Interspecies Implantation and Mitochondria Fate of Panda-Rabbit Cloned Embryos

• Published in: Biology of reproduction Vol. 67; no. 2; pp. 637 - 642
• Main Authors: CHEN, Da-Yuan, WEN, Duan-Cheng, KOU, Zhao-Hui, WU, Yu-Qi, CHEN, Yu-Cun, WANG, Peng-Yan, ZHANG, He-Min, ZHANG, Ya-Ping, SUN, Qing-Yuan, HAN, Zhi-Ming, LIU, Zhong-Hua, PENG SHI, LI, Jin-Song, XIANGYU, Jing-Gong, LI LIAN
• Format: Journal Article
• Language: English
• Published: Madison, WI Society for the Study of Reproduction 01-08-2002
• Subjects: Abdominal Muscles - cytology; Abdominal Muscles - ultrastructure; Animals; Base Sequence; Biological and medical sciences; Cats; Cell Nucleus - ultrastructure; Cells, Cultured; Cloning, Organism - methods; DNA, Mitochondrial - metabolism; Embryo Implantation - physiology; Embryo Transfer; Embryology: invertebrates and vertebrates. Teratology; Embryonic and Fetal Development - physiology; Female; Fundamental and applied biological sciences. Psychology; Microsatellite Repeats; Mitochondria - metabolism; Molecular embryology; Molecular Sequence Data; Pregnancy; Rabbits; Ursidae - physiology; Animal cloning; Fissipedia; Carnivora; Embryo; Endangered species; Interspecific association; Rabbit; Lagomorpha; Pregnancy; Vertebrata; Mitochondria; Mammalia; Ovum implantation; Cat
• ISSN: 0006-3363; 1529-7268
• DOI: 10.1095/biolreprod67.2.637

Somatic cell nuclei of giant pandas can dedifferentiate in enucleated rabbit ooplasm, and the reconstructed eggs can develop
to blastocysts. In order to observe whether these interspecies cloned embryos can implant in the uterus of an animal other
than the panda, we transferred approximately 2300 panda-rabbit cloned embryos into 100 synchronized rabbit recipients, and
none became pregnant. In another approach, we cotransferred both panda-rabbit and cat-rabbit interspecies cloned embryos into
the oviducts of 21 cat recipients. Fourteen recipients exhibited estrus within 35 days; five recipients exhibited estrus 43–48
days after embryo transfer; and the other two recipients died of pneumonia, one of which was found to be pregnant with six
early fetuses when an autopsy was performed. Microsatellite DNA analysis of these early fetuses confirmed that two were from
giant panda-rabbit cloned embryos. The results demonstrated that panda-rabbit cloned embryos can implant in the uterus of
a third species, the domestic cat. By using mitochondrial-specific probes of panda and rabbit, we found that mitochondria
from both panda somatic cells and rabbit ooplasm coexisted in early blastocysts, but mitochondria from rabbit ooplasm decreased,
and those from panda donor cells dominated in early fetuses after implantation. Our results reveal that mitochondria from
donor cells may substitute those from recipient oocytes in postimplanted, interspecies cloned embryos.