Aberrant expression of developmentally important signaling molecules in cloned porcine extraembryonic tissues.
Early embryonic losses are common in cloned embryos in the current cloning system. However, the reasons for embryonic losses in early developmental stages of cloned embryos remain unclear. To elucidate the cause of early defective development in cloned embryos, two porcine clones including extraembryonic tissues were obtained at 26 days of gestation. The expression of various molecules in developmentally important signaling pathways, including Notch, hedgehog (Hh), receptor tyrosine kinase (RTK), Janus kinase/signal transducer and activator of transcription (JAK/STAT), wingless related (Wnt), and transforming growth factor-beta (TGF-beta), was then examined in the extraembryonic tissues. Western blot analysis showed that the expression of key molecules involved in the Notch, Hh, RTK, and JAK/STAT signaling pathways was downregulated, whereas most Wnt and TGF-beta signaling pathway molecules were upregulated in cloned extraembryonic tissues compared to normal extraembryonic tissues. These results indicate that unbalanced coordination of signaling pathways might impair the early development of cloned embryos postimplantation, thereby resulting in embryonic losses during the first trimester.
Center for Regenerative Medicine, KRIBB, Daejeon, Korea.
Jung-Il
JI
Chae
Kweon
K
Yu
Seong-Keun
SK
Cho
Jin-Hoi
JH
Kim
Deog-Bon
DB
Koo
Kyung-Kwang
KK
Lee
Yong-Mahn
YM
Han
D000818:Animals; D019976:Cloning, Organism; D020964:Embryo Loss / Q000235:genetics*; D004622:Embryo, Mammalian / Q000002:abnormalities; D005321:Extraembryonic Membranes / Q000378:metabolism*; D018507:Gene Expression Regulation, Developmental; D005865:Gestational Age; D053823:Hedgehog Proteins / Q000378:metabolism; D053612:Janus Kinases / Q000378:metabolism; D008954:Models, Biological; D051880:Receptors, Notch / Q000378:metabolism; D050791:STAT Transcription Factors / Q000378:metabolism; D015398:Signal Transduction / Q000235:genetics; D034421:Sus scrofa; D016212:Transforming Growth Factor beta / Q000378:metabolism; D051153:Wnt Proteins / Q000378:metabolism
D053823:Hedgehog Proteins; D051880:Receptors, Notch; D050791:STAT Transcription Factors; D016212:Transforming Growth Factor beta; D051153:Wnt Proteins; D053612:Janus Kinases