Noninvasive metabolic profiling of cumulus cells, oocytes, and embryos via fluorescence lifetime imaging microscopy: a mini-review.

A major challenge in ART is to select high-quality oocytes and embryos. The metabolism of oocytes and embryos has long been linked to their viability, suggesting the potential utility of metabolic measurements to aid in selection. Here, we review recent work on noninvasive metabolic imaging of cumulus cells, oocytes, and embryos.

Metabolic state of human blastocysts measured by fluorescence lifetime imaging microscopy.

Study Question: Can non-invasive metabolic imaging via fluorescence lifetime imaging microscopy (FLIM) detect variations in metabolic profiles between discarded human blastocysts?

Summary Answer: FLIM revealed extensive variations in the metabolic state of discarded human blastocysts associated with blastocyst development over 36 h, the day after fertilization and blastocyst developmental stage, as well as metabolic heterogeneity within individual blastocysts.

What Is Known Already: Mammalian embryos undergo large changes in metabolism over the course of preimplantation development. Embryo metabolism has long been linked to embryo viability, suggesting its potential utility in ART to aid in selecting high quality embryos.

Metabolic imaging via fluorescence lifetime imaging microscopy for egg and embryo assessment.

Current strategies for embryo assessment in the assisted reproductive technology laboratories rely primarily on morphologic parameters that have limited accuracy for determining embryo viability. Even with the addition of invasive diagnostic interventions such as preimplantation genetic testing for aneuploidy alone or in combination with mitochondrial DNA copy number assessment, at least one third of embryos fail to implant. Therefore, at a time when the clinical benefits of single ET are widely accepted, improving viability assessment of embryos is ever more important.

Metabolic imaging with the use of fluorescence lifetime imaging microscopy (FLIM) accurately detects mitochondrial dysfunction in mouse oocytes.

Objective: To determine whether metabolic imaging with the use of fluorescence lifetime imaging microscopy (FLIM) identifies metabolic differences between normal oocytes and those with metabolic dysfunction.

Design: Experimental study.

Setting: Academic research laboratories.

Determining physical principles of subcellular organization.

Recent advances have transformed our understanding of cell biology, but we are still unable to predict the behaviors of these systems. One difficulty is that we lack an understanding of the physical principles of subcellular organization. Combining quantitative experiments with new theoretical insights may allow such principles to be developed.