PHYSIOLOGICALLY INACTIVE NUCLEOLI CONTAIN NUCLEOPLASMIC RIBONUCLEOPROTEINS - IMMUNOELECTRON MICROSCOPY OF MOUSE SPERMATIDS AND EARLY EMBRYOS
PHYSIOLOGICALLY INACTIVE NUCLEOLI CONTAIN NUCLEOPLASMIC RIBONUCLEOPROTEINS - IMMUNOELECTRON MICROSCOPY OF MOUSE SPERMATIDS AND EARLY EMBRYOS
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DOI：
10.1006/excr.1994.1172
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发表时间：
1994-07-01
影响因子：
3.7
通讯作者：
FAKAN, S
中科院分区：
文献类型：
--
作者：
BIGGIOGERA, M;MARTIN, TE;FAKAN, S
生理失活或重新激活核仁是研究核仁活性变化的良好模型，核仁活性变化在很大程度上影响了细胞器的形态。我们研究了小鼠精子细胞在逐渐失活过程中的核仁，以及小鼠早期植入前胚胎的核仁。在2-细胞系统中，无活性的核仁由均匀的细纤维状球体代表。与澄清这些核仁的组成的目的，我们已经分析了它们通过免疫电子显微镜使用针对核质snRNP，hnRNP，核糖体蛋白，或fibrillarin的特异性抗体，以及通过细胞化学方法可视化DNA和RNA。我们的研究结果表明，RNA存在于受精卵和2细胞核仁前体（NPB）以及4至8细胞或更先进的胚胎核仁，但不存在于无活性的精子细胞核仁。无活性的精子细胞核仁和NPB中不存在DNA，但存在于活性核仁的核仁相关染色质和核线中。构成合子和2-细胞胚胎的NPB的致密物质含有核糖体蛋白和原纤蛋白，但也含有hnRNP和核质snRNP。其中，只有原纤蛋白存在于精子细胞的残留核仁中。(C)1994年出版社出版。
Physiologically inactivating or reactivating nucleoli represent a good model to investigate modifications of the nucleolar activity, which influence to a great extent the morphology of this organelle. We have studied the nucleoli of mouse spermatids during gradual inactivation, as well as those of early mouse preimplantation embryos, which undergo reactivation. In the 2-cell systems, inactive nucleoli are represented by homogeneously, finely fibrillar spherical bodies. With the aim of clarifying the composition of these nucleoli, we have analyzed them by means of immunoelectron microscopy using specific antibodies directed against nucleoplasmic snRNPs, hnRNPs, ribosomal proteins, or fibrillarin as well as by cytochemical methods for visualizing DNA and RNA. Our results indicate that RNA is present in zygote and 2-cell nucleolus precursor bodies (NPBs) as well as in 4- to 8-cell or more advanced embryo nucleoli, but not in inactive spermatid nucleoli. DNA is absent from inactive spermatid nucleoli and NPBs but is present within the nucleolus-associated chromatin and the nucleolonema of active nucleoli. The dense masses constituting the NPBs of the zygote and 2-cell embryos contain ribosomal proteins and fibrillarin but also hnRNPs and nucleoplasmic snRNPs. Of these, only fibrillarin is present in the spermatid residual nucleoli. (C) 1994 Academic Press, Inc.