Imaging Mitochondrial Organization in Living Primate Oocytes and Embryos using Multiphoton Microscopy

Abstract

We employed multiphoton laser scanning microscopy (MPLSM) to image changes in mitochondrial distribution in living rhesus monkey embryos. This method of imaging does not impair development; thus, the same specimen can be visualized multiple times at various developmental stages. Not only does this increase the amount of information that can be gathered on a single specimen but it permits the correlation of early events with subsequent development in the same specimen. Here we demonstrate the utility of MPLSM for determining changes in mitochondrial organization at various developmental stages and show that rhesus zygotes possess a distinct accumulation of mitochondria between the pronuclei prior to syngamy. We present evidence that suggests that this pronuclear accumulation may be positively correlated with development to the blastocyst stage-in the same embryo-thereby illustrating how MPLSM can be used to correlate cellular dynamics of primate oocytes and early embryos with their developmental potential. Understanding the relationship between mitochondrial distribution and the subsequent development of mammalian embryos, particularly primates, will increase our ability to improve embryo culture technologies, including those used for human assisted reproduction.

Serotonin in pre-implantation mouse embryos is localized to the mitochondria and can modulate mitochondrial potential

“…This pattern may reflect a sub-stage following fertilization, where these puncta may be transiently located around fusing pronuclei. Mitochondria have been reported to localize around fusing pronuclei , Liu et al 2000, Van Blerkom et al 2002, Squirrell et al 2003, Acton et al 2004) similar to what we observed (Fig. 2).…”

Mitochondria in stem cells

“…Because of the continuum of development from fertilization through ES cells, it has been suggested that the mitochondrial characteristics of the pre-implantation embryo might have much in common with those of ES cells (Bavister, 2006). In several species, including hamster (Barnnett et al, 1996), mouse (Batten et al, 1987), monkey (Squirrell et al, 2003) and human (Wilding et al, 2001), the clustering of mitochondria around the pronuclei of fertilized oocytes and around the nuclei of cleaveage stage embryos ( Fig. 2) has led to the idea that a perinuclear arrangement of mitochondria might be a cellular marker for "stemness" (Lonergan et al, 2006).…”

Effect of blood plasma collected after adrenocorticotropic hormone administration during the preovulatory period in the sow on oocyte in vitro maturation

“…In agreement with this finding, the mitochondrial distribution under in vitro conditions differed from the in vivo situation [55]; relocation of mitochondria was altered by the exposure of porcine oocytes to polychlorinated biphenyls during maturation [53]. Using multiphoton laser scanning microscopy, it was found that the pronuclear accumulation of mitochondria may be positively correlated with development to the blastocyst stage in rhesus monkey embryos [56]. In our study, the different mitochondrial distribution pattern in the various treatment groups after IVM was not reflected by cleavage or blastocyst rates.…”