NuMA distribution and microtubule configuration in rabbit oocytes and cloned embryos.
The assembly of microtubules and the distribution of NuMA were analyzed in rabbit oocytes and early cloned embryos. Alpha-tubulin was localized around the periphery of the germinal vesicle (GV). After germinal vesicle breakdown (GVBD), multi-arrayed microtubules were found tightly associated with the condensed chromosomes and assembled into spindles. After the enucleated oocyte was fused with a fibroblast, microtubules were observed around the introduced nucleus in most reconstructed embryos and formed a transient spindle 2-4 h post-fusion (hpf). A mass of microtubules surrounded the swollen pseudo-pronucleus 5 hpf and a normal spindle was formed 13 hpf in cloned embryos. NuMAwas detected in the nucleus in germinal vesicle-stage oocytes, and it was concentrated at the spindle poles in both meiotic and mitotic metaphase. In both donor cell nucleus and enucleated oocyte cytoplasm, NuMA was not detected, while NuMA reappeared in pseudo-pronucleus as reconstructed embryo development proceeded. However, no evident NuMA staining was observed in the poles of transient spindle and first mitotic spindle in nuclear transfer eggs. These results indicate that NuMA localization and its spindle pole tethering function are different during rabbit oocyte meiosis and cloned embryo mitosis.
Yan
Li-Ying
LY
State Key Laboratory of Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, 25 Beisihuanxi Road, Haidian, Beijing 100080, China.
Huang
Jun-Cheng
JC
Zhu
Zi-Yu
ZY
Lei
Zi-Li
ZL
Shi
Li-Hong
LH
Nan
Chang-Long
CL
Zhao
Zhen-Jun
ZJ
Ouyang
Ying-Chun
YC
Song
Xiang-Fen
XF
Sun
Qing-Yuan
QY
Chen
Da-Yuan
DY
D000818:Animals; D002478:Cells, Cultured; D019976:Cloning, Organism; D004622:Embryo, Mammalian / Q000737:chemistry / Q000648:ultrastructure*; D005260:Female; D005307:Fertilization in Vitro; D008297:Male; D008540:Meiosis; D008677:Metaphase; D018613:Microscopy, Confocal; D008870:Microtubules / Q000648:ultrastructure*; D008938:Mitosis; D034521:Nuclear Matrix-Associated Proteins / Q000032:analysis*; D053652:Nuclear Transfer Techniques; D009865:Oocytes / Q000737:chemistry / Q000648:ultrastructure*; D011817:Rabbits; D008941:Spindle Apparatus / Q000648:ultrastructure; D014404:Tubulin / Q000648:ultrastructure
D034521:Nuclear Matrix-Associated Proteins; D014404:Tubulin