Abstract
We first review cortical-cytoplasmic rotation, a microtubule-mediated process by which the Xenopus egg, like other amphibian eggs, transforms its polarized cylindrical symmetry into bilateral symmetry within the first cell cycle after fertilization. This transformation, the earliest of many steps leading to dorsal development, involves the displacement of the egg's cortex relative to its cytoplasmic core by 30Γ in an animal-vegetal direction. As rotation is progressively reduced by microtubule-depolymerizing agents, embryos develop with body axes progressively deleted for dorsal structures at the anterior end. With no rotation, ventralized embryos are formed. In an effort to comprehend this progressive effect on embryonic organization, we go on to review subsequent developmental processes depending on rotation, and we propose, with evidence, that reduced rotation leads to a reduced number of vegetal dorsalizing cells, which induce during the blastula stage a Spemann organizer region of smaller than normal size. The reduced organizer then promotes a reduced amount of cell rearrangement (morphogenesis) at gastrulation. Reduced morphogenesis seems the proximate cause of the incompleteness of axial pattern, as shown further by the fact that embryos that are normal until the gastrula stage, if exposed to inhibitors of morphogenesis, develop body axes that are progressively less complete in their anterior dorsal organization the earlier their gastrulation had been blocked. We discuss why axial pattern might depend systematically on morphogenesis.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 37-51 |
| Number of pages | 15 |
| Journal | Development |
| Volume | 107 |
| Issue number | SUPPL. |
| State | Published - 1989 |
| Externally published | Yes |
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Keywords
- anteroposterior pattern
- cortical rotation
- DO
- dorsoventral pattern
- FGF
- gastrulation
- lithium
- mesoderm induction
- microtubules
- organizer
- polarity
- TGFβ
- Xenopus laevis
ASJC Scopus subject areas
- Anatomy
- Cell Biology
Cite this
Cortical rotation of the Xenopus egg : Consequences for the anteroposterior pattern of embryonic dorsal development. / Gerhart, J.; Danilchik, Michael; Doniach, T.; Roberts, S.; Rowning, B.; Stewart, R.
In: Development, Vol. 107, No. SUPPL., 1989, p. 37-51.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Cortical rotation of the Xenopus egg
T2 - Consequences for the anteroposterior pattern of embryonic dorsal development
AU - Gerhart, J.
AU - Danilchik, Michael
AU - Doniach, T.
AU - Roberts, S.
AU - Rowning, B.
AU - Stewart, R.
PY - 1989
Y1 - 1989
N2 - We first review cortical-cytoplasmic rotation, a microtubule-mediated process by which the Xenopus egg, like other amphibian eggs, transforms its polarized cylindrical symmetry into bilateral symmetry within the first cell cycle after fertilization. This transformation, the earliest of many steps leading to dorsal development, involves the displacement of the egg's cortex relative to its cytoplasmic core by 30Γ in an animal-vegetal direction. As rotation is progressively reduced by microtubule-depolymerizing agents, embryos develop with body axes progressively deleted for dorsal structures at the anterior end. With no rotation, ventralized embryos are formed. In an effort to comprehend this progressive effect on embryonic organization, we go on to review subsequent developmental processes depending on rotation, and we propose, with evidence, that reduced rotation leads to a reduced number of vegetal dorsalizing cells, which induce during the blastula stage a Spemann organizer region of smaller than normal size. The reduced organizer then promotes a reduced amount of cell rearrangement (morphogenesis) at gastrulation. Reduced morphogenesis seems the proximate cause of the incompleteness of axial pattern, as shown further by the fact that embryos that are normal until the gastrula stage, if exposed to inhibitors of morphogenesis, develop body axes that are progressively less complete in their anterior dorsal organization the earlier their gastrulation had been blocked. We discuss why axial pattern might depend systematically on morphogenesis.
AB - We first review cortical-cytoplasmic rotation, a microtubule-mediated process by which the Xenopus egg, like other amphibian eggs, transforms its polarized cylindrical symmetry into bilateral symmetry within the first cell cycle after fertilization. This transformation, the earliest of many steps leading to dorsal development, involves the displacement of the egg's cortex relative to its cytoplasmic core by 30Γ in an animal-vegetal direction. As rotation is progressively reduced by microtubule-depolymerizing agents, embryos develop with body axes progressively deleted for dorsal structures at the anterior end. With no rotation, ventralized embryos are formed. In an effort to comprehend this progressive effect on embryonic organization, we go on to review subsequent developmental processes depending on rotation, and we propose, with evidence, that reduced rotation leads to a reduced number of vegetal dorsalizing cells, which induce during the blastula stage a Spemann organizer region of smaller than normal size. The reduced organizer then promotes a reduced amount of cell rearrangement (morphogenesis) at gastrulation. Reduced morphogenesis seems the proximate cause of the incompleteness of axial pattern, as shown further by the fact that embryos that are normal until the gastrula stage, if exposed to inhibitors of morphogenesis, develop body axes that are progressively less complete in their anterior dorsal organization the earlier their gastrulation had been blocked. We discuss why axial pattern might depend systematically on morphogenesis.
KW - anteroposterior pattern
KW - cortical rotation
KW - DO
KW - dorsoventral pattern
KW - FGF
KW - gastrulation
KW - lithium
KW - mesoderm induction
KW - microtubules
KW - organizer
KW - polarity
KW - TGFβ
KW - Xenopus laevis
UR - http://www.scopus.com/inward/record.url?scp=0024834229&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0024834229&partnerID=8YFLogxK
M3 - Article
VL - 107
SP - 37
EP - 51
JO - Development (Cambridge)
JF - Development (Cambridge)
SN - 0950-1991
IS - SUPPL.
ER -