title: Fluorescence-based visualization of autophagic activity predicts mouse embryo viability.
abstract: Embryo quality is a critical parameter in assisted reproductive technologies. Although embryo quality can be evaluated morphologically, embryo morphology does not correlate perfectly with embryo viability. To improve this, it is important to understand which molecular mechanisms are involved in embryo quality control. Autophagy is an evolutionarily conserved catabolic process in which cytoplasmic materials sequestered by autophagosomes are degraded in lysosomes. We previously demonstrated that autophagy is highly activated after fertilization and is essential for further embryonic development. Here, we developed a simple fluorescence-based method for visualizing autophagic activity in live mouse embryos. Our method is based on imaging of the fluorescence intensity of GFP-LC3, a versatile marker for autophagy, which is microinjected into the embryos. Using this method, we show that embryonic autophagic activity declines with advancing maternal age, probably due to a decline in the activity of lysosomal hydrolases. We also demonstrate that embryonic autophagic activity is associated with the developmental viability of the embryo. Our results suggest that embryonic autophagic activity can be utilized as a novel indicator of embryo quality.
authors.affiliation: Laboratory Animal and Genome Sciences Section, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba 263-8555, Japan.
authors.forename: Satoshi
authors.initials: S
authors.lastname: Tsukamoto
authors.affiliation: 1] Laboratory of Molecular Traffic, Institute for Molecular and Cellular Regulation, Gunma University, Maebashi, Gunma 371-8512, Japan [2].
authors.forename: Taichi
authors.initials: T
authors.lastname: Hara
authors.affiliation: 1] Laboratory Animal and Genome Sciences Section, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba 263-8555, Japan [2] Comprehensive Reproductive Medicine, Graduate School, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-ku, Tokyo 113-8519, Japan [3].
authors.forename: Atsushi
authors.initials: A
authors.lastname: Yamamoto
authors.affiliation: Laboratory Animal and Genome Sciences Section, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba 263-8555, Japan.
authors.forename: Seiji
authors.initials: S
authors.lastname: Kito
authors.affiliation: Laboratory of Reproductive Biology, Graduate School of Agriculture, Kyoto University, Kyoto 606-8502, Japan.
authors.forename: Naojiro
authors.initials: N
authors.lastname: Minami
authors.affiliation: Comprehensive Reproductive Medicine, Graduate School, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-ku, Tokyo 113-8519, Japan.
authors.forename: Toshiro
authors.initials: T
authors.lastname: Kubota
authors.affiliation: Laboratory of Molecular Traffic, Institute for Molecular and Cellular Regulation, Gunma University, Maebashi, Gunma 371-8512, Japan.
authors.forename: Ken
authors.initials: K
authors.lastname: Sato
authors.affiliation: Laboratory Animal and Genome Sciences Section, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba 263-8555, Japan.
authors.forename: Toshiaki
authors.initials: T
authors.lastname: Kokubo
mesh_terms: D000818:Animals; D001343:Autophagy / Q000502:physiology*; D003593:Cytoplasm / Q000378:metabolism / Q000502:physiology; D047108:Embryonic Development / Q000502:physiology*; D005260:Female; D005453:Fluorescence; D049452:Green Fluorescent Proteins / Q000378:metabolism*; D008247:Lysosomes / Q000378:metabolism / Q000502:physiology; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D008869:Microtubule-Associated Proteins / Q000378:metabolism; D010588:Phagosomes / Q000378:metabolism / Q000502:physiology; D013194:Staining and Labeling / Q000379:methods*
chemical_list: C480860:Map1lc3b protein, mouse; D008869:Microtubule-Associated Proteins; D049452:Green Fluorescent Proteins