Effect of red light on the development and quality of mammalian embryos
Rong Li1, Kamilla Sofie Pedersen, Ying Liu
1Department of Animal Science, Aarhus University, Blichers Allé 20, DK-8830, Tjele, Denmark, Rong.Li2@agrsci.dk.
Purpose:
To assess irradiance and total energy dose from different microscopes during the in-vitro embryonic developmental cycle in mouse and pig and to evaluate its effect on embryonic development and quality in pig.
Method:
Spectral scalar irradiance (380-1050 nm) was measured by a fiber-optic microsensor in the focal plane of a dissection microscope, an inverted microscope and a time-lapse incubation system. Furthermore, the effect of three different red light levels was tested in the time-lapse system on mouse zygotes for 5 days, and on porcine zona-intact and zona-free parthenogenetically activated (PA) embryos for 6 days.
Results:
The time-lapse system used red light centered at 625 nm and with a lower irradiance level as compared to the white light irradiance levels on the dissection and inverted microscopes, which included more energetic radiation <550 nm. Even after 1000 times higher total energy dose of red light exposure in the time-lapse system, no significant difference was found neither in blastocyst development of mouse zygotes nor in blastocyst rates and total cell number of blastocysts of porcine PA embryos.
Conclusions:
Our results indicate that red light (625 nm, 0.34 W/m(2)) used in the time-lapse incubation system does not decrease the development and quality of blastocysts in both mouse zygotes and porcine PA embryos (both zona-intact and zona-free).
Insights
Red light used in time-lapse incubators does not harm mouse or pig embryo development. This study found no significant difference in blastocyst rates or quality, even with high doses of red light exposure.
Area of Science:
- Reproductive biology
- Embryology
- Microscopy
Background:
- Microscopes are essential tools in assisted reproductive technologies.
- Assessing the impact of light sources on embryo development is crucial for optimizing in-vitro fertilization (IVF) protocols.
Purpose of the Study:
- To measure light irradiance and energy dose from different microscopes during embryonic development.
- To evaluate the effect of red light exposure on mouse and pig embryo development and quality.
Main Methods:
- Spectral scalar irradiance was measured using a fiber-optic microsensor across various microscopes.
- Mouse zygotes and porcine embryos were exposed to different red light levels in a time-lapse system.
Main Results:
- Time-lapse systems utilize red light (625 nm) with lower irradiance than dissection and inverted microscopes.
- High total energy doses of red light did not significantly affect mouse blastocyst development or porcine embryo rates and cell numbers.
Conclusions:
- Red light (625 nm, 0.34 W/m²) in time-lapse incubators does not impair blastocyst development or quality in mouse and pig embryos.
- Current red light protocols in time-lapse systems are safe for early embryonic development.
