Growing an Embryo from a Single Cell: A Hurdle in Animal Life
Reads0
Chats0
TLDR
In mammals and in endoparasites, development in a nutritive environment releases the growth constraint, but growth of cells before gastrulation requires a new program to sustain pluripotency during this growth.Abstract:
A requirement that an animal be able to feed to grow constrains how a cell can grow into an animal, and it forces an alternation between growth (increase in mass) and proliferation (increase in cell number). A growth-only phase that transforms a stem cell of ordinary proportions into a huge cell, the oocyte, requires dramatic adaptations to help a nucleus direct a 10(5)-fold expansion of cytoplasmic volume. Proliferation without growth transforms the huge egg into an embryo while still accommodating an impotent nucleus overwhelmed by the voluminous cytoplasm. This growth program characterizes animals that deposit their eggs externally, but it is changed in mammals and in endoparasites. In these organisms, development in a nutritive environment releases the growth constraint, but growth of cells before gastrulation requires a new program to sustain pluripotency during this growth.read more
Citations
More filters
Nothing in Biology Makes Sense Except in the Light of Evolution
TL;DR: The theory that biological species are descended from common ancestors provides an indispensable heuristic to understand why living organisms are what they are and do what they do.
Journal ArticleDOI
Expression of engrailed proteins in arthropods, annelids and chordates
TL;DR: A monoclonal antibody is described that recognizes a conserved epitope in the homeodomain of engrailed proteins of a number of different arthropods, annelids, and chordates; this antibody is used to isolate the grasshopperEngrailed gene, a homeobox gene that has an important role in Drosophila segmentation.
Journal ArticleDOI
Zygotic Genome Activation in Vertebrates.
TL;DR: Progress in understanding vertebrate ZGA dynamics in frogs, fish, mice, and humans is reviewed to explore differences and emphasize common features.
Journal ArticleDOI
Waves of Cdk1 Activity in S Phase Synchronize the Cell Cycle in Drosophila Embryos
TL;DR: In Drosophila embryos, Cdk1 positive feedback serves primarily to ensure the rapid onset of mitosis, while wave propagation is regulated by S phase events, demonstrating a fundamental distinction between S phase Cdk 1 waves, which propagate as active trigger waves in an excitable medium, and mitotic Cdk2 waves, who propagate as passive phase waves.
Journal ArticleDOI
Capturing Totipotent Stem Cells
TL;DR: The biological and molecular characterization of cultured cells with developmental potential similar to totipotent blastomeres are reviewed, and recent progress toward the capture and stabilization of the totip powerless state in vitro is assessed.
References
More filters
Journal ArticleDOI
Induction of pluripotent stem cells from mouse embryonic and adult fibroblast cultures by defined factors.
TL;DR: Induction of pluripotent stem cells from mouse embryonic or adult fibroblasts by introducing four factors, Oct3/4, Sox2, c-Myc, and Klf4, under ES cell culture conditions is demonstrated and iPS cells, designated iPS, exhibit the morphology and growth properties of ES cells and express ES cell marker genes.
Journal ArticleDOI
Establishment in culture of pluripotential cells from mouse embryos
TL;DR: The establishment in tissue culture of pluripotent cell lines which have been isolated directly from in vitro cultures of mouse blastocysts are reported, able to differentiate either in vitro or after innoculation into a mouse as a tumour in vivo.
Journal ArticleDOI
Isolation of a pluripotent cell line from early mouse embryos cultured in medium conditioned by teratocarcinoma stem cells
TL;DR: In this article, the authors described the establishment directly from normal preimplantation mouse embryos of a cell line that forms teratocarcinomas when injected into mice and demonstrated the pluripotency of these embryonic stem cells by the observation that subclonal cultures, derived from isolated single cells, can differentiate into a wide variety of cell types.
Journal ArticleDOI
Nothing in Biology Makes Sense Except in the Light of Evolution
TL;DR: The Copernican world model has been shown to be a "mere theory" as mentioned in this paper, not a "fact," and it has not been verified by direct observations even to the extent the sphericity of the earth has been observed.
Journal ArticleDOI
A major developmental transition in early xenopus embryos: I. characterization and timing of cellular changes at the midblastula stage
TL;DR: The Xenopus embryo undergoes 12 rapid synchronous cleavages followed by a period of slower asynchronous divisions more typical of somatic cells, termed the midblastula transition (MBT), which shows that at the MBT the blastomeres become motile and transcriptionally active for the first time.
Related Papers (5)
A major developmental transition in early xenopus embryos: I. characterization and timing of cellular changes at the midblastula stage
Studies of nuclear and cytoplasmic behaviour during the five mitotic cycles that precede gastrulation in Drosophila embryogenesis
V.E. Foe,B.M. Alberts +1 more