Characterization of mouse myelin basic protein messenger RNAs with a myelin basic protein cDNA clone.

Abstract

Using a family of synthetic tetradecamer oligonucleotides as a primer for cDNA synthesis and a 2nd family of tetradecamers as a hybridization probe, a cDNA clone of mouse myelin basic protein (MBP) was prepared and isolated. The clone, pNZ111, corresponds to the region of the mRNA that codes for an amino acid sequence present in all 4 major forms of MBP. The relative abundance of MBP mRNA, estimated by dot blot hydridization, increased with the age of the mouse to a maximum at 18 days, then decreased to about one-fourth of that amount at later ages. Mouse MBP mRNA, selected by their ability to hybridize to the clone, translate into the 4 forms of MBP. In RNA blot analyses, pNZ111 hybridized to multiple species of mouse mRNA. The predominant hybridization is to a broad band of RNA ranging in length from 2350-2100 bases. These mRNA species are extremely long, considering that the largest MBP could be encoded by .apprx. 600 bases. In addition to these, there are also minor bands that hybridize with pNZ111, including a band of 4100 bases and smaller ones of 1900, 1500 and 1200 bases.