Chaperonin 10 in the rat oocytes and early embryos: its expression and activity for early pregnancy factor.
OBJECTIVE
The aim of this study was to investigate the expression of chaperonin (cpn) 10 and cpn 60 mRNA in oocytes or embryos, and to further explore the possibility that early pregnancy factor (EPF) is identical with cpn 10.


METHODS
The expressions of cpn 10 and cpn 60 mRNA in oocytes and embryos at the different stages (1-cell, 2-cell, 8-cell, and morula) were examined by polymerase chain reaction techniques. The EPF activity of native rat cpn 10 isolated from rat livers was evaluated by the rosette inhibition test.


RESULTS
Similar levels of mRNA of cpn 10 and cpn 60 were detected in oocytes and embryos at every stage. There were no detectable EPF activities in the native cpn 10. Immunoprecipitation using polyclonal antibodies against cpn 10 did not affect the activity of EPF in the pregnant rat serum.


CONCLUSIONS
Our results do not support the hypothesis that cpn 10 is identical with EPF.
Kawamura
K
K
Department of Obstetrics and Gynecology, Akita University School of Medicine, Japan. kawamurak@obgyn.akita-u.ac.jp
Fukuda
J
J
Itoh
H
H
Ito
K
K
Kodama
H
H
Kumagai
J
J
Kumagai
A
A
Tanaka
T
T
D000818:Animals; D000918:Antibody Specificity; D001483:Base Sequence; D018835:Chaperonin 10 / Q000235:genetics* / Q000276:immunology; D018834:Chaperonin 60 / Q000235:genetics; D002970:Cleavage Stage, Ovum / Q000378:metabolism*; D017931:DNA Primers / Q000235:genetics; D005260:Female; D015870:Gene Expression; D009028:Morula / Q000378:metabolism; D009500:Neutralization Tests; D009865:Oocytes / Q000378:metabolism*; D010455:Peptides / Q000235:genetics*; D011247:Pregnancy; D011257:Pregnancy Proteins; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012397:Rosette Formation; D013491:Suppressor Factors, Immunologic
D018835:Chaperonin 10; D018834:Chaperonin 60; D017931:DNA Primers; D010455:Peptides; D011257:Pregnancy Proteins; D012333:RNA, Messenger; D013491:Suppressor Factors, Immunologic; C025124:early pregnancy factor