Development, Vol 121, Issue 9 3035-3043, Copyright © 1995 by Company of Biologists

JOURNAL ARTICLES

Expression of the cell cycle control gene, cdc25, is constitutive in the segmental founder cells but is cell-cycle-regulated in the micromeres of leech embryos

ST Bissen
Department of Biology, University of Missouri-St Louis 63121-4499, USA.

The identifiable cells of leech embryos exhibit characteristic differences in the timing of cell division. To elucidate the mechanisms underlying these cell-specific differences in cell cycle timing, the leech cdc25 gene was isolated because Cdc25 phosphatase regulates the asynchronous cell divisions of postblastoderm Drosophila embryos. Examination of the distribution of cdc25 RNA and the zygotic expression of cdc25 in identified cells of leech embryos revealed lineage-dependent mechanisms of regulation. The early blastomeres, macromeres and teloblasts have steady levels of maternal cdc25 RNA throughout their cell cycles. The levels of cdc25 RNA remain constant throughout the cell cycles of the segmental founder cells, but the majority of these transcripts are zygotically produced. Cdc25 RNA levels fluctuate during the cell cycles of the micromeres. The levels peak during early G2, due to a burst of zygotic transcription, and then decline as the cell cycles progress. These data suggest that cells of different lineages employ different strategies of cell cycle control.
CiteULike    Complore    Connotea    Del.icio.us    Digg    Reddit    Technorati    Twitter    What's this?

This article has been cited by other articles:

				B A Edgar and S A Datar Zygotic degradation of two maternal Cdc25 mRNAs terminates Drosophila's early cell cycle program. Genes & Dev., August 1, 1996; 10(15): 1966 - 1977. [Abstract] [PDF]

				S. Bissen and C. Smith Unequal cleavage in leech embryos: zygotic transcription is required for correct spindle orientation in subset of early blastomeres Development, January 2, 1996; 122(2): 599 - 606. [Abstract] [PDF]