[In vitro maturation of agoutis (Dasyprocta prymnolopha) oocytes followed by in vitro fertilization and parthenogenetic activation]

ABSTRACT The objective was to evaluate IVM protocols for agouti oocytes, followed by in vitro fertilization (IVF) and parthenogenetic activation (PA). The immature oocytes (CCOs) were obtained by slicing the ovary after OSH and submitted to three groups: MAT - 16 (16 hours maturation), MAT - 20 (20 hours maturation) and MAT - (24 hours maturation), in a culture incubator at 38.8°C, with an atmosphere of 5% CO2 and 95% relative humidity. The maturation was analyzed by the presence of the first polar corpuscle. Then, mature CCOs were submitted to IVF, with co-incubation period of CCOs and spermatozoa from 15h to 38.8°C and 5% of CO2, and PA with inomycin. The IVM groups were analyzed using the chi-square test and in the FIV and PA experiment the rate of cleavage and the rate of embryonic development were analyzed. Statistical analysis was performed using the SAS program. There was a significant difference between the maturation groups, and the MAT - 20 and MAT - 24 groups showed a higher percentage of matured oocytes in vitro. The rates of cleavage and embryonic development were 8.6% and 2.9%, respectively in FIV and 63.6% and 15.1% in PA. However, in both cases the embryo did not pass beyond the morula stage.

摘要 本研究旨在评估刺豚鼠卵母细胞的体外成熟（in vitro maturation, IVM）方案，并开展后续的体外受精（in vitro fertilization, IVF）与孤雌激活（parthenogenetic activation, PA）实验。研究人员在OSH术后通过卵巢切片法获取未成熟卵丘-卵母细胞复合体（cumulus-oocyte complexes, CCOs），将其分为三组：成熟16小时组（MAT-16）、成熟20小时组（MAT-20）与成熟24小时组（MAT-24），于38.8℃、5%CO₂及95%相对湿度的培养箱中培养。通过第一极体的存在情况判定卵母细胞成熟状态。随后将成熟的CCOs分别进行IVF与PA实验：IVF组将CCOs与精子共孵育15小时，培养条件为38.8℃与5%CO₂；PA实验则采用伊屋诺霉素（inomycin）进行激活处理。采用卡方检验（chi-square test）对各组IVM效果进行分析，在FIV与PA实验中分别统计卵裂率与胚胎发育率，统计分析使用SAS统计软件完成。结果显示，不同成熟时长组的卵母细胞体外成熟率存在显著差异，其中MAT-20组与MAT-24组的成熟卵母细胞占比更高。FIV组的卵裂率与胚胎发育率分别为8.6%与2.9%，PA组则分别为63.6%与15.1%。但两组的胚胎发育均未突破桑椹胚（morula stage）阶段。