scholarly journals Species Tailoured Contribution of Volumetric Growth and Tissue Convergence to Posterior Body Elongation in Vertebrates

2015 ◽  
Author(s):  
Benjamin Steventon ◽  
Fernando Duarte ◽  
Ronan Lagadec ◽  
Sylvie Mazan ◽  
Jean-Fran&ccedilois Nicolas ◽  
...  
Keyword(s):  
Morphometric Analysis ◽  
Growth Characteristic ◽  
Female Parent ◽  
Growth Zone ◽  
The Body ◽  
Body Axis ◽  
Volumetric Growth ◽  
Tissue Volume ◽  
Axis Elongation ◽  
Differential Contribution

Axial elongation is a widespread mechanism propelling the generation of the metazoan body plan. A widely accepted model is that of posterior growth, where new tissue is continually added from the posterior unsegmented tip of the body axis. A key question is whether or not such a posterior growth zone generates sufficient additional tissue volume to generate elongation of the body axis, and the degree to which this is balanced with tissue convergence and/or growth in already segmented regions of the body axis. We applied a multi-scalar morphometric analysis during posterior axis elongation in zebrafish. Importantly, by labelling of specific regions/tissues and tracking their deformation, we observed that the unsegmented region does not generate additional tissue volume at the caudal tip. Instead, it contributes to axis elongation by extensive tissue deformation at constant volume. We show that volumetric growth occurs in the segmented portion of the axis and can be attributed to an increase in the size and length of the spinal cord and notochord. FGF inhibition blocks tissue convergence within the tailbud and unsegmented region rather than affecting volumetric growth, showing that a conserved molecular mechanism can control convergent morphogenesis, even if by different cell behaviours. Finally, a comparative morphometric analysis in lamprey, dogfish, zebrafish and mouse reveal a differential contribution of volumetric growth that is linked to a switch between external and internal modes of development. We propose that posterior growth is not a conserved mechanism to drive axis elongation in vertebrates. It is instead associated with an overall increase in growth characteristic of internally developing embryos that undergo embryonic development concomitantly with an increase in energy supply from the female parent.

scholarly journals MYC activity is required for maintenance of the Neuromesodermal Progenitor signalling network and for correct timing of segmentation clock gene oscillations

2017 ◽  
Author(s):  
Ioanna Mastromina ◽  
Laure Verrier ◽  
Kate G. Storey ◽  
J. Kim Dale
Keyword(s):  
Cell Cycle Progression ◽  
The Body ◽  
Body Axis ◽  
Cellular Functions ◽  
Segmentation Clock ◽  
Signalling Network ◽  
Undifferentiated State ◽  
Somite Formation ◽  
Axis Elongation ◽  
And Function

AbstractThe Myc transcriptional regulators are implicated in a range of cellular functions, including proliferation, cell cycle progression, metabolism and pluripotency maintenance. Here, we investigated the expression, regulation and function of Myc during mouse embryonic axis elongation and segmentation. Expression of both cMyc and MycN in the domains where neuromesodermal progenitors (NMPs) and underlying caudal pre-somitic mesoderm (cPSM) cells reside is coincident WNT and FGF signals; factors known to maintain progenitors in an undifferentiated state. Pharmacological inhibition of MYC activity, downregulates expression of WNT/FGF components. In turn, we find that cMyc expression is WNT, FGF and NOTCH regulated, placing it centrally in the signalling circuit that operates in the tail end that both sustains progenitors and drives maturation of the PSM into somites. Interfering with MYC function in the PSM, where it displays oscillatory expression, delays the timing of segmentation clock oscillations and thus of somite formation. In summary, we identify Myc as a component that links NMP maintenance and PSM maturation during the body axis elongation stages of mouse embryogenesis.Summary StatementMYC operates in a positive feedback loop with WNT/FGF signals to maintain the progenitors which facilitate body axis elongation while its activity is crucial for timing of the segmentation clock.

scholarly journals Development of a new method for assessing otolith function in mice using three-dimensional binocular analysis of the otolith-ocular reflex

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Shotaro Harada ◽  
Takao Imai ◽  
Yasumitsu Takimoto ◽  
Yumi Ohta ◽  
Takashi Sato ◽  
...  
Keyword(s):  
Eye Movement ◽  
Three Dimensional ◽  
Vertical Component ◽  
Inertial Force ◽  
Linear Acceleration ◽  
The Body ◽  
Body Axis ◽  
Gravitational Acceleration ◽  
Ocular Reflex ◽  
Translational Movement

AbstractIn the interaural direction, translational linear acceleration is loaded during lateral translational movement and gravitational acceleration is loaded during lateral tilting movement. These two types of acceleration induce eye movements via two kinds of otolith-ocular reflexes to compensate for movement and maintain clear vision: horizontal eye movement during translational movement, and torsional eye movement (torsion) during tilting movement. Although the two types of acceleration cannot be discriminated, the two otolith-ocular reflexes can distinguish them effectively. In the current study, we tested whether lateral-eyed mice exhibit both of these otolith-ocular reflexes. In addition, we propose a new index for assessing the otolith-ocular reflex in mice. During lateral translational movement, mice did not show appropriate horizontal eye movement, but exhibited unnecessary vertical torsion-like eye movement that compensated for the angle between the body axis and gravito-inertial acceleration (GIA; i.e., the sum of gravity and inertial force due to movement) by interpreting GIA as gravity. Using the new index (amplitude of vertical component of eye movement)/(angle between body axis and GIA), the mouse otolith-ocular reflex can be assessed without determining whether the otolith-ocular reflex is induced during translational movement or during tilting movement.

The Caenorhabditis elegans gene lin-44 controls the polarity of asymmetric cell divisions

Development ◽  
1994 ◽  
Vol 120 (5) ◽  
pp. 1035-1047 ◽  
Author(s):  
M.A. Herman ◽  
H.R. Horvitz
Keyword(s):  
Caenorhabditis Elegans ◽  
The Body ◽  
Body Axis ◽  
Nematode Caenorhabditis Elegans ◽  
Asymmetric Cell Divisions ◽  
Cell Divisions ◽  
Sister Cells

The generation and orientation of cellular and organismic polarity are fundamental aspects of development. Mutations in the gene lin-44 of the nematode Caenorhabditis elegans reverse both the relative positions of specific sister cells and the apparent polarities of these cells. Thus, lin-44 mutants appear to generate polar cells but to misorient these cells along the body axis of the animal. We postulate that lin-44 acts to specify the orientation of polar cells.

Head positioning control in a gravito-inertial field and in normal gravity

2004 ◽  
Vol 14 (4) ◽  
pp. 321-333
Author(s):  
Frédéric Sarès ◽  
Christophe Bourdin ◽  
Jean-Michel Prieur ◽  
Jean-Louis Vercher ◽  
Jean-Pierre Menu ◽  
...  
Keyword(s):  
Inertial Force ◽  
The Body ◽  
Body Axis ◽  
Positioning Control ◽  
Head Positioning ◽  
Subject Variability ◽  
Visual Frame ◽  
Vector Orientation ◽  
The Right ◽  
Within Subject Variability

The way in which the head is controlled in roll was investigated by dissociating the body axis and the gravito-inertial force orientation. Seated subjects (N = 8) were requested to align their head with their trunk, 30° to the left, 30° to the right or with the gravito-inertial vector, before, during (Per Rotation), after off-center rotation and on a tilted chair without rotation (Tilted). The gravito-inertial vector angle during rotation and the chair tilt angle were identical (17°). The subjects were either in total darkness or facing a visual frame that was fixed to the trunk. Both final error and within-subject variability of head positioning increased when the body axis and the gravito-inertial vector were dissociated (Per Rotation and Tilted). However, the behavior was different depending on whether the subjects were in the Tilted or Per Rotation conditions. The presentation of the visual frame reduced the within-subject variability and modified the perception of the gravito-inertial vector's orientation on the tilted chair. As head positioning with respect to the body and sensing of the gravito-inertial vector are modified when body axis and gravito-inertial vector orientation are dissociated, the observed decrease in performance while executing motor tasks in a gravito-inertial field may be at least in part attributed to the inaccurate sensing of head position.

scholarly journals How to attach the limb to the body axis

2010 ◽  
Vol 24 (S1) ◽  
Author(s):  
Johannes Streicher ◽  
Christine Pomikal
Keyword(s):  
The Body ◽  
Body Axis

scholarly journals A fluid-to-solid jamming transition underlies vertebrate body axis elongation

Nature ◽  
2018 ◽  
Vol 561 (7723) ◽  
pp. 401-405 ◽  
Author(s):  
Alessandro Mongera ◽  
Payam Rowghanian ◽  
Hannah J. Gustafson ◽  
Elijah Shelton ◽  
David A. Kealhofer ◽  
...  
Keyword(s):  
Body Axis ◽  
Jamming Transition ◽  
Axis Elongation

Intrinsic and extrinsic factors in the mechanism of neurulation: effect of curvature of the body axis on closure of the posterior neuropore

Development ◽  
1993 ◽  
Vol 117 (3) ◽  
pp. 1163-1172 ◽  
Author(s):  
H.W. van Straaten ◽  
J.W. Hekking ◽  
C. Consten ◽  
A.J. Copp
Keyword(s):  
Neural Tube ◽  
The Body ◽  
Body Axis ◽  
Normal Closure ◽  
General Mechanism ◽  
Extrinsic Factors ◽  
Caudal Region ◽  
Posterior Neuropore ◽  
Axial Curvature

Neurulation has been suggested to involve both factors intrinsic and extrinsic to the neuroepithelium. In the curly tail (ct) mutant mouse embryo, final closure of the posterior neuropore is delayed to varying extents resulting in neural tube defects. Evidence was presented recently (Brook et al., 1991 Development 113, 671–678) to suggest that enhanced ventral curvature of the caudal region is responsible for the neurulation defect, which probably originates from an abnormally reduced rate of cell proliferation affecting the hindgut endoderm and notochord, but not the neuroepithelium (Copp et al., 1988, Development 104, 285–295). This axial curvature probably generates a mechanical stress on the posterior neuropore, opposing normal closure. We predicted, therefore, that the ct/ct posterior neuropore should be capable of normal closure if the neuropore should be capable of normal closure if the neuroepithelium is isolated from its adjacent tissues. This prediction was tested by in vitro culture of ct/ct posterior neuropore regions, isolated by a cut caudal to the 5th from last somite. In experimental explants, the neuroepithelium of the posterior neuropore, together with the contiguous portion of the neural tube, were separated mechanically from all adjacent non-neural tissues. The posterior neuropore closed in these explants at a similar rate to isolated posterior neuropore regions of non-mutant embryos. By contrast, control ct/ct explants, in which the caudal region was isolated but the neuroepithelium was left attached to adjacent tissues, showed delayed neurulation. To examine further the idea that axial curvature may be a general mechanism regulating neurulation, we cultured chick embryos on curved substrata in vitro. Slight curvature of the body axis (maximally 1 degree per mm axial length), of either concave or convex nature, resulted in delay of posterior neuropore closure in the chick embryo. Both incidence and extent of closure delay correlated with the degree of curvature that was imposed. We propose that during normal embryogenesis the rate of neurulation is related to the angle of axial curvature, such that experimental alterations in curvature will have differing effects (either enhancement or delay of closure) depending on the angle of curvature at which neurulation normally occurs in a given species, or at a given level of the body axis.

scholarly journals Fundc1 is necessary for proper body axis formation during embryogenesis in zebrafish

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Gongyu Xu ◽  
Hao Shen ◽  
Emile Nibona ◽  
Kongyue Wu ◽  
Xiaomei Ke ◽  
...  
Keyword(s):  
T Cells ◽  
Mammalian Cells ◽  
Mitochondrial Protein ◽  
Ectopic Expression ◽  
The Body ◽  
Body Axis ◽  
Terminal Deoxynucleotidyl Transferase ◽  
Mitochondrial Outer Membrane ◽  
Axis Formation ◽  
Rare Minnow

AbstractFUN14 domain-containing protein 1 (FUNDC1) is a mitochondrial outer membrane protein which is responsible for hypoxia-induced mitophagy in mammalian cells. Knockdown of fundc1 is known to cause severe defects in the body axis of a rare minnow. To understand the role of Fundc1 in embryogenesis, we used zebrafish in this study. We used bioimaging to locate zebrafish Fundc1 (DrFundc1) with MitoTracker, a marker of mitochondria, and/or CellLight Lysosomes-GFP, a label of lysosomes, in the transfected ovary cells of grass carp. The use of Western blotting detected DrFundc1 as a component of mitochondrial proteins with endogenous COX IV, LC3B, and FUNDC1 in transgenic human embryonic kidney 293 T cells. DrFundc1 induced LC3B activation. The ectopic expression of Drfundc1 caused cell death and apoptosis as well as impairing cell proliferation in the 293 T cell line, as detected by Trypan blue, terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) and incorporation of BrdU. DrFundc1 up-regulated expression of both autophagy- and apoptosis-related genes, including ATG5, ATG7, LC3B, BECLIN1, and BAX in transgenic 293 T cells. A knockdown of Drfundc1 using short hairpin RNA (shRNA) led to midline bifurcation with two notochords and two spinal cords in zebrafish embryos. Co-injection of Drfundc1 mRNA repaired defects resulting from shRNA. Knockdown of Drfundc1 resulted in up- or down-regulation of genes related to autophagy and apoptosis, as well as decreased expression of neural genes such as cyclinD1, pax2a, opl, and neuroD1. In summary, DrFundc1 is a mitochondrial protein which is involved in mitophagy and is critical for typical body axis development in zebrafish.

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