title: The eggshell in the C. elegans oocyte-to-embryo transition.
abstract: In egg-laying animals, embryonic development takes place within the highly specialized environment provided by the eggshell and its underlying extracellular matrix. Far from being simply a passive physical support, the eggshell is a key player in many early developmental events. Herein, we review current understanding of eggshell structure, biosynthesis, and function in zygotic development of the nematode, C. elegans. Beginning at sperm contact or entry, eggshell layers are produced sequentially. The earlier outer layers are required for secretion or organization of inner layers, and layers differ in composition and function. Developmental events that depend on the eggshell include polyspermy barrier generation, high fidelity meiotic chromosome segregation, osmotic barrier synthesis, polar body extrusion, anterior-posterior polarization, and organization of membrane and cortical proteins. The C. elegans eggshell is proving to be an excellent, tractable system to study the molecular cues of the extracellular matrix that instruct cell polarity and early development.
authors.affiliation: Samuel Lunenfeld Research Institute, Mount Sinai Hospital, Toronto, Ontario, Canada, M5G 1X5. johnston@lunenfeld.ca
authors.forename: Wendy L
authors.initials: WL
authors.lastname: Johnston
authors.forename: James W
authors.initials: JW
authors.lastname: Dennis
mesh_terms: D000818:Animals; D017173:Caenorhabditis elegans / Q000196:embryology* / Q000254:growth & development*; D029742:Caenorhabditis elegans Proteins / Q000235:genetics / Q000378:metabolism; D016764:Cell Polarity; D020090:Chromosome Segregation; D004528:Egg Shell / Q000737:chemistry*; D005306:Fertilization; D008297:Male; D008540:Meiosis; D009995:Osmosis; D059705:Polar Bodies / Q000166:cytology / Q000378:metabolism*; D011505:Protein-Tyrosine Kinases / Q000235:genetics / Q000378:metabolism; D013094:Spermatozoa / Q000378:metabolism; D015053:Zygote / Q000378:metabolism
chemical_list: D029742:Caenorhabditis elegans Proteins; C514294:EGG-1 protein, C elegans; C478059:MBK-2 protein, C elegans; D011505:Protein-Tyrosine Kinases