Maurer R A, Gubbins E J, Erwin C R, Donelson J E
J Biol Chem. 1980 Mar 25;255(6):2243-6.
Recombinant DNA plasmids containing the coding sequence for rat prolactin or rat growth hormone have been used to investigate the presence of possible precursors for prolactin and growth hormone mRNA. Cytoplasmic and nuclear RNA was prepared from either rat pituitaries or fromthe GC pituitary cell line. RNA was electrophoresed on agarose gels containing methylmercury hydroxide and then transferred to diazobenzyloxymethyl paper. The paper was then hybridized to prolactin or growth hormone recombinant DNA probes labeled in vitro with 32P. The prolactin probe hybridized to RNA species of 7.0, 6.4, 3.8, 1.7, and 1.0 kilobases in nuclear RNA and only to a 1.0-kilobase species in cytoplasmic RNA. Hybridization with a growth hormone probe demonstrated nuclear RNA species of 6.7, 5.6, 2.3, and 1.0 kilobases. These findings demonstrate the presence of multiple species of prolactin and growth hormone RNA which are larger larger than the mature cytoplasmic mRNAs. The large nuclear RNAs are likely precursors for prolactin and growth hormone mRNA.
含有大鼠催乳素或大鼠生长激素编码序列的重组DNA质粒已被用于研究催乳素和生长激素mRNA可能的前体的存在情况。细胞质和细胞核RNA取自大鼠垂体或GC垂体细胞系。RNA在含有氢氧化甲基汞的琼脂糖凝胶上进行电泳，然后转移至重氮苄氧基甲基纸上。接着将该纸与用³²P体外标记的催乳素或生长激素重组DNA探针杂交。催乳素探针与细胞核RNA中7.0、6.4、3.8、1.7和1.0千碱基的RNA种类杂交，而在细胞质RNA中仅与1.0千碱基的种类杂交。用生长激素探针杂交显示出6.7、5.6、2.3和1.0千碱基的细胞核RNA种类。这些发现证明存在多种比成熟细胞质mRNA更大的催乳素和生长激素RNA。这些大的细胞核RNA可能是催乳素和生长激素mRNA的前体。
