Exposure of mouse cumulus cell nuclei to porcine ooplasmic extract eliminates TATA box protein binding to chromatin, but has no effect on DNA methylation.
OBJECTIVE
The low cloning efficiency with SCNT is due to incomplete or partial reprogramming of the donor somatic cell nuclei after microinjection into the enucleated oocyte. A possible solution may be to initiate nuclear reprogramming prior to SCNT.


METHODS
Pre-exposure of donor somatic cell nuclei to a novel porcine ooplasmic extract prior to microinjection could possibly extend the duration of exposure to ooplamic nuclear reprogramming factors. The effects of the porcine ooplamic extract on two major markers of nuclear preprogramming: (1) TATA box protein binding to chromation and (2) DNA methylation was investigated.


RESULTS
The results showed that pre-exposure of mouse cumulus cell nuclei to porcine ooplamic extract drastically reduced TATA box protein binding to chromatin, but had no effect on DNA methylation.


CONCLUSIONS
Pre-exposure to the porcine ooplasmic extract had some limited effects on nuclear reprogramming. Whether this can lead to enhanced cloning efficiency needs to be further investigated.
Tong
Guo Qing
GQ
Department of Obstetrics & Gynaecology, Yong Loo Lin School of Medicine, National University of Singapore, 5 Lower Kent Ridge Road, Singapore 119074, Singapore. denhenga@nus.edu.sg
Heng
Boon Chin
BC
Ng
Soon Chye
SC
D000818:Animals; D002467:Cell Nucleus / Q000502:physiology; D002843:Chromatin / Q000378:metabolism*; D019175:DNA Methylation; D005260:Female; D007150:Immunohistochemistry; D051379:Mice; D053652:Nuclear Transfer Techniques; D009865:Oocytes / Q000502:physiology*; D013552:Swine; D035181:TATA-Box Binding Protein / Q000378:metabolism*; D014020:Tissue Extracts / Q000494:pharmacology*
D002843:Chromatin; D035181:TATA-Box Binding Protein; D014020:Tissue Extracts