Effect of Sericin Supplementation in Collection Medium on Bovine Oocyte Nuclear Maturation

Abstract

Sericin is a water-soluble globular protein derived from silkworm Bombyx mori and has the competency as an antioxidant. This study was conducted to examine the effect of sericin supplementation in the collection medium on bovine oocyte nuclear maturation. Sericin with different concentration (0 (control), 0.1 %, 0.5 %, and 1%) was added to collection medium and maturated for 24 hour at 38.5 °C in 5% of CO2 air. Matured oocytes were stained with acetic-orcein and determined the oocyte nuclear stage under a stereomicroscope. After in vitro maturation, 74-87% of oocytes were reached nuclear maturation (metaphase II). The maturation rates of oocytes were significantly higher at 0.1% group (87.7%) (P<0.05) compared to other groups. There was no significant differences were observed between control group (74.6%), 0.5% group (79.4%), and 1% group (78.3%) (P>0.05). These findings showed that supplementation of 0.1% sericin in the collection medium improved the nuclear maturation of bovine oocytes.