the mechanisms underlying developmental disorders of megakaryopoiesis, which either uniquely affect fetuses and neonates or have different clinical presentations in neonatal compared with adult life.
Topics: Adult; Bone Marrow; Fetus; Humans; Infant, Newborn; Megakaryocyte Progenitor Cells; Megakaryocytes; Thrombopoiesis
PubMed: 35108353
DOI: 10.1182/blood.2020009301 -
PloS One 2022One challenge in avian embryology is establishing a standard developmental timetable, primarily because eggs incubated for identical durations can vary in developmental...
One challenge in avian embryology is establishing a standard developmental timetable, primarily because eggs incubated for identical durations can vary in developmental progress, even within the same species. For remedy, avian development is classified into distinct stages based on the formation of key morphological structures. Developmental stages exist for a few galliform species, but the literature is lacking a description of normal stages for California valley quail (Callipepla californica). Thus, the objective of this study was to stage and document the morphological and structural development of California valley quail. Over two laying seasons, 390 eggs were incubated at 37.8֯ C in 60% RH for ≤23 days. Eggs were opened every ≤6 hours to document embryonic development, including, blastoderm diameter, anterior angle of nostril to beak tip, and lengths of wing, tarsus, third toe, total beak, total foot, and embryo. California valley quail embryos were staged and compared to domestic chicken (Gallus gallus domesticus), the staging standard for galliformes, as well as Japanese quail (Coturnix japonica), blue-breasted quail (Synoicus chinensis) and northern bobwhite quail (Colinus virginianus). This study produced the first description of the 43 normal stages of development for California valley quail. Compared with other galliformes, the California valley quail has a different number of stages and displays developmental heterochrony in stages 1-24, and morphological and developmental differences in stages 25-hatch. The observed differences emphasize the importance of staging individual avian species instead of relying on poultry animal models or close relatives for developmental reference. This is extremely important in species-specific embryological studies that evaluate critical windows of development or evaluate the impacts of environmental change on avian development. This study also suggests that staging frequencies of ≤6 hours and egg transport protocols should be standardized for future staging studies.
Topics: Animals; Blastoderm; California; Chickens; Colinus; Coturnix; Galliformes; Quail
PubMed: 35580090
DOI: 10.1371/journal.pone.0268524 -
Current Diabetes Reviews 2015Developmentally-tailored diabetes self-care education and support are integral parts of contemporary multidisciplinary T1D care. The patient with T1D must have the... (Review)
Review
Developmentally-tailored diabetes self-care education and support are integral parts of contemporary multidisciplinary T1D care. The patient with T1D must have the support of the family and the diabetes team to maintain the rigors of diabetes management, but the specific roles of patients and families with regard to daily diabetes tasks change considerably throughout the developmental span of early childhood, middle childhood/school-age years, and adolescence. This review provides a framework of key normative developmental issues for each of these developmental stages. Within this context, ideal family diabetes management is reviewed within each developmental stage and anticipated challenges that can arise during these stages and that can adversely impact diabetes management are presented. This paper also summarizes empirical evidence for specific intervention and care strategies to support optimal diabetes management across these stages in order to maximize opportunities for a successful transfer of diabetes management tasks from parents to maturing youth. Finally, the review provides an emphasis on approaches to promote family teamwork and adolescent diabetes self-care adherence as well as opportunities to use novel technology platforms as a means to support optimal diabetes management.
Topics: Adolescent; Adolescent Behavior; Adolescent Development; Age Factors; Child; Child Behavior; Child Development; Child, Preschool; Diabetes Mellitus, Type 1; Family Relations; Health Behavior; Health Knowledge, Attitudes, Practice; Humans; Infant; Infant, Newborn; Self Care; Treatment Outcome; Young Adult
PubMed: 25901503
DOI: 10.2174/1573399811666150421114146 -
Platelets Aug 2020A growing body of research has made it increasingly clear that there are substantial biological differences between fetal/neonatal and adult megakaryopoiesis. Over the... (Review)
Review
A growing body of research has made it increasingly clear that there are substantial biological differences between fetal/neonatal and adult megakaryopoiesis. Over the last decade, studies revealed a developmentally unique uncoupling of proliferation, polyploidization, and cytoplasmic maturation in neonatal MKs that results in the production of large numbers of small, low ploidy, but mature MKs during this period of development, and identified substantial molecular differences between fetal/neonatal and adult MKs. This review will summarize our current knowledge on the developmental differences between fetal/neonatal and adult MKs, and recent advances in our understanding of the underlying molecular mechanisms, including newly described developmentally regulated pathways and miRNAs. We will also discuss the implications of these findings on the ways MKs interact with the environment, the response of neonates to thrombocytopenia, the pathogenesis of Down syndrome-transient myeloproliferative disorder (TMD), and the developmental stage specific-manifestations of congenital amegakaryocytic thrombocytopenia.
Topics: Animals; Cell Differentiation; Gene Expression Regulation, Neoplastic; Humans; Mice; Thrombopoiesis
PubMed: 32200697
DOI: 10.1080/09537104.2020.1742879 -
Zebrafish Feb 2020Zebrafish () are highly social animals that engage in a diverse variety of nonreproductive social behaviors that emerge as early as 14 days postfertilization (dpf)....
Zebrafish () are highly social animals that engage in a diverse variety of nonreproductive social behaviors that emerge as early as 14 days postfertilization (dpf). However, we observe considerable behavioral variability at this stage, and comparisons across studies are potentially complicated both by chronological gaps in measurements and inconsistencies in developmental staging. To address these issues, we adapted our assay for social orienting and cueing in the adult zebrafish and used it to probe behavior in a critical window of larval development. In addition, we performed measurements of body length and tested a cohort of larvae with impaired growth to understand if this morphological feature is predictive of individual sociality. We report that zebrafish exhibit increasingly complex social behaviors between 10 and 16 dpf, including place preference, orienting, and social cueing. Furthermore, social behavior is related to standard length on an individual basis beginning at 14 dpf, such that developmentally stunted 14 dpf zebrafish raised on dry feed do not exhibit social behaviors, suggesting some morphological features are more predictive than chronological age. This highly variable and early stage in development provides an opportunity to further understand how genetic and environmental factors affect the assembly of neural circuits underlying complex behaviors.
Topics: Animals; Body Size; Cues; Orientation, Spatial; Social Behavior; Zebrafish
PubMed: 31930951
DOI: 10.1089/zeb.2019.1815 -
PloS One 2018In most Eukaryotes, ubiquitin either exists as free monoubiquitin or as a molecule that is covalently linked to other proteins. These two forms cycle between each other...
In most Eukaryotes, ubiquitin either exists as free monoubiquitin or as a molecule that is covalently linked to other proteins. These two forms cycle between each other and due to the concerted antagonistic activity of ubiquitylating and deubiquitylating enzymes, an intracellular ubiquitin equilibrium is maintained that is essential for normal biological function. However, measuring the level and ratio of these forms of ubiquitin has been difficult and time consuming. In this paper, we have adapted a simple immunoblotting technique to monitor ubiquitin content and equilibrium dynamics in different developmental stages and tissues of Drosophila. Our data show that the level of total ubiquitin is distinct in different developmental stages, lowest at the larval-pupal transition and in three days old adult males, and highest in first instar larvae. Interestingly, the ratio of free mono-ubiquitin remains within 30-50% range of the total throughout larval development, but peaks to 70-80% at the larval-pupal and the pupal-adult transitions. It stays within the 70-80% range in adults. In developmentally and physiologically active tissues, the ratio of free ubiquitin is similarly high, most likely reflecting a high demand for ubiquitin availability. We also used this method to demonstrate the disruption of the finely tuned ubiquitin equilibrium by the abolition of proteasome function or the housekeeping deubiquitylase, Usp5. Our data support the notion that the ubiquitin equilibrium is regulated by tissue- and developmental stage-specific mechanisms.
Topics: Animals; Drosophila Proteins; Drosophila melanogaster; Mutation; Organ Specificity; Ubiquitin; Ubiquitin-Specific Proteases
PubMed: 30543682
DOI: 10.1371/journal.pone.0209080