scholarly journals Neural control of growth and size in the axolotl limb regenerate

eLife ◽  
2021 ◽  
Vol 10 ◽  
Author(s):  
Kaylee M Wells ◽  
Kristina Kelley ◽  
Mary Baumel ◽  
Warren A Vieira ◽  
Catherine D McCusker
Keyword(s):  
Rapid Growth ◽  
Neural Control ◽  
Developmental Stages ◽  
Allometric Growth ◽  
Final Size ◽  
Extrinsic Factors ◽  
Mexican Axolotl ◽  
Host Environment

The mechanisms that regulate growth and size of the regenerating limb in tetrapods such as the Mexican axolotl are unknown. Upon the completion of the developmental stages of regeneration, when the regenerative organ known as the blastema completes patterning and differentiation, the limb regenerate is proportionally small in size. It then undergoes a phase of regeneration that we have called the 'tiny-limb' stage, that is defined by rapid growth until the regenerate reaches the proportionally appropriate size. In the current study we have characterized this growth and have found that signaling from the limb nerves is required for its maintenance. Using the regenerative assay known as the Accessory Limb Model, we have found that growth and size of the limb positively correlates with nerve abundance. We have additionally developed a new regenerative assay called the Neural Modified-ALM (NM-ALM), which decouples the source of the nerves from the regenerating host environment. Using the NM-ALM we discovered that non-neural extrinsic factors from differently sized host animals do not play a prominent role in determining the size of the regenerating limb. We have also discovered that the regulation of limb size is not autonomously regulated by the limb nerves. Together, these observations show that the limb nerves provide essential cues to regulate ontogenetic allometric growth and the final size of the regenerating limb.

scholarly journals Neurotrophic control of size regulation during axolotl limb regeneration

2021 ◽  
Author(s):  
Kaylee M. Wells-Enright ◽  
Kristina Kelley ◽  
Mary Baumel ◽  
Warren A. Vieira ◽  
Catherine D. McCusker
Keyword(s):  
Rapid Growth ◽  
Developmental Stages ◽  
Limb Regeneration ◽  
Neurotrophic Control ◽  
Final Size ◽  
Extrinsic Factors ◽  
Mexican Axolotl ◽  
Host Environment ◽  
Size Regulation

AbstractThe mechanisms that regulate the sizing of the regenerating limb in tetrapods such as the Mexican axolotl are unknown. Upon the completion of the developmental stages of regeneration, when the regenerative organ known as the blastema completes patterning and differentiation, the limb regenerate is proportionally small in size. It then undergoes a phase of regeneration that we have called the “tiny-limb” stage, that is defined by rapid growth until the regenerate reaches the proportionally appropriate size. In the current study we have characterized this growth and have found that signaling from the limb nerves is required for its maintenance. Using the regenerative assay known as the Accessory Limb Model, we have found that the size of the limb can be positively and negatively manipulated by nerve abundance. We have additionally developed a new regenerative assay called the Neural Modified-ALM (NM-ALM), which decouples the source of the nerve from the regenerating host environment. Using the NM-ALM we discovered that non-neural extrinsic factors from differently sized host animals do not play a prominent role in determining the size of the regenerating limb. We have also discovered that the regulation of limb size is not autonomously regulated by the limb nerves. Together, these observations show that the limb nerves provide essential and instructive cues to regulate the final size of the regenerating limb.

scholarly journals Transcriptome Analysis of Ginkgo biloba L. Leaves across Late Developmental Stages Based on RNA-Seq and Co-Expression Network

Forests ◽  
2021 ◽  
Vol 12 (3) ◽  
pp. 315
Author(s):  
Hailin Liu ◽  
Xin Han ◽  
Jue Ruan ◽  
Lian Xu ◽  
Bing He
Keyword(s):  
Ginkgo Biloba ◽  
Leaf Development ◽  
Developmental Stages ◽  
Leaf Growth ◽  
Rna Seq ◽  
Final Size ◽  
Dioecious Species ◽  
Related Factors ◽  
New Genes ◽  
Gene Modules

The final size of plant leaves is strictly controlled by environmental and genetic factors, which coordinate cell expansion and cell cycle activity in space and time; however, the regulatory mechanisms of leaf growth are still poorly understood. Ginkgo biloba is a dioecious species native to China with medicinally and phylogenetically important characteristics, and its fan-shaped leaves are unique in gymnosperms, while the mechanism of G. biloba leaf development remains unclear. In this study we studied the transcriptome of G. biloba leaves at three developmental stages using high-throughput RNA-seq technology. Approximately 4167 differentially expressed genes (DEGs) were obtained, and a total of 12,137 genes were structure optimized together with 732 new genes identified. More than 50 growth-related factors and gene modules were identified based on DEG and Weighted Gene Co-expression Network Analysis. These results could remarkably expand the existing transcriptome resources of G. biloba, and provide references for subsequent analysis of ginkgo leaf development.

Growth, development and allometry of Philophthalmus nocturnus in the eyes of domestic chicks

1992 ◽  
Vol 66 (2) ◽  
pp. 100-107 ◽  
Author(s):  
V. G. M. Swarnakumari ◽  
R. Madhavi
Keyword(s):  
Growth Rate ◽  
Developmental Stages ◽  
Adult Stage ◽  
The Body ◽  
Lag Phase ◽  
Allometric Growth ◽  
Body Width ◽  
Rapid Phase ◽  
Growth Development ◽  
Two Phases

ABSTRACTFifty day-old chicks were each infected with 10 excysted metaccreariae of Philophthalimus nocturnus Looss. 1907 around each orbit and growth, development and allometry were studied. The growth rate showed two phases over a period of 35 days, a limited lag phase lasting two days post-infection in which flukes did not exceed 440 μm in length, and a rapid phase during which growth was rapid and flukes reached a size of 3·008–3·504 mm on day 35. Five developmental stages were noticed during the course of development of the metacercaria to the egg-producing adult stage. Eggs appeared in the uterus on day 14 and oculate miracidia on day 25. The hindhody, testes and ovary showed positive allometric growth, the pharnyx less so, whereas negative allometric growth was shown by the forebody. Body width, oral sucker and ventral sucker were close to isometry, growing at the same rate as the body length.

scholarly journals T'ain't What You Say, It's the Way That You Say It—Left Insula and Inferior Frontal Cortex Work in Interaction with Superior Temporal Regions to Control the Performance of Vocal Impersonations

2013 ◽  
Vol 25 (11) ◽  
pp. 1875-1886 ◽  
Author(s):  
Carolyn McGettigan ◽  
Frank Eisner ◽  
Zarinah K. Agnew ◽  
Tom Manly ◽  
Duncan Wisbey ◽  
...  
Keyword(s):  
Neural Control ◽  
Inferior Frontal Gyrus ◽  
Neural Correlates ◽  
Brain Regions ◽  
Extrinsic Factors ◽  
Voice Change ◽  
Significant Step ◽  
Speech Planning ◽  
Identity Perception ◽  
The Voice

Historically, the study of human identity perception has focused on faces, but the voice is also central to our expressions and experiences of identity [Belin, P., Fecteau, S., & Bedard, C. Thinking the voice: Neural correlates of voice perception. Trends in Cognitive Sciences, 8, 129–135, 2004]. Our voices are highly flexible and dynamic; talkers speak differently, depending on their health, emotional state, and the social setting, as well as extrinsic factors such as background noise. However, to date, there have been no studies of the neural correlates of identity modulation in speech production. In the current fMRI experiment, we measured the neural activity supporting controlled voice change in adult participants performing spoken impressions. We reveal that deliberate modulation of vocal identity recruits the left anterior insula and inferior frontal gyrus, supporting the planning of novel articulations. Bilateral sites in posterior superior temporal/inferior parietal cortex and a region in right middle/anterior STS showed greater responses during the emulation of specific vocal identities than for impressions of generic accents. Using functional connectivity analyses, we describe roles for these three sites in their interactions with the brain regions supporting speech planning and production. Our findings mark a significant step toward understanding the neural control of vocal identity, with wider implications for the cognitive control of voluntary motor acts.

scholarly journals Beyond Pokémon: Augmented Reality Is a Universal Design for Learning Tool

SAGE Open ◽  
2017 ◽  
Vol 7 (4) ◽  
pp. 215824401773781 ◽  
Author(s):  
Zachary Walker ◽  
Don D. McMahon ◽  
Kara Rosenblatt ◽  
Tracy Arner
Keyword(s):  
Augmented Reality ◽  
Rapid Growth ◽  
Universal Design ◽  
Developmental Stages ◽  
Universal Design For Learning ◽  
Digital Information ◽  
Diverse Range ◽  
Design For Learning ◽  
The Masses ◽  
Support Students

The success of Pokémon Go is demonstrating that augmented reality (AR) is reaching the masses quickly and can be a robust tool to enhance student engagement and learning. Leveraging AR for instructional purposes has the potential to become a powerful medium for Universal Design for Learning (UDL) by providing new tools for multiple means of representation, action and expression, and engagement. One of the advantages of using AR applications and AR platforms is the ability to display context relevant digital information to support students’ needs in real time and in specific contexts. Although many educational AR applications are in their developmental stages, the rapid growth of AR is likely to continue. The examples presented in this article focus on how educators can use mobile devices and AR to apply the principles of UDL. Combining AR with the principles of UDL can help educators create lessons that are accessible, engaging, and powerful for a diverse range of learners.

scholarly journals From Endoderm to Progenitors: An Update on the Early Steps of Thyroid Morphogenesis in the Zebrafish

2021 ◽  
Vol 12 ◽  
Author(s):  
Federica Marelli ◽  
Giuditta Rurale ◽  
Luca Persani
Keyword(s):  
Developmental Stages ◽  
Developmental Process ◽  
Experimental Models ◽  
Extrinsic Factors ◽  
Comprehensive Picture ◽  
Central Interest ◽  
Endodermal Cells ◽  
Gland Development ◽  
Early Developmental ◽  
Developmental Windows

The mechanisms underlying thyroid gland development have a central interest in biology and this review is aimed to provide an update on the recent advancements on the early steps of thyroid differentiation that were obtained in the zebrafish, because this teleost fish revealed to be a suitable organism to study the early developmental stages. Physiologically, the thyroid precursors fate is delineated by the appearance among the endoderm cells of the foregut of a restricted cell population expressing specific transcription factors, including pax2a, nkx2.4b, and hhex. The committed thyroid primordium first appears as a thickening of the pharyngeal floor of the anterior endoderm, that subsequently detaches from the floor and migrates to its final location where it gives rise to the thyroid hormone-producing follicles. At variance with mammalian models, thyroid precursor differentiation in zebrafish occurs early during the developmental process before the dislocation to the eutopic positioning of thyroid follicles. Several pathways have been implicated in these early events and nowadays there is evidence of a complex crosstalk between intrinsic (coming from the endoderm and thyroid precursors) and extrinsic factors (coming from surrounding tissues, as the cardiac mesoderm) whose organization in time and space is probably required for the proper thyroid development. In particular, Notch, Shh, Fgf, Bmp, and Wnt signaling seems to be required for the commitment of endodermal cells to a thyroid fate at specific developmental windows of zebrafish embryo. Here, we summarize the recent findings produced in the various zebrafish experimental models with the aim to define a comprehensive picture of such complicated puzzle.

scholarly journals Extrinsic Factors Regulating Dendritic Patterning

2021 ◽  
Vol 14 ◽  
Author(s):  
Tzu-Yang Lin ◽  
Pei-Ju Chen ◽  
Hung-Hsiang Yu ◽  
Chao-Ping Hsu ◽  
Chi-Hon Lee
Keyword(s):  
Dendritic Growth ◽  
Developmental Stages ◽  
Lipid Synthesis ◽  
Supporting Cells ◽  
Extrinsic Factors ◽  
Dendritic Trees ◽  
Downstream Signaling ◽  
Neuronal Identity ◽  
Receptor Interactions ◽  
Dendrite Morphogenesis

Stereotypic dendrite arborizations are key morphological features of neuronal identity, as the size, shape and location of dendritic trees determine the synaptic input fields and how information is integrated within developed neural circuits. In this review, we focus on the actions of extrinsic intercellular communication factors and their effects on intrinsic developmental processes that lead to dendrite patterning. Surrounding neurons or supporting cells express adhesion receptors and secreted proteins that respectively, act via direct contact or over short distances to shape, size, and localize dendrites during specific developmental stages. The different ligand-receptor interactions and downstream signaling events appear to direct dendrite morphogenesis by converging on two categorical mechanisms: local cytoskeletal and adhesion modulation and global transcriptional regulation of key dendritic growth components, such as lipid synthesis enzymes. Recent work has begun to uncover how the coordinated signaling of multiple extrinsic factors promotes complexity in dendritic trees and ensures robust dendritic patterning.

scholarly journals Histogenesis of potato light sprouts in healthy plants and those infected with potato leaf roll virus

2013 ◽  
Vol 34 (1) ◽  
pp. 29-44 ◽  
Author(s):  
Grażyna Garbaczewska
Keyword(s):  
Solanum Tuberosum ◽  
Rapid Growth ◽  
Developmental Stages ◽  
Leaf Roll ◽  
Potato Leaf Roll Virus ◽  
Ultrastructural Examination ◽  
Potato Leaf ◽  
Virus Particles ◽  
Early Stages ◽  
Companion Cells

Developmental stages of potato (<i>Solanum tuberosum</i>) light sprouts in healthy plants and those infected with potato leaf roll virus (PLRV) have been distinguished. Potato light sprouts from healthy tubers differentiate in the early stages to the apical and basal parts, which are characterized by distinct dynamics of growth. Ultrastructural examination of apex meristem and phloem ontogeny was carried out for healthy plants. In the development of potato light sprouts of plants infected with PLRV a great many anomalies have been described. Three types of light sprouts developed from infected tubers. Anatomical investigations indicated a rapid growth of the number of necroses in the phloem, and submicroscopic observations showed the presence of virus particles and cytopathological structures: tubular and vesicular structures, paramural bodies and callose deposits. In the companion cells of the phloem the occurrence of very regular inclusions of virus particles was recorded.

Evaluating Developmental Stages of Total Health Expenditures in China

2019 ◽  
Author(s):  
Qiu lei jie ◽  
Xu Li ◽  
Yan Wang ◽  
Qian Liu ◽  
Anning Ma ◽  
...  
Keyword(s):  
Rapid Growth ◽  
Developmental Stages ◽  
Healthcare Expenditure ◽  
Slow Growth ◽  
Growth Period ◽  
Logistic Function ◽  
Fast Growth ◽  
Eastern Region ◽  
Annual Growth Rate ◽  
Development Stages

Abstract Objective This study evaluated developmental stages and trends of Total Healthcare Expenditure (THE) of 18 provinces in China. We explored characteristics of different development stages during healthcare expenditure, to provide scientific reference for China's healthcare policy making and regional healthcare planning.Methods Firstly, curve fitting and parameter estimation using SPSS21 software were carried out for the Logistic function model, and then the three-point or four-point method was applied to estimate the value of saturation K. Finally the Logistic function equation and fitting graph were obtained. According to the nature of Logistic curve, the study divided THE into three stages, gradual, rapid and slow growth, and predicted and analyzed THE developments in 18 provinces.Results By 2019, 15 provinces have entered a period of rapid THE growth. Regionally, the time to enter fast growth period early to late are in the order of northeast ( in 2005), east China ( in 2008), northwest ( in 2010), south China ( in 2013), north China ( in 2015) and southwest ( in 2015). The earliest province to enter rapid growth period is Liaoning province (in 2005), Shandong province enter the period at latest (in 2045). In 2027, all 18 provinces will enter the rapid growth period, and end in 2045. In this period, rapid growth in total health expense will last for about 23 years, with an average annual growth rate of 8.69%. Conclusions THE growth pattern is in line with typical trend of "slow-fast-slow" growth function. The expense developments vary between regions. Eastern region entered rapid and slow growth period later than the central and western regions. THE development stages and duration of the rapid growth period is correlated to regional economic level. The earlier it enters the fast growth period, the shorter it lasts, and vice versa. The government should take advantage of this period, from 2015 to 2029, to make policy preparations to respond THE rapid growth in China.

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