Microinjection of mitochondria into zygotes creates a model for studying the inheritance of mitochondrial DNA during preimplantation development.
OBJECTIVE
To determine the effect of mutant mitochondria on preimplantation embryo development and of preimplantation embryo development on the survival of mutant mitochondrial DNA.


METHODS
Laboratory research.


METHODS
Academic research laboratory.


METHODS
None.


METHODS
Mutant and wild-type mitochondria, fractionated from tissue obtained from a patient with MELAS syndrome, a mitochondrial disease, were microinjected into mouse zygotes. Control zygotes received either no injection or sham injection.


METHODS
Preimplantation embryo development and survival of mutant mitochondrial DNA as determined by polymerase chain reaction analysis.


RESULTS
After microinjection into zygotes, the MELAS mutation could be identified by polymerase chain reaction until the hatched blastocyst stage of embryo development. The survival of MELAS-injected zygotes, observed for 4 days after injection, did not differ from the survival of zygotes injected with wild-type mitochondria or from the survival of uninjected or sham-injected controls.


CONCLUSIONS
It appears that preimplantation embryo development does not screen out mitochondrial DNA mutations introduced into fertilized oocytes, and low levels of mutant mitochondrial DNA do not disrupt early embryo development.
Rinaudo
P
P
Department of Obstetrics and Gynecology, Yale University School of Medicine, New Haven, Connecticut, USA.
Niven-Fairchild
T
T
Buradagunta
S
S
Massobrio
M
M
Revelli
A
A
Keefe
D L
DL
D000818:Animals; D017931:DNA Primers; D004272:DNA, Mitochondrial / Q000235:genetics*; D047108:Embryonic Development; D005260:Female; D051379:Mice; D008815:Mice, Inbred Strains; D008845:Microinjections / Q000379:methods; D009154:Mutation; D016133:Polymerase Chain Reaction / Q000379:methods; D011247:Pregnancy; D015053:Zygote
D017931:DNA Primers; D004272:DNA, Mitochondrial