Fisher J H, Emrie P A, Shannon J, Sano K, Hattler B, Mason R J
Department of Medicine, University of Colorado Health Sciences Center, Denver 80262.
Biochim Biophys Acta. 1988 Sep 7;950(3):338-45. doi: 10.1016/0167-4781(88)90130-3.
In rat, the surfactant-associated glycoprotein A, SP-A, is encoded by two mRNA species of 0.9 and 1.6 kb. Each transcript is polyadenylated and is found in approximately the same ratio in total cellular RNA isolated from either alveolar type II cells or from whole lung. The two mRNA species have identical coding regions and differ only in the length of the 3' untranslated sequences. Restriction analysis and partial sequence analysis of rat genomic clones indicate that each mRNA species arises from one gene, with the difference in size most easily accounted for by differential polyadenylation. During fetal development, the accumulation of mRNA encoding SP-A is detectable by day 18 but increases many-fold on day 19. However, there are no apparent alterations in the prevalence of either mRNA species during fetal development or in the early postnatal period.
在大鼠中，表面活性物质相关糖蛋白A（SP-A）由0.9 kb和1.6 kb的两种mRNA编码。每个转录本都进行了多聚腺苷酸化，并且在从II型肺泡细胞或全肺分离的总细胞RNA中以大致相同的比例存在。这两种mRNA具有相同的编码区域，仅在3'非翻译序列的长度上有所不同。对大鼠基因组克隆的限制性分析和部分序列分析表明，每种mRNA都来自一个基因，大小差异最容易通过差异多聚腺苷酸化来解释。在胎儿发育过程中，编码SP-A的mRNA在第18天就可检测到积累，但在第19天增加了许多倍。然而，在胎儿发育期间或出生后早期，这两种mRNA的流行率没有明显变化。
