This study was conducted to evaluate the effects of insulin and epidermal growth factor (EGF) in a in vitro growth (IVG) medium on oocyte growth, in vitro maturation (IVM) and embryonic development of pig oocytes derived from small antral follicles (SAF) less than 3 mm in diameter. SAF oocytes were cultured for 2 days to induce IVG in alpha-minimal essential medium supplemented with 1 mM dbcAMP and 15% (v/v) fetal bovine serum. After IVG culture, oocyte maturation was induced by culturing IVG oocytes in IVM medium for 44 h. IVM oocytes that extruded the first polar body were selected and induced for parthenogenesis (PA) by applying electric stimulus. SAF oocytes cultured under the insulin treatment showed a significantly increased (P < 0.05) nuclear maturation (73.8%) compared to those cultured with insulin and EGF (59.8%). After PA, the proportions of blastocysts based on the number of metaphase II oocytes were significantly higher (P < 0.05) in oocytes that were cultured for IVG with insulin, EGF, and insulin + EGF (32.4%, 35.2%, and 34.8%, respectively) than in control (22.9%). IVG oocytes treated with insulin showed an increased oocyte diameter (116.3 μm) compared to those treated with insulin and EGF (114.0 μm) (P < 0.05). Intra-oocyte GSH content significantly increased (1.07 pixels/oocyte) by insulin treatment during IVG compared to that of oocytes treated with insulin + EGF (0.78 pixels/oocyte). These results demonstrate that IVG culture of SAF oocytes under insulin or/and EGF treatment supports oocyte maturation and improves embryonic development to the blastocyst stage after PA in pigs.

본 연구에서는 도축장에서 분리된 Listeria monocytogenes를 저해할 수 있는 식물성 항균 물질을 탐색하고, 각 항균 물질의 최소살균농도(MBC)를 확인하였다. 잠재적인 항균 물질로 자몽종자 추출물, 감귤류 추출물, 생강 추출물, 배 추출물, 매실 농축액, 도라지 추출물, 대추 추출물, 오미자 추출물을 선정하였고, 대상 균주로는 국내 도축장에서 분리한 15 개의 L. monocytogenes 균주를 혼합하여 사용하였다. MBC 확인 결과, 최대 4.0 μg/mL 농도의 생강 추출물, 배 추출물, 매실 농축액, 도라지 추출물, 대추 추 출물, 오미자 추출물은 고농도의 L. monocytogenes (7 Log CFU/mL)에 대해 균 저해 효과가 전혀 나타나지 않았다. 반면, 7 Log CFU/mL의 L. monocytogenes에 대한 자몽종자 추출물과 감귤류 추출물의 MBC는 0.002 μg/mL인 것으로 확인되었다. 3 Log CFU/mL의 L. monocytogenes에 대한 MBC를 시험해 본 결과, 자몽종자 추출물과 감귤류 추출물의 MBC는 0.001 μg/mL로 나타났다. 이상의 결과로 볼 때 자몽종자 추출물과 감귤류 추출물은 L. monocytogenes를 제어하기 위해 적용될 수 있을 것으로 판단된다.

Crocin is a carotenoid that may protect cells against oxidative stress by scavenging free radicals particularly superoxide anions. It has been reported that oocyte maturation is influenced by the free radicals generated during in vitro culture (IVC) process. The objective of study was to examine the effect of crocin in in vitro maturation (IVM) medium as an antioxidant on oocyte maturation and embryonic development after parthenogenesis (PA). Cumulus-oocyte complexes (COCs) were collected from ovaries of prepubertal gilts. The basic medium for IVM was medium-199 containing 10% pig follicular fluid, cysteine, pyruvate, epidermal growth factor, kanamycin, insulin, and hormones. Oocytes were treated for 44 hours with crocin at 0, 25, 50, and 100 μg/ml during IVM. Oocytes reached the metaphase II stage were induced for PA and cultured for 7 days in porcine zygote medium-3. Nuclear maturation of oocytes was not influenced by various concentrations of crocin (89.0, 87.3, 84.3, and 94.1% for control, 25, 50, and 100 μg/ml crocin, respectively). IVM oocytes treated with 50 μg/ml crocin showed a higher (P<0.05) intraoocyte glutathione (GSH) contents than untreated oocytes (1.00 vs. 1.29 pixels/oocyte). Blastocyst formation of PA embryos treated with 50 (42.9%) and 100 μg/ml crocin (43.8%) was significantly higher (P<0.05) than oocytes treated with 25 μg/ml crocin (30.5%) but not different from that (35.2%) of untreated oocytes. In summary, crocin increases cytoplasmic maturation in terms of intraoocyte GSH content which may be beneficial for later embryonic development by protecting from harmful effect of reactive oxygen species. Further studies are needed to determine whether the beneficial effect of crocin treatment during IVC would be shown in embryonic development after in vitro fertilization and somatic cell nuclear transfer.

Crocin is a carotenoid that may protect cells against oxidative stress by scavenging free radicals particularly superoxide anions. It has been reported that oocyte maturation is influenced by the free radicals generated during in vitro culture (IVC) process. The objective of study was to examine the effect of crocin in in vitro maturation (IVM) medium as an antioxidant on oocyte maturation and embryonic development after parthenogenesis (PA). Cumulus-oocyte complexes (COCs) were collected from ovaries of prepubertal gilts. The basic medium for IVM was medium-199 containing 10% pig follicular fluid, cysteine, pyruvate, epidermal growth factor, kanamycin, insulin, and hormones. Oocytes were treated for 44 hours with crocin at 0, 25, 50, and 100 μg/ml during IVM. Oocytes reached the metaphase II stage were induced for PA and cultured for 7 days in porcine zygote medium-3. Nuclear maturation of oocytes was not influenced by various concentrations of crocin (89.0, 87.3, 84.3, and 94.1% for control, 25, 50, and 100 μg/ml crocin, respectively). IVM oocytes treated with 50 μg/ml crocin showed a higher (P<0.05) intraoocyte glutathione (GSH) contents than untreated oocytes (1.00 vs. 1.29 pixels/oocyte). Blastocyst formation of PA embryos treated with 50 (42.9%) and 100 μg/ml crocin (43.8%) was significantly higher (P<0.05) than oocytes treated with 25 μg/ml crocin (30.5%) but not different from that (35.2%) of untreated oocytes. In summary, crocin increases cytoplasmic maturation in terms of intraoocyte GSH content which may be beneficial for later embryonic development by protecting from harmful effect of reactive oxygen species. Further studies are needed to determine whether the beneficial effect of crocin treatment during IVC would be shown in embryonic development after in vitro fertilization and somatic cell nuclear transfer.