Cloning of An Intron of the Gene Coding for Porcine Acid-Labile Subunit(pALS) of the 150-kDa Insulin-like Growth Factor Complex and the 3' Untranslated Region of pALS Complementary DNA and Confirmation of pALS Gene Expression in Multiple Tissues

摘要

The aims of this study were as follows: 1) identification and cloning of an intron of the gene coding for porcine acid-labile subunit(pALS), a component of the 150-kDa ternary insulin-like growth factor(IGF) complex, and amplification and cloning of3' untranslated region(3' UT) of pALS complementary DNA, 2) identification of pALS gene expression in porcine tissues by reverse transcription-polymerase chain reaction using an intron-spanning primer pair and 3) identification of ALS gene expression inporcine hepatocytes. Following nucleotide sequencing after amplification of pALS gene by PCR using genomic DNA as template with a primer pair spanning the expected intron region and insertion of the PCR product into a plasmid vector, a 1,371-base pair(bp)intron of pALS gene has been identified at a site of pALS gene identical to those of other ALS genes of known species. Also identified and sequenced in the present study was a 147-bp 3' UT following 3' rapid amplification of cDNA end(3' RACE) using RNAisolated from the liver as starting template. Results of the RT-PCR have exhibited that pALS gene is expressed not only in the liver but in other internal organs(kidney, lung, spleen), female reproductive organs(ovary, oviduct, uterus) and skeletal muscle. Moreover, in the liver, the ALS gene was found to be expressed in hepatoctytes by in-situ hybridization. These results suggest a possibility that in addition to the known major role as plasma IGF reservoir/regulator, ALS may also have unknown role(s)in the extra-vascular space.