A study team, chaired by ZHU Zuoyan, an academician and research fellow at Institute of Hydrobiology, Chinese Academy of Sciences, discovered for the first time in the world new evidence telling the cytoplasm impacts on the growth of cloned fish at a molecular level. The finding confirms the fact that the recipient egg cytoplasm exercises a noticeable control over the development and morphogenesis of cloned fish.
The study team made an intraspecies cloning, and harvested seven cross-genus fish from 501 operating eggs, through transferring nuclei from transgenic common carp into enucleated eggs of goldfish. The cloned fish are phenotypically identical to their nuclear donors, rather than to goldfish. Both PCR testing and comparative analysis of DNA and RAPD confirm the fact that the nuclei genomes of cloned fish are exclusively derived from the nuclear donor species, or common carp. Meanwhile, one can find the co-existence of mitochondrial DNA from both the donor and recipient species in a cloned fetus, though before the blood circulation phase. However, the donor carp?痵 mitochondrial DNA would gradually disappear during the development of nuclear transfer (NT) embryos. As a result, of the seven cloned fish, six have a vertebral number between 26 and 28, and the rest at 31. Normally, a common carp has a vertebral number between 33 and 36, with goldfish between 26 and 28. Experimental data demonstrate that the recipient egg cytoplasm plays an important role in both development and morphogenesis of a cloned fish. The finding produces a new evidence for cytoplasm impacts on the growth of cloned fish at a molecular level, which is of important scientific and social significance. The finding was published in the latest March issue of journal Biology of Reproduction. |
