MESUT ÇEVİK, UĞUR ŞEN, ALPER KOÇYİĞİT, ERCAN SOYDAN, MEHMET KURAN

Effects of serum, gonadotropins, epidermal growth factor and estradiol 17-Beta on cumulus expansion and nuclear maturation of Bovine oocytes

Çalışmanın amacı, sığır ovaryumlarından elde edilen kumulus oosit komplekslerinin (KOK) nükleer olgunlaşma ve kumulus ekspansiyonu üzerine olgunlaşma medyumuna katılan folikül stimüle edici hormon (FSH), luteinleştirici hormon (LH), epidermal büyüme faktörü (EGF) ve östradiol 17-β (E2)’nin etkisini değerlendirmektir. KOK’lar oositlerin kumulus hücreleri ile kuşatılma derecesine göre iyi ve zayıf kaliteli olarak sınıflandırılmıştır. Sonrasında KOK’lar 24 saat süreyle TCM-199 medyumunda 38.5°C ve %5 $CO _2$’li ortamda olgunlaşmaya bırakılmıştır. Medyuma eklenen hormonların kompozisyonu şu şekildedir; T1=10% (v/v) inaktif Fötal Sığır Serumu (FBS); T2=5 μg/ml bLH, 0.5 μg/ml bFSH ve 10 ng/ml EGF; T3=FBS, bLH, bFSH ve EGF; T4=1 μg/ml E2; T5=FBS ve E2. Olgunlaşma medyumuna FBS hariç FSH, LH ve EGF eklenmesinin diğer muamele grupları ile karşılaştırıldığında kumulus ekspansiyonunu artırdığı görülmüştür (P

Anahtar Kelimeler:

metafaz, çekirdek, oosit olgunlaşması, yumurtalık follikülleri, oosit, yumurtalıklar, LH, sığır, sığır yetiştiriciliği, Grafiyan folikülleri, FSH, inek, kültür ortamı, kumulus ooforus, epidermal büyüme faktörü, östradiol, serum, gonadotropinler, in vitro kültür

Sığır oositlerinin kumulus ekspansiyonu ve nükleer maturasyon üzerine serum, gonadotropinler, epidermal büyüme faktörü ve östradiol 17-Beta’nın etkileri

The aim of the study was to evaluate the effects of follicle stimulating hormone (FSH), luteinizing hormone (LH), epidermal growth factor (EGF) and estradiol 17-β (E2) in maturation medium on nuclear maturation and cumulus expansion of cumulus-oocyte complexes (COCs) obtained from bovine ovaries. COCs were classified as good and poor quality grades based on cumulus investment. COCs were then subjected to in vitro maturation in TCM-199 in a humidified atmosphere of 5% $CO _2$ in air at 38.5°C for a period of 24 h. The combination of the hormones added to the medium was as follows: T1=10% (v/v) heat inactivated Fetal Bovine Serum (FBS); T2=5 μg/ml bLH, 0.5 μg/ml bFSH and 10 ng/ml EGF; T3=FBS, bLH, bFSH and EGF; T4=1 μg/ml E2; T5=FBS and E2. Supplementation of maturation medium with the FSH, LH, EGF irrespective to supplementation with FBS stimulated expansion of cumulus around the oocytes compared to oocytes in other treatment groups (P<0.05). However there were no significant differences between treatment groups in terms of proportion of oocytes reached to metaphase II (M II) stage determined by nuclear staining. In general cumulus expansion degree increased with the quality of COCs in all treatment groups (P<0.05). In conclusion, hormone and growth factor supplementation (FSH, LH and EGF) stimulated cumulus cell expansion and maturation rate.

Keywords:

metaphase, nuclei, oocyte maturation, ovarian follicles, oocytes, ovaries, LH, cattle, cattle farming, Graafian follicles, FSH, cows, culture media, cumulus oophorus, epidermal growth factor, estradiol, serum, gonadotropins, in vitro culture,

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