Increased Th1/Th2 (IFN-gamma/IL-4) Cytokine mRNA ratio of rat embryos in the pregnant mouse uterus.
Somatic cell nuclei can be dedifferentiated in ooplasm from another species, and interspecies cloned embryos can be implanted into the uteri of surrogates. However, no full pregnancies have been achieved through interspecific mammalian cloning. Rat blastocysts transferred into mouse uteri provide a unique model for studying the causes of interspecific pregnancy failure. In this study, intraspecific pregnancy (mouse-mouse) and interspecific pregnancy (rat-mouse) models were established. On Day 9 of pregnancy, the fetoplacental units were separated from the uterine implantation sites and the expression of messenger (m)RNA was quantitated by real-time PCR. We compared the mRNA expression levels of type-1 T helper (Th1) and type-2 T helper (Th2) cytokines, interferon-gamma (IFN-gamma), and interleukin-4 (IL-4) in fetoplacental units between intraspecific and interspecific pregnancy groups. The mRNA expression of IFN-gamma in the fetoplacental units of the interspecific pregnancy group was significantly higher than that of the intraspecific pregnancy group (P<0.05). The mRNA expression of IL-4 in the interspecific pregnancy group was significantly lower than that in the intraspecific pregnancy group (P<0.05). We also analyzed the ratio of IFN-gamma/IL-4 mRNA, and an increased IFN-gamma/IL-4 mRNA ratio was observed in the interspecific pregnancy compared with that in the intraspecific pregnancy group. The IFN-gamma and IL-4 mRNA expressions indicate that there is a Th1/Th2 imbalance in the feto-maternal interface of interspecific pregnancies. Bias of Th1 cytokine dominance may be a barrier to reproductive success between species.
Nan
Chang-Long
CL
State Key Laboratory of Reproductive Biology, Institute of Zoology,Chinese Academy of Sciences, Beijing, PR China.
Lei
Zi-Li
ZL
Zhao
Zhen-Jun
ZJ
Shi
Li-Hong
LH
Ouyang
Ying-Chun
YC
Song
Xiang-Fen
XF
Sun
Qing-Yuan
QY
Chen
Da-Yuan
DY
D000818:Animals; D021461:Animals, Outbred Strains; D010064:Embryo Implantation; D004622:Embryo, Mammalian / Q000166:cytology / Q000502:physiology*; D005260:Female; D005786:Gene Expression Regulation; D007371:Interferon-gamma / Q000235:genetics*; D015847:Interleukin-4 / Q000235:genetics*; D008297:Male; D051379:Mice; D010920:Placenta / Q000502:physiology; D011247:Pregnancy; D011270:Pregnancy, Animal; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D013045:Species Specificity; D018417:Th1 Cells / Q000502:physiology*; D018418:Th2 Cells / Q000502:physiology*; D014599:Uterus / Q000502:physiology*
D012333:RNA, Messenger; D015847:Interleukin-4; D007371:Interferon-gamma