Conversion of Ectoderm to Mesoderm by Cytoplasmic Extrusion in Leech Embryos

@article{Nelson1991ConversionOE,
  title={Conversion of Ectoderm to Mesoderm by Cytoplasmic Extrusion in Leech Embryos},
  author={B H Nelson and David A. Weisblat},
  journal={Science},
  year={1991},
  volume={253},
  pages={435 - 438}
}
The role of cytoplasmic domains in the determination of the fates of ectodermal and mesodermal cells has been investigated in leech embryos. When yolk-deficient cytoplasm (teloplasm) was extruded from the animal pole of the zygote, the ectodermal precursor blastomere was converted to a mesodermal fate. This change of fate can be prevented by replacement of the extruded animal teloplasm with teloplasm from the vegetal pole. The fate of the mesodermal precursor blastomere was unaffected by… 
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Cytoplasmic and cortical determinants interact to specify ectoderm and mesoderm in the leech embryo.
TLDR
In leech embryos, segmental ectoderm and mesoderm are produced by a pair of sister cells located near the animal and vegetal poles, respectively, and it is proposed that these determinants segregate to the ectodermal precursor and interact with factors in teloplasm to transform the fate of this cell from a mesodermal ground state to ectODerm.
Early events leading to fate decisions during leech embryogenesis.
TLDR
The expression pattern of Hro-nos, a leech homolog to the Drosophila gene nanos, suggests that it may be a determinant associated with the animal cortex and inducing the ectodermal fate in the animal daughter cell of the D' macromere.
Unequal cleavage in leech embryos: zygotic transcription is required for correct spindle orientation in subset of early blastomeres.
TLDR
Analysis of the different types of cells produced in embryos injected with the transcriptional inhibitor, alpha-amanitin, revealed that the symmetry of cell division is perturbed in these large D'-derived cells during this early period of development.
An investigation of the specification of unequal cleavages in leech embryos.
Localization of polyadenylated RNAs during teloplasm formation and cleavage in leech embryos
TLDR
The results indicate that polyA+ RNA colocalizes with teloplasm during cytoplasmic rearrangements resulting in Teloplasm formation, and that it remains concentrated in the teloplasms during the cell divisions and a second cy toplasmics rearrangement during early embryogenesis.
Cell Fate Specification in Glossiphoniid Leech: Macromeres, Micromeres, and Proteloblasts
Spatiotemporal expression of a twist homolog in the leech Helobdella austinensis
TLDR
Hau-twist, a twist homolog from the leech Helobdella austinensis, a tractable lophotrochozoan representative, is characterized and results suggest that twist gene of the leeches HelobDella might function in mesoderm differentiation.
Formation and specification of neurons during the development of the leech central nervous system.
TLDR
The differential specification of neuronal phenotypes within the leech central nervous system occurs in multiple steps and would seem to involve the lineal inheritance of developmental commitments made by one of the neuron's progenitors.
A leech homolog of twist: evidence for its inheritance as a maternal mRNA.
D quadrant specification in the leech Helobdella: actomyosin contractility controls the unequal cleavage of the CD blastomere.
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References

SHOWING 1-10 OF 38 REFERENCES
Centrifugation redistributes factors determining cleavage patterns in leech embryos.
Animal and vegetal teloplasms mix in the early embryo of the leech, Helobdella triserialis.
Cell clones and segmentation in leech development
Embryonic development of the glossiphoniid leech Theromyzon rude: characterization of developmental stages.
Cell interactions in the developing epidermis of the leech Helobdella triserialis.
Embryonic development of the glossiphoniid leech Theromyzon rude: structure and development of the germinal bands.
Cell lineage and segmentation in the leech.
  • D. Weisblat, M. Shankland
  • Biology
    Philosophical transactions of the Royal Society of London. Series B, Biological sciences
  • 1985
TLDR
The precise relationship between blast cell clones and segments in the leech is established, with the following conclusions: in the M, O and P cell lines, one blast cell generates one segmental complement of progeny, but serially homologous blast clones intermix so that no segment boundaries can be defined based on primary blastcell clones.
Embryonic origins of cells in the leech Helobdella triserialis.
Cell lineage, cell-cell interaction, and segment formation in the ectoderm of a glossiphoniid leech embryo.
Structure and development of the egg of the glossiphoniid leech Theromyzon rude: characterization of developmental stages and structure of the early uncleaved egg
TLDR
Development of the uncleaved egg, from the time of oviposition to completion of the first cleavage division, has been sub-divided into six stages, based on observations of both live and fixed/cleared eggs.
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