Molecular Identity of Maternal Regulators of the Egg to Embryo Transition

在所有动物中，大规模合子转录通常在受精后启动几个细胞周期 母合子过渡期（MZT）在合子转录开始之前，胚胎依赖于 影响卵子中的母体因素来推动其早期发育。因此，鸡蛋被赋予了大量的 受精、卵子激活、早期细胞周期和其他在合子形成之前起作用的过程的关键因素 基因组激活虽然对生殖至关重要，但这些前MZT过程很少被研究。一 独特的收集母亲效应突变体的斑马鱼与前MZT缺陷将在这里进行调查， 有望揭示这些过程中的新分子参与者。因为鸡蛋提供了所有的因素 为了满足胚胎早期发育的需要，卵子非常大。人们对巨大的 这些大的胚胎细胞的细胞质充满了几次细胞分裂所需的成分， 它将储存的成分组装到每次随后的细胞分裂中。两个母体效应突变基因 限制细胞骨架装配在鸡蛋将被研究和基因的分子性质确定。 这些被认为是细胞骨架组装的新型阻遏物，在卵中特异性地发挥作用， 调节这些因子的母体供应。几个额外的母体突变基因，影响特定的 还将研究卵活化和细胞周期启动的方面。根据染色体 突变基因、新基因或先前已知的具有新的、意想不到的功能的基因的位置， 预计将被识别。基因的分子身份将通过RNA-Seq 方法，然后进行CRISPR-Cas9基因组编辑以验证基因的身份。未来的研究将 然后将这些新的因子整合到已知的分子框架中， 这一过程有望填补空白和/或为未来的研究产生新的分子切入点。

In all animals, large-scale zygotic transcription typically initiates several cell cycles following fertilization at the maternal-zygotic transition (MZT). Prior to wholesale zygotic transcription initiation, the embryo depends on maternal factors in the egg to drive its early development. Hence, eggs are endowed with a multitude of factors critical for fertilization, egg activation, early cell cycles, and other processes acting prior to zygotic genome activation. Although essential to reproduction, these pre-MZT processes have been little studied. A unique collection of maternal-effect mutants in the zebrafish with pre-MZT defects will be investigated here and are expected to reveal new molecular players in these processes. Because the egg supplies all the factors needed by the embryo for its early development, eggs are very large. Little is known about how the enormous cytoplasm of these large embryonic cells, full of components needed for several cell divisions, is restricted in its assembly of the stored components to each ensuing cell division. Two maternal-effect mutant genes that restrict cytoskeletal assembly in the egg will be studied and the molecular nature of the genes determined. These are expected to be novel repressors of cytoskeletal assembly that function specifically in the egg to regulate the maternal supply of these factors. Several additional maternal mutant genes that affect specific aspects of egg activation and the initiation of cell cycles will also be studied. Based on the chromosomal locations of the mutant genes, novel genes or previously known genes with new, unexpected functions are expected to be identified. The molecular identity of the genes will be determined through an RNA-Seq approach, followed by CRISPR-Cas9 genome editing to verify the identities of the genes. Future studies will then integrate these new factors into the known molecular framework for each particular maternally controlled process, which is expected to fill gaps and/or generate new molecular entry points for future investigation.