Salilew-Wondim Dessie, Ahmad Ijaz, Gebremedhn Samuel, Sahadevan Sudeep, Hossain M D Munir, Rings Franca, Hoelker Michael, Tholen Ernst, Neuhoff Christiane, Looft Christian, Schellander Karl, Tesfaye Dawit
Institute of Animal Science, Animal Breeding and Husbandry Group, University of Bonn, Bonn, Germany.
Department of Animal Breeding and Genetics, Bangladesh Agricultural University, Mymensingh, Bangladesh.
PLoS One. 2014 Sep 5;9(9):e106795. doi: 10.1371/journal.pone.0106795. eCollection 2014.
This study aimed to investigate the miRNA expression patterns in granulosa cells of subordinate (SF) and dominant follicle (DF) during the early luteal phase of the bovine estrous cycle. For this, miRNA enriched total RNA isolated from granulosa cells of SF and DF obtained from heifers slaughtered at day 3 and day 7 of the estrous cycle was used for miRNAs deep sequencing. The results revealed that including 17 candidate novel miRNAs, several known miRNAs (n = 291-318) were detected in SF and DF at days 3 and 7 of the estrous cycle of which 244 miRNAs were common to all follicle groups. The let-7 families, bta-miR-10b, bta-miR-26a, bta-miR-99b and bta-miR-27b were among abundantly expressed miRNAs in both SF and DF at both days of the estrous cycle. Further analysis revealed that the expression patterns of 16 miRNAs including bta-miR-449a, bta-miR-449c and bta-miR-222 were differentially expressed between the granulosa cells of SF and DF at day 3 of the estrous cycle. However, at day 7 of the estrous cycle, 108 miRNAs including bta-miR-409a, bta-miR-383 and bta-miR-184 were differentially expressed between the two groups of granulosa cell revealing the presence of distinct miRNA expression profile changes between the two follicular stages at day 7 than day 3 of the estrous cycle. In addition, unlike the SF, marked temporal miRNA expression dynamics was observed in DF groups between day 3 and 7 of the estrous cycle. Target gene prediction and pathway analysis revealed that major signaling associated with follicular development including Wnt signaling, TGF-beta signaling, oocyte meiosis and GnRH signaling were affected by differentially expressed miRNAs. Thus, this study highlights the miRNA expression patterns of granulosa cells in subordinate and dominant follicles that could be associated with follicular recruitment, selection and dominance during the early luteal phase of the bovine estrous cycle.
本研究旨在调查牛发情周期黄体早期次级卵泡（SF）和优势卵泡（DF）颗粒细胞中的miRNA表达模式。为此，从发情周期第3天和第7天屠宰的小母牛的SF和DF颗粒细胞中分离出富含miRNA的总RNA，用于miRNA深度测序。结果显示，在发情周期第3天和第7天的SF和DF中检测到包括17种候选新miRNA在内的几种已知miRNA（n = 291 - 318），其中244种miRNA在所有卵泡组中都有。let - 7家族、bta - miR - 10b、bta - miR - 26a、bta - miR - 99b和bta - miR - 27b是发情周期两天中SF和DF中均大量表达的miRNA。进一步分析表明，发情周期第3天，包括bta - miR - 449a、bta - miR - 449c和bta - miR - 222在内的16种miRNA在SF和DF颗粒细胞中的表达模式存在差异。然而，在发情周期第7天，包括bta - miR - 409a、bta - miR - 383和bta - miR - 184在内的108种miRNA在两组颗粒细胞之间存在差异表达，这表明发情周期第7天两个卵泡阶段之间的miRNA表达谱变化比第3天更为明显。此外，与SF不同，在发情周期第3天和第7天之间，DF组中观察到明显的miRNA表达动态变化。靶基因预测和通路分析表明，与卵泡发育相关的主要信号通路，包括Wnt信号通路、TGF - β信号通路、卵母细胞减数分裂和GnRH信号通路，都受到差异表达miRNA的影响。因此，本研究突出了次级卵泡和优势卵泡颗粒细胞中的miRNA表达模式，这些模式可能与牛发情周期黄体早期的卵泡募集、选择和优势化有关。
