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The Arabidopsis cyclin‐dependent kinase gene cdc2bAt is preferentially expressed during S and G 2 phases of the cell cycle
Author(s) -
Segers Gerda,
Gadisseur Isabelle,
Bergounioux Catherine,
Engler Janice,
Jacqmard Annie,
Montagu Marc,
Inzé Dirk
Publication year - 1996
Publication title -
the plant journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.058
H-Index - 269
eISSN - 1365-313X
pISSN - 0960-7412
DOI - 10.1046/j.1365-313x.1996.10040601.x
Subject(s) - cyclin dependent kinase , cell cycle , biology , meristem , polo like kinase , cyclin , microbiology and biotechnology , mitosis , restriction point , gene , genetics
Cell cycle progression is regulated by cyclin‐dependent kinases (CDKs). Arabidopsis thaliana contains two cdk genes, cdc2aAt and cdc2bAt . This paper compares the developmental and cell cycle phase‐dependent transcription of both cdk genes. In situ hybridizations revealed that cdc2bAt steady‐state mRNAs, much like cdc2aAt , are found both in meristematic cells and cells with a high proliferative competence. Cdc2aAt is expressed in every meristematic cell whereas cdc2bAt is found to be expressed in a patchy pattern. An even smaller number of meristematic cells express the mitotic cyc1At . These data indicate that cdc2bAt and cyc1At mRNAs accumulate in a particular cell cycle phase in agreement with evidence provided by hybridization experiments of flow cytometry‐sorted nuclei and the use of cell cycle blockers on roots. The data indicate that cdc2bAt is preferentially expressed in S and G 2 phases whereas cdc2aAt expression is constitutive throughout the cell cycle, as shown previously. The existence of two distinct CDK classes in plants is proposed: (i) constitutively expressed CDKs containing a PSTAIRE motif (e.g. cdc2aAt ) and (ii) CDKs with divergent motifs which are expressed during a limited interval of the cell cycle (e.g. cdc2bAt ).