Growing an Embryo from a Single Cell: A Hurdle in Animal Life
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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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RNA binding proteins Smaug and Cup induce CCR4-NOT-dependent deadenylation of the <i>nanos</i> mRNA in a reconstituted system
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TL;DR: In this paper , an in vitro reconstitution of the Drosophila CCR4-NOT complex and Smaug-dependent deadenylation was reported, and it was shown that Smaug by itself is sufficient to cause deadening in an SRE-dependent manner.
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Concerted evolution of ribosomal DNA: Somatic peace amid germinal strife: Intranuclear and cellular selection maintain the quality of rRNA.
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Dodecaploid <i>Xenopus longipes</i> provides insight into the emergence of size scaling relationships during development
TL;DR: In this article , a cross-species study of frogs of the genus Xenopus showed that cell size was determined primarily by egg size, while nuclear size correlated with genome size during embryogenesis, resulting in different nuclear-cytoplasmic ratios at the mid-blastula transition.
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Zebrafish as a Model to Understand Vertebrate Development
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References
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Journal ArticleDOI
Nothing in Biology Makes Sense Except in the Light of Evolution
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Journal ArticleDOI
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