Successful production of buffalo embryos from vitrified immature and mature oocytes in vitro

Abstract EN

The current study was conducted to produce buffalo embryos in vitro from vitrified immature and mature oocytes.

Cumulus oocytes complexes (COCs) were obtained from ovaries which collected from a local abattoir.

Good quality COCs (immature oocytes) were vitrified immediately after collection.

After 22-24 hours of COCs culture, mature oocytes were vitrified similarly.

All oocytes (immature and mature) were exposed to verification solution of different concentrations (glycerol : 3.3, 6.6 and 10 %) at 5, 5 and 10 minutes intervals respectively.

The oocytes were finally placed in 10 % glycerol and immediately loaded in 0.25 ml plastic straws, each containing 100 µl of 10 % sucrose in Modified phosphate buffer saline (M-PBS).

The straws were stored in liquid nitrogen for 4-6 months.

The straws were thawed in water at 37˚C for 30 seconds.

After thawing immature oocytes have been exposed to further maturation for 22-24 h.

mature oocytes were fertilized with frozen-thawed semen capacitated in modified fertilization TALP medium.

After insemination, the oocytes were cultured for 6-7 days and the frequency of morale and/or blastocyst was recorded.

Data analysis revealed that, the proportion of buffalo oocytes found to be normal after verification-thawing procedures was significantly different between immature and mature oocytes (55.4% and 70.6% respectively) and a significantly higher (p 0.05 ) percentage of embryos development (morale an blastocyst) was derived from vitrified mature buffalo oocytes than those obtained from immature ones ( 10.3 % Vs 2.6%).