Growing an Embryo from a Single Cell: A Hurdle in Animal Life
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
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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.
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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.
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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.
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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.
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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
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Journal ArticleDOI
A Balbiani body and the fusome mediate mitochondrial inheritance during Drosophila oogenesis.
Rachel T. Cox,Allan C. Spradling +1 more
TL;DR: These findings reveal new similarities between oogenesis in Drosophila and vertebrates, and support the hypothesis that developing oocytes contain specific mechanisms to ensure that germ plasm is endowed with highly functional organelles.
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Sperm decondensation in xenopus egg cytoplasm is mediated by nucleoplasmin
TL;DR: It is concluded that nucleoplasmin is both necessary and sufficient for the first stage of sperm decondensation in Xenopus eggs.
Journal Article
Withdrawal of differentiation inhibitory activity/leukemia inhibitory factor up-regulates D-type cyclins and cyclin-dependent kinase inhibitors in mouse embryonic stem cells.
TL;DR: It is proposed that the G1/S transition may be regulated by a minimal mechanism in mouse embryonic stem cells through the establishment of a more sophisticated mechanism involving both cyclin D/CDK4- and CDK inhibitor-associated control of G1-phase progression.
Journal ArticleDOI
Germline cysts: a conserved phase of germ cell development?
TL;DR: It is argued that cysts play an important and general role in germ line development and, in conjunction with morphological evidence, suggest that the process is highly conserved during evolution.
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A short G1 phase is an intrinsic determinant of naïve embryonic stem cell pluripotency.
Diana Coronado,Murielle Godet,Pierre-Yves Bourillot,Yann Tapponnier,Yann Tapponnier,Agnieszka Bernat,Agnieszka Bernat,Maxime Petit,Maxime Petit,Marielle Afanassieff,Suzy Markossian,Anna Malashicheva,Anna Malashicheva,Roberto Iacone,Konstantinos Anastassiadis,Pierre Savatier +15 more
TL;DR: It is concluded that the short G1 phase observed in murine ESCs was a determinant of naïve pluripotency and was partially under the control of LIF signaling.
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