Morphological left-right asymmetry of Hensen's node precedes the asymmetric expression of Shh and Fgf8 in the chick embryo

2002 ◽  
Vol 205 (5-6) ◽  
pp. 343-354 ◽  
Author(s):  
Verena Dathe ◽  
Anton Gamel ◽  
Jörg Männer ◽  
Beate Brand-Saberi ◽  
Bodo Christ
Keyword(s):  
Chick Embryo ◽  
Left Right Asymmetry ◽  
Asymmetric Expression

scholarly journals Embryonic chirality and the evolution of spiralian left–right asymmetries

2016 ◽  
Vol 371 (1710) ◽  
pp. 20150411 ◽  
Author(s):  
José M. Martín-Durán ◽  
Bruno C. Vellutini ◽  
Andreas Hejnol
Keyword(s):  
Early Event ◽  
Animal Group ◽  
Differential Activation ◽  
Membranipora Membranacea ◽  
Axis Specification ◽  
Left Right Asymmetry ◽  
Cytoskeleton Dynamics ◽  
Lineus Ruber ◽  
Asymmetric Expression

The group Spiralia includes species with one of the most significant cases of left–right asymmetries in animals: the coiling of the shell of gastropod molluscs (snails). In this animal group, an early event of embryonic chirality controlled by cytoskeleton dynamics and the subsequent differential activation of the genes nodal and Pitx determine the left–right axis of snails, and thus the direction of coiling of the shell. Despite progressive advances in our understanding of left–right axis specification in molluscs, little is known about left–right development in other spiralian taxa. Here, we identify and characterize the expression of nodal and Pitx orthologues in three different spiralian animals—the brachiopod Novocrania anomala , the annelid Owenia fusiformis and the nemertean Lineus ruber —and demonstrate embryonic chirality in the biradial-cleaving spiralian embryo of the bryozoan Membranipora membranacea . We show asymmetric expression of nodal and Pitx in the brachiopod and annelid, respectively, and symmetric expression of Pitx in the nemertean. Our findings indicate that early embryonic chirality is widespread and independent of the cleavage programme in the Spiralia. Additionally, our study illuminates the evolution of nodal and Pitx signalling by demonstrating embryonic asymmetric expression in lineages without obvious adult left–right asymmetries. This article is part of the themed issue ‘Provocative questions in left–right asymmetry’.

scholarly journals Asymmetric expression of antivin/lefty1 in the early chick embryo

2000 ◽  
Vol 90 (1) ◽  
pp. 115-118 ◽  
Author(s):  
Yoshiyasu Ishimaru ◽  
Hidefumi Yoshioka ◽  
Hirotaka Tao ◽  
Bernard Thisse ◽  
Christine Thisse ◽  
...  
Keyword(s):  
Chick Embryo ◽  
Early Chick Embryo ◽  
Asymmetric Expression

scholarly journals Unveiling the establishment of left–right asymmetry in the chick embryo

2004 ◽  
Vol 121 (9) ◽  
pp. 1043-1054 ◽  
Author(s):  
Angel Raya ◽  
Juan Carlos Izpisua Belmonte
Keyword(s):  
Chick Embryo ◽  
Left Right Asymmetry

scholarly journals Presence of midline cilia supersedes the expression of Lefty1 in forming the midline barrier during the establishment of left-right asymmetry

2018 ◽  
Author(s):  
Natalia A Shylo ◽  
Dylan A Ramrattan ◽  
Scott D Weatherbee
Keyword(s):  
Transition Zone ◽  
Lateral Plate Mesoderm ◽  
Lateral Plate ◽  
Left Isomerism ◽  
Left Right Asymmetry ◽  
Asymmetric Expression ◽  
R Symmetry

Cilia in the vertebrate left-right organizer are required for the original break in left-right (L-R) symmetry. Subsequently, proper L-R patterning relies on asymmetric expression of Nodal in the lateral plate mesoderm (LPM). Lefty1, expressed in the embryonic midline, has been defined as the midline barrier, restricting the expression of Nodal to the left LPM. Here we use the mouse ciliary transition zone mutant Mks1krc, that has left isomerism and bilateral expression of the NODAL target Pitx2, to reveal that the expression of Lefty1 in the midline is insufficient for the establishment of the midline barrier. We further show through a comparison of two Tmem107 mutants that cilia in the midline are required to supplement Lefty1 expression and establish the functional midline barrier. Tmem107null mutants have no cilia in the midline and display left isomerism due to the loss of the midline barrier, whereas Tmem107schlei hypomorphic mutants have numerous cilia in the node and the midline, leading to normal Lefty1 expression and L-R patterning. This study reveals a novel role for cilia in the maintenance of L-R asymmetry.

scholarly journals Distinct requirements for extra-embryonic and embryonic bone morphogenetic protein 4 in the formation of the node and primitive streak and coordination of left-right asymmetry in the mouse

Development ◽  
2002 ◽  
Vol 129 (20) ◽  
pp. 4685-4696 ◽  
Author(s):  
Takeshi Fujiwara ◽  
Deborah B. Dehart ◽  
Kathleen K. Sulik ◽  
Brigid L. M. Hogan
Keyword(s):  
Chick Embryo ◽  
Bone Morphogenetic Protein ◽  
Primitive Streak ◽  
Positional Information ◽  
Bone Morphogenetic Protein 4 ◽  
Lateral Plate ◽  
Morphogenetic Protein ◽  
Normal Node ◽  
Bmp4 Expression ◽  
Left Right Asymmetry

In the mouse and chick embryo, the node plays a central role in generating left-right (LR) positional information. Using several different strategies, we provide evidence in the mouse that bone morphogenetic protein 4 (Bmp4) is required independently in two different sites for node morphogenesis and for LR patterning. Bmp4 expression in the trophoblast-derived extra-embryonic ectoderm is essential for the normal formation of the node and primitive streak. However, tetraploid chimera analysis demonstrates that Bmp4 made in epiblast-derived tissues is required for robust LR patterning, even when normal node morphology is restored. In the absence of embryonic Bmp4, the expression of left-side determinants such as Nodal and Lefty2 is absent in the left lateral plate mesoderm (LPM). Noggin-mediated inhibition of Bmp activity in cultured wild-type embryos results in suppression of Nodal expression in the LPM. Thus, unlike previous models proposed in the chick embryo in which Bmp4 suppresses left-sided gene expression, our results suggest that Bmp acts as a positive facilitator of the left-sided molecular cascade and is required for Nodal induction and maintenance in the left LPM.

scholarly journals BMP inhibition by DAN in Hensen's node is a critical step for the establishment of left–right asymmetry in the chick embryo

2012 ◽  
Vol 363 (1) ◽  
pp. 15-26 ◽  
Author(s):  
Kenjiro Katsu ◽  
Daisuke Tokumori ◽  
Norifumi Tatsumi ◽  
Atsushi Suzuki ◽  
Yuji Yokouchi
Keyword(s):  
Chick Embryo ◽  
Critical Step ◽  
Left Right Asymmetry

Otoconia formation in the chick embryo

1983 ◽  
Vol 41 ◽  
pp. 572-573
Author(s):  
C.D. Fermin ◽  
M. Igarashi
Keyword(s):  
Chick Embryo ◽  
Inner Ear ◽  
Gallus Domesticus ◽  
The Body ◽  
Abnormal Behavior ◽  
Intensive Study ◽  
Basic Fuchsin ◽  
Gestational Period ◽  
Sensory Epithelia ◽  
Transmission Electron

Otoconia are microscopic geometric structures that cover the sensory epithelia of the utricle and saccule (gravitational receptors) of mammals, and the lagena macula of birds. The importance of otoconia for maintanance of the body balance is evidenced by the abnormal behavior of species with genetic defects of otolith. Although a few reports have dealt with otoconia formation, some basic questions remain unanswered. The chick embryo is desirable for studying otoconial formation because its inner ear structures are easily accessible, and its gestational period is short (21 days of incubation).The results described here are part of an intensive study intended to examine the morphogenesis of the otoconia in the chick embryo (Gallus- domesticus) inner ear. We used chick embryos from the 4th day of incubation until hatching, and examined the specimens with light (LM) and transmission electron microscopy (TEM). The embryos were decapitated, and fixed by immersion with 3% cold glutaraldehyde. The ears and their parts were dissected out under the microscope; no decalcification was used. For LM, the ears were embedded in JB-4 plastic, cut serially at 5 micra and stained with 0.2% toluidine blue and 0.1% basic fuchsin in 25% alcohol.

Sign in / Sign up

Export Citation Format

Share Document