Maternal cyclin B levels "Chk" the onset of DNA replication checkpoint control in Drosophila.
In many animals, early development of the embryo is characterized by synchronous, biphasic cell divisions. These cell divisions are controlled by maternally inherited proteins and RNAs. A critical question in developmental biology is how the embryo transitions to a later pattern of asynchronous cell divisions and transfers the prior maternal control of development to the zygotic genome. The most-common model regarding how this transition from maternal to zygotic control is regulated posits that this is a consequence of the limitation of maternal gene products, due to their titration during early cell divisions. Here we discuss a recent article by Crest et al.1 that instead proposes that the balance of Cyclin-dependent Kinase 1 and Cyclin B (Cdk1-CycB) activity relative to that of the Drosophila checkpoint kinase Chk1 determines when asynchronous divisions begin.
Yellajoshyula
Dhananjay
D
Department of Molecular Biology and Pharmacology, Washington University School of Medicine, St. Louis, MO 63110, USA.
Patterson
Ethan S
ES
Kroll
Kristen L
KL
D000818:Animals; D016203:CDC2 Protein Kinase / Q000378:metabolism*; D000071877:Checkpoint Kinase 1; D019926:Cyclin B / Q000378:metabolism*; D056744:Cyclin B1; D004261:DNA Replication; D004330:Drosophila / Q000196:embryology* / Q000235:genetics; D004625:Embryo, Nonmammalian; D005260:Female; D008954:Models, Biological; D011494:Protein Kinases / Q000378:metabolism*; D013997:Time Factors
D019926:Cyclin B; D056744:Cyclin B1; D011494:Protein Kinases; D000071877:Checkpoint Kinase 1; D016203:CDC2 Protein Kinase