SMALL B2 RNAS IN MOUSE OOCYTES, EMBRYOS, AND SOMATIC TISSUES
SMALL B2 RNAS IN MOUSE OOCYTES, EMBRYOS, AND SOMATIC TISSUES
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DOI：
10.1016/0012-1606(88)90346-6
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发表时间：
1988-12-01
影响因子：
2.7
通讯作者：
BACHVAROVA, R
中科院分区：
文献类型：
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作者：
BACHVAROVA, R
使用单链RNA探针，在北方印迹上分析了完全生长的小鼠卵母细胞、排卵卵、胚胎和体细胞组织的RNA，以确定是否存在与B2元件同源的小转录物，B2元件是基因组中的一个重复的180个核苷酸（N）序列。除了其他人报道的异质性200- 600-N多聚腺苷酸基团外，胞质RNA还含有离散的B2相关RNA的非腺苷酸种类，长度约为100，120，155和180 N。在卵母细胞减数分裂成熟过程中，200- 600-N组下降，155-N种类变得更加突出。在与oligo（dT）杂交并用RNase H切割以去除poly（A）区域后，200-至600-N基团被去除，180-N种类大大增加，并且155-N种类略微增加。基本上所有的200- 600-N物质都与聚（U）琼脂糖凝胶结合。我们的结论是，多聚腺苷酸化，而不是运行上转录的B2元素占大多数的异质性的200- 600-N组和一些deadenylation和裂解发生在成熟过程中。小B2 RNA占卵母细胞和卵子中总RNA的0.04%，是大脑中的6- 9倍。作为比较，一种已知的小RNA，4.5 S RNA在卵母细胞中相对稀疏，在卵子中几乎不存在。10-NB 2相关的物种已被初步确定为4.5 SI RNA;相对于总RNA，它在卵母细胞和体细胞组织中保持大致恒定。在发育到胚泡阶段期间，每个胚胎的小B2 RNA增加数倍，但作为总RNA的一部分下降。在植入后发育中，它们继续向大脑中发现的水平下降。hnRNA中B2转录物的表达在发育10天左右上升到大脑中发现的水平。小B2 RNA表达的时间过程表明在发育中的重要作用。
RNAs of full-grown mouse oocytes, ovulated eggs, embryos, and somatic tissues have been analyzed on Northern blots for the presence of small transcripts homologous to the B2 element, a repetitive 180-nucleotide (N) sequence in the genome, using a single stranded RNA probe. In addition to the heterogeneous 200- to 600-N polyadenylated group reported by others, cytoplasmic RNA contains discrete nonadenylated species of B2-related RNA, approximately 100, 120, 155, and 180 N in length. During meiotic maturation of oocytes, the 200-to 600-N group decline and the 155-N species becomes more prominent. Upon hybridization to oligo(dT) and cleavage with RNase H to remove poly(A) regions, the 200- to 600-N group is removed, the 180-N species increased greatly, and the 155-N species increased slightly. Essentially all of the 200- to 600-N species bind to poly(U) sepharose. We conclude that polyadenylation rather than run-on transcription of B2 elements accounts for most of the heterogeneity of the 200- to 600-N group and that some deadenylation and cleavage take place during maturation. Small B2 RNAs make up 0.04% of total RNA in oocytes and eggs, 6- to 9-fold more than in brain. For comparison, a known small RNA, 4.5 S RNA is relatively sparse in oocytes and almost absent in eggs. The 10-N B2-related species has been tentatively identified as 4.5 SI RNA; relative to total RNA, it remains approximately constant in oocytes and somatic tissues. During development to the blastocyst stage, small B2 RNAs per embryo increase severalfold, but decline as a fraction of total RNA. In postimplantation development, they continue to decline toward the level found in brain. Expression of B2 transcripts in hnRNA rises around 10 days of development to the level found in brain. The time course of expression of small B2 RNAs suggests an important role in development.