摘要
Oocyte quality is crucial for subsequent embryo development and so it is a major challenge in assisted reproductive technologies. The aim of the present work was to evaluate the morphometric parameters of oocytes (experiment 1) and the relative gene expression of oocytes and cumulus cells (CCs) (experiment 2) as biomarkers of oocyte quality after individually culturing them (one oocyte or embryo/drop). In experiment 1, individually matured oocytes were measured and classified into small, intermediate, and large oocytes after a cluster analysis, based on total diameter (with zona pellucida, ZP), oocyte diameter (without ZP), and ZP thickness. These oocytes were individually fertilized in vitro and cultured. The embryo development was evaluated up to the blastocyst stage. According to the total diameter, oocyte diameter, and ZP thickness, the blastocyst rate decreased in the small oocytes group (3.1 ± 3.1, 14.1 ± 9.4, and 26.7 ± 3.9, respectively) compared to the intermediate (29.4 ± 5.2, 30.5 ± 10.1, and 28.6 ± 9.6, respectively) and large oocytes groups (54.2 ± 13.5, 44.4 ± 3.9, and 67.6 ± 12.4, respectively). In addition, the probability of reaching the blastocyst stage was positively related to the total diameter (p < 0.001), oocyte diameter (p < 0.05), and ZP thickness (p < 0.001). Furthermore, the relative gene expression of BAX, BCL2, GDF9, and GJA1 was lower in oocytes classified as large. In experiment 2, the mRNA transcript relative abundance pattern of genes in CCs was evaluated according to oocyte total diameter and developmental stage reached. CCs from oocytes classified as large and oocytes capable of developing to the blastocyst stage had a lower relative expression of BAX, STAR, and PTGS2, while a higher expression of HAS2 and SDC2 transcript was observed for those oocytes. In conclusion, oocyte morphometric parameters and gene expression analysis in oocytes and CCs provide methods for the identification of the most competent oocytes for assisted reproductive technologies in sheep.
摘要译文
卵母细胞质量对于随后的胚胎发育至关重要，因此这是辅助生殖技术的主要挑战。本作本作的目的是评估卵母细胞（实验1）的形态测量参数和卵母细胞和巨粒细胞（CCS）（实验2）作为卵母细胞质量的生物标志物（一个卵母细胞或胚胎/）作为卵母细胞质量的生物标志物降低）。在实验1中，基于总直径（具有Zona Pellucida，ZP），卵母细胞直径（不含ZP）和ZP厚度，将单独成熟的卵母细胞进行测量并分为小，中间和大卵母细胞，并分为小，中间和大卵母细胞，卵母细胞直径（无ZP）和ZP厚度。这些卵母细胞在体外单独施肥和培养。胚胎发育达到胚泡阶段。根据总直径，卵母细胞直径和ZP厚度，与中间体相比，小卵母细胞组（分别为3.1±3.1,14.1±9.4和26.7±3.9，分别为26.7±3.9）减少（29.4±5.2,30.5±10.1分别为28.6±9.6分别为28.6±9.6分别为大卵ytes组（分别为54.2±13.5,44.4±3.9和67.6±12.4）。此外，到达胚泡阶段的概率与总直径（P <0.001），卵母细胞直径（P <0.05）和ZP厚度（P <0.001）呈正相关。此外，Bax，Bcl2，GDF9和GJA1的相对基因表达在卵母细胞中较大。在实验2中，根据卵母细胞总直径和达到的发育阶段评价CCS中的mRNA转录物的相对丰度模式。卵母细胞的CCS被分类为能够发展到胚泡阶段的大和卵母细胞具有较低的BAX，星和PTGS2的相对表达，而对于那些卵母细胞，观察到具有较高表达HAS2和SDC2转录物的表达。总之，卵母细胞和CCS中的卵母细胞形态学参数和基因表达分析提供了鉴定羊辅助生殖技术最合情位的卵母细胞的方法。
Carolina Maside[ 1;2;3;[*]; Irene Sánchez-Ajofrín[ 1]; Daniela Medina-Chávez[ 1]; Benner Alves[ 4]; José Julián Garde[ 1];Ana Josefa Soler[ 1]. Oocyte Morphometric Assessment and Gene Expression Profiling of Oocytes and Cumulus Cells as Biomarkers of Oocyte Competence in Sheep[J]. Animals, 2021,11(10): 2818