Functional analysis of lysosomes during mouse preimplantation embryo development.
Lysosomes are acidic and highly dynamic organelles that are essential for macromolecule degradation and many other cellular functions. However, little is known about lysosomal function during early embryogenesis. Here, we found that the number of lysosomes increased after fertilization. Lysosomes were abundant during mouse preimplantation development until the morula stage, but their numbers decreased slightly in blastocysts. Consistently, the protein expression level of mature cathepsins B and D was high from the one-cell to morula stages but low in the blastocyst stage. One-cell embryos injected with siRNAs targeted to both lysosome-associated membrane protein 1 and 2 (LAMP1 and LAMP2) were developmentally arrested at the two-cell stage. Pharmacological inhibition of lysosomes also caused developmental retardation, resulting in accumulation of lipofuscin. Our findings highlight the functional changes in lysosomes in mouse preimplantation embryos.
Laboratory Animal and Genome Sciences Section, National Institute of Radiological Sciences, Chiba 263-8555, Japan. s_tsuka@nirs.go.jp
Satoshi
S
Tsukamoto
Taichi
T
Hara
Atsushi
A
Yamamoto
Yuki
Y
Ohta
Ayako
A
Wada
Yuka
Y
Ishida
Seiji
S
Kito
Tetsu
T
Nishikawa
Naojiro
N
Minami
Ken
K
Sato
Toshiaki
T
Kokubo
D000818:Animals; D001755:Blastocyst / Q000502:physiology; D002401:Cathepsin B / Q000378:metabolism; D002402:Cathepsin D / Q000378:metabolism; D047108:Embryonic Development / Q000502:physiology*; D005260:Female; D005307:Fertilization in Vitro; D008062:Lipofuscin / Q000378:metabolism; D052118:Lysosomal-Associated Membrane Protein 1 / Q000378:metabolism; D052119:Lysosomal-Associated Membrane Protein 2 / Q000378:metabolism; D008247:Lysosomes / Q000378:metabolism / Q000502:physiology*; D051379:Mice; D008810:Mice, Inbred C57BL; D008854:Microscopy, Electron; D008856:Microscopy, Fluorescence; D009028:Morula / Q000502:physiology; D034741:RNA, Small Interfering / Q000378:metabolism
D008062:Lipofuscin; D052118:Lysosomal-Associated Membrane Protein 1; D052119:Lysosomal-Associated Membrane Protein 2; D034741:RNA, Small Interfering; D002401:Cathepsin B; D002402:Cathepsin D