Restarting life: fertilization and the transition from meiosis to mitosis.
Fertilization triggers a complex cellular programme that transforms two highly specialized meiotic germ cells, the oocyte and the sperm, into a totipotent mitotic embryo. Linkages between sister chromatids are remodelled to support the switch from reductional meiotic to equational mitotic divisions; the centrosome, which is absent from the egg, is reintroduced; cell division shifts from being extremely asymmetric to symmetric; genomic imprinting is selectively erased and re-established; and protein expression shifts from translational control to transcriptional control. Recent work has started to reveal how this remarkable transition from meiosis to mitosis is achieved.
Medical Research Council Laboratory of Molecular Biology (MRC LMB), Cambridge CB2 0QH, UK.
Dean
D
Clift
Melina
M
Schuh
D047108:Embryonic Development / Q000235:genetics / Q000502:physiology*; D005260:Female; D005306:Fertilization / Q000235:genetics / Q000502:physiology*; D018507:Gene Expression Regulation, Developmental; D006801:Humans; D008297:Male; D008540:Meiosis / Q000235:genetics / Q000502:physiology*; D008938:Mitosis / Q000235:genetics / Q000502:physiology*; D010063:Ovum / Q000166:cytology / Q000378:metabolism; D013094:Spermatozoa / Q000166:cytology / Q000378:metabolism