Coexistence of Bos taurus and B. indicus mitochondrial DNAs in nuclear transfer-derived somatic cattle clones.
We investigated the mitochondrial DNA (mtDNA) composition in one of the largest adult somatic mammalian clones (n = 20) reported so far. The healthy cloned cattle were derived from nuclear transfer of an identical nuclear genetic background (mural granulosa donor cells including surrounding cytoplasm) into enucleated oocytes with either Bos indicus or B. taurus mtDNA. Here we report the first cases of coexisting mtDNAs of two closely related subspecies following nuclear transfer. Heteroplasmy (0.6-2.8%) was found in 4 out of 11 cross-subspecies cloned cattle. Quantitation was performed using "amplification refractory mutation system (ARMS) allele-specific real-time PCR." We determined that the ratio of donor cell to recipient cytoplast mtDNA copy number was 0.9% before nuclear transfer. Therefore, we concluded that the percentage of donor cell mtDNA in the heteroplasmic intersubspecific cloned animals is in accordance with neutral transmission of donor mtDNA. We determined an amino acid sequence divergence of up to 1.3% for the two subspecies-specific mtDNA haplotypes. In addition, intrasubspecific B. indicus heteroplasmy of approximately 1% (but up to 7.3 and 12.7% in muscle and follicular cells of one animal) was detected in 7 out of the 9 B. indicus intrasubspecific cloned cattle.
Steinborn
Ralf
R
Institute of Animal Breeding and Genetics, University of Veterinary Medicine, A-1210 Vienna, Austria. Ralf.Steinborn@vu-wien.ac.at
Schinogl
Pamela
P
Wells
David N
DN
Bergthaler
Andreas
A
Müller
Mathias
M
Brem
Gottfried
G
D000818:Animals; D002417:Cattle; D002467:Cell Nucleus / Q000235:genetics*; D019976:Cloning, Organism; D004272:DNA, Mitochondrial; D018628:Gene Dosage; D008928:Mitochondria / Q000235:genetics* / Q000378:metabolism; D008969:Molecular Sequence Data; D010802:Phylogeny
D004272:DNA, Mitochondrial