IMR Press / FBL / Volume 11 / Issue 2 / DOI: 10.2741/1932

Frontiers in Bioscience-Landmark (FBL) is published by IMR Press from Volume 26 Issue 5 (2021). Previous articles were published by another publisher on a subscription basis, and they are hosted by IMR Press on imrpress.com as a courtesy and upon agreement with Frontiers in Bioscience.

Open Access Article
Dynamic changes in NuMA and microtubules in monkey-rabbit nuclear transfer embryos
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1 State Key Laboratory of Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing 100080, China
2 Graduate School, Chinese Academy of Sciences, Beijing 100080, China
3 Center for Developmental Biology, Shanghai Second Medical University / Laboratory of Stem Cell Biology, Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, 1665 Kong Jiang Road, Shanghai 200092, China
4 College of Life Science, Shandong Normal University, Jinan 250014, China, 5 College of Life Science, Suzhou University, Suzhou 215006, China
Front. Biosci. (Landmark Ed) 2006, 11(2), 1892–1900; https://doi.org/10.2741/1932
Published: 1 May 2006
Abstract

Previous reports have indicated that failure in cloning monkey is attributed to the removal of nuclear mitotic apparatus (NuMA) during enucleation and subsequent abnormal organization of mitotic apparatus. This study investigated the transformation and assembly of tubulin and NuMA protein during the first cell cycle of cloned monkey embryos reconstructed by using enucleated rabbit oocytes as recipients. After the oocyte fused with a fibroblast, extensive microtubule organization was observed around the introduced nucleus in most reconstructed embryos, suggesting the introduction of a somatic cell centrosome. A high proportion of fibroblast nuclei transferred into non-activated oocytes underwent premature chromosome condensation (PCC), transient spindle organization and chromosomes separation, followed by the formation of two pronucleus-like structures. In contrast, fibroblast nuclei in pre-activated ooplasm rarely underwent PCC, but formed a swollen pronucleus-like structure. Normal spindles were observed in about one third of the cloned embryos reconstructed by both methods. After transferring monkey fibroblasts into NuMA-removed enucleated rabbit oocytes, NuMA was localized in pseudo-pronuclei and gradually moved to mitotic spindle poles at the first mitotic spindle poles. NuMA antibody microinjection resulted in spindle disorganization and chromosome misalignment, but did not significantly affect early cleavage. Our findings indicate that: 1. NuMA in donor monkey fibroblast may contribute to form a normal spindle in enucleated rabbit oocyte; 2. when non-activated cytoplasts and pre-activated cytoplasts are used as recipients, the donor nuclei undergo different morphological changes, but yield similar early embryo development; 3. although abnormal spindle organization and chromosome alignment may cause low efficiency of animal cloning, these abnormalities do not significantly affect early cleavage.

Keywords
Non-Human Primate
Somatic Cell Nuclear Transfer
First Cell Cycle
Nuclear Mitotic Apparatus Protein
Microtubule
Activation
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