Lomedico P, Rosenthal N, Efstratidadis A, Gilbert W, Kolodner R, Tizard R
Cell. 1979 Oct;18(2):545-58. doi: 10.1016/0092-8674(79)90071-0.
In the rat, there are two nonallelic genes for preproinsulin. The insulin end products are very similar and are equally expressed. We have isolated clones carrying these genes and their flanking sequences, and characterized them by DNA sequencing and electron microscopic analysis. We have established the primary structure of the preproinsulin mRNAs and the signal peptides of these two proteins. One of the genes contains two introns: a 499 bp intron interrupting the region encoding the connecting peptide and a 119 bp intron interrupting the segment encoding the 5 noncoding region of the mRNA. The introns are transcribed and present in a preproinsulin mRNA precursor. The other gene possesses the smaller, but not the larger, of the two introns. Calculations based on the divergence of the two preproinsulin nucleotide and amino acid sequences indicate that these genes are the products of a recent duplication. Thus one of the genes gained or lost an intron since that time.
在大鼠中，有两个非等位基因负责前胰岛素原的合成。胰岛素终产物非常相似且表达量相同。我们已经分离出携带这些基因及其侧翼序列的克隆，并通过DNA测序和电子显微镜分析对其进行了表征。我们已经确定了前胰岛素原mRNA的一级结构以及这两种蛋白质的信号肽。其中一个基因包含两个内含子：一个499 bp的内含子打断了编码连接肽的区域，一个119 bp的内含子打断了编码mRNA 5'非编码区的片段。这些内含子被转录并存在于前胰岛素原mRNA前体中。另一个基因只拥有两个内含子中较小的那个，而没有较大的那个。基于两个前胰岛素原核苷酸和氨基酸序列的差异进行的计算表明，这些基因是近期基因复制的产物。因此，自那时起其中一个基因获得或失去了一个内含子。
