Embryogenesis

Important Papers

[1] Potent and specific genetic interference by double-stranded RNA in C. elegans

  • Fire A at al.
  • Nature. 1998 Feb 19;391(6669):806-11
  • Experimental introduction of RNA into cells can be used in certain biological systems to interfere with the function of an endogenous gene. Such effects have been proposed to result from a simple antisense mechanism that depends on hybridization between the injected RNA and endogenous messenger RNA transcripts. RNA interference has been used in the nematode Caenorhabditis elegans to manipulate gene expression.
  • Here we investigate the requirements for structure and delivery of the interfering RNA. To our surprise, we found that double-stranded RNA was substantially more effective at producing interference than was either strand individually.
  • After injection into adult animals, purified single strands had at most a modest effect, whereas double-stranded mixtures caused potent and specific interference. The effects of this interference were evident in both the injected animals and their progeny. Only a few molecules of injected double-stranded RNA were required per affected cell, arguing
  • against stochiometric interference with endogenous mRNA and suggesting that there could be a catalytic or amplification component in the interference process.

[2] EARLY PATTERNING OF THE C. ELEGANS EMBRYO

  • Lesilee S. Rose and Kenneth J. Kemphues
  • Annual Review of Genetics, Vol. 32: 521-545 (Volume publication date December 1998)
  • Studies of about 20 maternally expressed genes are providing an understanding of mechanisms of patterning and cell-fate determination in the early Caenorhabditis elegans embryo.
  • The analyses have revealed that fates of the early blastomeres are specified by a combination of intrinsically asymmetric cell divisions and two types of cell-cell interactions: inductions and polarizing interactions.
  • In this review they summarize the current level of understanding of the molecular mechanisms underlying these processes in the specification of cell fates in the pregastrulation embryo.
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[3] Functional genomic analysis of cell division in C. elegans using RNAi of genes on chromosome III

  • Pierre Gönczy et al.
  • Nature 408, 331-336 (16 November 2000) | doi:10.1038/35042526
  • Genome sequencing projects generate a wealth of information; however, the ultimate goal of such projects is to accelerate the identification of the biological function of genes. This creates a need for comprehensive studies to fill the gap between sequence and function.
  • Here they report the results of a functional genomic screen to identify genes required for cell division in Caenorhabditis elegans.
  • They inhibited the expression of 96% of the 2,300 predicted open reading frames on chromosome III using RNA-mediated interference (RNAi). By using an in vivo time-lapse differential interference contrast microscopy assay, they identified 133 genes (6%) necessary for distinct cellular processes in early embryos.
  • These results indicate that these genes represent most of the genes on chromosome III that are required for proper cell division in C. elegans embryos.

Embryonic Development during 12 Hours

This is the movie showing the embryonic development of C. elegans during 12 hours.