Is Basonuclin essential for Oogenesis

描述（由申请人提供）：Basonuclin是一种120 kDa的锌指蛋白，可能是一种增强核糖体RNA（rRNA）基因转录的转录因子。其表达仅限于睾丸和卵巢的生殖细胞以及复层上皮的角质形成细胞。rRNA基因的转录是决定核糖体产生的关键因素，其转录水平受细胞蛋白质合成水平的调控。某些细胞生理状态，如增殖（精子发生）或蛋白质积累（卵子发生）需要高水平的蛋白质合成。虽然已经描述了与增殖期间高水平核糖体合成相关的转录因子，但这些因子似乎是普遍存在的，而rRNA合成的细胞类型特异性调节剂尚未报道。Basonuclin，因为它：（1）有限的细胞类型分布，（2）在间期和有丝分裂中与rRNA基因相关，（3）与rRNA基因的启动子相互作用，和（4）增加rDNA启动子转录的能力，很可能是细胞类型特异性rRNA转录因子，这是第一个此类转录因子;（5）我们尝试用常规技术敲除basonuclin基因没有成功，因为无效突变不能传递到生殖细胞中，这表明basonuclin对于生殖细胞发育是单倍不足的。此外，我们最近的研究结果表明，basonuclin在小鼠卵子发生过程中起着关键作用。基于这些观察结果，我们推测，basonuclin是必不可少的核糖体生物发生在早期小鼠卵子发生。如果是这样的话，抑制，或有针对性的中断，在卵母细胞中的basonuclin的功能应该扰乱其发展，或来自it. Because我们早期的失败，在创建一个basonuelin敲除常规技术的胚胎的发展，在本申请中，我们建议，在一个单一的具体目标，以测试采用两个最近开发的条件基因破坏技术的可行性。子目标1将使用RNAi方法来减少卵母细胞中的基础核蛋白的量;子目标2将使用Cre重组酶来敲除卵母细胞中的基础核蛋白基因。

DESCRIPTION (provided by applicant): Basonuclin, a zinc finger protein of 120 kDa, is likely to be a transcription factor that enhances transcription of ribosomal RNA (rRNA) genes. Its expression is restricted to the germ cells of the testis and ovary, and keratinocytes of the stratified epithelium. It has been long recognized that rRNA gene transcription, a key factor in determining ribosome production, is regulated according to the level of cellular protein synthesis. Certain cellular physiological states, such as proliferation (spermatogenesis) or protein accumulation (oogenesis) require a high level of protein synthesis. Although transcription factors associated with the high level of ribosome synthesis during proliferation have been described, these factors appear to be ubiquitous, whereas cell-type specific regulators of rRNA synthesis have not been reported. Basonuclin, because of its: (1) restricted cell-type distribution, (2) association with the rRNA genes in interphase as well as in mitosis, (3) interaction with the promoter of the rRNA genes, and (4) ability to increase transcription from an rDNA promtor, is likely to be a cell-type specific rRNA transcription factor, the first of its kind; (5) our attempt to knockout basonuclin gene by conventional technique was not successful because the null mutation cannot be transmitted into the germline, suggesting that basonuclin is haploinsufficient for germ cell development. Furthermore, the results of our recent study suggest that basonuclin plays a critical role during mouse oogenesis. Based on these observations, we hypothesize that basonuclin is essential in ribosome biogenesis during early mouse oogenesis. If so, inhibition, or targeted disruption, of the function of basonuclin in an oocyte should perturb its development, or the development of the embryo derived from it. Because of our earlier failure in creating a basonuelin knockout by conventional techniques, in this application, we propose, in a single Specific Aim, to test the feasibility of employing two recently developed conditional gene-disruption techniques. Sub aim 1 will use an RNAi approach to reduce the amount of basonuclin in oocytes; Sub aim 2 will use the Cre recombinase to knockout [the] basonuclin gene in oocytes.