Lawrence Charles Smith

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Mitochondria play a key role in a number of physiological events during all stages of life, including the very first stages following fertilization. It is, therefore, important to understand the mechanisms controlling mitochondrial activity during early embryogenesis to determine their role in development outcome. The objective of this study was to(More)
Nuclear reprogramming requires the removal of epigenetic modifications imposed on the chromatin during cellular differentiation and division. The mammalian oocyte can reverse these alterations to a state of totipotency, allowing the production of viable cloned offspring from somatic cell nuclei. To determine whether nuclear reprogramming is complete in(More)
Due to the exclusively maternal inheritance of mitochondria, mitochondrial genotypes can be coupled to a particular nuclear genotype by continuous mating of founder females and their female offspring to males of the desired nuclear genotype. However, backcrossing is a gradual procedure that, apart from being lengthy, cannot ascertain that genetic and(More)
The domesticated horse represents substantial value for the related sports and recreational fields, and holds enormous potential as a model for a range of medical conditions commonly found in humans. Most notable of these are injuries to muscles, tendons, ligaments and joints. Induced pluripotent stem (iPS) cells have sparked tremendous hopes for future(More)
Mitochondrial genotypes have been shown to segregate both rapidly and slowly when transmitted to consecutive generations in mammals. Our objective was to develop an animal model to analyze the patterns of mammalian mitochondrial DNA (mtDNA) segregation and transmission in an intraspecific heteroplasmic maternal lineage to investigate the mechanisms(More)
Abnormal placental development limits success in ruminant pregnancies derived from somatic cell nuclear transfer (SCNT), due to reduction in placentome number and consequently, maternal/fetal exchange. In the primary stages of an epithelial-chorial association, the maternal/fetal interface is characterized by progressive endometrial invasion by specialized(More)
In contrast to nuclear inheritance, cytoplasmic inheritance in mammals is derived mostly, if not exclusively, from the maternal line. Mitochondria, and their DNA molecules (mtDNA), are the genetic units of this method of inheritance. Mammalian mtDNA codes for 13 enzymes used in the mitochondrial energy-generating pathway, oxidative phosphorylation, 22 tRNAs(More)
In vitro transfection of cultured cells combined with nuclear transfer currently is the most effective procedure to produce transgenic livestock. In the present study, bovine primary fetal fibroblasts were transfected with a green fluorescent protein (GFP)-reporter transgene and used as nuclear donor cells in oocyte reconstructions. Because cell(More)
It was hypothesized the lower fertility of repeat-breeder (RB) Holstein cows is associated with oocyte quality and this negative effect is enhanced during summer heat stress (HS). During the summer and the winter, heifers (H; n=36 and 34, respectively), peak-lactation (PL; n=37 and 32, respectively), and RB (n=36 and 31, respectively) Holstein cows were(More)
The extensive replication of mitochondria during oogenesis and the wide variability in mitochondrial DNA (mtDNA) copy numbers present in fully grown oocytes indicate that mtDNA amount may play an important role during early embryogenesis. Using bovine oocytes derived from follicles of different sizes to study the influence of mtDNA content on development,(More)