Publication: The kinetics of donor cell mtDNA in embryonic and somatic donor cell-derived bovine embryos
Loading...
Date
Advisor
Coadvisor
Graduate program
Undergraduate course
Journal Title
Journal ISSN
Volume Title
Publisher
Mary Ann Liebert, Inc.
Type
Article
Access right
Acesso aberto
Abstract
The mechanisms controlling the outcome of donor cell-derived mitochondrial DNA (mtDNA) in cloned animals remain largely unknown. This research was designed to investigate the kinetics of somatic and embryonic mtDNA in reconstructed bovine embryos during preimplantation development, as well as in cloned animals. The experiment involved two different procedures of embryo reconstruction and their evaluation at five distinct phases of embryo development to measure the proportion of donor cell mtDNA (Bos indicus), as well as the segregation of this mtDNA during cleavage. The ratio of donor cell (B. indicus) to host oocyte (B. taurus) mtDNA (heteroplasmy) from blastomere- (NT-B) and fibroblast- (NT-F) reconstructed embryos was estimated using an allele-specific PCR with fluorochrome-stained specific primers in each sampled blastomere, in whole blastocysts, and in the tissues of a fibroblast-derived newborn clone. NT-B zygotes and blastocysts show similar levels of heteroplasmy (11.0% and 14.0%, respectively), despite a significant decrease at the 9-16 cell stage (5.8%; p < 0.05). Heteroplasmy levels in NT-F reconstructed zygotes, however, increased from an initial low level (4.7%), to 12.9% (p < 0.05) at the 9-16 cell stage. The NT-F blastocysts contained low levels of heteroplasmy (2.2%) and no somatic-derived mtDNA was detected in the gametes or the tissues of the newborn calf cloned. These results suggest that, in contrast to the mtDNA of blastomeres, that of somatic cells either undergoes replication or escapes degradation during cleavage, although it is degraded later after the blastocyst stage or lost during somatic development, as revealed by the lack of donor cell mtDNA at birth.
Description
Keywords
Language
English
Citation
Cloning and Stem Cells. New Rochelle: Mary Ann Liebert Inc., v. 9, n. 4, p. 618-629, 2007.
