Cao Q P, Crain W R
Worcester Foundation for Experimental Biology, Shrewsbury, Massachusetts, USA.
Dev Genet. 1995;17(3):263-71. doi: 10.1002/dvg.1020170311.
In a search for genes expressed in preimplantation mouse embryos that are important for the earliest steps in differentiation, we identified an abundant mRNA that codes for a sulfated glycoprotein, SGP-1. The amount of this RNA rises approximately 100-fold during preimplantation development to a level approximately equal to that of beta-actin mRNA in blastocysts, although the level of these transcripts per cell remains fairly constant during these stages at approximately 2,000-4,000 copies. An antisense RNA that is complementary to approximately the last one-third of the message and contains an open reading frame of 455 nt was found in blastocysts at a 2-3-fold higher level than the mRNA. In situ hybridization with sense and antisense riboprobes showed that both strands are distributed throughout the embryo. The abundance of the SGP-1 mRNA indicates that the encoded protein may play an important role in the development of embryos, and the excess of antisense RNA raises the possibility of an unusual mechanism of regulating its expression.
为了寻找在着床前小鼠胚胎中表达且对分化的最早阶段至关重要的基因，我们鉴定出一种丰富的mRNA，它编码一种硫酸化糖蛋白SGP-1。在着床前发育过程中，这种RNA的量增加了约100倍，达到与囊胚中β-肌动蛋白mRNA水平大致相当的水平，尽管在这些阶段每个细胞中这些转录本的水平在约2000 - 4000个拷贝时保持相当恒定。在囊胚中发现了一种反义RNA，它与大约最后三分之一的信息互补，含有一个455 nt的开放阅读框，其水平比mRNA高2 - 3倍。用 sense 和反义核糖探针进行原位杂交表明，两条链都分布在整个胚胎中。SGP-1 mRNA的丰度表明编码的蛋白质可能在胚胎发育中起重要作用，而反义RNA的过量增加了调节其表达的异常机制的可能性。
