Light intensity and wavelength during embryo manipulation are important factors for maintaining viability of preimplantation embryos in vitro.
OBJECTIVE
To optimize embryo culture system by evaluating lighting effect during in vitro manipulation.


METHODS
Randomized prospective study using an animal model.


METHODS
Gamete and Stem Cell Biotechnology Laboratory at Seoul National University in Korea.


METHODS
Twelve- to 15-week-old hamsters (Mesocricetus auratus).


METHODS
Two-cell embryos were manipulated in vitro under lighting of different intensities and wavelengths.


METHODS
Preimplantation development, Hsp70 expression, reactive oxygen species (ROS) generation, and blastomere apoptosis.


RESULTS
A significant increase in morula and blastocyst formation was detected at 200 lux compared with 900 lux visible ray lighting, but not compared with 500 lux. At 200-lux lighting, red (620-750 nm) ray yielded the best development, whereas blue (445-500 nm) decreased blastocyst formation. Compared with the visible ray, Hsp70 expression and ROS generation in morula were increased in the blue ray but decreased in the red ray lighting. The blue ray also reduced blastocyst quality with increasing blastomere apoptosis.


CONCLUSIONS
Specific wavelength of visible ray increases Hsp70 expression, ROS generation, and blastomere apoptosis. Therefore, removing this stress factor improves embryo development.
Oh
Seo Jin
SJ
Gamete and Stem Cell Biotechnology Laboratory, Seoul National University, Seoul, Korea.
Gong
Seung Pyo
SP
Lee
Seung Tae
ST
Lee
Eun Ju
EJ
Lim
Jeong Mook
JM
D000818:Animals; D001483:Base Sequence; D001755:Blastocyst / Q000502:physiology* / Q000528:radiation effects*; D002470:Cell Survival / Q000502:physiology / Q000528:radiation effects; D006224:Cricetinae; D004624:Embryo Transfer; D047108:Embryonic Development / Q000502:physiology / Q000528:radiation effects; D005260:Female; D008027:Light; D008297:Male; D008969:Molecular Sequence Data; D011247:Pregnancy; D011446:Prospective Studies; D011897:Random Allocation