Inhomogeneous distribution of egg RNA sequences in the early embryo
Inhomogeneous distribution of egg RNA sequences in the early embryo
复制标题
早期胚胎中卵子RNA序列的不均匀分布
DOI：
10.1016/0092-8674(78)90114-9
复制
发表时间：
1978
期刊：
影响因子：
64.5
通讯作者：
P. Gross
中科院分区：
文献类型：
--
作者：
W. Rodgers;P. Gross
用单拷贝DNA探针（+卵DNA）对从单拷贝DNA转录的卵RNA序列进行RNA过量杂交，测定16细胞海胆胚胎分离的卵裂球总RNA的序列复杂性。RNA从整个16-细胞胚胎，原肠胚，并从合并的中粒和大粒反应+鸡蛋DNA的90%的鸡蛋RNA/+鸡蛋DNA反应的程度。然而，来自微粒体的总RNA与+卵DNA的杂交程度仅为16细胞胚胎RNA、原肠胚RNA或中-大微粒体RNA的67-60%。同样的结果也可以用在放线菌素D的转录阻断下发育的卵裂球或整个胚胎的RNA得到。卵裂球RNA杂交到与卵RNA序列（-卵DNA）不同源的复制DNA探针显示，正如放线菌素D中生长的胚胎RNA复杂性的数据一样，新合成的或核RNA的参与在卵裂球RNA/+卵DNA杂交中观察到的饱和水平的设定中在数量上是微不足道的。因此，这些数据表明，在16细胞阶段，甚至可能更早，有一个很大的不对称性之间的信息RNA序列的微粒和胚胎的其他部分。他们强烈地暗示，这种不对称性存在于受精前存在于卵子中的RNA中，也就是说，存在于“母体”RNA中。
The sequence complexity of total RNA from sep arated blastomeres of 16-cell sea urchin embryos was assayed by RNA excess hybridization using a single-copy DNA probe (+ egg DNA) for those egg RNA sequences that are transcribed from single-copy DNA. RNA from whole 16-cell embryos, from gastrulae, and from pooled mesomeres and macromeres reacted with+ egg DNA to 90% of the extent of the egg RNA/+ egg DNA reaction. Total RNA from micromeres, however, reacted only to 67-60% of the extent of hybridiration shown by 16-cell embryo RNA, gastrula RNA or meso-macromere RNA with+ egg DNA. The same results were obtained with RNA from blastomeres or whole embryos developing under a transcription block imposed by actinomycin D. Hybridization of blastomere RNAs to a singlecopy DNA probe not homologous to egg RNA sequences(-egg DNA) showed, as do the data on complexity of RNA from embryos grown in actinomycin D, that participation of newly synthesized or nuclear RNA was quantitatively insignificant in setting saturation levels observed in the blastomere RNA/+ egg DNA hybridizations. These data therefore indicate that at the 16-cell stage and probably even earlier, there is a large asymmetry of informational RNA sequences between the micromeres and other parts of the embryo. They suggest strongly that the asymmetry resides in RNA which was present in the egg before fertilization-that is, in “maternal” RNA.