Microarray analyses of newborn mouse ovaries lacking Nobox
Microarray analyses of newborn mouse ovaries lacking Nobox
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DOI：
10.1095/biolreprod.107.060459
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发表时间：
2007-08-01
影响因子：
3.6
通讯作者：
Rajkovic, Aleksandar
中科院分区：
文献类型：
--
作者：
Choi, Youngsok;Qin, Yingying;Rajkovic, Aleksandar
Nobox 是一种在卵母细胞中表达的同源框基因，对卵子发生至关重要。 Nobox 缺陷会导致出生后卵母细胞快速丢失。人们对早期卵母细胞分化知之甚少。我们假设 Nobox 的缺乏会扰乱优先在卵母细胞中表达的基因以及 microRNA 的整体表达。我们使用 Affymetrix 430 2.0 微阵列平台比较了 Nobox 敲除和野生型卵巢。我们发现，在没有Nobox的情况下下调超过5倍的38个基因中，有28个（74％）优先在卵母细胞中表达，而在没有Nobox的情况下上调超过5倍的33个基因中，只有5个（15％）优先在卵母细胞中表达。蛋白质结合微阵列有助于识别 NOBOX 结合的核苷酸基序以及推定启动子区域内包含的几个下调基因。缺乏 Nobox 的新生儿卵巢中的 MicroRNA 数量基本上不受影响。预测会分泌但以前未知在早期卵子发生过程中显着表达的蛋白质的基因在 Nobox 敲除中下调，包括虾红素样金属内肽酶 (Astl)、Jagged I (Jag1)、卵母细胞分泌蛋白 I (Oosp1)、胎球蛋白 β (Fetub) 和 R-spondin 2 (Rspo2)。此外，多能性相关基因 Pou5f1 和 Sall4 在 Nobox 缺陷的卵巢中急剧下调，而睾丸决定基因 Dmrt1 过度表达。我们的研究结果表明，Nobox 可能是卵母细胞特异性基因表达的激活剂，并表明卵母细胞在抑制雄性决定基因（例如 Dmrt1）的表达中发挥着重要作用。
Nobox is a homeobox gene expressed in oocytes and critical in oogenesis. Nobox deficiency leads to rapid loss of postnatal oocytes. Early oocyte differentiation is poorly understood. We hypothesized that lack of Nobox perturbs global expression of genes preferentially expressed in oocytes as well as microRNAs. We compared Nobox knockout and wild-type ovaries using Affymetrix 430 2.0 microarray platform. We discovered that 28 (74%) of 38 of the genes downregulated more than 5-fold in the absence of Nobox were preferentially expressed in oocytes, whereas only 5 (15%) of 33 genes upregulated more than 5-fold in the absence of Nobox were preferentially expressed in oocytes. Protein-binding microarray helped identify nucleotide motifs that NOBOX binds and that several downregulated genes contain within putative promoter regions. MicroRNA population in newborn ovaries deficient of Nobox was largely unaffected. Genes whose proteins are predicted to be secreted but were previously unknown to be significantly expressed in early oogenesis were downregulated in Nobox knockouts and included astacin-like metalloendopeptidase (Astl), Jagged I (Jag1), oocyte-secreted protein I (Oosp1), fetuin beta (Fetub), and R-spondin 2 (Rspo2). In addition, pluripotency-associated genes Pou5f1 and Sall4 are drastically downregulated in Nobox-deficient ovaries, whereas testes-determining gene Dmrt1 is overexpressed. Our findings indicate that Nobox is likely an activator of oocyte-specific gene expression and suggest that the oocyte plays an important role in suppressing expression of male-determining genes, such as Dmrt1.