Taylor M V, Gusse M, Evan G I, Dathan N, Mechali M
EMBO J. 1986 Dec 20;5(13):3563-70. doi: 10.1002/j.1460-2075.1986.tb04683.x.
A Xenopus cDNA clone highly homologous to the proto-oncogene c-myc has been isolated and used to derive a homologous probe to study myc expression during embryonic development. Myc RNA is identified as a member of the class of maternal mRNAs expressed before fertilisation. It is highly accumulated from early oogenesis and an unfertilised egg contains 8 pg, about 10(5)-fold the myc content of proliferative somatic cells. After fertilisation a post-transcriptional regulation of the gene is induced and the accumulated myc RNA is degraded (t1/2 = 4 h 20 min) to reach a level at gastrula of 10 transcripts per cell; a value maintained during subsequent embryonic development. The Xenopus myc protein has also been identified by both myc-specific antibodies and hybrid selection experiments. Translation in vitro of Xenopus myc RNA shows that it encodes a 62-kd protein which is also recognised by myc antibodies in oocyte extracts. This protein is accumulated in late oogenesis. The results indicate an unusual uncoupling of myc expression and cell proliferation linked to a stabilisation of the RNA product.
已分离出一种与原癌基因c-myc高度同源的非洲爪蟾cDNA克隆，并用于制备同源探针，以研究胚胎发育过程中的myc表达。Myc RNA被鉴定为受精前表达的母源mRNA类别的成员。它从早期卵子发生开始就大量积累，未受精卵中含有8 pg，约为增殖性体细胞中myc含量的10⁵倍。受精后，该基因的转录后调控被诱导，积累的myc RNA被降解（半衰期=4小时20分钟），在原肠胚期达到每个细胞10个转录本的水平；该值在随后的胚胎发育过程中保持不变。非洲爪蟾myc蛋白也已通过myc特异性抗体和杂交筛选实验得到鉴定。非洲爪蟾myc RNA的体外翻译表明，它编码一种62-kd的蛋白，该蛋白在卵母细胞提取物中也能被myc抗体识别。这种蛋白在卵子发生后期积累。结果表明，myc表达与细胞增殖之间存在异常的解偶联，这与RNA产物的稳定性有关。
