In vitro maturation of dromedary she-camel oocytes exposed to laser irradiation

Abstract EN

The objective of this study was to study the effect of laser irradiation on maturation rate of dromedary she-camel oocytes.

Although in vitro fertilization (IVF) technique in she-camel has been established, but maturation rate of camel oocytes is still low comparing with other animal species.

Several studies performed to improve in-vitro maturation rate using different types of media with different incubation times.

In order to establish high sensitive and low cost maturation improvement technique, laser irradiation has been suggested in the present work.

Cumulus oocytes complexes (COCʼs) were collected from ovaries by aspiration method and grade (A) oocytes were chosen and divided into five different groups, 62 oocytes served as control group, an un-irradiated (group 1), 64 oocytes exposed to 2 minutes of laser irradiation (group 2), 57 oocytes exposed to 3 minutes of laser irradiation (group 3), 49 oocytes exposed to 4 minutes of laser irradiation (group 4) and 52 oocytes exposed to 5 minutes of laser irradiation (group 5) with a total output power of 3 mW for different exposure durations; 2, 3, 4 and 5 minutes.

Afterwards, oocytes were matured in TCM-199 medium at 38.5oC and 5% CO2 in humidified air for 42 h.

Maturation rate was calculated based on expulsion of the first polar body and statistically analyzed by one way ANOVA test.

The obtained results showed that, the oocytes reached germinal vesicles (GV) which exposed to laser beam for 5 minutes at 488 nm wavelength represent significantly (P<0.05) the highest value (42.31% ) compared to control (not irradiated, 16.13% ).

However, other groups of GV showed insignificant differences with the control group.

The metaphase II (M II) in the control oocytes represents significantly (P<0.05) the highest value (75.81% ) compared to 3-5 minutes exposed groups.

The degenerated oocytes exposed to laser beam for 5 minutes at 488 nm wavelength represent significantly (P<0.05) the highest value (40.38% ) compared to control (not irradiated, 8.06% ).

In conclusion‚ these results indicated that the exposure of laser irradiation for 2 minutes may improve in-vitro nuclear maturation of immature oocytes in dromedary she-camels as compared to other durations (3-5 minutes) at 488 nm wavelength (blue laser).