|Budget Amount *help
¥2,200,000 (Direct Cost : ¥2,200,000)
Fiscal Year 1994 : ¥400,000 (Direct Cost : ¥400,000)
Fiscal Year 1993 : ¥1,800,000 (Direct Cost : ¥1,800,000)
Multinucleate cells have been reported in many organisms, including fungi, animals and plants.It is well known that the cell cycle (or, proceeding of DNA synthesis and mitosis) of each nucleus in the multinucleate cells pregresses synchronously.While, in multinucleate green algae, several types of mitotic pattern can be observed.In Bryopsis, each nucleus divides independently.Almost synchronous nuclear division occurs in discrete patches in Boergesenia.And in Acrosiphonia, almost all nuclei in the cell divide synchronously.When considering the cell cycle regulation by p34^<cdc2> and cyclins, these phenomena in the multinucleate green algae are unusual.In this study.I tried to examine the mechanism in the cell cycle regulation in the green algae using cytological and molecular biological techniques.Especially, a cDNA clone of Acrosiphonia that is homologous to the cdc2 genes was isolated using PCR,and its nucleotide and deduced amino acid sequences was determined.
Putative amino acid sequence of Acrosiphonia cdc2 gene showed 47.2% homology to yeast cdc2 protein kinase.When analyzed with a monoclonal antibody (PSTAIRE antibody) against a cdc2 protein kinase, a band of Mr38,000 was recognized.Protein kinase encoded in cdc2 gene of the eukaryotes has always ahown Mr34,000, therefore, the molecular weight of Acrosiphonia cdc2 protein kinase was very unique.Adding to it, the antibody could not detect any protein in Bryopsis and Boergesenia.These results might suggest that the regulation in the cell cycle of the multinucleate green algae was carried out by considerably deviated cdc2 gene product from other eukaryotes.