1991 Fiscal Year Final Research Report Summary
Flexibility of initiation sites for DNA replication during animal embryogenesis
| Project/Area Number |
02804061
|
|---|
| Research Category |
Grant-in-Aid for General Scientific Research (C)
|
| Allocation Type | Single-year Grants |
|---|
| Research Field |
動物発生・生理学
|
|---|
| Research Institution | Tokyo University |
|---|
Principal Investigator |
SHIODA Masaki Tokyo University, Faculty of Medicine, Assistant, 医学部(医), 助手 (80134526)
|
|---|
| Project Period (FY) |
1990 – 1991
|
| Keywords | Xenopus laevis / Embryogenesis / Egg / Embryo / DNA replication / Initiation site / Initiator protein / Initiation of DNA replication |
|---|
| Research Abstract |
Initiation sites and initiator proteins for DNA replication was examined in a Xenopus egg cell-free DNA replication system. The system catalyzed DNA. replication with exogenous double-stranded DNA as templates in which efficiency of DNA replication depended of the species of DNA or restriction fragments of a DNA added. Insertion of a restriction fragment having high ability to initiate DNA replication into a DNA having little ability to initiate DNA replication made the DNA having high ability to initiate DNA replication. These results suggest that DNA replication initiates on specific sites of chromosomal DNA in this system. Analysis of initiation sites in-a DNA having high ability to initiate DNA replication showed. that the sites locate on DNA at interval of every 1-5 kilobases, thereby suggesting that specific DNA sequence with 5-6 bases may function as initiation sites for DNA replication.
On the other hand, we found that a protein with a molecular mass of about 60 kDa is required for initiation of DNA synthesis with double-stranded DNA templates in vitro. The protein showed a similar template-preference to that shown in the above cellfree DNA replication, to initiate DNA synthesis. Therefore, it is concluded that the protein functions as an initiator protein for DNA replication and determine the initiation sites in the present system.
|
