Impairments in embryonic genome activation in rhesus monkey somatic cell nuclear transfer embryos.
Somatic cell nuclear transfer (SCNT) is a remarkable process in which a somatic cell nucleus is acted upon by the ooplasm via mechanisms that today remain unknown. Here we show the developmental competence (% blastocyst) of embryos derived from SCNT (21%) was markedly (p < 0.05) impaired compared with those derived from in vitro fertilization (IVF) (42.1%) in rhesus monkey. Also, SCNT embryos were abnormal in their time course of embryonic development. SCNT produced embryos reached the eight-cell stage faster than did IVF produced embryos. We compare the transcription patterns of five nucleolar-related proteins-nucleolin, nucleophosmin, fibrillarin, PAF53, and UBF-in single IVF and SCNT blastocysts by RT-PCR. The SCNT embryos showed abnormal gene transcription. Immunolocalization of fibrillarin was undetectable in 8-cell and 16-cell SCNT embryos, indicating embryonic genomic activation was delayed in monkey embryos produced by SCNT compared to their IVF-derived counterparts. Some of SCNT embryos appeared to relative higher developmental potential and fibrillarin expression by prolonged exposure of incoming nuclei to a cytoplasm. Thus, our data show that SCNT embryos are characterized by abnormal cleavage and the timely onset of embryonic genome transcription, deficits that may explain their reduced pre- and postimplantation developmental capacity.
Niu
Yuyu
Y
Kunming Primate Research Center & Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, Yunnan, People's Republic of China.
Yang
Shihua
S
Yu
Yang
Y
Ding
Chenhui
C
Yang
Jifeng
J
Wang
Shufen
S
Ji
Shaohui
S
He
Xiechao
X
Xie
Yunhua
Y
Tang
Xianghui
X
Zhou
Qi
Q
Ji
Weizhi
W
D000818:Animals; D004624:Embryo Transfer / Q000662:veterinary; D004622:Embryo, Mammalian; D047108:Embryonic Development / Q000235:genetics* / Q000502:physiology; D005260:Female; D005307:Fertilization in Vitro; D020869:Gene Expression Profiling; D018507:Gene Expression Regulation, Developmental; D016678:Genome; D008253:Macaca mulatta / Q000196:embryology / Q000235:genetics* / Q000502:physiology*; D053652:Nuclear Transfer Techniques / Q000662:veterinary*; D013997:Time Factors