To obtain a new gene having a correlation with reverse transcriptase activity and useful in, e.g. cancer diagnosis.
This new gene which encodes a protein having reverse transcriptase motif, is a CRT-1 gene having a base sequence of the formula, and obtained by the following procedure: mRNA is prepared from e.g. human promyelogenous leukemia cell line HL60 cells, and through the preparation of the whole RNA and poly(A)+RNA(mRNA), the cDNA library for HL-60 to be used in 5'RACE and 3'RACE is prepared, followed by gene amplification, and the resulting reaction product is purified, and then subcloned to an appropriate vector; the base sequence of the resultant gene fragment thus cloned is determined, and based on the gene fragment afforded by 5'RACE and 3'RACE methods, a primer to be hybridized with both the 5'-terminal and 3'-terminal of cDNA is designed, and the aimed whole-length gene is obtained by RT-PCR or the like, and the base sequence thereof is determined by a commonly well- known method.
YOSHIDA KENJI
