Titration of Four Replication Factors Is Essential for the Xenopus laevis Midblastula Transition

• DOI: 10.1126/science.1241530
• Publication Date: 2013-08-02T05:07:22Z
• Authors: Clara Collart; George E. Allen; Charles R. Bradshaw; James C. Smith; Philip Zegerman
• Keywords: DNA Replication; DNA-Binding Proteins; Xenopus laevis; 0303 health sciences; 03 medical and health sciences; RecQ Helicases; Chromosomal Proteins, Non-Histone; Animals; Cell Cycle Proteins; Blastula; Xenopus Proteins; Carrier Proteins

Regulating the MBT

It has been known for more than 30 years that a defined number of cell divisions in the frog embryo precede a crucial developmental event called the midblastula transition (MBT).

Collart et al.

(p. 893 , published online 1 August) now elucidate a mechanism involved in the control of the MBT. DNA replication initiation factors are titrated out during early cell divisions, which controls the elongation of the cell cycle and the onset of zygotic transcription during the MBT.