A shotgun proteomics study using isobaric tags for relative and absolute quantification labeling was conducted to characterize proteins in chicken ovarian follicles immediately before and after cyclic recruitment. Granulosa cell (GC) layers from the most recently recruited follicle (GC9) and from each of the four largest prerecruitment follicles (GC1–4) plus theca tissue (TH) from the most recently recruited (TH9) and largest prerecruitment (TH1) follicles were compared. Of 1535 proteins identified, none were determined to be differentially expressed between TH9 and TH1. A pairwise comparison between GC9 and GC1, GC2, GC3, or GC4 resulted in one, five, five, and six differentially expressed proteins, respectively, including yolk and cholesterol transport proteins (vitellogenin 1–3 and apolipoprotein B). In addition, transforming growth factor-beta 1 and microRNA-21 pathways were predicted to be activated at recruitment. We also report, for the first time, the expression of the neuropeptide, RELAXIN-3 (RLN3), in GC. Quantitative polymerase chain reaction determined RLN3 expression to be highest in GC9 and GC1, but its receptors, RXFP1 and RXFP3, were highest in TH and ovarian stroma, respectively. Overall, cyclic recruitment is associated with changes in protein expression predominantly within follicle GC, and a potential role for RLN3 in follicle recruitment and the initiation of GC differentiation warrants further investigation.

中文翻译：

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循环募集前后鸡卵泡的蛋白质组分析

使用等压标签进行相对和绝对定量标记的鸟枪蛋白质组学研究，以表征鸡卵巢卵泡中的蛋白质，即在循环募集前后。最近招募的卵泡 (GC9) 和四个最大的招募前卵泡 (GC1-4) 中的每一个加上最近招募的卵泡 (TH9) 和最大的招募前 (TH1) 卵泡中的颗粒细胞 (GC) 层进行了比较。在鉴定的 1535 种蛋白质中，没有一种被确定在 TH9 和 TH1 之间有差异表达。GC9 和 GC1、GC2、GC3 或 GC4 之间的成对比较分别导致 1、5、5 和 6 种差异表达的蛋白质，包括蛋黄和胆固醇转运蛋白（卵黄蛋白 1-3 和载脂蛋白 B）。此外，转化生长因子-β1 和 microRNA-21 通路预计在招募时被激活。我们还首次报道了神经肽 RELAXIN-3 (RLN3) 在 GC 中的表达。定量聚合酶链反应测定RLN3在 GC9 和 GC1 中的表达最高，但其受体RXFP1和RXFP3分别在 TH 和卵巢基质中最高。总体而言，循环募集与主要在卵泡 GC 内的蛋白质表达变化有关，RLN3 在卵泡募集和 GC 分化启动中的潜在作用值得进一步研究。