The Influence of Nuclear Content on Developmental Competence of Gaur × Cattle Hybrid In Vitro Fertilized and Somatic Cell Nuclear Transfer Embryos

• Published in: Biology of reproduction Vol. 76; no. 3; pp. 514 - 523
• Main Authors: MASTROMONACO, Gabriela F, FAVETTA, Laura A, SMITH, Lawrence C, FILION, France, KING, W. Allan
• Format: Journal Article
• Language: English
• Published: Madison, WI Society for the Study of Reproduction 01-03-2007
• Subjects: Biological and medical sciences; Birth control; Gynecology. Andrology. Obstetrics; Medical sciences; Sterility. Assisted procreation; Embryonic development; assisted reproductive technology; Cell nucleus; Assisted procreation; Ox; embryo; Nucleocytoplasmic interaction; Gene expression; Fecundation; In vitro; Vertebrata; Mammalia; Interspecific hybridization; Transfer; in vitro fertilization; Artiodactyla; Ungulata
• ISSN: 0006-3363; 1529-7268
• DOI: 10.1095/biolreprod.106.058040

In nondomestic and endangered species, the use of domestic animal oocytes as recipients for exotic donor nuclei causes the
normal pattern of cytoplasmic inheritance to be disrupted, resulting in the production of nuclear-cytoplasmic hybrids. Evidence
suggests that conflict between nuclear and cytoplasmic control elements leads to a disruption of normal cellular processes,
including metabolic function and cell division. This study investigated the effects of nuclear-cytoplasmic interactions on
the developmental potential of interspecies embryos produced by in vitro fertilization and somatic cell nuclear transfer:
cattle × cattle, gaur × cattle, hybrid × cattle. Cattle control and hybrid embryos were examined for development to the blastocyst
stage and blastocyst quality, as determined by cell number and allocation, apoptosis incidence, and expression patterns of
mitochondria-related genes. These analyses demonstrated that a 100% gaur nucleus within a domestic cattle cytoplasmic environment
was not properly capable of directing embryo development in the later preimplantation stages. Poor blastocyst development
accompanied by developmental delay, decreased cell numbers, and aberrant apoptotic and related gene expression profiles, all
signs of disrupted cellular processes associated with mitochondrial function, were observed. Developmental potential was improved
when at least a portion of the nuclear genome corresponded to the inherited cytoplasm, indicating that recognition of cytoplasmic
components by the nucleus is crucial for proper cellular function and embryo development. A better understanding of the influence
of the cytoplasmic environment on embryonic processes is necessary before interspecies somatic cell nuclear transfer can be
considered a viable alternative for endangered species conservation.