Regulation of endoreduplication in maize (Zea mays L.) endosperm. Isolation of a novel B1-type cyclin and its quantitative analysis.
To investigate the involvement of cyclin in mitotic and endoreduplicative cell cycle control, we have isolated a mitotic cyclin clone from a maize endosperm cDNA library. The deduced amino acid sequence of this clone identifies a novel B1-type cyclin with distinctly different sequence in regions with putative involvement in intracellular localization. This cyclin, designated Zeama;CycB 1;3 (CycZme1), was shown by RNA gel blots and quantitative RT-PCR to be specific for tissues engaging in cell proliferation. It accumulated in metaphase-arrested cells and declined rapidly upon release into G1 phase. During the transition from mitosis to endoreduplication in maize endosperm, CycZme1 transcript declined precipitously while transcripts associated with S phase (histone-H3 and PCNA) and multiple phases of the cell cycle (Cdc2, alpha-tubulin) remained at moderate to high levels. We conclude that CycZme1 down-regulation is involved in the cellular transition to endoreduplication.
Sun
Y
Y
Department of Soil, Crop and Atmospheric Sciences, Cornell University, Ithaca, NY 14853, USA.
Flannigan
B A
BA
Setter
T L
TL
D000595:Amino Acid Sequence; D001483:Base Sequence; D002453:Cell Cycle; D003001:Cloning, Molecular; D019926:Cyclin B / Q000235:genetics* / Q000378:metabolism; D056744:Cyclin B1; D018744:DNA, Plant; D008938:Mitosis; D008969:Molecular Sequence Data; D010940:Plant Proteins / Q000235:genetics* / Q000378:metabolism; D018517:Plant Roots / Q000378:metabolism; D018749:RNA, Plant; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000379:methods; D017386:Sequence Homology, Amino Acid; D014018:Tissue Distribution; D003313:Zea mays / Q000235:genetics*
D019926:Cyclin B; D056744:Cyclin B1; D018744:DNA, Plant; D010940:Plant Proteins; D018749:RNA, Plant