Gene expression analysis of granulosa cells from Fzd1 WT and KO mice

WNT4 is required for normal ovarian follicle development and female fertility in mice, but how its signal is transduced remains unknown. Fzd1 encodes a WNT receptor whose expression is markedly induced in both mural granulosa cells and cumulus cells during the preovulatory period, in a manner similar to Wnt4. To study the physiological roles of FZD1 in ovarian physiology and to determine if it serves as receptor for WNT4, Fzd1-null mice were created by gene targeting. Whereas rare Fzd1-/- females were sterile due to uterine fibrosis and ovarian tubulostromal hyperplasia, the majority were subfertile, producing ~ 1 less pup per litter on average relative to controls. Unlike WNT4-deficient mice, ovaries from Fzd1-/- mice had normal weights, numbers of follicles, steroid hormone production and WNT4 target gene expression levels. Microarray analyses of granulosa cells from periovulatory follicles revealed few genes whose expression was altered in Fzd1-/- mice. However, gene expression analyses of cumulus-oocyte complexes (COCs) revealed a blunted response of both oocyte (Zp3, Dppa3, Nlrp5, Bmp15) and cumulus (Btc, Ptgs2, Sema3a, Ptx3, Il6, Nts, Alcam, Cspg2) genes to the ovulatory signal, whereas the expression of these genes was not altered in WNT4-deficient COCs from Wnt4tm1.1Boer/tm1.1Boer;Tg(CYP19A1-cre)1Jri mice. Despite altered gene expression, cumulus expansion appeared normal in Fzd1-/- COCs both in vitro and in vivo. Together, these results indicate that Fzd1 is required for normal female fertility and may act in part to regulate oocyte maturation and cumulus cell function, but is unlikely to function as the sole ovarian WNT4 receptor. Triplicate RNA samples from granulosa cells of Fzd1 KO mice are compared to triplicate RNA samples from granulosa cells of control Fzd1 WT miceWNT4在小鼠正常卵巢卵泡发育及雌性生育过程中发挥必需作用，但其信号转导机制仍未阐明。Fzd1基因编码一种WNT受体，其在排卵前期的壁颗粒细胞与卵丘细胞中表达均显著上调，表达模式与Wnt4高度相似。为探究FZD1在卵巢生理中的功能，并明确其是否为WNT4的功能性受体，研究人员通过基因靶向技术构建了Fzd1敲除（Fzd1-null）小鼠模型。 少数Fzd1纯合敲除（Fzd1-/-）雌性小鼠因子宫纤维化及卵巢管状基质增生而完全不育，多数敲除小鼠则表现为生育力低下，平均每胎产仔数较野生型对照组少约1只。与WNT4缺陷小鼠不同，Fzd1-/-小鼠的卵巢重量、卵泡数量、类固醇激素生成水平及WNT4靶基因表达量均维持正常。对排卵前卵泡颗粒细胞的基因芯片分析显示，Fzd1-/-小鼠中表达发生显著改变的基因极少。 然而针对卵丘-卵母细胞复合体（cumulus-oocyte complexes, COCs）的基因表达分析发现，卵母细胞相关基因（Zp3、Dppa3、Nlrp5、Bmp15）与卵丘细胞相关基因（Btc、Ptgs2、Sema3a、Ptx3、Il6、Nts、Alcam、Cspg2）对排卵信号的应答均出现显著减弱；但在Wnt4tm1.1Boer/tm1.1Boer;Tg(CYP19A1-cre)1Jri小鼠的WNT4缺陷型COCs中，上述基因的表达并未发生改变。尽管基因表达谱出现异常，Fzd1-/-小鼠的COCs在体外与体内的卵丘扩展过程均表现正常。 综上，上述实验结果表明，Fzd1对雌性正常生育功能不可或缺，其可能部分通过调控卵母细胞成熟及卵丘细胞功能发挥生理作用，但不太可能是卵巢中唯一的WNT4受体。本数据集将Fzd1敲除（Fzd1 KO）小鼠颗粒细胞的三份重复RNA样本，与对照的野生型Fzd1（Fzd1 WT）小鼠颗粒细胞的三份重复RNA样本进行了比较分析。