2005 Fiscal Year Final Research Report Summary
Research for the Cellular RNA Elongation in Mouse Fertilized Egg
| Project/Area Number |
15370005
|
|---|
| Research Category |
Grant-in-Aid for Scientific Research (B)
|
| Allocation Type | Single-year Grants |
|---|
| Section | 一般 |
|---|
| Research Field |
Genetics/Genome dynamics
|
|---|
| Research Institution | School of Medicine, Tokai University |
|---|
Principal Investigator |
KIMURA Minoru Tokai University, School of Medicine, Professor, 医学部, 教授 (10146706)
|
|---|
| Co-Investigator(Kenkyū-buntansha) |
SAKURAI Takayuki Shinshu University, School of Medicine, Assistant Professor, 医学部, 講師 (80317825)
|
|---|
| Project Period (FY) |
2003 – 2005
|
| Keywords | mouse / embryo / gene expression / maternal RNA / poly(A) |
|---|
| Research Abstract |
Polyadenylation of maternal RNAs in growing oocytes has been extensively analyzed in Xenopus and mouse. It seems to be important for translation of them. Recently, we found that SSEC-D (stage specific expressed clone-D, now Bri3) is expressed in mouse oocytes and it is supposed to be polyadenytlated after fertilization in fertilized egg. In additon to SSEC-D, Spin, -catenin, Ptp4a1, and Maid have been found to exhibit de novo independent polyadenylation after fertilization.
To obtain an overall picture of post-fertilization polyadenylation events, we developed a novel method for constructing murine fertilized egg cDNA library enriched with cDNAs exhibiting de novo independent polyadenylation. As a pilot study, we isolated at least four new maternal mRNAs exhibiting extension of poly(A) tail in fertilized 1-cell eggs. This is the first report of successful construction of a cDNA library enriched with newly polyadenylated maternal mRNAs derived from post-fertilized mouse eggs.
Next, we performed RNA blot analysis to examine the elongation in maternal RNAs using 20 representative cDNA clones isolated from the library as probes. Various patterns of elongation, shortening, and/or degradation of maternal RNAs were observed from fully grown oocytes to early 2-cell embryos and could be roughly classified into three types and seven subtypes. These findings indicate that poly(A) elongation and shortening of maternal RNAs are not restricted to certain types of maternal RNAs but occur in many of them, and suggest a complex mechanism governing modification of the 3' end of maternal RNAs during the oocyte-to-embryo transition.
|
