Transformation of ram sperm nuclei in oocytes cytoplasm during in vitro fertilization

Abstract

ABSTRAKTujuan penelitian ini adalah untuk memahami transformasi inti sperma domba di dalam sitoplasma oosit saat fertilisasi secara in vitro. Oosit didapatkan dari rumah potong hewan. Sebelum fertilisasi, oosit dimatangkan secara in vitro selama 24 jam. Oosit (n= 635) kemudian difertilisasi dengan sperma (5x10 6 spermatozoa/ ml) dalam inkubator dengan 5% CO 2 pada 38.5°C. Proses inkubasi dilakukan selama 3, 6, 9, 12, dan 15 jam untuk setiap perlakuan. Setelah fertilisasi selesai, oosit difiksasi dan diwarnai dengan aceto-orcein 2% sebelum dievaluasi dengan mikroskop fase kontras. Transformasi inti sperma dievaluasi sesuai dengan status inti dari sperma, seperti kondensasi, dekondensasi, dan pembentukan prepronukleus dan pronukleus. Kondensasi dan dekondensasi sperma terlihat pada tiga jam setelah inkubasi sperma dengan oosit. Enam jam setelah inkubasi ditemukan prepronukelus dan pronukelus. Pronukleus mulai terbentuk pada enam jam setelah inkubasi dan secara nyata meningkat pada sembilan jam setelah inkubasi (P<0.05). Kejadian polispermia mengalami peningkatan secara signifikan pada 12-15 jam setelah interaksi sperma dengan oosit (P<0.05). Disimpulkan bahwa penetrasi sperma ke dalam sitoplasma oosit sudah terjadi pada tiga jam periode fertilisasi. Pronukleus sudah terbentuk pada 6 jam setelah inkubasi dan kejadian polispermia meningkat seiring dengan bertambahnya waktu fertilisasi.Kata kunci: domba, fertilisasi in vitro, inti spermatozoa, transformasi . ABSTRACTThe aim of present study was to understand the transformation of ram sperm nuclei within oocyte cytoplasm during in vitro fertilization. The oocytes were collected from slaughterhouse ovaries. Before fertilization, the oocytes were maturated in vitro for 24 hours in the incubator with 5% CO 2 at 38.5°C. Then the oocytes (n= 635) was fertilized by incubating the oocytes with sperm (5x10 6 spermatozoa/ ml) for 3, 6, 9, 12, and 15 hours. At the end of incubating period, the oocytes were fixed and stained with aceto-orcein 2% before evaluated under phase contrast microscope. Sperm nuclear transformation was evaluated according to sperm nuclear status of sperm, such as condensation, decondensation, and formation of prepronuclei and pronuclei. Sperm condensation and decondensation were seen at 3 hours after incubation. Prepronuclei and pronuclei were found at 6 hours of incubation. Pronuclei formation was significantly increased in the 9 hours after incubation (P<0.05). The incidence of polyspermia was significantly increased at 12-15 hours after incubation (P<0.05). In conclusion penetration of sperm into oocytes has been occurred at 3 hour of fertilization period. The formation of pronuclei was found at 6 hours after incubation and the incidence of polyspermia was increased when the fertilization period 146