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Alternative temporal control systems for hypodermal cell differentiation in Caenorhabditis elegans
Nature (1991)
  • Zhongchi Liu, Harvard University
  • Victor R. Ambros, Harvard University
Beginning of article: In certain multicellular organisms, genetic regulatory systems that specify the timing of cell division, differentiation and morpho-genesis must accommodate environmental and physiological contingencies that perturb or arrest development. For example, Caenorhabditis elegans can either develop continuously through four larval stages (L1–L4) or arrest indefinitely as a 'dauer larva' at the second larval (L2) moult, and later resume L3 and L4 development. At the larva-to-adult (L4) moult of both con-tinuous and 'post-dauer' development, hypodermal cells switch (the 'L/A switch') from a proliferating state to the terminally differentiated state. Four temporal regulators, lin-4, lin-14, lin-28 and lin-29, have been identified in C. elegans by mutations that cause precocious or retarded expression of stage-specific post-embryonic development events, including the L/A switch. These genes have been organized into a genetic pathway that controls the timing of the L/A switch during continuous development: lin-29 activates the switch and the other heterochronic genes regulate it indirectly by regulating lin-29. We have now examined how the proper timing of this event is specified in alternative developmental pathways. In continuously developing lin-4, lin-14 and lin-28 mutants the L/A switch occurs at abnormally early or late moults, but during post-dauer development of the same mutants the L/A switch occurs normally. Thus hypodermal cell differentiation is regulated by separate temporal control systems, depending on the developmental history.
Publication Date
March 14, 1991
Citation Information
Liu Z, Ambros V. Alternative temporal control systems for hypodermal cell differentiation in Caenorhabditis elegans. Nature. 1991 Mar 14;350(6314):162-5. PubMed PMID: 26502479.