DEVELOPMENT OF OOCYTES FROM SYNCHRONIZED FOLLICLES OF EARLY PREPUBERTAL GOATS UNDER EXOTIC HORMONE CONTROL
SHA Hong Ying~1 SUN Jian Hua~2 CHEN Juan~(1,3) CHEN Jian Quan~(1,3) XU Xu Jun~(1,3) WU You Bin~3 HUANG Zhi Jun~3 HU Da Wei~3 CHENG Guo Xiang~(1,3*) (~1Schoal of Life Science and Technology,Tongji University,Shanghai 200092,China;~2East China Normal University,Shanghai 200062,China;~3Shanghai Transgenic Research Center,Shanghai 201203.China)
The aim of this study was to establish whether early prepubertal Sannen dairy goat could provide a large source of ova for SCNT.The effects of different hormonal treatments including untreated control,FSH alone,estadiol plus progesterone (E2-P4),and E2-P4 and FSH (E2-P4-FSH) on ovary size,follicle number and size were studied using the early prepubertal goats aged 39-60 days. Then prepubertal goats aged 39-120 days were categorized into three groups to study the effect of age on recruited follicle number.The meiotic competence of oocytes derived from≥3mm follicles recov- ered from the early prepubertal goats treated with E2-P4-FSH was compared with those treated with FSH alone.Finally,the development competence of the ova from the early goats treated with E2-P4- FSH was evaluated by SCNT. The E2-P4-FSH treatment produced the largest ovaries,the highest numbers of total follicles and follicles≥3mm diameter compared with the other treatments.The number of≥3mm follicles per goat treated with E2-P4-FSH was significantly higher for those in the age groups 39-60 days than those in the age groups 61-90 days and 91-120 days.The FSH alone treatment resulted in a lower proportion matured ova in vitro within 27 hr than from those goats treated with E2-P4-FSH.Ova de- rived from the early prepubetal goats resulted in lower rate of blastoeyst in SCNT (15.3% versus 22.1%, P0.01)than that of adult goat.However,the number of ova recovered per goat was substantially greater for the prepubertal goats (108±10.3 Versus 28±5.0).Consequently,the younger goats produced signifieantly more blastocyst(7.1±2.7 versus 4.2±1.4)per head.It was concluded that early pubertal goats treated with E2-P4-FSH could provide a relatively high number of developmentally competent o- va for SCNT studies.