Calcium levels correlate with cell cycle phase and affect the level of the cyclin B transcript in Dictyostelium discoideum.
In pre-aggregation amoebae of Dictyostelium discoideum, phenotypic differences with respect to cellular Ca2+ and cell cycle phases are known to bias post-aggregative cell-type choice. Using chlortetracycline fluorescence as an indicator, we found that cellular Ca2+ is highest at the S phase of the cell cycle. Upon increasing the level of Ca2+ with the help of the calcium ionophore A23187, there is a significant decrease in the cyclin B (clb1) mRNA level; the cdc2 mRNA level shows a marginal decrease. These results suggest that the effect of Ca2+ and the cell cycle on cell fate could be exerted at the level of transcription, or message stability, of specific genes.
Azhar
M
M
Developmental Biology and Genetics Laboratory, Indian Institute of Science, Bangalore, India.
Krefft
M
M
Saran
S
S
Weeks
G
G
Nanjundiah
V
V
D000818:Animals; D016203:CDC2 Protein Kinase / Q000235:genetics; D002118:Calcium / Q000378:metabolism*; D002453:Cell Cycle; D019926:Cyclin B / Q000235:genetics*; D004023:Dictyostelium / Q000502:physiology*; D012333:RNA, Messenger / Q000032:analysis*
D019926:Cyclin B; D012333:RNA, Messenger; D016203:CDC2 Protein Kinase; D002118:Calcium